Studies and Applications of the Separation and Preconcentration of Trace Elements with Nanometer Titanium Dioxide and Determination by Atomic Absorption Spectrometry
The atomic adsorption spectrometry (AAS), which has the merits of low cost and detection limit, good precision and accuracy, and wide linear range, has been widely applied in trace analysis.By coupling solid-phase extraction (SPE) with AAS, the analytical performance of the analytical method, such as sensitivity, detection limit and selective capability could be efficiently improved. At the same time, it also extends the application field of SPE. And the choice of adsorb materials is the decisive factor that affects analytical sensitivity and selectivity.Nanometer material is a new function material that gained development and importance in recent years. Nanometer Segment neodymium magnets materials are made of nanometer particles, the regime of particle is from 1 nm to 100 nm, falls between the classic fields of chemistry and solid-state physics. The sizes, surface structures and particles interactions of nanometer materials determine their unique properties and the improved performances. One of the specific properties is that a high percent of the atoms of the nanometer particle is on the surface. The surface atoms are unsaturated and can therefore bind with other atoms easily, possess highly chemical activity. Consequently, nanometer materials can adsorb metal ions with high adsorption capacity.In this paper, the self-made nanometer TiO2 was applied in field of analytical detemination, and the adsorption characteristics of some trace elements on nanometer TiO2 material was systematically studied with AAS.A novel method was developed for determination of trace elements such as Pb, Au, La, which combined AAS with separation/preconcentration by nanometer TiO2 with good stability and high selectively, sestively and pollution-free. The major contents are described as follows:1. The methods of separation/preconcentration and kinds of adsorption materials in atomic adsorption spectrometry detemination were reviewed. The characteristics and application in separation/preconcentration of new adsorption material- nanometer material were introduced in detail.2.
The samples of nanometer TiO2 of uniform particle diameter were prepared by improved Sol-Gel method. Then, the product was to be determined by TEM. It was found that the product is nanometer TiO2. There is little agglomeration and the particle diameter is in the 10～30 nm region. So it is suitable for solid phase adsorbent. The adsorption characteristics of heavy metal ions Pb2+ on nanometer TiO2 under static condition were studied, and the conditions http://www.999magnet.com/ such as sorption kinetics, effect of pH on adsorption ratio, and adsorption capacity for preconcentration of trace elements were optimized. The proposed method has been applied for the determination of trace Pb in water samples with satisfactory results. The recoveries of Pb2+ ranged from 94.5% to 102.5%. The detection limit of this method for Pb2+ was 2.57 ng/mL, and relative standard deviation was 2.45% (n=11, c=0.10μg/mL).3. The adsorption characteristics of precious element Au on supported nanometer Ti02 under dynamic condition were studied. Selective preconcentration of gold was obtained at pH=3.5. The linear range for gold was 00.40μg/mL ,A=1.755C+0.0205(C:μg/mL,r=0.9993),detection limit(3σ, n=11) of this method for gold was 2.34 ng/mL; And the relative standard deviation for gold was 2.9% (n=6, c=0.10μg/mL). The method has been applied for the determination of trace gold in water samples with satisfactory results. The recovery was in the range of 96.7% to 101.7%.4. A PTFE micro column packed with 1-phenyl-3-methyl-4-bonzoil-5-pyrazone (PMBP) on nanometer TiO2 was used in FI (flow injection)-FAAS (flame atomic adsorption spectrometry) system for the determination of trace La. The adsorption characteristics of rare earth element La on nanometer Ti02 under static condition were studied, and the conditions for preconcentration of this element were optimized. The method has been applied for the determination of trace La in environmental and biological samples with satisfactory result
2012年7月31日星期二
苯酚选择性加氢制环己酮高效催化剂的研究
苯酚选择性加氢制环己酮高效催化剂的研究
