Synthesis and Fluorescence Properties of Rare Earths Doped Fluorides and Nanocomposites of Luminescence
In the dissertation, nanoparticles of YF3:Eu, YF3:Tb, YF3:Ce and YF3:Er were prepared from the quaternary microemulsions of CTAB, n-butanol, n-octance and water based .The X-ray diffraction (XRD) patterns were indexed to a pure YF3 orthorhombic phase. Envrionment scanning electron microscopy (ESEM) images showed spherical YF3:Eu,YF3:Tb,YF3:Ce and YF3:Er nanoparticles which were about 13-40 nm in diameter.The emission of YF3: Eu nanoparticles peaked at 592 nm attributed to Eu3+ 5D0→7F1 transition.The emission of YF3:Tb neodymium magnets nanoparticles peaked at 544 nm attributed to Tb3+ 5D4→7F5 transition which is the green transition emission of 5D4 level.The emission peak of YF3:Ce nanoparticles located at 340 nm belong to luminesence of near ultraviolet.The emission of YF3: Er peaked at 1547nm. There is red shift and up-conversion in YF3:Er nanoparticles which emits red and green.The synthesis of YF3:Eu/PMMA and YF3:Tb/PMMA composite materials were primarily studied. Compared to YF3:Eu and YF3:Tb http://www.chinamagnets.biz/ nanoparticles, the emission and excitation peaks do not change but the intensity weaken of YF3:Eu and YF3:Tb nanoparticles and PMMA composite materials by the fluorescent spectra.
2012年6月29日星期五
2012年6月27日星期三
Provenance Analysis of the Permian Sedimentary Sandstones in Keshiketeng of Inner Mongolia
Provenance Analysis of the Permian Sedimentary Sandstones in Keshiketeng of Inner Mongolia
The thesis takes west of northeast China as its study area which including Keshiketeng,Linxi,Dongwu Banner,Horqin’s Ring Wing Front Banner and Solon area. The geographical position for the north part of north latitude 42°,east part of east longitude 110°30′. Its geotectonic position lies in the intersection part of Siberia Plate,North China Plate and Pacific Plate,which suffered from interaction time after time. When Pre-mesozoic the area was influenced by the Paleo- Special shape NdFeB magnets Asian ocean tectonic domain,and went through a evolution history of subduction of Paleo-Asian ocean,the accretion between two Plates margines,at last matching each other. Since Mesozoic Era,it experienced a strong reform and superposed acrrection from Pacific Plate. So it become a hot area in geological studies. Simulately,there still have many arguments in tectonic evolution of this area.Aiming at these problems,this article make a source analysis on Permian sedimentary rock from Eastern Inner Mongolia. As a important method of sedimentary basin analysis,Source analysis is widely applied in deducting different sedimentary basins evolution.Through systematic sampling and statistical data,the paper considers that Permian sedimentary rock samples(Linxi Formation、
Yujiabeigou Formation、Gegen’aobao Formation、Zhesi Formation) in the study area are feldspathic lithic sandstone,this show that the transportation distance of sediments is very short. And a great deal of immature crustal components provided provenance to Permian sedimentary rocks. Futhermore,most of Permian sedimentary rock samples fall in the recycled Orogen Provenances in the QtFL and QmFLt triangular diagram delinested by Dickinson(1979). But in the QpLvLs triangular diagram we can see samples of south part which include Keshiketeng and Linxi fall in mixed Orogen Provenances,and samples of north part which include Dongwu Banner and Solon fall in island arc Orogen Provenances. Studys from microscopy observation,rare earth and trace http://www.999magnet.com/ element geochemical analysis show that the major source area was tectonic background of continental island arc and active continental margin. The provenance of south part are Xar Moron River Matching Belt and island arc orogenic belt in the North.And the source area of north part is island arc orogenic belt. Moreover,Permian sedimentary rock in study part is characterized by relatively enriched light rare earths,obvious fractionation of REE and a negative Eu anomaly. This has similar distribution of basic trend with PAAS and NASC,so it shows that its original substance mainly come from felsic rock of upper crust. To contrast with upwards geochemical analysis and distribution , lithologic fearures and geochemical analysis of the Late Palaeozoic volcanics in research area,it was clear that the provenance probably be the volcanic rocks in Late Devonian to Early Carboniferous and Late Carboniferous to Early Permian. In addition,by the contrast this study and geochemical analysis of old basements from surrounding area,they have certain similarity and affinity. So the provenance also contains these old basements——Xinghuadukou Group and epimetamorphic rock series in Zhalantun area.
The thesis takes west of northeast China as its study area which including Keshiketeng,Linxi,Dongwu Banner,Horqin’s Ring Wing Front Banner and Solon area. The geographical position for the north part of north latitude 42°,east part of east longitude 110°30′. Its geotectonic position lies in the intersection part of Siberia Plate,North China Plate and Pacific Plate,which suffered from interaction time after time. When Pre-mesozoic the area was influenced by the Paleo- Special shape NdFeB magnets Asian ocean tectonic domain,and went through a evolution history of subduction of Paleo-Asian ocean,the accretion between two Plates margines,at last matching each other. Since Mesozoic Era,it experienced a strong reform and superposed acrrection from Pacific Plate. So it become a hot area in geological studies. Simulately,there still have many arguments in tectonic evolution of this area.Aiming at these problems,this article make a source analysis on Permian sedimentary rock from Eastern Inner Mongolia. As a important method of sedimentary basin analysis,Source analysis is widely applied in deducting different sedimentary basins evolution.Through systematic sampling and statistical data,the paper considers that Permian sedimentary rock samples(Linxi Formation、
Yujiabeigou Formation、Gegen’aobao Formation、Zhesi Formation) in the study area are feldspathic lithic sandstone,this show that the transportation distance of sediments is very short. And a great deal of immature crustal components provided provenance to Permian sedimentary rocks. Futhermore,most of Permian sedimentary rock samples fall in the recycled Orogen Provenances in the QtFL and QmFLt triangular diagram delinested by Dickinson(1979). But in the QpLvLs triangular diagram we can see samples of south part which include Keshiketeng and Linxi fall in mixed Orogen Provenances,and samples of north part which include Dongwu Banner and Solon fall in island arc Orogen Provenances. Studys from microscopy observation,rare earth and trace http://www.999magnet.com/ element geochemical analysis show that the major source area was tectonic background of continental island arc and active continental margin. The provenance of south part are Xar Moron River Matching Belt and island arc orogenic belt in the North.And the source area of north part is island arc orogenic belt. Moreover,Permian sedimentary rock in study part is characterized by relatively enriched light rare earths,obvious fractionation of REE and a negative Eu anomaly. This has similar distribution of basic trend with PAAS and NASC,so it shows that its original substance mainly come from felsic rock of upper crust. To contrast with upwards geochemical analysis and distribution , lithologic fearures and geochemical analysis of the Late Palaeozoic volcanics in research area,it was clear that the provenance probably be the volcanic rocks in Late Devonian to Early Carboniferous and Late Carboniferous to Early Permian. In addition,by the contrast this study and geochemical analysis of old basements from surrounding area,they have certain similarity and affinity. So the provenance also contains these old basements——Xinghuadukou Group and epimetamorphic rock series in Zhalantun area.
The Alteration Characteristics and Mechanism of the LiangZhu Culture Jade Artifacts Excavated from Zhuangqiaofen Site
The Alteration Characteristics and Mechanism of the LiangZhu Culture Jade Artifacts Excavated from Zhuangqiaofen Site
Throughout the ancient world, China was the only country with prosperous and continuous jade culture lasting 8000 years. So jade culture was often regarded as the initial watershed between the eastern and western civilization, and also one of the most important Chinese traditional culture symbols. For the special culture of Chinese jade, it was widely collection as the cultural wealth from home and abroad. Natural colored antique tremolite nephrite jades are much more valuable than artifical colored ones, so it is significant for identification of antique tremolite nephrite jade to distinguish whether its color is natural or artificial. It is helpful for the technology improvement of antique tremolite nephrite jade identification to study the genesis of its natural color and artificial color. However, such studies are few.In this paper, through macroscopic examination and magnification observing the Block Neodymium magnets alteration characteristics of the 361 pieces of jade artifacts excavated from Zhuangqiaofen site, and do the reflection and transmission of infrared absorption spectrum (IR), Raman spectroscopy (Raman), Electron probe micro-analysis (EPMA), scanning electron microscopy (SEM) and laser erosion inductively coupled plasma mass spectrometry (ICP-MS) test to a few samples, and analysis ancient jade in terms of identification, the material origin and the secondary change, we’ve got some conclusions:1) After the test of FTIR, Raman and EPMA, we concluded the six more fresh samples was tremolite and the four white chicken bone samples was the serpentine. After weathering, the transparency, gloss and hardness are lower, but the jade materials have no changed.2) Through geological occurrence type of method, six tremolite samples were originated from the magnesia in the marble.3) REE content distribution is applied to staying the tremolite-origin. The result indicates that the REE distribution patterns and characteristic ratios of the samples are the same, show that they have similar occurrence. Cluster analysis method is applied to staying the tremolite-origin. The result indicates that sample M11 was further away from the A07, A08, F06, the distance reflects the close relations between the mine. And the test results matched their optical characteristics and mechanical characteristics.4) The ICP-MS data of the more serious erosion samples http://www.999magnet.com/ was separated by two parts, for their skin and internal have different chemical composition, and this is also reflected on the content of REE. After the erosion, the content of REE has increased on surface, and it enriched of light REE. Maybe the absorption capacity of the surface of sample have enhanced after erosion, so it can adsorption the light REE in clay sediments.
5) The most of jade which artifacts excavated from Zhuangqiaofen site were erosion from mild to thorough. The look of erosion part of jade have eroded hole (Mayi Dong), Hang erosion, erosion spots, erosion ditch, erosion vein (mesh and whirlpool) and surface erosion, and so on. The different jades have different alteration characteristics, the weathering morphology of agate shows spots, the fluorite is layered, and the green quartzite is netlike.6) Using a large number of different degrees of the jade artifacts, we can concluded the development process of how ancient jade turns into chicken bone-like color. The determining factor of the weathering shape was the lines of polishing at first, while the crystal granules at last. The burial environment is the primary factor of erosion. The Block Neodymium magnets different erosion degree and shape was seen on one jade, and this proves that the reasons of chicken bone-like color can not be conducted just to deal with.7) The main elements of jade was lost while erosion, the erosion degree and other elements of external is higher than internal, Trace elements in the process of erosion also have some changes: Na and K elements only higher on the surface, not to internal erosion, show that these two elements was only absorption into the ancient jade. Observation from SEM, we’ve found the tubular clay minerals and irregular Flake kaolinite in the internal of jade, it proved that the elements of Al have erosion to internal part of jade.8 ) Through our Observation, proofed that the jade had gone through the weathering-eluviating stage and penertrating-cementing stage.C11 sample with the special yellow structure is the infiltration of the penertrating-cementing stage.
Throughout the ancient world, China was the only country with prosperous and continuous jade culture lasting 8000 years. So jade culture was often regarded as the initial watershed between the eastern and western civilization, and also one of the most important Chinese traditional culture symbols. For the special culture of Chinese jade, it was widely collection as the cultural wealth from home and abroad. Natural colored antique tremolite nephrite jades are much more valuable than artifical colored ones, so it is significant for identification of antique tremolite nephrite jade to distinguish whether its color is natural or artificial. It is helpful for the technology improvement of antique tremolite nephrite jade identification to study the genesis of its natural color and artificial color. However, such studies are few.In this paper, through macroscopic examination and magnification observing the Block Neodymium magnets alteration characteristics of the 361 pieces of jade artifacts excavated from Zhuangqiaofen site, and do the reflection and transmission of infrared absorption spectrum (IR), Raman spectroscopy (Raman), Electron probe micro-analysis (EPMA), scanning electron microscopy (SEM) and laser erosion inductively coupled plasma mass spectrometry (ICP-MS) test to a few samples, and analysis ancient jade in terms of identification, the material origin and the secondary change, we’ve got some conclusions:1) After the test of FTIR, Raman and EPMA, we concluded the six more fresh samples was tremolite and the four white chicken bone samples was the serpentine. After weathering, the transparency, gloss and hardness are lower, but the jade materials have no changed.2) Through geological occurrence type of method, six tremolite samples were originated from the magnesia in the marble.3) REE content distribution is applied to staying the tremolite-origin. The result indicates that the REE distribution patterns and characteristic ratios of the samples are the same, show that they have similar occurrence. Cluster analysis method is applied to staying the tremolite-origin. The result indicates that sample M11 was further away from the A07, A08, F06, the distance reflects the close relations between the mine. And the test results matched their optical characteristics and mechanical characteristics.4) The ICP-MS data of the more serious erosion samples http://www.999magnet.com/ was separated by two parts, for their skin and internal have different chemical composition, and this is also reflected on the content of REE. After the erosion, the content of REE has increased on surface, and it enriched of light REE. Maybe the absorption capacity of the surface of sample have enhanced after erosion, so it can adsorption the light REE in clay sediments.
5) The most of jade which artifacts excavated from Zhuangqiaofen site were erosion from mild to thorough. The look of erosion part of jade have eroded hole (Mayi Dong), Hang erosion, erosion spots, erosion ditch, erosion vein (mesh and whirlpool) and surface erosion, and so on. The different jades have different alteration characteristics, the weathering morphology of agate shows spots, the fluorite is layered, and the green quartzite is netlike.6) Using a large number of different degrees of the jade artifacts, we can concluded the development process of how ancient jade turns into chicken bone-like color. The determining factor of the weathering shape was the lines of polishing at first, while the crystal granules at last. The burial environment is the primary factor of erosion. The Block Neodymium magnets different erosion degree and shape was seen on one jade, and this proves that the reasons of chicken bone-like color can not be conducted just to deal with.7) The main elements of jade was lost while erosion, the erosion degree and other elements of external is higher than internal, Trace elements in the process of erosion also have some changes: Na and K elements only higher on the surface, not to internal erosion, show that these two elements was only absorption into the ancient jade. Observation from SEM, we’ve found the tubular clay minerals and irregular Flake kaolinite in the internal of jade, it proved that the elements of Al have erosion to internal part of jade.8 ) Through our Observation, proofed that the jade had gone through the weathering-eluviating stage and penertrating-cementing stage.C11 sample with the special yellow structure is the infiltration of the penertrating-cementing stage.
Synthesis, Structure and Catalytic Activity of Organolanthanide Complexes with N-piperidineethyl Substitued Cyclopentadienyl Ligands
Synthesis, Structure and Catalytic Activity of Organolanthanide Complexes with N-piperidineethyl Substitued Cyclopentadienyl Ligands
All experiments were carried out under an atmosphere of dry argon with the rigid exclusion of air and moisture using standard Schlenk techniques.Reaction of C5H10NCH2CH2Cl with 1 equiv of CH3C5H4Na in THF yielded C5H10NCH2CH2C5H4CH3(1)in 53%yield.Treatment of 1 with 1 equiv of n-BuLi in THF at 0℃,followed by reaction with 2 equiv of Me3SiCl yielded C5H10NCH2CH2C5H3(CH3)(SiMe3)(2)in 86%yield.Segment neodymium magnets Treatment of[(Me3Si)2N]3YbⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 and 2 in toluene at 80℃via a homolytic reaction,gave the corresponding ytterbium(Ⅱ)complexes[η5;η1-(C5H10NCH2CH2C5H3CH3)]2YbⅡ(3)in 49% yield,and {η5;η1-[C5H10NCH2CH2C5H2(CH3)(SiMe3)]}2YbⅡ(5)in 42% yield.Treatment of[(Me3Si)2N]3EuⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 and 2 in toluene at room temperature via a homolytic reaction,gave the corresponding europium(Ⅱ)complexes[η5;η1-(C5H10NCH2CH2C5H3CH3)]2 EuⅡ(4)in 56%yield and {η5;η1-[C5H10NCH2CH2C5H2(CH3)(SiMe3)]}2EuⅡ(6)in 52%yield.All the compounds were fully characterized by spectroscopic methods and elemental analyses.These results further certify the heteroatom coordination promoted homolytic reaction of the Ln-N(Ln=Yb,Eu)bond.This work further extends the new methodology to prepare organolanthanide(Ⅱ)complexes.At the same time,We have studied the catalytic activity of the organolanthanide(Ⅱ)complexes http://www.999magnet.com/ as single-component polymerization catalysts ofε-caprolactone.It was found that the catalysts above have catalytic activity in catalyzingε-CL polymerization.Studies also showed that the solvents,temperatures,the mole ratio of catalyst and monomer,the volume ratio of solvents and monomer have influences on activities of catalysts,the molecular weight and its distribution.
All experiments were carried out under an atmosphere of dry argon with the rigid exclusion of air and moisture using standard Schlenk techniques.Reaction of C5H10NCH2CH2Cl with 1 equiv of CH3C5H4Na in THF yielded C5H10NCH2CH2C5H4CH3(1)in 53%yield.Treatment of 1 with 1 equiv of n-BuLi in THF at 0℃,followed by reaction with 2 equiv of Me3SiCl yielded C5H10NCH2CH2C5H3(CH3)(SiMe3)(2)in 86%yield.Segment neodymium magnets Treatment of[(Me3Si)2N]3YbⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 and 2 in toluene at 80℃via a homolytic reaction,gave the corresponding ytterbium(Ⅱ)complexes[η5;η1-(C5H10NCH2CH2C5H3CH3)]2YbⅡ(3)in 49% yield,and {η5;η1-[C5H10NCH2CH2C5H2(CH3)(SiMe3)]}2YbⅡ(5)in 42% yield.Treatment of[(Me3Si)2N]3EuⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 and 2 in toluene at room temperature via a homolytic reaction,gave the corresponding europium(Ⅱ)complexes[η5;η1-(C5H10NCH2CH2C5H3CH3)]2 EuⅡ(4)in 56%yield and {η5;η1-[C5H10NCH2CH2C5H2(CH3)(SiMe3)]}2EuⅡ(6)in 52%yield.All the compounds were fully characterized by spectroscopic methods and elemental analyses.These results further certify the heteroatom coordination promoted homolytic reaction of the Ln-N(Ln=Yb,Eu)bond.This work further extends the new methodology to prepare organolanthanide(Ⅱ)complexes.At the same time,We have studied the catalytic activity of the organolanthanide(Ⅱ)complexes http://www.999magnet.com/ as single-component polymerization catalysts ofε-caprolactone.It was found that the catalysts above have catalytic activity in catalyzingε-CL polymerization.Studies also showed that the solvents,temperatures,the mole ratio of catalyst and monomer,the volume ratio of solvents and monomer have influences on activities of catalysts,the molecular weight and its distribution.
Synthesis of Metal Oxide Nanomaterials by Thermo-decomposition of Organometallic Complex
Synthesis of Metal Oxide Nanomaterials by Thermo-decomposition of Organometallic Complex
The thermolysis of organometallic precursors in combined solvents is one of the most effective methods for preparing highly crystalline and size-controlled nanocrystals.The aim of this dissertation is to synthesize some cheap,air-stable and low-toxicity single precursor for preparation of size-controlled nanomaterials by thermal decomposition method.
The as-prepared nanomaterials are characterized by XRD,TEM,HRTEM, SEM and their growth mechanism is also briefly investigated.The major contents can be summarized as follows;1.Preparation of size-controlled In2O3 nanoparticles by thermal Magnetic lifter decomposition of precursors.Highly crystalline and monodisperse In2O3 nanoparticles were firstly prepared by thermal decomposition of In(dipy)2Cl3·3H2O in oleylamine and oleic acid under inert atmosphere. The size of In2O3 nanoparticles can be readily tuned from 10～15 nm to 40～50 nm,depending on the molar ratio of.precursor to combined solvents in the reaction system.The size-controlled mechanism and PL emission of the In2O3 nanoparticles is briefly explained.The center-body cubic nanoparticles were prepared by thermal decomposition of In(phen)3Cl3·H2O in combined solvents.The size of In2O3 nanoparticles is 40-45 nm.If direct calcination of In(phen)3Cl3·H2O, the mixed phase of In2O3 nanoparticles were prepared.
The phase of product transformed from mixed phase to pure body-center phase when the precursor was heated from 300℃to 700℃.So the methods and temperature of decomposition precursor are key factors to determine the phase of products.In(cup)3 is another precursor for prepare In2O3 nanoparticles.12 nm In2O3 nanoparticles were prepared by thermal decomposition of In(cup)3 in complex solutions The size can be readily tuned 25 nm http://www.999magnet.com/ by change the molar ratio of precursor to combined solvent.We synthesized new precursor using(Me3Si)2NLi reacting with InCl3. Thermal decomposition of the precursor,we got In2O3 by XRD character.2.Preparation of lanthanide oxychloride nanoplates.We synthesized precursors.Ln(dipy)2Cl3·2H2O(Ln=Nd,Pr)and obtained PrOCl and NdOCl nanoplates by thermolysis them in oleic acid/oleyamine solvents. A possible formation mechanism was discussed.This is the first report of synthesis of lanthanide oxychloride nanoplates.We synthesized[(Me3Si)2N]3Nd(μ-Cl)Li(THF)3 complex and studied thermal-decomposition of this precursor in combined solvents.
The thermolysis of organometallic precursors in combined solvents is one of the most effective methods for preparing highly crystalline and size-controlled nanocrystals.The aim of this dissertation is to synthesize some cheap,air-stable and low-toxicity single precursor for preparation of size-controlled nanomaterials by thermal decomposition method.
The as-prepared nanomaterials are characterized by XRD,TEM,HRTEM, SEM and their growth mechanism is also briefly investigated.The major contents can be summarized as follows;1.Preparation of size-controlled In2O3 nanoparticles by thermal Magnetic lifter decomposition of precursors.Highly crystalline and monodisperse In2O3 nanoparticles were firstly prepared by thermal decomposition of In(dipy)2Cl3·3H2O in oleylamine and oleic acid under inert atmosphere. The size of In2O3 nanoparticles can be readily tuned from 10～15 nm to 40～50 nm,depending on the molar ratio of.precursor to combined solvents in the reaction system.The size-controlled mechanism and PL emission of the In2O3 nanoparticles is briefly explained.The center-body cubic nanoparticles were prepared by thermal decomposition of In(phen)3Cl3·H2O in combined solvents.The size of In2O3 nanoparticles is 40-45 nm.If direct calcination of In(phen)3Cl3·H2O, the mixed phase of In2O3 nanoparticles were prepared.
The phase of product transformed from mixed phase to pure body-center phase when the precursor was heated from 300℃to 700℃.So the methods and temperature of decomposition precursor are key factors to determine the phase of products.In(cup)3 is another precursor for prepare In2O3 nanoparticles.12 nm In2O3 nanoparticles were prepared by thermal decomposition of In(cup)3 in complex solutions The size can be readily tuned 25 nm http://www.999magnet.com/ by change the molar ratio of precursor to combined solvent.We synthesized new precursor using(Me3Si)2NLi reacting with InCl3. Thermal decomposition of the precursor,we got In2O3 by XRD character.2.Preparation of lanthanide oxychloride nanoplates.We synthesized precursors.Ln(dipy)2Cl3·2H2O(Ln=Nd,Pr)and obtained PrOCl and NdOCl nanoplates by thermolysis them in oleic acid/oleyamine solvents. A possible formation mechanism was discussed.This is the first report of synthesis of lanthanide oxychloride nanoplates.We synthesized[(Me3Si)2N]3Nd(μ-Cl)Li(THF)3 complex and studied thermal-decomposition of this precursor in combined solvents.
The VUV Luminescence Properties
The VUV Luminescence Properties of M2SiO4:RE (M=Mg, Sr, Ba, RE=Tm～(3+),Tb～(3+))
Now, more and more scholars pay their attention to the phosphors used for PDP (plasma display panel). Silicate phosphors are promising as candidates of host materials for the new VUV phosphors with various crystal structures and high chemical stability. Neodymium Magnets In this article, it was attempted to prepare rare ion doped M2SiO4 phosphor by the solid-state reaction and their luminescent properties under VUV were investigated.The X-ray powder diffraction data of M2SiO4: RE (M=Mg, Sr, Ba, RE=Tm3+, Tb3+) is in agreement of JCPDS standard card (87-0061, 39-1256, 26-1403), which indicates that the doped rare ion have little influence on the structure of luminescent host. It indicates that single-phased M2SiO4 phosphor can be obtained in such synthesis process.The VUV excitation spectrum under 457nm of M2SiO4: Tm3+ (M=Mg, Sr, Ba) shows two peaks at about 170nm and 190nm and a broad excitation band from 211nm to 300nm. The former can be http://www.999magnet.com/ assigned to the absorption of the host lattice, which is shifted towards longer wavelengths as the radius of alkali earth ion in M site increases
Now, more and more scholars pay their attention to the phosphors used for PDP (plasma display panel). Silicate phosphors are promising as candidates of host materials for the new VUV phosphors with various crystal structures and high chemical stability. Neodymium Magnets In this article, it was attempted to prepare rare ion doped M2SiO4 phosphor by the solid-state reaction and their luminescent properties under VUV were investigated.The X-ray powder diffraction data of M2SiO4: RE (M=Mg, Sr, Ba, RE=Tm3+, Tb3+) is in agreement of JCPDS standard card (87-0061, 39-1256, 26-1403), which indicates that the doped rare ion have little influence on the structure of luminescent host. It indicates that single-phased M2SiO4 phosphor can be obtained in such synthesis process.The VUV excitation spectrum under 457nm of M2SiO4: Tm3+ (M=Mg, Sr, Ba) shows two peaks at about 170nm and 190nm and a broad excitation band from 211nm to 300nm. The former can be http://www.999magnet.com/ assigned to the absorption of the host lattice, which is shifted towards longer wavelengths as the radius of alkali earth ion in M site increases
2012年6月26日星期二
The Experimental Study on the Removal of Nitrogen and Phosphate with the Zeolite Modified by Lanthanum
The Experimental Study on the Removal of Nitrogen and Phosphate with the Zeolite Modified by Lanthanum
With the improvement of standard of living and the development of economy, in lately years, the pollution of nitrogen and phosphate is more serious than before. The excessive nitrogen and phosphate will cause the water abundant in alimentation, and affect the environment. So how to control and decrease the concentration of nitride and phosphate in the wastewater and dispose of slightly polluted water has become the new task in the modern wastewater dispose field.This investigation used the lanthanum loaded on the nano-power , and the modified zeolite can adsorb ammoniac nitride and phosphate simultaneous, the capability of adsorption , the period of adsorbent, Cylinder neodymium magnet easy to recycle, used convenienceThe main content of the described as follows:(1)the zeiolite modified with lanthanum, the best concentration and pH value of modified solution, the time and temperature of modified process were studied (2) Study the Influential factors of nitride and phosphate removal, including: ,the variation of wastewater (such as pH range of the solution , the concentration of pollutant ) the dosage , the time and the interfere ions in solution .(3) determine the condition of recycle (4) do some primary analyse to the mechanism of modified and adsorption.
The result of researches show that:(1) when the time of dipping was 16 hours , the pH value was 12, the ratio of zeolite and solution was 1:50 and the dry temperature was 100℃are the optimal condition of modified (2) when the concentration of ammnoia nitrogen and phosphate was 30 mg/L and 5 mg/L respectively, the optimal adsorb condition was :the dosage was 3g/L,pH value was 5 and the time of adsorbed was greater than or equal to 30 minutes.(3) the phosphate in solution not has obvious influence to the removal of ammnoia nitrogen, however, the ammnoia nitrogen can promote the adsorbent to adsorbed the phosphate ,the kalium ion and nitrate nitrogen http://www.chinamagnets.biz/ not has obvious influence to the removal of ammnoia nitrogen and phosphate, the ion of calcium inhibiting the removal of ammnoia nitrogen, but promoting the removal of phosphate , the ion of fluorine not has obvious influence to the removal of ammnoia nitrogen, has competitive efect with phosphate. (4) the reclaim solution was alkalinity, the optimal effect can be reached when the concentration of reclaim solution was 0.15mol/L and the time was 4 hours.(5) do some primary analyse to the mechanism of modified and adsorption, the main reason of the modified material can adsorb the ammnoia nitrogen was the nano-zeolite has the capability of ions exchange, the active site to removal phosphate is the rare earth oxide doped on the nano-zeolite.(6)after the measuring and fitting, the adsorption isotherm of ammnoia nitrogen was correspond with the model of Langmuir, the adsorption isotherm of phosphate was correspond with the model of muti-layer.
With the improvement of standard of living and the development of economy, in lately years, the pollution of nitrogen and phosphate is more serious than before. The excessive nitrogen and phosphate will cause the water abundant in alimentation, and affect the environment. So how to control and decrease the concentration of nitride and phosphate in the wastewater and dispose of slightly polluted water has become the new task in the modern wastewater dispose field.This investigation used the lanthanum loaded on the nano-power , and the modified zeolite can adsorb ammoniac nitride and phosphate simultaneous, the capability of adsorption , the period of adsorbent, Cylinder neodymium magnet easy to recycle, used convenienceThe main content of the described as follows:(1)the zeiolite modified with lanthanum, the best concentration and pH value of modified solution, the time and temperature of modified process were studied (2) Study the Influential factors of nitride and phosphate removal, including: ,the variation of wastewater (such as pH range of the solution , the concentration of pollutant ) the dosage , the time and the interfere ions in solution .(3) determine the condition of recycle (4) do some primary analyse to the mechanism of modified and adsorption.
The result of researches show that:(1) when the time of dipping was 16 hours , the pH value was 12, the ratio of zeolite and solution was 1:50 and the dry temperature was 100℃are the optimal condition of modified (2) when the concentration of ammnoia nitrogen and phosphate was 30 mg/L and 5 mg/L respectively, the optimal adsorb condition was :the dosage was 3g/L,pH value was 5 and the time of adsorbed was greater than or equal to 30 minutes.(3) the phosphate in solution not has obvious influence to the removal of ammnoia nitrogen, however, the ammnoia nitrogen can promote the adsorbent to adsorbed the phosphate ,the kalium ion and nitrate nitrogen http://www.chinamagnets.biz/ not has obvious influence to the removal of ammnoia nitrogen and phosphate, the ion of calcium inhibiting the removal of ammnoia nitrogen, but promoting the removal of phosphate , the ion of fluorine not has obvious influence to the removal of ammnoia nitrogen, has competitive efect with phosphate. (4) the reclaim solution was alkalinity, the optimal effect can be reached when the concentration of reclaim solution was 0.15mol/L and the time was 4 hours.(5) do some primary analyse to the mechanism of modified and adsorption, the main reason of the modified material can adsorb the ammnoia nitrogen was the nano-zeolite has the capability of ions exchange, the active site to removal phosphate is the rare earth oxide doped on the nano-zeolite.(6)after the measuring and fitting, the adsorption isotherm of ammnoia nitrogen was correspond with the model of Langmuir, the adsorption isotherm of phosphate was correspond with the model of muti-layer.
Study on Composition Optimization and Memory Performance of Fe-Mn-Si SMA
Study on Composition Optimization and Memory Performance of Fe-Mn-Si SMA
Fe-Mn-Si series shape memory alloys in iron-based memory alloys had been produced by using low raw material, ordinary induction furnace, special smelting technology, and the effect of Cr, Ni, C, RE on the mechanical properties and memory effect had been discussed by means of method of orthogonal experiment, and the result indicated that properties of alloys were greatly affected by Cr Ni C. Mechanical properties decreased with the increasing C content when C content was less than 0.3%, and increased when C content was more than 0.3%. Shape memory effect of alloys decreased rapidly when the C content was increased. The increasing Cr was beneficial to Cube neodymium magnet the shape memory effect and mechanical properties of alloys. Both mechanical properties and shape memory effect decreased slightly when the Ni content was increased. Tensile properties increased with the increasing Rare Earth content.
The impact properties and shape memory effect decreased with the increasing RE content when the RE content was less than 0.1%, and increased when the RE content was more than 0.1%. Analyzed comprehensively, the optimum composition was 0.2%C, 15%Mn, 5%Si, 10%Cr.Second, the best composition was optimized by orthogonal design method, and the effect of factors of pre-deformation, thermal mechanical training, restoring temperature, quenching temperature on the memory effect of alloys was discussed. It had been found that the shape recovery ratio of the alloy decreased with increasing pre-deformation, and being relative to the pre-deformation it had a stationary zone (2.78%~4.17%) in which shape recovery ratio varied slightly, and the memory effect was stable, and shape recovery ratio decreased rapidly with the increasing pre- deformation when pre-deformation was out of this range, more or less. Shape recovery ratio of alloy increased with the http://www.chinamagnets.biz/ increasing restoring temperature, and when the temperature reached to 650℃,the variation of memory recovery ratio was stable. Shape recovery ratio increased obviously with the increasing thermal-mechanical training times; however, it slightly decreased when the training came to certain times which was related to alloy composition. The better shape recovery ratio can not be obtained when the quenching temperature was low to certain level, and can be obtained when the quenching temperature was in given range which was wide and was different according to the varying composition of alloy.Finally, the electrochemical corrosion test of alloy with 0.2%C, 15%Mn, 5%Si, 10%C indicated that this shape memory alloy was liable to passivation, and it had low passivation potential and large passivation region, in addition its passive film was stable and its electrochemical corrosion resistance was equal to stainless steel.
Fe-Mn-Si series shape memory alloys in iron-based memory alloys had been produced by using low raw material, ordinary induction furnace, special smelting technology, and the effect of Cr, Ni, C, RE on the mechanical properties and memory effect had been discussed by means of method of orthogonal experiment, and the result indicated that properties of alloys were greatly affected by Cr Ni C. Mechanical properties decreased with the increasing C content when C content was less than 0.3%, and increased when C content was more than 0.3%. Shape memory effect of alloys decreased rapidly when the C content was increased. The increasing Cr was beneficial to Cube neodymium magnet the shape memory effect and mechanical properties of alloys. Both mechanical properties and shape memory effect decreased slightly when the Ni content was increased. Tensile properties increased with the increasing Rare Earth content.
The impact properties and shape memory effect decreased with the increasing RE content when the RE content was less than 0.1%, and increased when the RE content was more than 0.1%. Analyzed comprehensively, the optimum composition was 0.2%C, 15%Mn, 5%Si, 10%Cr.Second, the best composition was optimized by orthogonal design method, and the effect of factors of pre-deformation, thermal mechanical training, restoring temperature, quenching temperature on the memory effect of alloys was discussed. It had been found that the shape recovery ratio of the alloy decreased with increasing pre-deformation, and being relative to the pre-deformation it had a stationary zone (2.78%~4.17%) in which shape recovery ratio varied slightly, and the memory effect was stable, and shape recovery ratio decreased rapidly with the increasing pre- deformation when pre-deformation was out of this range, more or less. Shape recovery ratio of alloy increased with the http://www.chinamagnets.biz/ increasing restoring temperature, and when the temperature reached to 650℃,the variation of memory recovery ratio was stable. Shape recovery ratio increased obviously with the increasing thermal-mechanical training times; however, it slightly decreased when the training came to certain times which was related to alloy composition. The better shape recovery ratio can not be obtained when the quenching temperature was low to certain level, and can be obtained when the quenching temperature was in given range which was wide and was different according to the varying composition of alloy.Finally, the electrochemical corrosion test of alloy with 0.2%C, 15%Mn, 5%Si, 10%C indicated that this shape memory alloy was liable to passivation, and it had low passivation potential and large passivation region, in addition its passive film was stable and its electrochemical corrosion resistance was equal to stainless steel.