Cyclohexanone is an important chemical material which is widely used in the production of fiber, synthetic rubber, industrial coating, medicine, pesticide and also used as an organic solvent. Currently, Cyclohexanone is produced mainly by either oxidation of cyclohexane in the liquid-phase or by hydrogenation of phenol to cyclohexanol followed by dehydrogenation to cyclohexanone; such processes usually cause pollution of environment and waste of energy. The one-step hydrogenation of phenol to cyclohexanone has the advantage of simple operation and reduced undesirable products. The current researches centered on the gas-phase hydrogenation of phenol, although the liquid-phase method was energy saving and operation conveniently, little attention had been focused on this field. The key was the shortage of suitable catalysts. The amorphous alloys are a kind of materials with short-range ordering while long-range disordering structure. Their Alnico magnets unique structure can result in excellent catalytic properties. Meanwhile, little or even no environmental pollution may be produced during the preparation process of amorphous alloys and their application in catalysis. Thus the amorphous alloys represent new powerful catalysts for modern chemical engineering production, i.e. the green chemistry and the economic reaction. Due to the industrial requirements and environmental considerations, amorphous alloy catalysts caused much attention by both chemists and chemical engineers. However, the preparation of metal amorphous alloy catalysts had the drawbacks of easy crystallization and poor thermal stability.In this thesis, the catalytic performances of the amorphous catalysts were evaluated using phenol hydrogenation to cyclohexanone in the liquid-phase. This thesis covered the following aspects: (1) The preparation and filtration of various catalysts; (2) The evaluation of catalytic performances and characterization of various catalysts; (3) The kinetic studies and the correlation of the catalytic performance to both the structural properties and electronic characteristics were discussed. The followings were in details: 1. Catalyst preparation(1) Prepare double metal Pd-Ce-B amorphous catalysts: the Pd-Ce-B amorphous catalysts were prepared by chemical reduction of the PdCl2 and Ce(NO3)3 mixed solutions by KBH4 in aqueous solution which was added drop-wise into the solution. Change the quantity of the Ce(NO3)3 in the solution resulted in the Pd-Ce-B amorphous alloys http://www.999magnet.com/ with different Ce-dopants.(2) Prepare the Pd-Ce-B catalysts assisted by using ultra method: the Pd-Ce-B amorphous catalysts were prepared by chemical reduction of the PdCl2 and Ce(NO3)3 mixed solutions by KBH4 in aqueous solution while ultrasonic with a certain ultra power.(3) prepare the supported catalysts: Different supports were impregnated with some precursor solution, dried by the oven and then were calcined and reduced by KBH4 aqueous solution to obtain the supported amorphous catalysts.2. Activity testPhenol hydrogenation was performed in a 250 ml stainless steel autoclave containing certain amount of the as-prepared catalysts, 0.5 g/ml phenol solution and EtOH, at 1.0 MPa hydrogen pressure and a desired temperature. The results showed:(1) the catalytic performance of ultra-fine Pd-Ce-B catalysts increased with the increscent of Ce dopants.
The maximum yield of cyclohexanone reached 83.0% after reacted for 3 hours on the Pd-Ce-B catalyst with XCe = 0.44%. After used repeatedly for 5 times without obvious deactivation, showing the promising industrial application;(2) the hydrogenation activity enhanced greatly by using ultra during the preparation of catalysts, the selectivity to cyclohexanone remained very high even after the phenol was totally converted. In the same reaction conditions, with the ultra-power 90W, the maximum yield of cyclohexanone reached 91% after reacted for 45 min; (3) Comparing different supports on the performance of the Pd-Ce-B catalysts. When the hydrotalcite support with different acid-base sites was chose, the undesired-product was restrained effectively. The maximum yield of cyclohexanone reached 65.6% after reacted for 3 hours on the 5.8%Pd-Ce-B/HT catalysts. 3. The correlation of the catalytic performance and the structural propertiesAccording to a series of characterizations of the catalysts, the following questions were discussed briefly:(1) By doping rare earth Ce to obtain Pd-Ce-B catalysts, the Ce element was existed in the form of Ce2O3. The promoting effects of Ce to catalytic performance and the selectivity of cyclohexanone could be attributed to the stabilizing effects of Pd-B amorphous structure; donating partial electrons to active sites Pd; enhancing the basic sites on the surface of the catalysts because of the formation of Ce2O3.(2) The Pd-Ce-B catalysts prepared by http://www.999magnet.com/ using the ultra method could reduce the size, increase the dispersion of active sites, create more surface defects, add more active hydrogen in the catalyst interior, fortify the adsorption intensity of hydrogen, it could also force the active hydrogen enter the crystal lattice of the catalysts by shock wave and participate the formation of catalysts.(3) By using different supports to prepare supported catalysts could reduce the quantity of noble metal and inhibit the formation of undesirable products. The supports with suitable acid-base sites favored the formation of cyclohexanone, on the one hand, basic sites favored the non-planar form of phenol, thus hydrogenated to cyclohexanone; on the other hand, certain acid sites favored the isomerisation of 1-hydroxycyclohexene to cyclohexanone.