2012年6月19日星期二
Synthesis, Structure and Catalytic Activity of Organolanthanide Complexes with N-piperidineethyl Substituted Fluorenyl Ligands
Synthesis, Structure and Catalytic Activity of Organolanthanide Complexes with N-piperidineethyl Substituted Fluorenyl Ligands
All experiments were carried out under the dry and oxygen-free argon atmosphere by using standard Schlenk techniques.Reaction of C5H10NCH2CH2Cl with 1 equiv of C13H9Li in Et2O at O°C yielded C5H10NCH2CH2C13H9(1)in 73%yield.Interaction of[(Me3Si)2N]3YbⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene for 24 hours,after Special shape NdFeB magnets recrystallization from toluene,gave an ytterbium(Ⅱ)complex[η5;μ1-C5H10NCH2CH2C13H8]2YbⅡ(2)in 64%yield.Interaction of[(Me3Si)2N]3 EuⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene for 24 hours,gave a europium(Ⅱ)complex[η5;η1-C5H10NCH2CH2C13H8]2EuⅡ(3)in 70%yield.Interaction of[(Me3Si)2N]3NdⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene for 24 hours,after recrystallization from toluene,gave a neodymium(Ⅲ)complex[η5;η1- C5H10NCH2CH2C13H8]2-NdⅢCl(4)in 47%yield;Interaction of 1 with 1 equiv ofn-BuLi in THF yielded C5H10NCH2CH2C13H5Li(THF)2(5)in 81%yield;Reaction of 5 with 0.5 equiv of YCl3 in THF yielded[η5;η1-C5H10NCH2CH2C13H8]2-yⅢCl(6)in 62%yield.All the complexes were fully characterized by elemental and spectroscopic analyses.The structures of complexes 3 and 5 were determined by X-ray diffraction.On the basis of the above experimental results,these experiments further certify that the internal donor ligands coordination promoted homolytic reaction of the Ln-N bond,The activities of the ytterbium(Ⅱ) and europium(Ⅱ)complexes http://www.999magnet.com/ as single-component catalysts in catalyzing MMA andε-CL polymerization were examined.It was found that the activities of the catalysts,stereo-regularity of PMMA,and the molecular weight of polymers were dependent on the solvents,temperature and the central metal of the catalysts.
All experiments were carried out under the dry and oxygen-free argon atmosphere by using standard Schlenk techniques.Reaction of C5H10NCH2CH2Cl with 1 equiv of C13H9Li in Et2O at O°C yielded C5H10NCH2CH2C13H9(1)in 73%yield.Interaction of[(Me3Si)2N]3YbⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene for 24 hours,after Special shape NdFeB magnets recrystallization from toluene,gave an ytterbium(Ⅱ)complex[η5;μ1-C5H10NCH2CH2C13H8]2YbⅡ(2)in 64%yield.Interaction of[(Me3Si)2N]3 EuⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene for 24 hours,gave a europium(Ⅱ)complex[η5;η1-C5H10NCH2CH2C13H8]2EuⅡ(3)in 70%yield.Interaction of[(Me3Si)2N]3NdⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene for 24 hours,after recrystallization from toluene,gave a neodymium(Ⅲ)complex[η5;η1- C5H10NCH2CH2C13H8]2-NdⅢCl(4)in 47%yield;Interaction of 1 with 1 equiv ofn-BuLi in THF yielded C5H10NCH2CH2C13H5Li(THF)2(5)in 81%yield;Reaction of 5 with 0.5 equiv of YCl3 in THF yielded[η5;η1-C5H10NCH2CH2C13H8]2-yⅢCl(6)in 62%yield.All the complexes were fully characterized by elemental and spectroscopic analyses.The structures of complexes 3 and 5 were determined by X-ray diffraction.On the basis of the above experimental results,these experiments further certify that the internal donor ligands coordination promoted homolytic reaction of the Ln-N bond,The activities of the ytterbium(Ⅱ) and europium(Ⅱ)complexes http://www.999magnet.com/ as single-component catalysts in catalyzing MMA andε-CL polymerization were examined.It was found that the activities of the catalysts,stereo-regularity of PMMA,and the molecular weight of polymers were dependent on the solvents,temperature and the central metal of the catalysts.
偶氮苯酰亚胺类树枝功能化材料的合成及其发光性能研究
偶氮苯酰亚胺类树枝功能化材料的合成及其发光性能研究
The properties and application of poly (amido amine) (PAMAM) dendrimers and its derivatives have been investigated extensively. Azobenzene and its derivatives are typical molecules showing cis-trans photoisomerization, and they have been attracted much interest for the viewpoint of fundamental photochemistry and their high potential in industrial applications. Hence, study in this area can profound the mechanism of azobenzene derivatives light-response structure character and photos peculiarity. Also providing theory directioning to molecule materials design. In this paper, photo character as well as other properties of azobenzenes function PAMAM derivatives has been extensively investigated by a variety of physicochemical methods such as UV-visible absorption,fluorescent spectra, fluorescent life, quantum yield and theoretical calculations. Based on these Alnico magnets communication, we have also investigate the effect of intermingle with rare earth ions, transition metal, CF3SO3H acid and triethylamine.The results obtained have shown that: (1) The absorption spectrum contains abroad band at 290nm , which originates from not only the azobenzene aggregates but also theπ→π* transition of the trans azobenzene units. The absorption at 395nm extends to 450nm, where the forbidden n→π* transition of the trans isomer is located.
The steady-state fluorescence spectrum exhibit both S2 fluorescence (395 nm) and S1 fluorescence (760 nm), this may be due to the fact that the peripheral chromophores of the different generations possessing different sterically crowded structure and conjugation, which in turn prevents the dendrimers from parallel arrangement and the cis-trans photoisomerization of azobenzene units. (2) The fact that donating or pulling electron of carboxylic acid and protonation of–OH function decreases the luminescence intensity of Gn in acidity, but appreciably enhance in alkalescence. Both of them showed pH dependence in fluorescence intensity. (3) The effect of the rare earth ions (Er3+, Eu3+, Gd3+, Nd3+, Tb3+, Yb3+) and transition metal Cu2+ upon the fluorescent intensity of generation polyamidoamine dendrimers with a peripheral azobenzene group have been http://www.999magnet.com/ systematically investigated. The fluorescence spectrum have been quenched both at 395 nm and 760 nm emission reveal that the metal ions act as the electron receptor cause quenching of the excited state of the fluorophore by PET , and UV-visible absorption hole the location but a strong ligand-to-metal charge-transfer (LMCT) transition centered at 300nm emerges, suggesting the metal ions and ligand form exciplex at ground state.
The difference of quenching effect resulted from the different electronic shell of metal ions and their ionic radius. Lower generations of the dendrimers are highly symmetric and tend to existing in an open and extended form. In contrast, the higher generations present a three dimensional globular structure with a densely packed chromophore shell. Therefore, stronger signals of fluorescence quenching have been observed in higher generations. Finally, we further testify it by three-dimensional fluorescence spectra, from them we find the dendrimers excited state can be adjusted through changing the length of ligand branch and pH, importing the external species and so on. The results obtained reveal that the azobenzene derivatives are useful for the fluorescent probe techniques, light-driven switches, and image storage devices.
The properties and application of poly (amido amine) (PAMAM) dendrimers and its derivatives have been investigated extensively. Azobenzene and its derivatives are typical molecules showing cis-trans photoisomerization, and they have been attracted much interest for the viewpoint of fundamental photochemistry and their high potential in industrial applications. Hence, study in this area can profound the mechanism of azobenzene derivatives light-response structure character and photos peculiarity. Also providing theory directioning to molecule materials design. In this paper, photo character as well as other properties of azobenzenes function PAMAM derivatives has been extensively investigated by a variety of physicochemical methods such as UV-visible absorption,fluorescent spectra, fluorescent life, quantum yield and theoretical calculations. Based on these Alnico magnets communication, we have also investigate the effect of intermingle with rare earth ions, transition metal, CF3SO3H acid and triethylamine.The results obtained have shown that: (1) The absorption spectrum contains abroad band at 290nm , which originates from not only the azobenzene aggregates but also theπ→π* transition of the trans azobenzene units. The absorption at 395nm extends to 450nm, where the forbidden n→π* transition of the trans isomer is located.
The steady-state fluorescence spectrum exhibit both S2 fluorescence (395 nm) and S1 fluorescence (760 nm), this may be due to the fact that the peripheral chromophores of the different generations possessing different sterically crowded structure and conjugation, which in turn prevents the dendrimers from parallel arrangement and the cis-trans photoisomerization of azobenzene units. (2) The fact that donating or pulling electron of carboxylic acid and protonation of–OH function decreases the luminescence intensity of Gn in acidity, but appreciably enhance in alkalescence. Both of them showed pH dependence in fluorescence intensity. (3) The effect of the rare earth ions (Er3+, Eu3+, Gd3+, Nd3+, Tb3+, Yb3+) and transition metal Cu2+ upon the fluorescent intensity of generation polyamidoamine dendrimers with a peripheral azobenzene group have been http://www.999magnet.com/ systematically investigated. The fluorescence spectrum have been quenched both at 395 nm and 760 nm emission reveal that the metal ions act as the electron receptor cause quenching of the excited state of the fluorophore by PET , and UV-visible absorption hole the location but a strong ligand-to-metal charge-transfer (LMCT) transition centered at 300nm emerges, suggesting the metal ions and ligand form exciplex at ground state.
The difference of quenching effect resulted from the different electronic shell of metal ions and their ionic radius. Lower generations of the dendrimers are highly symmetric and tend to existing in an open and extended form. In contrast, the higher generations present a three dimensional globular structure with a densely packed chromophore shell. Therefore, stronger signals of fluorescence quenching have been observed in higher generations. Finally, we further testify it by three-dimensional fluorescence spectra, from them we find the dendrimers excited state can be adjusted through changing the length of ligand branch and pH, importing the external species and so on. The results obtained reveal that the azobenzene derivatives are useful for the fluorescent probe techniques, light-driven switches, and image storage devices.
2012年6月18日星期一
Study on Synthesis Fluorescent Properties and Antibacterial Activity of Rare Complexes of Benzohydroxamic Acids
Study on Synthesis Fluorescent Properties and Antibacterial Activity of Rare Complexes of Benzohydroxamic Acids
Rare earth complexes of 4-butoxybenzohydroxamic acid and 4-octyloxybenzohydroxamic acid have been synthesized.These complexes were characterized by IR spectra,UV spectra,thermal analysis and elemental analysis.Element analysis has proved strong magnets that the formula of these complexes(Ⅰ) is asfollow: (C4H9O-(?)-CONHO)3Ln·xH2O (Ln=La,Ce,Sm,Eu,Tb,Er,Tm,Yb,x=4; Ln=Pr,Nd,Gd,Dy, x=3; Ln=Ho,x=1) ; these complexes(Ⅱ): (C8H17O-(?)-CONHO)3Ln·xH2O ( Ln=La,Ce,Sm,Eu,Tb,Tm,Yb,x=4; Ln= Pr,Nd,Gd,Dy, Er x=3; Ln=Ho,x=1) .IR shows the ligand coordinates through two oxygen atoms and the construction of the complexes is five membered chelate ring.TG-DSC indicates that the weight-loss is identical with the theoretical amount. The fluorescent properties of some complexes were measured http://www.chinamagnets.biz/ and investigated.The main fluorescence peak emission of the complexe of TbL3 (Ⅱ)·4H2O appeared at 489、544、584nm; The main fluoresecence peak emission of the complex of EuL3 (Ⅰ)·4H2O appeared at 591、614nm.Tests of antibacterial activity showed two ligands and their complexes all had inhibitory actions against G(+)Staphylococcus and G(-)Escherichia coli.
Rare earth complexes of 4-butoxybenzohydroxamic acid and 4-octyloxybenzohydroxamic acid have been synthesized.These complexes were characterized by IR spectra,UV spectra,thermal analysis and elemental analysis.Element analysis has proved strong magnets that the formula of these complexes(Ⅰ) is asfollow: (C4H9O-(?)-CONHO)3Ln·xH2O (Ln=La,Ce,Sm,Eu,Tb,Er,Tm,Yb,x=4; Ln=Pr,Nd,Gd,Dy, x=3; Ln=Ho,x=1) ; these complexes(Ⅱ): (C8H17O-(?)-CONHO)3Ln·xH2O ( Ln=La,Ce,Sm,Eu,Tb,Tm,Yb,x=4; Ln= Pr,Nd,Gd,Dy, Er x=3; Ln=Ho,x=1) .IR shows the ligand coordinates through two oxygen atoms and the construction of the complexes is five membered chelate ring.TG-DSC indicates that the weight-loss is identical with the theoretical amount. The fluorescent properties of some complexes were measured http://www.chinamagnets.biz/ and investigated.The main fluorescence peak emission of the complexe of TbL3 (Ⅱ)·4H2O appeared at 489、544、584nm; The main fluoresecence peak emission of the complex of EuL3 (Ⅰ)·4H2O appeared at 591、614nm.Tests of antibacterial activity showed two ligands and their complexes all had inhibitory actions against G(+)Staphylococcus and G(-)Escherichia coli.
Study on Preparation and Property of BaTiO3 and Res Doped BaTiO3 as Radar Absorbing Materials
Study on Preparation and Property of BaTiO3 and Res Doped BaTiO3 as Radar Absorbing Materials
As the key of stealthy technology, radar-absorbing material (RAM) has been widely used in both military and civil fields. On one hand, RAM is used in weapons to protect them from being detected by radar; on the other hand, RAM is used to protect people from being hurt by electromagnetic radiation. Barium titanate(BaTiO3) is a kind of dielectric material with microwave absorption property, including dielectric loss as the major and magnetic loss as strong magnets the minor. As far as dielectric loss is concerned, its mechanism of action is chiefly contributed to conductivity, relaxing polarization and harmonic oscillation.In this thesis, nano powder of BaTiO3 was synthesized by sol-gel method, and the technique parameters were optimized and determined as following: precursor concentration 0.5mol/L, glacial-acetic acid dosage 400ml/mol precursor, water area temperature 60℃, gel aging time 4h and calcining temperature 850℃for 2h should be employed best. Then BaTiO3 with Ln REs 0.2% doped was synthesized by the optimum technique process. And the REs chosen were La, Ce, Nd, Eu, Gd, Dy. Besides, with considerations of the improvement of microwave absorption property which La doping had brought, BaTiO3 with different amount of La(0.6% and 1.0%)doped were also prepared.Then, the dry gel of BaTiO3 was analyzed by the means of DSC and FT-IR. And the crystal structure and the surface appearance of BaTiO3 and BaTiO3 with REs doped were studied by XRD, FT-IR,
Raman spectrum and SEM, and the microwave performance by the network-analyzing equipment. At last, we obtained BaTiO3 with Nd 0.2% doped http://www.chinamagnets.biz/ with Rmin -60dB at 2～18GHz band, and BaTiO3 with La 0.6% doped with Rmin -44dB at X band.By comparison of BaTiO3 with 6 kinds of REs 0.2% doped, it was found that doping of REs caused lattice distortion and then a grew larger, c/a and particle diameter decreased and volume of cristal cell shrinked. Besides, the peak intensity of the electromagnetic property constants of BaTiO3 decreased and the peaks shifted towards blue rigions. Radar absorption property was also improved. And by comparison, it was concluded that Nd or La doping brought a large effect on the electromagnetic property and the microwave absorption property; the effect of Dy doping was less; that of Ce doping was the least; and that of Eu or Gd doping depended on the target property.By analyzing the structure and property of BaTiO3 with different amount of La doped, we proposed the migration regularity of La3+ in BaTiO3 crystal on the reasonable premise. Based on the above theory, the effect of different amount of La doping was strong magnets analyzed. Then it was found that: with the amount of La doped increasing, a decreased, the particle diamater and c/a and the volume of crystal cell increased first and decreased afterwards. The peaks of the electromagnetic property constants shifted towards blue rigions and their intensity decreased. The radar absorption property was also improved. But the effect of La doing turned the opposite after some critical value.
As the key of stealthy technology, radar-absorbing material (RAM) has been widely used in both military and civil fields. On one hand, RAM is used in weapons to protect them from being detected by radar; on the other hand, RAM is used to protect people from being hurt by electromagnetic radiation. Barium titanate(BaTiO3) is a kind of dielectric material with microwave absorption property, including dielectric loss as the major and magnetic loss as strong magnets the minor. As far as dielectric loss is concerned, its mechanism of action is chiefly contributed to conductivity, relaxing polarization and harmonic oscillation.In this thesis, nano powder of BaTiO3 was synthesized by sol-gel method, and the technique parameters were optimized and determined as following: precursor concentration 0.5mol/L, glacial-acetic acid dosage 400ml/mol precursor, water area temperature 60℃, gel aging time 4h and calcining temperature 850℃for 2h should be employed best. Then BaTiO3 with Ln REs 0.2% doped was synthesized by the optimum technique process. And the REs chosen were La, Ce, Nd, Eu, Gd, Dy. Besides, with considerations of the improvement of microwave absorption property which La doping had brought, BaTiO3 with different amount of La(0.6% and 1.0%)doped were also prepared.Then, the dry gel of BaTiO3 was analyzed by the means of DSC and FT-IR. And the crystal structure and the surface appearance of BaTiO3 and BaTiO3 with REs doped were studied by XRD, FT-IR,
Raman spectrum and SEM, and the microwave performance by the network-analyzing equipment. At last, we obtained BaTiO3 with Nd 0.2% doped http://www.chinamagnets.biz/ with Rmin -60dB at 2～18GHz band, and BaTiO3 with La 0.6% doped with Rmin -44dB at X band.By comparison of BaTiO3 with 6 kinds of REs 0.2% doped, it was found that doping of REs caused lattice distortion and then a grew larger, c/a and particle diameter decreased and volume of cristal cell shrinked. Besides, the peak intensity of the electromagnetic property constants of BaTiO3 decreased and the peaks shifted towards blue rigions. Radar absorption property was also improved. And by comparison, it was concluded that Nd or La doping brought a large effect on the electromagnetic property and the microwave absorption property; the effect of Dy doping was less; that of Ce doping was the least; and that of Eu or Gd doping depended on the target property.By analyzing the structure and property of BaTiO3 with different amount of La doped, we proposed the migration regularity of La3+ in BaTiO3 crystal on the reasonable premise. Based on the above theory, the effect of different amount of La doping was strong magnets analyzed. Then it was found that: with the amount of La doped increasing, a decreased, the particle diamater and c/a and the volume of crystal cell increased first and decreased afterwards. The peaks of the electromagnetic property constants shifted towards blue rigions and their intensity decreased. The radar absorption property was also improved. But the effect of La doing turned the opposite after some critical value.
Study on Modification of Ethylene-Vinyl Acetate Rubber by Lithium Methacrylate and LaCl3
Study on Modification of Ethylene-Vinyl Acetate Rubber by Lithium Methacrylate and LaCl3
The salts of unsaturated carboxylic acids are effective reinforcing agents for rubbers. In this dissertation, the reinforcement of ethylene-vinyl acetate rubber (EVM) by a salt of unsaturated carboxylic acid Lithium Methacrylate (LiMAA) was studied. The curing properties of EVM compounds, the mechanical properties and crosslinking structure of EVM vulcanizates were studied in detail. Then, effects of rare earth compound LaCl3 on the EVM/LiMAA system were investigated. EVM/LiMAA/LaCl3 system was compared with EVM/LiMAA system on rare earth magnets curing properties, mechanical properties, crosslinking structure, aging resistance and electric properties. The mechanism of the effects were also explored.Firstly, through the neutralization of methacrylic acid (MAA) and LiOH, LiMAA was in situ prepared in EVM compound. The results showed that LiMAA had good reinforcing effects on EVM vulcanizates. The curing rates of EVM compounds were greatly accelerated with the increase of LiMAA content.
The ionic crosslink density and gross density of EVM vulcanizates also obviously increased, and covalent crosslink density is the main part of the gross crosslink density. The effects of LiMAA content and LiOH/MAA mol ratio on the mechanical properties of EVM vulcanizates were studied. The formulation of 3.0 phr DCP, 30 phr LiMAA and LiOH/MAA mol ratio 1.0 is recommended for EVM vulcanizate with good mechanical properties. The tensile strength, tear strength and elongation at break are 30.9MPa, 93.4kN·m-1 and 383%, respectively. Scanning Electronic Microscope (SEM) observation indicated that nanoscale particles disperse uniformly in EVM vulcanizates with the size ranging from 101 nm to 102 nm.Secondly, LaCl3 was chosen as a modifier to http://www.chinamagnets.biz/ the EVM/LiMAA system. When the LaCl3 content was not more than 20 phr, the covalent crosslink density and gross density of EVM vulcanizates slightly decreased with the increase of LaCl3 content, but ionic crosslink density increased. Ionic crosslink density became main part of the gross crosslink density when the LaCl3 content was 20 phr. Mechanical properties of EVM vulcanizates decreased to some extent with the addition of LaCl3. But after aging in air the EVM/LiMAA/LaCl3 vulcanizate had much better maintenance of mechanical properties than EVM/LiMAA vulcanizate.The effect of LaCl3 on electric properties of EVM/LiMAA vulcanizate was also researched. EVM vulcanizates can transfer from insulated to antistatic materials with addition of LaCl3, volume resisitivity (Rv) of which can reach 3.00×1010Ω·cm. After moisture absorbing in the constant humidity environment, the Rv of EVM/LiMAA/ LaCl3 vulcanizate decreased dramaticly with the increase of water-absorbing ratio. Rv of the EVM/LiMAA/ LaCl3 vulcanizate reached 104Ω·cm when the water-absorbing ratio was above 10%, which made the vulcanizate conductive. Fourier transform infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) tests showed that there were probably coordination bonds between La3+ and MAA-, which let Li+ transfer more freely and caused the enhancement of conductivity.
The salts of unsaturated carboxylic acids are effective reinforcing agents for rubbers. In this dissertation, the reinforcement of ethylene-vinyl acetate rubber (EVM) by a salt of unsaturated carboxylic acid Lithium Methacrylate (LiMAA) was studied. The curing properties of EVM compounds, the mechanical properties and crosslinking structure of EVM vulcanizates were studied in detail. Then, effects of rare earth compound LaCl3 on the EVM/LiMAA system were investigated. EVM/LiMAA/LaCl3 system was compared with EVM/LiMAA system on rare earth magnets curing properties, mechanical properties, crosslinking structure, aging resistance and electric properties. The mechanism of the effects were also explored.Firstly, through the neutralization of methacrylic acid (MAA) and LiOH, LiMAA was in situ prepared in EVM compound. The results showed that LiMAA had good reinforcing effects on EVM vulcanizates. The curing rates of EVM compounds were greatly accelerated with the increase of LiMAA content.
The ionic crosslink density and gross density of EVM vulcanizates also obviously increased, and covalent crosslink density is the main part of the gross crosslink density. The effects of LiMAA content and LiOH/MAA mol ratio on the mechanical properties of EVM vulcanizates were studied. The formulation of 3.0 phr DCP, 30 phr LiMAA and LiOH/MAA mol ratio 1.0 is recommended for EVM vulcanizate with good mechanical properties. The tensile strength, tear strength and elongation at break are 30.9MPa, 93.4kN·m-1 and 383%, respectively. Scanning Electronic Microscope (SEM) observation indicated that nanoscale particles disperse uniformly in EVM vulcanizates with the size ranging from 101 nm to 102 nm.Secondly, LaCl3 was chosen as a modifier to http://www.chinamagnets.biz/ the EVM/LiMAA system. When the LaCl3 content was not more than 20 phr, the covalent crosslink density and gross density of EVM vulcanizates slightly decreased with the increase of LaCl3 content, but ionic crosslink density increased. Ionic crosslink density became main part of the gross crosslink density when the LaCl3 content was 20 phr. Mechanical properties of EVM vulcanizates decreased to some extent with the addition of LaCl3. But after aging in air the EVM/LiMAA/LaCl3 vulcanizate had much better maintenance of mechanical properties than EVM/LiMAA vulcanizate.The effect of LaCl3 on electric properties of EVM/LiMAA vulcanizate was also researched. EVM vulcanizates can transfer from insulated to antistatic materials with addition of LaCl3, volume resisitivity (Rv) of which can reach 3.00×1010Ω·cm. After moisture absorbing in the constant humidity environment, the Rv of EVM/LiMAA/ LaCl3 vulcanizate decreased dramaticly with the increase of water-absorbing ratio. Rv of the EVM/LiMAA/ LaCl3 vulcanizate reached 104Ω·cm when the water-absorbing ratio was above 10%, which made the vulcanizate conductive. Fourier transform infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) tests showed that there were probably coordination bonds between La3+ and MAA-, which let Li+ transfer more freely and caused the enhancement of conductivity.
Preliminary Studies on Rapid Propagation in Vitro and Rooting Mechanism of Cyclocarya Paliurus
Preliminary Studies on Rapid Propagation in Vitro and Rooting Mechanism of Cyclocarya Paliurus
Cyclocarya paliurus has multiple applications,such as medicine,health care,timber use, ornamental use,etc..But the development and utilization is severely restricted because of natural regeneration difficulty.In this research,excised embryos from four provenances (included 3 per plants)were chosen as plantlets to establish a tissue culture technical system. This system started from culturing excised embryos to inducting adventitious roots.Also, cotyledon was used as Cylinder neodymium magnet material to explore the rooting mechanism.The paper aims at establishing an efficient tissue culture and rapid propagation system and providing theoretical basis for industrial seedling.The main conclusions and achievements are as followings.(1)In this paper,comparing the growth of excised embryo in different culture,the result showed that the CK culture medium with 20g/L sucrose greatly increased the germination rate. In this medium,the growth situation of excised embryoes differed between per plants:the highest seedling rate was 06lushan1#,which was 72.66%;
The second were 06jianhe3# and 06yunnan4#,the seedling rate were 44.00%and 39.33%;The worst was 06 hefeng Provenance, the corresponding rate was just 17.33%.(2)According to excised embryo culture results and requirement of cardinal number,three per plants,06lushan1#,06jianhe3# and 06yunnan4# were chosen for a farther multiple buds induction and generation tests.The initial culture and subculture results proved the growth differences between per plants.The initial culture test factors were rate of adventitious shoots and multiplication coefficient,and subculture test factors were multiplication coefficient and seedling height.It can draw that 6-BA0.5～1.0mg/L+ IBA0.01mg/L was the best hormone combination for initial culture and subculture.The results suggested that 06jianhe3# grew best in hormone combination with 6-BA1.0mg/L+ IBA0.01mg/L,rate of adventitious shoots in the medium was 100%,multiplication coefficient was 6.08,and the seedling height was http://www.chinamagnets.biz/ 3.87cm. 061ushan1# and 06yunnan4#’ s best media differed from 06jianhe3#,06lushan1#’s highest rate of adventitious shoots was 93.33%,multiplication coefficient was 5.22,seedling height was 3.12cm.06yunnan4#’s highest rate of adventitious shoots was 63.33%,multiplication coefficient was 2.99,seedling height was 3.40cm.(3)Rare earth lanthanum and uniconazole were chosen as growth regulators,06jianhe3# and 06lushan1# as experiment materials,for strong seedling culture.
Corresponding growth indexes and physiological indexes were tested to compare the strong seedling effects.The results showed that rare earth lanthanum 5mg/L mainly improve fresh weight,chlorophyll content, soluble sugar content,promote multiple shoot differentiation and height growth.It can concluded that rare earth lanthanum is a suitable additives to be add in enrichment medium. Uniconazole 0.5mg/L could inhibit seedling height,improve chlorophyll content and resistance, and it can be a good growth regulator to add in strong seedling culture medium after enrichment http://www.chinamagnets.biz/ medium.(4)Plantlets,after subculture at lest 5 times,first inducted root in 1/2WPM+IBA0.05～0.1 mg/L+sucrose 20g/L for 15 days in dark condition,then changed into 1/2WPM+sucrose20g/L in normal illumination,about one month later,rooting rate of 06lushan1# was 23.33%.(5)Cotyledon adventitious rooting rate was 100%with IBA1.5mg/L.Comparing dynamic changes of four endogenous hormones during cotyledon rooting,the research showed endogenous IAA was the critical factor in cotyledon rooting:root primordium starting needed high endogenous IAA and root formation and elongation needed lower level.The ratios of IAA/ABA,IAA/GA3 gave good reflection between different endogenous hormones,GA3 does not appear to be the key inhibition factor in cotyledon rooting.
Cyclocarya paliurus has multiple applications,such as medicine,health care,timber use, ornamental use,etc..But the development and utilization is severely restricted because of natural regeneration difficulty.In this research,excised embryos from four provenances (included 3 per plants)were chosen as plantlets to establish a tissue culture technical system. This system started from culturing excised embryos to inducting adventitious roots.Also, cotyledon was used as Cylinder neodymium magnet material to explore the rooting mechanism.The paper aims at establishing an efficient tissue culture and rapid propagation system and providing theoretical basis for industrial seedling.The main conclusions and achievements are as followings.(1)In this paper,comparing the growth of excised embryo in different culture,the result showed that the CK culture medium with 20g/L sucrose greatly increased the germination rate. In this medium,the growth situation of excised embryoes differed between per plants:the highest seedling rate was 06lushan1#,which was 72.66%;
The second were 06jianhe3# and 06yunnan4#,the seedling rate were 44.00%and 39.33%;The worst was 06 hefeng Provenance, the corresponding rate was just 17.33%.(2)According to excised embryo culture results and requirement of cardinal number,three per plants,06lushan1#,06jianhe3# and 06yunnan4# were chosen for a farther multiple buds induction and generation tests.The initial culture and subculture results proved the growth differences between per plants.The initial culture test factors were rate of adventitious shoots and multiplication coefficient,and subculture test factors were multiplication coefficient and seedling height.It can draw that 6-BA0.5～1.0mg/L+ IBA0.01mg/L was the best hormone combination for initial culture and subculture.The results suggested that 06jianhe3# grew best in hormone combination with 6-BA1.0mg/L+ IBA0.01mg/L,rate of adventitious shoots in the medium was 100%,multiplication coefficient was 6.08,and the seedling height was http://www.chinamagnets.biz/ 3.87cm. 061ushan1# and 06yunnan4#’ s best media differed from 06jianhe3#,06lushan1#’s highest rate of adventitious shoots was 93.33%,multiplication coefficient was 5.22,seedling height was 3.12cm.06yunnan4#’s highest rate of adventitious shoots was 63.33%,multiplication coefficient was 2.99,seedling height was 3.40cm.(3)Rare earth lanthanum and uniconazole were chosen as growth regulators,06jianhe3# and 06lushan1# as experiment materials,for strong seedling culture.
Corresponding growth indexes and physiological indexes were tested to compare the strong seedling effects.The results showed that rare earth lanthanum 5mg/L mainly improve fresh weight,chlorophyll content, soluble sugar content,promote multiple shoot differentiation and height growth.It can concluded that rare earth lanthanum is a suitable additives to be add in enrichment medium. Uniconazole 0.5mg/L could inhibit seedling height,improve chlorophyll content and resistance, and it can be a good growth regulator to add in strong seedling culture medium after enrichment http://www.chinamagnets.biz/ medium.(4)Plantlets,after subculture at lest 5 times,first inducted root in 1/2WPM+IBA0.05～0.1 mg/L+sucrose 20g/L for 15 days in dark condition,then changed into 1/2WPM+sucrose20g/L in normal illumination,about one month later,rooting rate of 06lushan1# was 23.33%.(5)Cotyledon adventitious rooting rate was 100%with IBA1.5mg/L.Comparing dynamic changes of four endogenous hormones during cotyledon rooting,the research showed endogenous IAA was the critical factor in cotyledon rooting:root primordium starting needed high endogenous IAA and root formation and elongation needed lower level.The ratios of IAA/ABA,IAA/GA3 gave good reflection between different endogenous hormones,GA3 does not appear to be the key inhibition factor in cotyledon rooting.
2012年6月13日星期三
Research on Mineralogy of K-feldspar and Pyrite in Halasu Porphyry Copper Deposit of Altai Mountain
Research on Mineralogy of K-feldspar and Pyrite in Halasu Porphyry Copper Deposit of Altai Mountain
The Halasu porphyry copper deposit is located at the southern margin of the east section of Altai mountain. The geotectonics is part of the oblique collision and joint between the southwest margin of Siberia plate and the northeast margin of Zungar plate. This district provides good geological ore-forming conditions, especially for the ore-forming of porphyry copper deposit. In this paper based on field geological work,we have done some research on the Special shape NdFeB magnets chemical components, the structure parameters, trace elements, lanthanon of the main minerals, such as K-feldspar, pyrite and biotite, through microscope observation and other modern testing methods, in order to provide some evidence for the genesis and exploration of the mine.
Study on chemical components and structure of K-feldspar by EPMA and XRD analysis indicates that K-feldspar is high in degree of order and low in structure; the trademark of plagioclase which coexist with K-feldsper is An3,and the temperature is calculated to be from 300℃to 400℃; The K-feldsper phenocryst is microcline-orthoclase, which is evidence for ore-bearing. The lowest temperature for K-feldspar to reach the state of stability is about 300℃.The data analysis of main elements ,trace elements and lanthanon compositions of pyrites show that there are sulphur deficiency, higher Co,Ni and Co/ Ni (>1),which indicate the genetic of pyrite in this deposit is hydrothermal alteration and the S/Se distribution in 1×104 to 2×104 indicates it is ore-forming fluid deposit.The http://www.999magnet.com/ research of lanthanon in pyrite shows: The content of lanthanon(ΣREE) in theⅢepoch is much more than in theⅠ,Ⅱepochs .The ratios of LREE/HREE in all epochs are more than 1 showing the enrichment of light lanthanon and .TheⅠepoch andⅡepoch are rich in MREE ,TheⅢepoch distribution curve leaning to right that indicates it is rich in light lanthanon.According to the previous studies on the typomorphic components of biotite, Mg / Fe values> 0.5 for Cu-porphyry and Mg / Fe values <0.5 for non-porphyry ore. Mg / Fe values of Biotite are greater than 0.5 in this district, and pertain to the high magnesium biotite, it can reflect that oxygen fugacity is high when granite magma crystallizes, and validate that this deposit pertains to porphyry copper deposit type. The biotite in this area is from the source of mantle according to the illustration of the mantle rocks.
The Halasu porphyry copper deposit is located at the southern margin of the east section of Altai mountain. The geotectonics is part of the oblique collision and joint between the southwest margin of Siberia plate and the northeast margin of Zungar plate. This district provides good geological ore-forming conditions, especially for the ore-forming of porphyry copper deposit. In this paper based on field geological work,we have done some research on the Special shape NdFeB magnets chemical components, the structure parameters, trace elements, lanthanon of the main minerals, such as K-feldspar, pyrite and biotite, through microscope observation and other modern testing methods, in order to provide some evidence for the genesis and exploration of the mine.
Study on chemical components and structure of K-feldspar by EPMA and XRD analysis indicates that K-feldspar is high in degree of order and low in structure; the trademark of plagioclase which coexist with K-feldsper is An3,and the temperature is calculated to be from 300℃to 400℃; The K-feldsper phenocryst is microcline-orthoclase, which is evidence for ore-bearing. The lowest temperature for K-feldspar to reach the state of stability is about 300℃.The data analysis of main elements ,trace elements and lanthanon compositions of pyrites show that there are sulphur deficiency, higher Co,Ni and Co/ Ni (>1),which indicate the genetic of pyrite in this deposit is hydrothermal alteration and the S/Se distribution in 1×104 to 2×104 indicates it is ore-forming fluid deposit.The http://www.999magnet.com/ research of lanthanon in pyrite shows: The content of lanthanon(ΣREE) in theⅢepoch is much more than in theⅠ,Ⅱepochs .The ratios of LREE/HREE in all epochs are more than 1 showing the enrichment of light lanthanon and .TheⅠepoch andⅡepoch are rich in MREE ,TheⅢepoch distribution curve leaning to right that indicates it is rich in light lanthanon.According to the previous studies on the typomorphic components of biotite, Mg / Fe values> 0.5 for Cu-porphyry and Mg / Fe values <0.5 for non-porphyry ore. Mg / Fe values of Biotite are greater than 0.5 in this district, and pertain to the high magnesium biotite, it can reflect that oxygen fugacity is high when granite magma crystallizes, and validate that this deposit pertains to porphyry copper deposit type. The biotite in this area is from the source of mantle according to the illustration of the mantle rocks.
Study of PET Fibers Structure and Their Properties
Study of PET Fibers Structure and Their Properties
PET (Polyethylene terephthalae) is a kind of popular textile materials. However, the macromolecule is lack of the functional groups which can react with the dyestuff directly. And PET with high degree of crystallinity and tight structure which can have hydrogen bond with disperse dye. So it is hard for the dye molecule to get inside the fiber. It means PET is difficult to dye. That is why it is with great sense of improving the PET fibers’ dyeing behavior.There are many factors influencing the dyeing behavior of fibers and textile things. For fibers, firstly the factors are Block Neodymium magnets chemistry structure, mainly referring to chemical components, degree of polymerization, molecule stereo-structure ect.. Then macromolecule structure, mainly referring to degree of crystallinity , crystallite size, degree of orientation ,size of amorphous regions ,and size and distribution of the porosity ect.. In this paper, we used DSC, crystallization rate detector, polarizing microscope and DMTA to study the relationships between the dyeing behavior and degree of crystallinity, rate of crystallization, crystallite size, transition temperature in four sea-island fibers.