Cyclohexanone is an important chemical material which is widely used in the production of fiber, synthetic rubber, industrial coating, medicine, pesticide and also used as an organic solvent. Currently, Cyclohexanone is produced mainly by either oxidation of cyclohexane in the liquid-phase or by hydrogenation of phenol to cyclohexanol followed by dehydrogenation to cyclohexanone; such processes usually cause pollution of environment and waste of energy. The one-step hydrogenation of phenol to cyclohexanone has the advantage of simple operation and reduced undesirable products. The current researches centered on the gas-phase hydrogenation of phenol, although the liquid-phase method was energy saving and operation conveniently, little attention had been focused on this field. The key was the shortage of suitable catalysts. The amorphous alloys are a kind of materials with short-range ordering while long-range disordering structure. Their Alnico magnets unique structure can result in excellent catalytic properties. Meanwhile, little or even no environmental pollution may be produced during the preparation process of amorphous alloys and their application in catalysis. Thus the amorphous alloys represent new powerful catalysts for modern chemical engineering production, i.e. the green chemistry and the economic reaction. Due to the industrial requirements and environmental considerations, amorphous alloy catalysts caused much attention by both chemists and chemical engineers. However, the preparation of metal amorphous alloy catalysts had the drawbacks of easy crystallization and poor thermal stability.In this thesis, the catalytic performances of the amorphous catalysts were evaluated using phenol hydrogenation to cyclohexanone in the liquid-phase. This thesis covered the following aspects: (1) The preparation and filtration of various catalysts; (2) The evaluation of catalytic performances and characterization of various catalysts; (3) The kinetic studies and the correlation of the catalytic performance to both the structural properties and electronic characteristics were discussed. The followings were in details: 1. Catalyst preparation(1) Prepare double metal Pd-Ce-B amorphous catalysts: the Pd-Ce-B amorphous catalysts were prepared by chemical reduction of the PdCl2 and Ce(NO3)3 mixed solutions by KBH4 in aqueous solution which was added drop-wise into the solution. Change the quantity of the Ce(NO3)3 in the solution resulted in the Pd-Ce-B amorphous alloys http://www.999magnet.com/ with different Ce-dopants.(2) Prepare the Pd-Ce-B catalysts assisted by using ultra method: the Pd-Ce-B amorphous catalysts were prepared by chemical reduction of the PdCl2 and Ce(NO3)3 mixed solutions by KBH4 in aqueous solution while ultrasonic with a certain ultra power.(3) prepare the supported catalysts: Different supports were impregnated with some precursor solution, dried by the oven and then were calcined and reduced by KBH4 aqueous solution to obtain the supported amorphous catalysts.2. Activity testPhenol hydrogenation was performed in a 250 ml stainless steel autoclave containing certain amount of the as-prepared catalysts, 0.5 g/ml phenol solution and EtOH, at 1.0 MPa hydrogen pressure and a desired temperature. The results showed:(1) the catalytic performance of ultra-fine Pd-Ce-B catalysts increased with the increscent of Ce dopants.
The maximum yield of cyclohexanone reached 83.0% after reacted for 3 hours on the Pd-Ce-B catalyst with XCe = 0.44%. After used repeatedly for 5 times without obvious deactivation, showing the promising industrial application;(2) the hydrogenation activity enhanced greatly by using ultra during the preparation of catalysts, the selectivity to cyclohexanone remained very high even after the phenol was totally converted. In the same reaction conditions, with the ultra-power 90W, the maximum yield of cyclohexanone reached 91% after reacted for 45 min; (3) Comparing different supports on the performance of the Pd-Ce-B catalysts. When the hydrotalcite support with different acid-base sites was chose, the undesired-product was restrained effectively. The maximum yield of cyclohexanone reached 65.6% after reacted for 3 hours on the 5.8%Pd-Ce-B/HT catalysts. 3. The correlation of the catalytic performance and the structural propertiesAccording to a series of characterizations of the catalysts, the following questions were discussed briefly:(1) By doping rare earth Ce to obtain Pd-Ce-B catalysts, the Ce element was existed in the form of Ce2O3. The promoting effects of Ce to catalytic performance and the selectivity of cyclohexanone could be attributed to the stabilizing effects of Pd-B amorphous structure; donating partial electrons to active sites Pd; enhancing the basic sites on the surface of the catalysts because of the formation of Ce2O3.(2) The Pd-Ce-B catalysts prepared by http://www.999magnet.com/ using the ultra method could reduce the size, increase the dispersion of active sites, create more surface defects, add more active hydrogen in the catalyst interior, fortify the adsorption intensity of hydrogen, it could also force the active hydrogen enter the crystal lattice of the catalysts by shock wave and participate the formation of catalysts.(3) By using different supports to prepare supported catalysts could reduce the quantity of noble metal and inhibit the formation of undesirable products. The supports with suitable acid-base sites favored the formation of cyclohexanone, on the one hand, basic sites favored the non-planar form of phenol, thus hydrogenated to cyclohexanone; on the other hand, certain acid sites favored the isomerisation of 1-hydroxycyclohexene to cyclohexanone.