The results showed low degree of crystallinity, slow rate of crystallization, large crystallite dimension and low transition temperature would benefit the improvement of PET fibers’ dyeing behavior.The experiments used three physically blending modifier to enhance the dyeing behavior of PET.1.Using PC(Polycarbonate)/PEG(Polyethylene glycol) blending modifier to decrease the degree of crystallinity and transition temperature, and change the crystallite structure to enhance the dyeing behavior of PET. Through the experiments we found that the loading level of PC 0.4% and PEG 1% could enhance the visual color depth value above 2.5 order. Considering the results PC/PEG modified the spinnability and mechanical performance, after analysising the POY and DTY properties we found the above loading level could get the best combined properties.2. Using Clay /PEG blending modifier to change the crystallite structure of PET and decrease the degree of crystallinity to get the http://www.999magnet.com/ PET with better dyeing behavior. We found that the loading level of PEG 0.5% and Clay 1% could enhance the visual color depth value above 2.0 order. Considering the spinnability and mechanical performance, the best loading level is above that could get the best combined properties.3. Using Rare Earth/Clay blending modifier to decrease the degree of crystallinity to get better dyeability and low cost PET fibers with dye concentration. We found that the loading level of Clay 0.5 % and Rare Earth 0.25% could enhance the visual color depth value above 1.5 order. Considering the spinnability and mechanical performance, the best loading level is above that could get the best combined properties.
PET (Polyethylene terephthalae) is a kind of popular textile materials. However, the macromolecule is lack of the functional groups which can react with the dyestuff directly. And PET with high degree of crystallinity and tight structure which can have hydrogen bond with disperse dye. So it is hard for the dye molecule to get inside the fiber. It means PET is difficult to dye. That is why it is with great sense of improving the PET fibers’ dyeing behavior.There are many factors influencing the dyeing behavior of fibers and textile things. For fibers, firstly the factors are Block Neodymium magnets chemistry structure, mainly referring to chemical components, degree of polymerization, molecule stereo-structure ect.. Then macromolecule structure, mainly referring to degree of crystallinity , crystallite size, degree of orientation ,size of amorphous regions ,and size and distribution of the porosity ect.. In this paper, we used DSC, crystallization rate detector, polarizing microscope and DMTA to study the relationships between the dyeing behavior and degree of crystallinity, rate of crystallization, crystallite size, transition temperature in four sea-island fibers.
The results showed low degree of crystallinity, slow rate of crystallization, large crystallite dimension and low transition temperature would benefit the improvement of PET fibers’ dyeing behavior.The experiments used three physically blending modifier to enhance the dyeing behavior of PET.1.Using PC(Polycarbonate)/PEG(Polyethylene glycol) blending modifier to decrease the degree of crystallinity and transition temperature, and change the crystallite structure to enhance the dyeing behavior of PET. Through the experiments we found that the loading level of PC 0.4% and PEG 1% could enhance the visual color depth value above 2.5 order. Considering the results PC/PEG modified the spinnability and mechanical performance, after analysising the POY and DTY properties we found the above loading level could get the best combined properties.2. Using Clay /PEG blending modifier to change the crystallite structure of PET and decrease the degree of crystallinity to get the http://www.999magnet.com/ PET with better dyeing behavior. We found that the loading level of PEG 0.5% and Clay 1% could enhance the visual color depth value above 2.0 order. Considering the spinnability and mechanical performance, the best loading level is above that could get the best combined properties.3. Using Rare Earth/Clay blending modifier to decrease the degree of crystallinity to get better dyeability and low cost PET fibers with dye concentration. We found that the loading level of Clay 0.5 % and Rare Earth 0.25% could enhance the visual color depth value above 1.5 order. Considering the spinnability and mechanical performance, the best loading level is above that could get the best combined properties.
Synthesis, Structure and Catalytic Activity of Organolanthanide Complexes with Substituted 1, 3-Diaminopropane Ligands
Synthesis, Structure and Catalytic Activity of Organolanthanide Complexes with Substituted 1, 3-Diaminopropane Ligands
In this artical we retrospect the origination and the development of organolanthnide complexes,introduced the catalysis of the organolanthanide complexes in nowdays.Herein we changed the organolanthanide by which we want to improve the catalysity.All experiments were carried out under the dry and oxygen-free argon atmosphere by using Segment neodymium magnets standard Schlenk techniques.Reaction of H2NCH2CH2CH2NH2 with 2 equiv of n-BuLi in THF at -78℃yielded LiNHCH2CH2CH2NHLi.And then added 2 equiv(i-Pr)3SiCl at 0℃resulted (i-Pr)3SiNHCH2CH2CH2NHSi(z-Pr)3.Interaction of SmCl3 with 2 equiv of (i-Pr)3SiLiNHCH2CH2CH2NHLiSi(i-Pr)3 in refluxing THF for 24 hours,after recrystallization from Hexane,gave an Samarium(Ⅲ)complex [(i-Pr)3SiNCH2CH2CH2NSi(i-Pr)2]2SmⅢ?Li(THF)4(1)in 65%yield.Interaction of EuCl3 with 2 equiv of(i-Pr)3SiNHCH2CH2CH2NHSi(i-Pr)3 in THF at 50℃for 24 hours,gave a Europium(Ⅲ)complex [(i-Pr)3SiNCH2CH2CH2NSi(i-Pr)3]2EuⅢ·Li(THF)4(2)in 55%yield.Reaction of LiNHCH2CH2CH2NHLi with 2 equiv Me3SiCl in THF at -78℃yielded Me3SiNHCH2CH2CH2NHSiMe2 in 80%yield.And then added 2 equiv Me3SiCl at 0℃resulted Me3SiNHCH2CH2CH2NHSiMe3.Interaction of EuCl3 with 2 equiv of Me3SiLiNHCH2CH2CH2NHLiSiMe3 in refluxing THF for 24 hours, after recrystallization from Hexane,gave an Europium(Ⅲ)complex [Me3SiNCH2CH2CH2NSiMe3EuⅢCl(THF)]2(3)in 66%yield.Interaction of SmCl3 with 2 equiv of Me3SiLiNHCH2CH2CH2NHLiSiMe3 in refluxing THF for 24 hours,after recrystallization from Hexane,gave an Samarium(Ⅲ) complex[Me3SiNCH2CH2CH2NSiMe3SmⅢ(THF)Cl]2·2LiCl(4)in 60%yield.
Interaction of YbCl3 with 2 equiv of Me3SiLiNHCH2CH2CH2NHLiSiMe3 in refluxing THF for 24 hours,after recrystallization from Hexane,gave an Ytterbium(Ⅲ)complex[Me3SiNCH2CH2CH2NSiMe3YbⅢ(THF)Cl]2 ? 2LiCl(5) in 56%yield.Interaction of YCl3 with 2 equiv of Me3SiLiNHCH2CH2CH2NHLiSiMe3 in http://www.999magnet.com/ refluxing THF for 24 hours,after recrystallization from Hexane,gave an Yttrium(Ⅲ)complex [Me3SiNCH2CH2CH2NSiMe3YⅢ(THF)Cl]2 ? 2LiCl(6)in 58%yield.The structures of complexes 1 were determined by X-ray diffraction.Complexes 3,4,5,6 were fully characterized by elemental and spectroscopic analyses.On the basis of the above experimental results,these experiments provides a methodology to prepare the organolanthanide complexes with substituted 1,3-Diaminopropane ligands.The activities of the organolanthanide complexes as single-component catalysts in catalyzing MMA andε-CL polymerization were examined.It was found that the activities of the catalysts,stereo-regularity of PMMA,and the molecular weight of polymers were dependent on the solvents,temperature and the central metal of the catalysts.
In this artical we retrospect the origination and the development of organolanthnide complexes,introduced the catalysis of the organolanthanide complexes in nowdays.Herein we changed the organolanthanide by which we want to improve the catalysity.All experiments were carried out under the dry and oxygen-free argon atmosphere by using Segment neodymium magnets standard Schlenk techniques.Reaction of H2NCH2CH2CH2NH2 with 2 equiv of n-BuLi in THF at -78℃yielded LiNHCH2CH2CH2NHLi.And then added 2 equiv(i-Pr)3SiCl at 0℃resulted (i-Pr)3SiNHCH2CH2CH2NHSi(z-Pr)3.Interaction of SmCl3 with 2 equiv of (i-Pr)3SiLiNHCH2CH2CH2NHLiSi(i-Pr)3 in refluxing THF for 24 hours,after recrystallization from Hexane,gave an Samarium(Ⅲ)complex [(i-Pr)3SiNCH2CH2CH2NSi(i-Pr)2]2SmⅢ?Li(THF)4(1)in 65%yield.Interaction of EuCl3 with 2 equiv of(i-Pr)3SiNHCH2CH2CH2NHSi(i-Pr)3 in THF at 50℃for 24 hours,gave a Europium(Ⅲ)complex [(i-Pr)3SiNCH2CH2CH2NSi(i-Pr)3]2EuⅢ·Li(THF)4(2)in 55%yield.Reaction of LiNHCH2CH2CH2NHLi with 2 equiv Me3SiCl in THF at -78℃yielded Me3SiNHCH2CH2CH2NHSiMe2 in 80%yield.And then added 2 equiv Me3SiCl at 0℃resulted Me3SiNHCH2CH2CH2NHSiMe3.Interaction of EuCl3 with 2 equiv of Me3SiLiNHCH2CH2CH2NHLiSiMe3 in refluxing THF for 24 hours, after recrystallization from Hexane,gave an Europium(Ⅲ)complex [Me3SiNCH2CH2CH2NSiMe3EuⅢCl(THF)]2(3)in 66%yield.Interaction of SmCl3 with 2 equiv of Me3SiLiNHCH2CH2CH2NHLiSiMe3 in refluxing THF for 24 hours,after recrystallization from Hexane,gave an Samarium(Ⅲ) complex[Me3SiNCH2CH2CH2NSiMe3SmⅢ(THF)Cl]2·2LiCl(4)in 60%yield.
Interaction of YbCl3 with 2 equiv of Me3SiLiNHCH2CH2CH2NHLiSiMe3 in refluxing THF for 24 hours,after recrystallization from Hexane,gave an Ytterbium(Ⅲ)complex[Me3SiNCH2CH2CH2NSiMe3YbⅢ(THF)Cl]2 ? 2LiCl(5) in 56%yield.Interaction of YCl3 with 2 equiv of Me3SiLiNHCH2CH2CH2NHLiSiMe3 in http://www.999magnet.com/ refluxing THF for 24 hours,after recrystallization from Hexane,gave an Yttrium(Ⅲ)complex [Me3SiNCH2CH2CH2NSiMe3YⅢ(THF)Cl]2 ? 2LiCl(6)in 58%yield.The structures of complexes 1 were determined by X-ray diffraction.Complexes 3,4,5,6 were fully characterized by elemental and spectroscopic analyses.On the basis of the above experimental results,these experiments provides a methodology to prepare the organolanthanide complexes with substituted 1,3-Diaminopropane ligands.The activities of the organolanthanide complexes as single-component catalysts in catalyzing MMA andε-CL polymerization were examined.It was found that the activities of the catalysts,stereo-regularity of PMMA,and the molecular weight of polymers were dependent on the solvents,temperature and the central metal of the catalysts.
Synthesis of One-Dimensional Functional Nanomaterials Using Alumina Membrane as Template
Synthesis of One-Dimensional Functional Nanomaterials Using Alumina Membrane as Template
One-dimensional nanomaterials can be widely applied in many fields,such as solar energy conversion,chemical sensor,catalysis,absorption and separation due to its novel electrical,optical,magnetic,thermal and chemical properties.So,research on the preparation and properties of one-dimensional nanomaterials are very important and are one of the most exciting areas in materials science.Among the different fabrication methods,using porous alumina as template is one of the most efficacious methods to synthesize one-dimensional nanomaterials.The goal of the thesis is to provide a simple and convenient way for preparing various Alnico magnets functional nanotube (nanorod)arrays at room temperature using alumina membrane as a nanoreactor,and investigate some new methods of the electrodeposition,chemical reduction to fabricate one-dimensional nanomaterials,and researche the relationship among the synthesis conditions,structures and properties of one-dimensional nanomaterials.Firstly,we tried to prepare the magnetism Fe-group alloys(Fe-Co,Fe-Ni,Co-Ni) and rare earth alloys(Co-Sin,Co-Nd,Ni-Nd)nanotubes using porous alumina membrane as the template.The products were characterized by transmission electron microscopy,selected-area electron diffraction,scanning electron microscopy,and X-ray powder diffraction.The amorphous Fe-group and rare earth alloys nanotubes with outer diameters of 250-320 nm and length up to 30μm were obtained.It is very easy to produce nanotubes by using mercury as cathode http://www.999magnet.com/ due to their unusual electrochemistry and physics properties.
The possible mechanism for the nanotubes was discussed.What’s more,the amorphous nanotubes can be crystallized after being heated,which can improve and change their properties.So electrodeposition with mercury cathod is one of the efficiency methods to fabricate the metal nanotubes.Secondly,the amorphous Co-Sm and Co-Ni alloys nanotubes with outer diameters of 250-320 nm or 350-40 nm,and length of 30μm are prepared by liquid-liquid reaction in the holes of porous alumina membrane with the reducing agent NaBH4 and the aqueous solutions of different metal salt(Co2+and Sm3+,Co2+ and Ni2+)at room temperature.The products were characterized by Alnico magnets transmission electron microscopy,selected-area electron diffraction,scanning electron microscopy, energy-dispersive X-ray spectrometer attached to the field emission scanning electron microscopy and X-ray powder diffraction.The gas can give out in the reducing reactions,which contributes to the formation of tubular products in the hole of alumna membrane.The method improves the way of prepare other inorganic nanotubes.
Thirdly,using porous alumina as reaction vessel,we tried to prepare one-dimensional organic optical nanomaterials.The nanorod arrays of 8-hydroxy quinoline aluminium with the diameter of 220-250 nm and the length of 25μm and 8-hydroxy quinoline zinc with the diameter of 285-300 nm and the length of 20μm have been prepared at room temperature by liquid-liquid reaction with the encounter of 8-hydroxy quinoline molecule with Zn2+or Al3+,respectively.The products were characterized by X-ray powder diffraction,transmission electron microscopy, scanning Alnico magnets electron microscopy and energy-dispersive X-ray spectrometer attached to the field emission scanning electron,which indicated that the structure of 8-hydroxy quinoline aluminium is crystal,but that of 8-hydroxy quinoline zinc is amorphous. Comparing with 8-hydroxy quinoline,as-obtained 8-hydroxy quinoline aluminium and 8-hydroxy quinoline zinc have much stronger fluorescence intensity with "blue-shift" in ethanol.
One-dimensional nanomaterials can be widely applied in many fields,such as solar energy conversion,chemical sensor,catalysis,absorption and separation due to its novel electrical,optical,magnetic,thermal and chemical properties.So,research on the preparation and properties of one-dimensional nanomaterials are very important and are one of the most exciting areas in materials science.Among the different fabrication methods,using porous alumina as template is one of the most efficacious methods to synthesize one-dimensional nanomaterials.The goal of the thesis is to provide a simple and convenient way for preparing various Alnico magnets functional nanotube (nanorod)arrays at room temperature using alumina membrane as a nanoreactor,and investigate some new methods of the electrodeposition,chemical reduction to fabricate one-dimensional nanomaterials,and researche the relationship among the synthesis conditions,structures and properties of one-dimensional nanomaterials.Firstly,we tried to prepare the magnetism Fe-group alloys(Fe-Co,Fe-Ni,Co-Ni) and rare earth alloys(Co-Sin,Co-Nd,Ni-Nd)nanotubes using porous alumina membrane as the template.The products were characterized by transmission electron microscopy,selected-area electron diffraction,scanning electron microscopy,and X-ray powder diffraction.The amorphous Fe-group and rare earth alloys nanotubes with outer diameters of 250-320 nm and length up to 30μm were obtained.It is very easy to produce nanotubes by using mercury as cathode http://www.999magnet.com/ due to their unusual electrochemistry and physics properties.
The possible mechanism for the nanotubes was discussed.What’s more,the amorphous nanotubes can be crystallized after being heated,which can improve and change their properties.So electrodeposition with mercury cathod is one of the efficiency methods to fabricate the metal nanotubes.Secondly,the amorphous Co-Sm and Co-Ni alloys nanotubes with outer diameters of 250-320 nm or 350-40 nm,and length of 30μm are prepared by liquid-liquid reaction in the holes of porous alumina membrane with the reducing agent NaBH4 and the aqueous solutions of different metal salt(Co2+and Sm3+,Co2+ and Ni2+)at room temperature.The products were characterized by Alnico magnets transmission electron microscopy,selected-area electron diffraction,scanning electron microscopy, energy-dispersive X-ray spectrometer attached to the field emission scanning electron microscopy and X-ray powder diffraction.The gas can give out in the reducing reactions,which contributes to the formation of tubular products in the hole of alumna membrane.The method improves the way of prepare other inorganic nanotubes.
Thirdly,using porous alumina as reaction vessel,we tried to prepare one-dimensional organic optical nanomaterials.The nanorod arrays of 8-hydroxy quinoline aluminium with the diameter of 220-250 nm and the length of 25μm and 8-hydroxy quinoline zinc with the diameter of 285-300 nm and the length of 20μm have been prepared at room temperature by liquid-liquid reaction with the encounter of 8-hydroxy quinoline molecule with Zn2+or Al3+,respectively.The products were characterized by X-ray powder diffraction,transmission electron microscopy, scanning Alnico magnets electron microscopy and energy-dispersive X-ray spectrometer attached to the field emission scanning electron,which indicated that the structure of 8-hydroxy quinoline aluminium is crystal,but that of 8-hydroxy quinoline zinc is amorphous. Comparing with 8-hydroxy quinoline,as-obtained 8-hydroxy quinoline aluminium and 8-hydroxy quinoline zinc have much stronger fluorescence intensity with "blue-shift" in ethanol.
2012年6月11日星期一
Gaseous La/Eu/Er Permeation of TiO2 and Photocatalytic Properties
Gaseous La/Eu/Er Permeation of TiO2 and Photocatalytic Properties
The TiO2 semiconductor has excellent photocatalytic performance, and is widely used in wastewater treatment. But the wide energy gap and the recombination of e- /h + pairs greatly decrease the photocatalysis efficiency of TiO 2 . So TiO 2 must be modified to improve its photocatalytic performance.In this experiment, the anatase TiO2 was the study object as the photo catalyst to decolorized Methyl Orange(MO) and the effects of pH value, initial solution concentration Ring neodymium magnet and calcined condition on photocatalytic oxidation MO of unpermeated TiO2 were studied. And the rare earth permeation techniques of TiO 2 are analyzed. The effect of the permeation technics of TiO 2 with LaCl3, EuCl 3 and ErCl3 on photocatalytic properties and the mechanism of decolorization for MO were elementarily studied.
The main contents of experiment were as follow:The results showed that the effect of pH value on the rate of MO decolorization was obvious, the rate of MO decolorization in the acid solution was bigger than that in the alkaline and neutral solution. The bigger the intial solution concentration was, the more the MO reaction amout in unit time, but the rate of MO decolorization reduced. When the unpermeation TiO2 calcined at 600℃, the photocatalytic property declined.Non-detection of lanthanon compounds in the XRD detection results showed that the content have ounce; XPS detection results reviewed that La, Eu and Er elements were the tervalent ions in TiO 2 , with the most http://www.chinamagnets.biz/ Ti 4+ and a little of Ti3+ on the surface of TiO 2 ; The responding photocatalytic wavelength of LaCl3, EuCl 3 , ErCl 3 permeated to TiO2 powder had intensity adsorbance in visible range, owing to the reduction of originate energy that electron transition needed. Rare earth ions permeated in TiO2 had higher photocatalytic activity and they actted as sensible and assitant catalyst; FT-IR detection results reviewed that MO was decomposed in conjugatedπbond structure of nitrogen in the acid.The photocatalytic activities of permeation TiO2 were measured and the results reviewed that the photocatalytic property was intensively improved, and the degree was obviously affected by the condition of permeation. When the
The TiO2 semiconductor has excellent photocatalytic performance, and is widely used in wastewater treatment. But the wide energy gap and the recombination of e- /h + pairs greatly decrease the photocatalysis efficiency of TiO 2 . So TiO 2 must be modified to improve its photocatalytic performance.In this experiment, the anatase TiO2 was the study object as the photo catalyst to decolorized Methyl Orange(MO) and the effects of pH value, initial solution concentration Ring neodymium magnet and calcined condition on photocatalytic oxidation MO of unpermeated TiO2 were studied. And the rare earth permeation techniques of TiO 2 are analyzed. The effect of the permeation technics of TiO 2 with LaCl3, EuCl 3 and ErCl3 on photocatalytic properties and the mechanism of decolorization for MO were elementarily studied.
The main contents of experiment were as follow:The results showed that the effect of pH value on the rate of MO decolorization was obvious, the rate of MO decolorization in the acid solution was bigger than that in the alkaline and neutral solution. The bigger the intial solution concentration was, the more the MO reaction amout in unit time, but the rate of MO decolorization reduced. When the unpermeation TiO2 calcined at 600℃, the photocatalytic property declined.Non-detection of lanthanon compounds in the XRD detection results showed that the content have ounce; XPS detection results reviewed that La, Eu and Er elements were the tervalent ions in TiO 2 , with the most http://www.chinamagnets.biz/ Ti 4+ and a little of Ti3+ on the surface of TiO 2 ; The responding photocatalytic wavelength of LaCl3, EuCl 3 , ErCl 3 permeated to TiO2 powder had intensity adsorbance in visible range, owing to the reduction of originate energy that electron transition needed. Rare earth ions permeated in TiO2 had higher photocatalytic activity and they actted as sensible and assitant catalyst; FT-IR detection results reviewed that MO was decomposed in conjugatedπbond structure of nitrogen in the acid.The photocatalytic activities of permeation TiO2 were measured and the results reviewed that the photocatalytic property was intensively improved, and the degree was obviously affected by the condition of permeation. When the
Synthesis of Nano Cerium Dioxide Related Materials and Investigation of Their Properties
Synthesis of Nano Cerium Dioxide Related Materials and Investigation of Their Properties
Cerium is an important rare earth metal, and is richly contained in the earth. Ceria is a cheap and widely used material, which has been applied in the areas of luminous material, UV absorption material, catalyst, polishing, election ceramics, and so on. Recent years, with the development of nanotechnology and new rare earth materials, it is found that nano ceria powder have some novel properties and applications. So the research of synthesize, functional properties and application of nano ceria materials is an interesting subject.In this study, we developed a novel simple method composite-hydroxide-mediated (CHM) route to synthesize ceria nanoparticles, carbon nanotubes coated Special shape NdFeB magnets with ceria nanoparticles and Ba doped ceria nanowire. This method only requires low synthesis temperature and pressure, which is beneficial for mass-production with low costs.The ceria nanoparticles synthesized though CHM method are characterized by XRD, TEM, HRTEM and UV-vis analysis. The diameter of the nanopaticles is found to be very small, about 2-8 nm. We discover strong agglomeration of the nanoparticles, which induce the abnormal XRD pattern.
The carbon nanotubes pretreated by nitric acid are coated with ceria nanoparticles. The products are characterized by XRD, SEM, UV-vis and FTIR analysis. We find that carbon nanotubes of perfect graphite structure can be hardly deposited with ceria nanoparticles. But when carbon nanotubes are pretreated by nitric acid, the graphite structure is partially destroyed with connecting hydroxyl and carboxyl on their surface. These functional groups work as active centers and make ceria nanoparticles deposit on the carbon nanotubes. So the surface modification of carbon nanotubes is very important for the coating of carbon nanotubes by ceria nanoparticles.Ba-doped ceria nanowires are synthesized by CHM method. Characterized by XRD, SEM, TEM, and HRTEM, http://www.999magnet.com/
the nanowires are found to have the typical fluorite structure, single crystal, and the length of 3-20μm. The growth direction of the nanowies is [110], and a‘dissolution- crystallization’model is proposed to explain the growth mechanism. The film electrode composed with Ba-doped ceria nanowires has an excellent humidity property, the resistance change sharply with the humidity. The response time and recover time of the humidity sensor are found to be 1 minute and 2 minute, respectively. The mechanism of humidity sensitivity is explained by the ion conductance model.The Ba-doped nanowire as building block contrusts a single nanowire FET with the help of Focused Ion Beam technology. The I-V curve of a single Ba-doped ceria nanowire is measured. The I-V curve is found to have a nonlinear behavior, which is explained by the metal- semiconductor contacting effect.
Cerium is an important rare earth metal, and is richly contained in the earth. Ceria is a cheap and widely used material, which has been applied in the areas of luminous material, UV absorption material, catalyst, polishing, election ceramics, and so on. Recent years, with the development of nanotechnology and new rare earth materials, it is found that nano ceria powder have some novel properties and applications. So the research of synthesize, functional properties and application of nano ceria materials is an interesting subject.In this study, we developed a novel simple method composite-hydroxide-mediated (CHM) route to synthesize ceria nanoparticles, carbon nanotubes coated Special shape NdFeB magnets with ceria nanoparticles and Ba doped ceria nanowire. This method only requires low synthesis temperature and pressure, which is beneficial for mass-production with low costs.The ceria nanoparticles synthesized though CHM method are characterized by XRD, TEM, HRTEM and UV-vis analysis. The diameter of the nanopaticles is found to be very small, about 2-8 nm. We discover strong agglomeration of the nanoparticles, which induce the abnormal XRD pattern.
The carbon nanotubes pretreated by nitric acid are coated with ceria nanoparticles. The products are characterized by XRD, SEM, UV-vis and FTIR analysis. We find that carbon nanotubes of perfect graphite structure can be hardly deposited with ceria nanoparticles. But when carbon nanotubes are pretreated by nitric acid, the graphite structure is partially destroyed with connecting hydroxyl and carboxyl on their surface. These functional groups work as active centers and make ceria nanoparticles deposit on the carbon nanotubes. So the surface modification of carbon nanotubes is very important for the coating of carbon nanotubes by ceria nanoparticles.Ba-doped ceria nanowires are synthesized by CHM method. Characterized by XRD, SEM, TEM, and HRTEM, http://www.999magnet.com/
the nanowires are found to have the typical fluorite structure, single crystal, and the length of 3-20μm. The growth direction of the nanowies is [110], and a‘dissolution- crystallization’model is proposed to explain the growth mechanism. The film electrode composed with Ba-doped ceria nanowires has an excellent humidity property, the resistance change sharply with the humidity. The response time and recover time of the humidity sensor are found to be 1 minute and 2 minute, respectively. The mechanism of humidity sensitivity is explained by the ion conductance model.The Ba-doped nanowire as building block contrusts a single nanowire FET with the help of Focused Ion Beam technology. The I-V curve of a single Ba-doped ceria nanowire is measured. The I-V curve is found to have a nonlinear behavior, which is explained by the metal- semiconductor contacting effect.
高介X8R电容器介质材料的研究
高介X8R电容器介质材料的研究
Multilayer ceramic capacitors(MLCC) are important electric components which are used in almost all areas of electronics.Barium titanate(BaTiO3) was the most widely developed and used perovskite ferroelectrics.The reason behind a wide range of applications is that the barium titanate boasts of high specific permittivity and long lifetime of insulation resistance.The goal of this study was to investigate temperature stable MLCC dielectrics based on BaTiO3.Segment neodymium magnets A few of compounds have been doped into BaTiO3 system to obtain the X8R materials,and the dielectric properties and microstructures of BaTiO3-based ceramics has been investigated.Finally we accomplished its commercial production requirement.The influence of oxide dopants upon dielectric properties of BaTiO3-Nb2O5-ZnO system are investigated.The amount of Nb2O5 is very important in BaTiO3-Nb2O5-ZnO system,The proportion of the non-ferroelectric phase with abundant Nb-Ba(Tix Nb1-x)O3 which increases as Nb2O5 contents increase.The formation of the non-ferroelectric phase of Ba(Tix Nb1-x)O3 is presumed to be the factor that the dielectric constant at room temperature decrease of BaTiO3 ceramics.
The rare earth is one of important dopants in BaTiO3 systerm.In this paper,the influence of two rare earth oxide-Gd2O3 and Sm2O3 doped upon dielectric properties of BaTiO3-Nb2O5-ZnO system are investigated.The vary of the dielectric constant at room temperature can be explained by the occupational sites of ions in perovskite structure.And on this basis,high performance was observed in Gd/Sm Co-doped BaTiO3 ceramics,experimental best value of Gd/Sm is 0.7wt%/0.2wt%.In the experiment,the way of B-site substitution using precursor in BaTiO3-NiNb2O6-MnNb2O6 system was also studied.Doping glass flux into this system can lower down it’s sintering temperature. http://www.999magnet.com/ The mechanics of precursor replacement of B-site ion was also discussed.The results listed as follows:K>2800,dielectric loss<1.0%,insulation resistance>7×1010Ω,ΔC/C<±12%(-55℃～150℃)Microwave dielectric ceramics BiNbO4 and ZMT with low dielectric loss and low temperature coefficient can be doped into BaTiO3 systerm,on this basis,the systerm showed high performance.
The experiment results have revealed that,the dielectric constant at room temperature decrease with the increase amount of BiNbO4,but a proper usage of BiNbO4 can improve dielectric properties of BaTiO3 cerimics at high temperature.The high performance dielectrics satisfying X8R are achieved in the BaTiO3-Nb2O5-ZMT new system.The influence of Nb2O5 and ZMT addition on phase transition,microstructure have been studied profoundly.In this paper,we doped rare quantity donor/acceptor into BaTiO3 system to optimize the properies,X8R type MLCC prepared from our composite with independent intelligence had good dielectric properties:K=2370±100,dielectric loss<1.6%,insulation resistance>3×1010Ω,ΔC/C<±14%(-55℃～150℃),average breakdown voltage>800V/mil.
Multilayer ceramic capacitors(MLCC) are important electric components which are used in almost all areas of electronics.Barium titanate(BaTiO3) was the most widely developed and used perovskite ferroelectrics.The reason behind a wide range of applications is that the barium titanate boasts of high specific permittivity and long lifetime of insulation resistance.The goal of this study was to investigate temperature stable MLCC dielectrics based on BaTiO3.Segment neodymium magnets A few of compounds have been doped into BaTiO3 system to obtain the X8R materials,and the dielectric properties and microstructures of BaTiO3-based ceramics has been investigated.Finally we accomplished its commercial production requirement.The influence of oxide dopants upon dielectric properties of BaTiO3-Nb2O5-ZnO system are investigated.The amount of Nb2O5 is very important in BaTiO3-Nb2O5-ZnO system,The proportion of the non-ferroelectric phase with abundant Nb-Ba(Tix Nb1-x)O3 which increases as Nb2O5 contents increase.The formation of the non-ferroelectric phase of Ba(Tix Nb1-x)O3 is presumed to be the factor that the dielectric constant at room temperature decrease of BaTiO3 ceramics.
The rare earth is one of important dopants in BaTiO3 systerm.In this paper,the influence of two rare earth oxide-Gd2O3 and Sm2O3 doped upon dielectric properties of BaTiO3-Nb2O5-ZnO system are investigated.The vary of the dielectric constant at room temperature can be explained by the occupational sites of ions in perovskite structure.And on this basis,high performance was observed in Gd/Sm Co-doped BaTiO3 ceramics,experimental best value of Gd/Sm is 0.7wt%/0.2wt%.In the experiment,the way of B-site substitution using precursor in BaTiO3-NiNb2O6-MnNb2O6 system was also studied.Doping glass flux into this system can lower down it’s sintering temperature. http://www.999magnet.com/ The mechanics of precursor replacement of B-site ion was also discussed.The results listed as follows:K>2800,dielectric loss<1.0%,insulation resistance>7×1010Ω,ΔC/C<±12%(-55℃～150℃)Microwave dielectric ceramics BiNbO4 and ZMT with low dielectric loss and low temperature coefficient can be doped into BaTiO3 systerm,on this basis,the systerm showed high performance.
The experiment results have revealed that,the dielectric constant at room temperature decrease with the increase amount of BiNbO4,but a proper usage of BiNbO4 can improve dielectric properties of BaTiO3 cerimics at high temperature.The high performance dielectrics satisfying X8R are achieved in the BaTiO3-Nb2O5-ZMT new system.The influence of Nb2O5 and ZMT addition on phase transition,microstructure have been studied profoundly.In this paper,we doped rare quantity donor/acceptor into BaTiO3 system to optimize the properies,X8R type MLCC prepared from our composite with independent intelligence had good dielectric properties:K=2370±100,dielectric loss<1.6%,insulation resistance>3×1010Ω,ΔC/C<±14%(-55℃～150℃),average breakdown voltage>800V/mil.
2012年6月7日星期四
Study on the AgSnO2 Contact Material with the Addition of Rare Earth Oxide
Study on the AgSnO2 Contact Material with the Addition of Rare Earth Oxide
AgCdO has been replaced by AgSnO2 because of its no damage to the environment and the same performance as AgCdO. But it has been also found that contact resistance and temperature rise of AgSnO2 are higher than those of AgCdO in the AC3 operation condition. It is necessary for us to develop a kind of AgSnO2 contact materials with addition of rare earth oxide.First, the development of AgSnO2 in home and abroad is summarized in this paper. The significant and the content of the study are presented on the basis of studying the advantage and the weakness of AgSnO2.Then Ring neodymium magnet on the basis of studying the sample preparation, the method of how to make specimen is presented. We also present the process of the sample preparation. Second, we analysis the basic behavior parameters of AgSnO2-La2O3 and indicate the best ratio of constituents of AgSnO2-La2O3-Bi2O3. Then we make an analysis about the physical and mechanical properties, microstructure and electrical properties of the specimen. Last, compare the result of AgSnO2-La2O3-Bi2O3 to AgSnO2 (12) and AgCdO(12).We found that the main physical and mechanical properties of the three http://www.chinamagnets.biz/ are similar. In addition, the electrical behavior of AgSnO2-La2O3-Bi2O3 is good. The result indicate that the new AgSnO2-La2O3-Bi2O3 contact material has better application outlook, and it will be the substitution of AgSnO2(12) and AgCdO(12).
AgCdO has been replaced by AgSnO2 because of its no damage to the environment and the same performance as AgCdO. But it has been also found that contact resistance and temperature rise of AgSnO2 are higher than those of AgCdO in the AC3 operation condition. It is necessary for us to develop a kind of AgSnO2 contact materials with addition of rare earth oxide.First, the development of AgSnO2 in home and abroad is summarized in this paper. The significant and the content of the study are presented on the basis of studying the advantage and the weakness of AgSnO2.Then Ring neodymium magnet on the basis of studying the sample preparation, the method of how to make specimen is presented. We also present the process of the sample preparation. Second, we analysis the basic behavior parameters of AgSnO2-La2O3 and indicate the best ratio of constituents of AgSnO2-La2O3-Bi2O3. Then we make an analysis about the physical and mechanical properties, microstructure and electrical properties of the specimen. Last, compare the result of AgSnO2-La2O3-Bi2O3 to AgSnO2 (12) and AgCdO(12).We found that the main physical and mechanical properties of the three http://www.chinamagnets.biz/ are similar. In addition, the electrical behavior of AgSnO2-La2O3-Bi2O3 is good. The result indicate that the new AgSnO2-La2O3-Bi2O3 contact material has better application outlook, and it will be the substitution of AgSnO2(12) and AgCdO(12).
Synthesis and Characterization of (μ3-CR)Co3 Tetrahedral Carbonyl Clusters Containing Triphosphine Ligand and Cobalt Carbonyl Clusters Containing Lanthanide
Synthesis and Characterization of (μ3-CR)Co3 Tetrahedral Carbonyl Clusters Containing Triphosphine Ligand and Cobalt Carbonyl Clusters Containing Lanthanide
There are two sections in this paper. 1. Reactions of a series of tetrahedral cobalt carbonylclusters with organic triphosphine compound were carried out to construct the multinuclearcarbonyl clusters. 2. Several rare earth complexes coordinated with cobalt carbonyl cluster werealso attempted to prepare in order to obtain the complexes containing lanthanide andtransition-metal.First, five tetrahedral cobalt carbonyl clusters, PhCCo3(CO)9, CHCo3(CO)9, ClCCo3(CO)9,HOOCCCo3(CO)9, (CH3)3CO2CCCo3(CO)9 were synthesized according to the methods ofliteratures. rare earth magnets The reaction of these tetrahedron cobalt clusters with the triphosphine compound[(C6H5)2PCH2]3CCH3 (1,1-Tris(diphenylphosphiomethyl)ethane) (L) afforded eight (μ3-CR)Co3tetrahedral carbonyl clusters containing triphosphine ligand. All clusters were characterized by C/Hanalysis, IR and 1H NMR; several of them were characterized by 31P-NMR and MS analysis.Clusterlwas determined by X-ray single crystal diffraction analysis. According to the analysis data,we know that three phosphorus atoms of ligand L bonded to three cobalt atoms of tetrahedral cobaltcarbonyl cluster in cluster 1, respectively, and the structure of cluster 4 is similar to that of cluster1. And in other clusters, http://www.chinamagnets.biz/ the three cobalt atoms not only were coordinated with three phosphorusatoms but also were bonded with one or two Co(CO)3 unit, respectively.Second, reactions of lanthanide complexes with cobalt carbonyl cluster containing the hydroxylgroup were also carried out in order to obtain the complexes containing lanthanide andtransition-metal for the study of electrochemistry. Unfortunately, we did not obtain the desired products and only got some unknown complexes which were simply characterized by C/H analysis,IR, fluorescent spectroscopy and ICP.
There are two sections in this paper. 1. Reactions of a series of tetrahedral cobalt carbonylclusters with organic triphosphine compound were carried out to construct the multinuclearcarbonyl clusters. 2. Several rare earth complexes coordinated with cobalt carbonyl cluster werealso attempted to prepare in order to obtain the complexes containing lanthanide andtransition-metal.First, five tetrahedral cobalt carbonyl clusters, PhCCo3(CO)9, CHCo3(CO)9, ClCCo3(CO)9,HOOCCCo3(CO)9, (CH3)3CO2CCCo3(CO)9 were synthesized according to the methods ofliteratures. rare earth magnets The reaction of these tetrahedron cobalt clusters with the triphosphine compound[(C6H5)2PCH2]3CCH3 (1,1-Tris(diphenylphosphiomethyl)ethane) (L) afforded eight (μ3-CR)Co3tetrahedral carbonyl clusters containing triphosphine ligand. All clusters were characterized by C/Hanalysis, IR and 1H NMR; several of them were characterized by 31P-NMR and MS analysis.Clusterlwas determined by X-ray single crystal diffraction analysis. According to the analysis data,we know that three phosphorus atoms of ligand L bonded to three cobalt atoms of tetrahedral cobaltcarbonyl cluster in cluster 1, respectively, and the structure of cluster 4 is similar to that of cluster1. And in other clusters, http://www.chinamagnets.biz/ the three cobalt atoms not only were coordinated with three phosphorusatoms but also were bonded with one or two Co(CO)3 unit, respectively.Second, reactions of lanthanide complexes with cobalt carbonyl cluster containing the hydroxylgroup were also carried out in order to obtain the complexes containing lanthanide andtransition-metal for the study of electrochemistry. Unfortunately, we did not obtain the desired products and only got some unknown complexes which were simply characterized by C/H analysis,IR, fluorescent spectroscopy and ICP.
VUV-excited Luminescence Properties
MAl2B2O7：Re(M=Ca，Sr，Ba;Re=Eu～(3+)，Tb～(3+)，Eu～(2+))在VUV激发下的发光性能研究
VUV-excited Luminescence Properties of MAl2B2O7: Re(M=Sr, Ba, Ca; Re=Eu～(3+), Tb～(3+), Eu～(2+))
In recent years, more attention has been paid to PDP (Plasma display panel )because of its potential market in the illumination. Special attention has been paid to the development of new and efficient VUV-excited phosphors. On the other hand, borates are of interest as host lattices for luminescent ions, because of their large band gap. Based on this consideration, it is valuable to investigate the alkaline borate family. In this paper, The VUV excitation and luminescence characteristics of MAl2B2O7:Re(M = Sr, Ba, Ca; Re= Eu3+,Tb3+, Eu2+) have been studied.In this Alnico magnets work, a series of powder samples of MAl2B2O7:Re(M=Ca, Sr, Ba; Re= Eu3+,Tb3+, Eu2+)was prepared under a reducing atmosphere by solid-state reaction.. The X-ray powder diffraction data of MAl2B2O7:Re are in agreement of JCPDS standard card which indicates that single-phased phosphor can be obtained in such synthesis process.The excitation spectrum of MAl2B2O7: Eu3+ (M=Sr, Ba, Ca) are composed of two broad bands. One band in the range from 130 nm to 170 nm is attributed to the borate groups, and the other band at 230 nm is due to the charge-transfer state (CTS) of the Eu3+ ion.
The excitation peak shifts from 167nm to 172nm when the Sr2+ ions are completely replaced by the Ba2+ and Ca2+ ions. It is obvious that the wavelength positions of the excitation bands depend much more on hosts. The lattice parameters of the phosphors increase and the crystal-field strength decrease with increasing of the ionic radius of Ca2+, Sr2+ and Ba2+.Because Eu3+ ions doped into CaAl2B2O7 occupy centrosymmetric site, the emission of magnetic dipole transition 5D0→7F1 is stronger than electric dipole transition. As Eu3+ ions doped into MAl2B2O7 (M=Sr, Ba) occupy Ba2+ or Sr2+ sites which is non-centrosymmetric site, so that the emission of electric dipole transition 5D0→7F2 is stronger than magnetic dipole transition in those series sample. The strong emission line at 613 nm is due to the hypersensitive electric dipole transition of 5D0→7F2. The weaker http://www.999magnet.com/ emission around 592 nm is due to the magnetic dipole transition 5D0→7F1.As for MAl2B2O7:Tb3+ (M=Sr, Ba, Ca) the VUV excited spectra consists of one broad band in the range from 120 nm to 170 nm and the band peaking around 226 nm, and 270 nm respectively. The band (130～170nm) is also assigned to absorption of the borate groups. The bands which cover the spectral range from 160 to 270nm are due to the transitions of Tb3+(4f8→4f75d ).When Ce3+ is doped into the samples, the absorption band of samples obviously decreased in VUV. In PL spectra of MAl2B2O7:Tb3+ (M=Sr, Ba, Ca), there are four peaks at 487 nm, 546 nm, 589 nm and 619 nm corresponding to 5D4 →7FJ (J=6,5,4,3) transition of Tb3+ respectively. Among these transitions, the green emission around 545 nm (5D4→7F5) is the strongest because it is a magnetic dipole allowed transition with △J=±1The excitation spectrum of BaAl2B2O7: Eu2+show a high absorption band which obviously decreased in VUV. The emission spectrum of Ba1-xSrxA12B2O7:Eu2+move to longer wavelength with increasing of Sr2+ mole concentration.
VUV-excited Luminescence Properties of MAl2B2O7: Re(M=Sr, Ba, Ca; Re=Eu～(3+), Tb～(3+), Eu～(2+))
In recent years, more attention has been paid to PDP (Plasma display panel )because of its potential market in the illumination. Special attention has been paid to the development of new and efficient VUV-excited phosphors. On the other hand, borates are of interest as host lattices for luminescent ions, because of their large band gap. Based on this consideration, it is valuable to investigate the alkaline borate family. In this paper, The VUV excitation and luminescence characteristics of MAl2B2O7:Re(M = Sr, Ba, Ca; Re= Eu3+,Tb3+, Eu2+) have been studied.In this Alnico magnets work, a series of powder samples of MAl2B2O7:Re(M=Ca, Sr, Ba; Re= Eu3+,Tb3+, Eu2+)was prepared under a reducing atmosphere by solid-state reaction.. The X-ray powder diffraction data of MAl2B2O7:Re are in agreement of JCPDS standard card which indicates that single-phased phosphor can be obtained in such synthesis process.The excitation spectrum of MAl2B2O7: Eu3+ (M=Sr, Ba, Ca) are composed of two broad bands. One band in the range from 130 nm to 170 nm is attributed to the borate groups, and the other band at 230 nm is due to the charge-transfer state (CTS) of the Eu3+ ion.
The excitation peak shifts from 167nm to 172nm when the Sr2+ ions are completely replaced by the Ba2+ and Ca2+ ions. It is obvious that the wavelength positions of the excitation bands depend much more on hosts. The lattice parameters of the phosphors increase and the crystal-field strength decrease with increasing of the ionic radius of Ca2+, Sr2+ and Ba2+.Because Eu3+ ions doped into CaAl2B2O7 occupy centrosymmetric site, the emission of magnetic dipole transition 5D0→7F1 is stronger than electric dipole transition. As Eu3+ ions doped into MAl2B2O7 (M=Sr, Ba) occupy Ba2+ or Sr2+ sites which is non-centrosymmetric site, so that the emission of electric dipole transition 5D0→7F2 is stronger than magnetic dipole transition in those series sample. The strong emission line at 613 nm is due to the hypersensitive electric dipole transition of 5D0→7F2. The weaker http://www.999magnet.com/ emission around 592 nm is due to the magnetic dipole transition 5D0→7F1.As for MAl2B2O7:Tb3+ (M=Sr, Ba, Ca) the VUV excited spectra consists of one broad band in the range from 120 nm to 170 nm and the band peaking around 226 nm, and 270 nm respectively. The band (130～170nm) is also assigned to absorption of the borate groups. The bands which cover the spectral range from 160 to 270nm are due to the transitions of Tb3+(4f8→4f75d ).When Ce3+ is doped into the samples, the absorption band of samples obviously decreased in VUV. In PL spectra of MAl2B2O7:Tb3+ (M=Sr, Ba, Ca), there are four peaks at 487 nm, 546 nm, 589 nm and 619 nm corresponding to 5D4 →7FJ (J=6,5,4,3) transition of Tb3+ respectively. Among these transitions, the green emission around 545 nm (5D4→7F5) is the strongest because it is a magnetic dipole allowed transition with △J=±1The excitation spectrum of BaAl2B2O7: Eu2+show a high absorption band which obviously decreased in VUV. The emission spectrum of Ba1-xSrxA12B2O7:Eu2+move to longer wavelength with increasing of Sr2+ mole concentration.
2012年6月6日星期三
The Luminescence Properties of YBO3: Eu～(3+) Nanocrystal
The Luminescence Properties of YBO3: Eu～(3+) Nanocrystal
Great attention has been paid to the nanosized material because of its unique properties in comparison with the bulk. Nano-science and technology will play an important role in the 21st century. For the large surface to volume ratio in nanosized materials, the influence of surface effect cannot be negligible in understanding its spectroscopic properties.In this thesis, rare earth doped nanocrystals were prepared, spectroscopic properties were studied and compared to that in the corresponding bulk material, and the influence of the surface effect was discussed.Trivalent Special shape NdFeB magnets Europium ion has been successfully applied as a spectral probe for detecting local environment in various materials. YBO3:Eu3+ nanoparticles were prepared via hydrothermal method. Particle sizes ranged from 30-80nm were obtained. By adjusting the pH value, the average size and morphology of the nanoparticles could be controlled.
The samples were characterized by XRD and TEM. Spectra of YBO3:Eu3+ nanoparticles at room temperature indicates that with the decreasing of the particle sizes the branch ratio I(5D0-7F2)/I(5D0-7F1) increases, thus makes the chromaticity varied. Besides, the luminescence intensity decreases, and new spectral lines may appear. These phenomena are all related to surface effect. As the particle size decreases, the number of the luminescent ions close to the surface increases, their energy level split differently with the ions near the particle center. As the site occupied by Eu3+ changes from the particle center toward the surface, local symmetry decreases. A large portion http://www.999magnet.com/ of the doped rare earth ions located at the sites with micro-environments affected by the surface, Such an influence could enhance the Judd-OffeltΩ2 parameter, and hence increase the relative intensity of the Eu3+ 5D0→7F2 emission and improve the chromaticity of the red phosphor. The temperature dependence of the 5D0→7F1 emission spectra was also measured at different temperatures. The emission intensity decreases since the additional nonradiative transition path aroused by quench centers at the surface.
Great attention has been paid to the nanosized material because of its unique properties in comparison with the bulk. Nano-science and technology will play an important role in the 21st century. For the large surface to volume ratio in nanosized materials, the influence of surface effect cannot be negligible in understanding its spectroscopic properties.In this thesis, rare earth doped nanocrystals were prepared, spectroscopic properties were studied and compared to that in the corresponding bulk material, and the influence of the surface effect was discussed.Trivalent Special shape NdFeB magnets Europium ion has been successfully applied as a spectral probe for detecting local environment in various materials. YBO3:Eu3+ nanoparticles were prepared via hydrothermal method. Particle sizes ranged from 30-80nm were obtained. By adjusting the pH value, the average size and morphology of the nanoparticles could be controlled.
The samples were characterized by XRD and TEM. Spectra of YBO3:Eu3+ nanoparticles at room temperature indicates that with the decreasing of the particle sizes the branch ratio I(5D0-7F2)/I(5D0-7F1) increases, thus makes the chromaticity varied. Besides, the luminescence intensity decreases, and new spectral lines may appear. These phenomena are all related to surface effect. As the particle size decreases, the number of the luminescent ions close to the surface increases, their energy level split differently with the ions near the particle center. As the site occupied by Eu3+ changes from the particle center toward the surface, local symmetry decreases. A large portion http://www.999magnet.com/ of the doped rare earth ions located at the sites with micro-environments affected by the surface, Such an influence could enhance the Judd-OffeltΩ2 parameter, and hence increase the relative intensity of the Eu3+ 5D0→7F2 emission and improve the chromaticity of the red phosphor. The temperature dependence of the 5D0→7F1 emission spectra was also measured at different temperatures. The emission intensity decreases since the additional nonradiative transition path aroused by quench centers at the surface.
Research on Tribological Performance of Ureido-Dcarbamido Grease Filled with Nano Particles
Research on Tribological Performance of Ureido-Dcarbamido Grease Filled with Nano Particles
Currently, more than 80% of the rolling bearings are lubricated with grease, and the performance of the grease depends largely on the performance of the additives. With the development of modern industry, many machines are operated in the situations of high-temperature, high-speed, automation, and so on, and noise pollution, environmental protection and other factors must Special shape NdFeB magnets also considered, which set higher demands on lubricating grease. Since ureido-Dcarbamido grease with high dripping temperature, long life, withstand high temperatures, high-speed, anti-water, it has broad industrial applications, but the ability of resisting high pressure is not well which limit its development more or less.
This article proposed an idea of using nanometer science and technology to change the property of the grease .we added the nano particles into the grease, and dispersed them uniformly and stably, to make different products which contain kinds of content. We filtered more than 11 nano particles from the results of the long-time friction tests, and focused on three kinds http://www.999magnet.com/ of prescriptions which have outstanding performance. Experiments have shown that the nano silicon dioxide particles, nano Teflon particles and calcium carbonate/rare earth compound particles have good performance on reducing the friction and resisting the wear. In addition, this article also researched the friction marks Special shape NdFeB magnets of steel ball after long-time friction tests with SEM images and spectrum analysis, and summarized the principle how to reduce friction and wear of three prescriptions. The nanometer silicon dioxide’s principle is“micro rolling bearing" effect, and nanometer Teflon is due to the film in a surface which has low shear strength and high compressive strength, the nano calcium carbonate is due to the effect cooperate with "micro rolling bearing" effect, sediment film and effect of intensify layer in the surface. Test results showed 1% silicon dioxide, PTFE3% and calcium carbonate complex prescriptions(calcium carbonate and rare earth compound particles are both 1%)have good effect on reducing the friction and wear, and has prominent role in industrial applications of high value.
Currently, more than 80% of the rolling bearings are lubricated with grease, and the performance of the grease depends largely on the performance of the additives. With the development of modern industry, many machines are operated in the situations of high-temperature, high-speed, automation, and so on, and noise pollution, environmental protection and other factors must Special shape NdFeB magnets also considered, which set higher demands on lubricating grease. Since ureido-Dcarbamido grease with high dripping temperature, long life, withstand high temperatures, high-speed, anti-water, it has broad industrial applications, but the ability of resisting high pressure is not well which limit its development more or less.
This article proposed an idea of using nanometer science and technology to change the property of the grease .we added the nano particles into the grease, and dispersed them uniformly and stably, to make different products which contain kinds of content. We filtered more than 11 nano particles from the results of the long-time friction tests, and focused on three kinds http://www.999magnet.com/ of prescriptions which have outstanding performance. Experiments have shown that the nano silicon dioxide particles, nano Teflon particles and calcium carbonate/rare earth compound particles have good performance on reducing the friction and resisting the wear. In addition, this article also researched the friction marks Special shape NdFeB magnets of steel ball after long-time friction tests with SEM images and spectrum analysis, and summarized the principle how to reduce friction and wear of three prescriptions. The nanometer silicon dioxide’s principle is“micro rolling bearing" effect, and nanometer Teflon is due to the film in a surface which has low shear strength and high compressive strength, the nano calcium carbonate is due to the effect cooperate with "micro rolling bearing" effect, sediment film and effect of intensify layer in the surface. Test results showed 1% silicon dioxide, PTFE3% and calcium carbonate complex prescriptions(calcium carbonate and rare earth compound particles are both 1%)have good effect on reducing the friction and wear, and has prominent role in industrial applications of high value.
The Research of Corrosion Electrochemical Behavior and Inhibitors of Aluminium Anodes in 3.5% NaCl Solution
The Research of Corrosion Electrochemical Behavior and Inhibitors of Aluminium Anodes in 3.5% NaCl Solution
Aluminum-air fuel battery is a new kind of high energy chemical power,due to its high energy density, abundance in nature, no pollution,low price,long life.In recent years, there are more and more needs of the safe and convenient power for frequent ocean exploiture, especially in the fields of the petroleum and natural gas mine in the sea and sub-sea applications.So briny aluminum- Segment neodymium magnets air fuel cell seems to be promising in the future.Though there are lots of advantage of the briny aluminum-air fuel battery, aluminum anode has a short life because of its self-corrosion and the corrosion of Cl- in the sea. This topic launches under this background..This dissertation uses aluminum anode of the aluminum air battery as the research object, studies the corrosion of electrochemcal behavior and the rare earth inhibitor CeCl3 of the aluminum anode from three points of views: the influence factors of the aluminum anode discharge in 3.5% NaCl solution.The rare earth CeCl3 was chosen as the inhibitor of aluminum anode by the curve of
potential-time(ET).The discharge performance of aluminum anode was studied by the EIS from there points of view: the inhibitor concentration, the electrolyte temperature and the pH of electrolyte containing CeCl3.The optimum discharge conditions of aluminum anode were determined as: the rare earth inhibitor concentration of CeCl3 is 500mg/L, the electrolyte temperature is 30℃, the pH of electrolyte containing CeCl3 is 5~6. In the discharge curve it showed that the http://www.999magnet.com/ discharge performance of aluminum anode in3.5%NaCl with inhibitor was better than in the blank 3.5% NaCl solution.The dissolution curve of aluminum anode was investigated by the strong area of the Tafel curve.With the help of different the equivalent circuit of EIS, the pit corrosion mechanism was studied in the excessively passive section of aluminum anode,expatiate the reason why the variety of dissolution current density is nonlinear in the passivation section of aluminum anode, at the same time explain that the third apex in Bade represent aluminum cathode. It also found that the stable existent condition of aluminum anode passive film is pH 5~6 in 3.5% NaCl solution. In the end, the author got the conclusion that the
Aluminum-air fuel battery is a new kind of high energy chemical power,due to its high energy density, abundance in nature, no pollution,low price,long life.In recent years, there are more and more needs of the safe and convenient power for frequent ocean exploiture, especially in the fields of the petroleum and natural gas mine in the sea and sub-sea applications.So briny aluminum- Segment neodymium magnets air fuel cell seems to be promising in the future.Though there are lots of advantage of the briny aluminum-air fuel battery, aluminum anode has a short life because of its self-corrosion and the corrosion of Cl- in the sea. This topic launches under this background..This dissertation uses aluminum anode of the aluminum air battery as the research object, studies the corrosion of electrochemcal behavior and the rare earth inhibitor CeCl3 of the aluminum anode from three points of views: the influence factors of the aluminum anode discharge in 3.5% NaCl solution.The rare earth CeCl3 was chosen as the inhibitor of aluminum anode by the curve of
potential-time(ET).The discharge performance of aluminum anode was studied by the EIS from there points of view: the inhibitor concentration, the electrolyte temperature and the pH of electrolyte containing CeCl3.The optimum discharge conditions of aluminum anode were determined as: the rare earth inhibitor concentration of CeCl3 is 500mg/L, the electrolyte temperature is 30℃, the pH of electrolyte containing CeCl3 is 5~6. In the discharge curve it showed that the http://www.999magnet.com/ discharge performance of aluminum anode in3.5%NaCl with inhibitor was better than in the blank 3.5% NaCl solution.The dissolution curve of aluminum anode was investigated by the strong area of the Tafel curve.With the help of different the equivalent circuit of EIS, the pit corrosion mechanism was studied in the excessively passive section of aluminum anode,expatiate the reason why the variety of dissolution current density is nonlinear in the passivation section of aluminum anode, at the same time explain that the third apex in Bade represent aluminum cathode. It also found that the stable existent condition of aluminum anode passive film is pH 5~6 in 3.5% NaCl solution. In the end, the author got the conclusion that the
径向磁场双转子永磁电机研究
径向磁场双转子永磁电机研究
High efficiency and high torque density are two basic features for an electric machine. Rare earth permanent magnet machine has high efficiency and high torque density because of the use of rare earth permanent magnet. However, the cost of the machine is raised . So it has very important sense to design a ferrite permanent magnet machine with high force index and low cost. The thesis makes a primary research of an electric machine which can satisfy the advantages Alnico magnets above. Generally speaking, the research of the thesis mainly includes the following points:In the first part, the structure and principle of the machine are discussed.
Then the thesis gives the analytical method and sums up the advantages of the machine compared to the traditional ones.The second part gives the calculation of the inductance. First of all, this part establishes the magnetic circuit model of the machine by which the inductance is calculated. The inductance formula is given. In order to check the formula, the thesis also calculates the inductance using electromagnetic software. Then this part gives the contrast of the two kinds of results, giving the characteristics of each result.The third part analyzes the cogging torque in detail. First of all, this part gives some methods for reducing the torque fluctuation of the machine. The methods includes slot opening shifting, varying slot opening angular width, varying PM angular width, varying the middle line of the http://www.999magnet.com/ PM. In order to check the methods, the thesis gives the formula of cogging torque first, and then proves the methods using the formula. The thesis also calculates the cogging torque using electromagnetic software, giving the curve of the cogging torque. Through the two different ways, the methods are proved to be practical. At last, this part gives the infection to average torque of the methods.The fourth part discusses the design thought, bringing forward the
High efficiency and high torque density are two basic features for an electric machine. Rare earth permanent magnet machine has high efficiency and high torque density because of the use of rare earth permanent magnet. However, the cost of the machine is raised . So it has very important sense to design a ferrite permanent magnet machine with high force index and low cost. The thesis makes a primary research of an electric machine which can satisfy the advantages Alnico magnets above. Generally speaking, the research of the thesis mainly includes the following points:In the first part, the structure and principle of the machine are discussed.
Then the thesis gives the analytical method and sums up the advantages of the machine compared to the traditional ones.The second part gives the calculation of the inductance. First of all, this part establishes the magnetic circuit model of the machine by which the inductance is calculated. The inductance formula is given. In order to check the formula, the thesis also calculates the inductance using electromagnetic software. Then this part gives the contrast of the two kinds of results, giving the characteristics of each result.The third part analyzes the cogging torque in detail. First of all, this part gives some methods for reducing the torque fluctuation of the machine. The methods includes slot opening shifting, varying slot opening angular width, varying PM angular width, varying the middle line of the http://www.999magnet.com/ PM. In order to check the methods, the thesis gives the formula of cogging torque first, and then proves the methods using the formula. The thesis also calculates the cogging torque using electromagnetic software, giving the curve of the cogging torque. Through the two different ways, the methods are proved to be practical. At last, this part gives the infection to average torque of the methods.The fourth part discusses the design thought, bringing forward the
水性铝基金属微粉涂层形层机理研究
水性铝基金属微粉涂层形层机理研究
Waterborne aluminium-based metallic micro-powder coating is the coating that Al-Zn powder, the aqueous solution of the inorganic metal salt, a small amount of chromium anhydride , organic or inorganic reducing agent is mixed into the material of thick liquid, put into surfactant and other additive, mix into a waterborne metallic micro-powder coating , coat it on the metal surface, form the coating of metal base through fritting. Because technology of this coating adopts the substituting chromium anhydride of compound phosphate part as binder of the coating, therefore has reduced the content of the chromium in the coating. However, with the strengthening of regulation of environmental protection, no-chromium has become the development trend of technology of this coating, waterborne Magnetic lifter aluminium-based metallic micro-powder coating of short of chromium has not adapted the strict requirement for environment protection more and more. In addition, the mechanism of shaping coating of waterborne aluminium-based metallic micro-powder coating is studied not enough deep, this cause this coating craft there is blindness of a certain degree in concrete application, there is no precise theoretical direction, has influenced application and development of technology of this coating.To solve these situation, this paper in improving original short chromium waterborne aluminium-based metallic micro-powder coating foundation that craft fills a prescription, develop , have no chromium waterborne aluminium-based metallic micro-powder coating , combine the study on coating , performance, attempt to study mechanism of shaping coating of waterborne aluminium-based metallic micro-powder coating.The paper start with preparation of powder, utilize basic theory knowledge of particle studying , physics , chemistry , metallorgaphy, ore dressing and mechanical alloy, have studied and confirmed the relevant parameters of preparing the craft of micro-powder.
The metal micro-powder suitable for technology of this coating have been prepared.The paper utilize orthogonal test improve short chromium waterborne aluminium-based metallic micro-powder coating treatment liquid of coating fill a prescription and prepare technological process, develop , have chromium waterborne aluminium-based metallic micro-powder coating craft of coating fill a prescription on this basis.Through paint layer able to bear corrosivity , heat resistance , combine intensity and hole experiment of rate thesis, short of chromium with have chromium waterborne Magnetic lifter aluminium-based metallic micro-powder coating with plate layer compare while being other, carry on comprehensive analysis on every performance index . People for in painting because it plate whether layer mark by trough mark of matriceses deep, to investigate is different to scribble (plate) by layers of corrosion behavior and protection situation against matrices at states damaged. Through compare with , have anti-corrosion performance of coating that rare-earth element put into , analyze the rare-earth element impact on corrosion resistance of coating.Use the metallography microscope, the modern material detection means of analyzing etc. that scan the electric mirror , energy spectrum, observe and research in shape looks , combination state of matrices , space position to the coating ,etc., chemical composition in the coating of statistical analysis.According to the study on performance of coating, structure, set up the structural models of the coating tentatively, propose one layer of mechanism of shape of the coating. Waterborne aluminium-based metallic micro-powder coating have no electric crystallization in the forming process of coating, have no high-temperature metallurgy react, shape its one layer of mechanism different from the traditional Magnetic lifter crystallization way, so technology of this coating belongs to one kind among the technology of obtaining the dense plural alloy-layer by way of there is no crystallizationing.
Waterborne aluminium-based metallic micro-powder coating is the coating that Al-Zn powder, the aqueous solution of the inorganic metal salt, a small amount of chromium anhydride , organic or inorganic reducing agent is mixed into the material of thick liquid, put into surfactant and other additive, mix into a waterborne metallic micro-powder coating , coat it on the metal surface, form the coating of metal base through fritting. Because technology of this coating adopts the substituting chromium anhydride of compound phosphate part as binder of the coating, therefore has reduced the content of the chromium in the coating. However, with the strengthening of regulation of environmental protection, no-chromium has become the development trend of technology of this coating, waterborne Magnetic lifter aluminium-based metallic micro-powder coating of short of chromium has not adapted the strict requirement for environment protection more and more. In addition, the mechanism of shaping coating of waterborne aluminium-based metallic micro-powder coating is studied not enough deep, this cause this coating craft there is blindness of a certain degree in concrete application, there is no precise theoretical direction, has influenced application and development of technology of this coating.To solve these situation, this paper in improving original short chromium waterborne aluminium-based metallic micro-powder coating foundation that craft fills a prescription, develop , have no chromium waterborne aluminium-based metallic micro-powder coating , combine the study on coating , performance, attempt to study mechanism of shaping coating of waterborne aluminium-based metallic micro-powder coating.The paper start with preparation of powder, utilize basic theory knowledge of particle studying , physics , chemistry , metallorgaphy, ore dressing and mechanical alloy, have studied and confirmed the relevant parameters of preparing the craft of micro-powder.
The metal micro-powder suitable for technology of this coating have been prepared.The paper utilize orthogonal test improve short chromium waterborne aluminium-based metallic micro-powder coating treatment liquid of coating fill a prescription and prepare technological process, develop , have chromium waterborne aluminium-based metallic micro-powder coating craft of coating fill a prescription on this basis.Through paint layer able to bear corrosivity , heat resistance , combine intensity and hole experiment of rate thesis, short of chromium with have chromium waterborne Magnetic lifter aluminium-based metallic micro-powder coating with plate layer compare while being other, carry on comprehensive analysis on every performance index . People for in painting because it plate whether layer mark by trough mark of matriceses deep, to investigate is different to scribble (plate) by layers of corrosion behavior and protection situation against matrices at states damaged. Through compare with , have anti-corrosion performance of coating that rare-earth element put into , analyze the rare-earth element impact on corrosion resistance of coating.Use the metallography microscope, the modern material detection means of analyzing etc. that scan the electric mirror , energy spectrum, observe and research in shape looks , combination state of matrices , space position to the coating ,etc., chemical composition in the coating of statistical analysis.According to the study on performance of coating, structure, set up the structural models of the coating tentatively, propose one layer of mechanism of shape of the coating. Waterborne aluminium-based metallic micro-powder coating have no electric crystallization in the forming process of coating, have no high-temperature metallurgy react, shape its one layer of mechanism different from the traditional Magnetic lifter crystallization way, so technology of this coating belongs to one kind among the technology of obtaining the dense plural alloy-layer by way of there is no crystallizationing.
Study on Microstructure and Propertise of Mg-Al-Sr-RE Magnesium Alloys
Study on Microstructure and Propertise of Mg-Al-Sr-RE Magnesium Alloys
Magnesium alloy is one of the lightest metal structure materials in the practical application, which have many special advantages, such as low density, high specific strength, high specific rigidity, good machinability, good electromagnetie shielding performance and easy recycling etc. They have been successfully used in various structures such as navigation, space flight, 3C product, power tool and traffic etc. However, the commercial die casting magnesium alloys fail to meet the requirement of drive train and other systems in automobiles. This is mainly on account of their imperfect strength and toughness, especially the weak strength in high temperature.At present, Al is the Neodymium Magnets main alloying elements in the major industrial magnesium alloys. Mg17Al12 is the most important strengthening phase for Mg-Al series alloys, but its low melting point, poor stability and reticular existing in magnesium alloys. Practice shows that alloying can effectively improve the mechanical properties. The sizes of crystalline grains affect the mechanics properties of the magnesium alloys. Research shows that rare earth and alkaline earth elements Sr have a better refinement on magnesium alloys grain organizations. Therefore, this paper adopt the Mg, Al, Sr and RE alloys to determine the existing way and strengthening mechanism of RE and Sr in Mg-Al based Alloys.In this paper, Mg-Sr master alloys, AJ62 magnesium alloy and various Y, Nd content of the AJ62 alloy were prepared by "mixture method".
Then the microstructure of various Y, Nd content of the AJ62 alloy were analyzed by XRD and EDS, and also the mechanical properties were tested, Finally the fracture morphology were studied and determined the fracture mechanism by SEM.The results show that:①Mg-4Sr master alloy is consist of a-Mg, Mg17Sr2, and Mg17Sr2 is distributed along the boundary of matrix grain. Mg-6Al-2Sr is consisted of a-Mg、Mg17Al12 and Al4Sr, and Al4Sr is distributed along grain boundaries.②Y ,rare earth elements, has refining effect on magnesium alloy structure. While adding 1.5wt% Y, the grain of AJ62+Y is finest. XRD and EDS show that new high-temperature and hard phases Neodymium Magnets Al2Y and Al3Y are formed in the alloys, which are distributed in grain boundary and intragranular after adding Y. The mechanical property test shows that containing 1.5wt% Y, AJ62 alloy reached the best mechanical properties, which tensile strength, yielding strength and elongation respectively improves 20.6%,24.6% and 52.9%, and the fracture mechanism mainly are cleavage fracture and quasi-cleavage fracture.③Nd has refining effect on alloy grain structure too. http://www.999magnet.com/ When containing 0.5wt% Nd, the structure refinement effect of the alloy is best; XRD Analysis and EDS spectrum show that with adding Nd the alloy formed the high-temperature and hard new phases Al2Nd and Al3Nd, The mechanical property test shows that containing 0.5wt% Nd, the alloy reached the best mechanical properties, which tensile strength, yielding strength and elongation respectively improves 13.5%, 15.9% and 49.1%, and the fracture morphology mechanism mainly is quasi-cleavage fracture. 更多还原
Magnesium alloy is one of the lightest metal structure materials in the practical application, which have many special advantages, such as low density, high specific strength, high specific rigidity, good machinability, good electromagnetie shielding performance and easy recycling etc. They have been successfully used in various structures such as navigation, space flight, 3C product, power tool and traffic etc. However, the commercial die casting magnesium alloys fail to meet the requirement of drive train and other systems in automobiles. This is mainly on account of their imperfect strength and toughness, especially the weak strength in high temperature.At present, Al is the Neodymium Magnets main alloying elements in the major industrial magnesium alloys. Mg17Al12 is the most important strengthening phase for Mg-Al series alloys, but its low melting point, poor stability and reticular existing in magnesium alloys. Practice shows that alloying can effectively improve the mechanical properties. The sizes of crystalline grains affect the mechanics properties of the magnesium alloys. Research shows that rare earth and alkaline earth elements Sr have a better refinement on magnesium alloys grain organizations. Therefore, this paper adopt the Mg, Al, Sr and RE alloys to determine the existing way and strengthening mechanism of RE and Sr in Mg-Al based Alloys.In this paper, Mg-Sr master alloys, AJ62 magnesium alloy and various Y, Nd content of the AJ62 alloy were prepared by "mixture method".
Then the microstructure of various Y, Nd content of the AJ62 alloy were analyzed by XRD and EDS, and also the mechanical properties were tested, Finally the fracture morphology were studied and determined the fracture mechanism by SEM.The results show that:①Mg-4Sr master alloy is consist of a-Mg, Mg17Sr2, and Mg17Sr2 is distributed along the boundary of matrix grain. Mg-6Al-2Sr is consisted of a-Mg、Mg17Al12 and Al4Sr, and Al4Sr is distributed along grain boundaries.②Y ,rare earth elements, has refining effect on magnesium alloy structure. While adding 1.5wt% Y, the grain of AJ62+Y is finest. XRD and EDS show that new high-temperature and hard phases Neodymium Magnets Al2Y and Al3Y are formed in the alloys, which are distributed in grain boundary and intragranular after adding Y. The mechanical property test shows that containing 1.5wt% Y, AJ62 alloy reached the best mechanical properties, which tensile strength, yielding strength and elongation respectively improves 20.6%,24.6% and 52.9%, and the fracture mechanism mainly are cleavage fracture and quasi-cleavage fracture.③Nd has refining effect on alloy grain structure too. http://www.999magnet.com/ When containing 0.5wt% Nd, the structure refinement effect of the alloy is best; XRD Analysis and EDS spectrum show that with adding Nd the alloy formed the high-temperature and hard new phases Al2Nd and Al3Nd, The mechanical property test shows that containing 0.5wt% Nd, the alloy reached the best mechanical properties, which tensile strength, yielding strength and elongation respectively improves 13.5%, 15.9% and 49.1%, and the fracture morphology mechanism mainly is quasi-cleavage fracture. 更多还原
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