Research on Design of Giant Magnetostrictive Actuator and Its Characteristics in Application
Research on Design of Giant Magnetostrictive Actuator and Its Characteristics in Application
With the unceasing development of the technique, the hydraulic fluid control technique and computer control technique are making high progress. Especially in recent years, with the development and improvement of computer, especially SBC or micro-actuator of low price provides indispensable conditions for digital of the hydraulic systems. The digital technique has been applied widely in hydraulic control system, this make the mechatronic technique of the hydraulic components step grown up.This thesis mainly studies the application of the direct digital technology on hydraulic systems, viz. the technique of the fast on/off digital valve. High speed on/off digital valve is Block Neodymium magnets an excellent conversion element can directed contact with computer which has been raised since 1990’s, it has many merits such as high response speed, good ability of resisting contaminated oil. This kind of hydraulic valve has the control function through the PWM signal, and carries on the continual control to the hydraulic valve current capacity through the control of pulse frequency or the pulse width. Because this kind of valve and the micro controller no longer needs the A/D transformation connection, the complex connection electric circuit has been greatly simplified.
So high speed on/off digital valve is a promising digital valve, and it is necessary for modernization of industry to develop this digital valve.The new high speed digital on/off valve was composed of PWM modulator, actuator using GMM, displacement lever amplifier and cylindrical slide valve, In order to form undulates slightly continuously fluid, must enhance its on/off frequency. Therefore the key to make this kind of valve practical application is further enhancing the response frequency of the high speed figure switch valve, reducing its response time, improving its performance. This thesis considered the difference between actuator making with GMM and traditional actuators such as: electro-magnetic, electro-strict .Then we got the merit of the actuator with GMM. On the basis of the theory of high speed on/off valve, this thesis studies and analyzes its construction, work principle. According to its electromagnetism characteristics and machinery characteristics, we established the http://www.999magnet.com/ mathematics model and then turned the mathematics model into linearization and converted into the transfer function pane diagram using the matlab with simulink software, we converted the mathematics module into simulation module. After fell number into parameter, digital simulation. In this foundation, studied and analyzed the influence of each kind of parameter (pulse width, coil number of windings, displacement enlargement factor, frequency and so on) to the high speed figure switch valve, and obtained the rules. By the optimization ITAE, the high speed on/off valve model was carried out parameter optimization, we can get optimization parameters. For the lack of experiment conditions, we got the result just by the simulation. From the simulation result, we can know that change the ratio of the lever and winding, performance of the high speed on/off valve was enhanced.This goal of this topic is promoting the development of the hydraulic control technology, making the fluid control technology and the computer control technology unified well, in order to adapt the technical trend of mechatronics.
With the unceasing development of the technique, the hydraulic fluid control technique and computer control technique are making high progress. Especially in recent years, with the development and improvement of computer, especially SBC or micro-actuator of low price provides indispensable conditions for digital of the hydraulic systems. The digital technique has been applied widely in hydraulic control system, this make the mechatronic technique of the hydraulic components step grown up.This thesis mainly studies the application of the direct digital technology on hydraulic systems, viz. the technique of the fast on/off digital valve. High speed on/off digital valve is Block Neodymium magnets an excellent conversion element can directed contact with computer which has been raised since 1990’s, it has many merits such as high response speed, good ability of resisting contaminated oil. This kind of hydraulic valve has the control function through the PWM signal, and carries on the continual control to the hydraulic valve current capacity through the control of pulse frequency or the pulse width. Because this kind of valve and the micro controller no longer needs the A/D transformation connection, the complex connection electric circuit has been greatly simplified.
So high speed on/off digital valve is a promising digital valve, and it is necessary for modernization of industry to develop this digital valve.The new high speed digital on/off valve was composed of PWM modulator, actuator using GMM, displacement lever amplifier and cylindrical slide valve, In order to form undulates slightly continuously fluid, must enhance its on/off frequency. Therefore the key to make this kind of valve practical application is further enhancing the response frequency of the high speed figure switch valve, reducing its response time, improving its performance. This thesis considered the difference between actuator making with GMM and traditional actuators such as: electro-magnetic, electro-strict .Then we got the merit of the actuator with GMM. On the basis of the theory of high speed on/off valve, this thesis studies and analyzes its construction, work principle. According to its electromagnetism characteristics and machinery characteristics, we established the http://www.999magnet.com/ mathematics model and then turned the mathematics model into linearization and converted into the transfer function pane diagram using the matlab with simulink software, we converted the mathematics module into simulation module. After fell number into parameter, digital simulation. In this foundation, studied and analyzed the influence of each kind of parameter (pulse width, coil number of windings, displacement enlargement factor, frequency and so on) to the high speed figure switch valve, and obtained the rules. By the optimization ITAE, the high speed on/off valve model was carried out parameter optimization, we can get optimization parameters. For the lack of experiment conditions, we got the result just by the simulation. From the simulation result, we can know that change the ratio of the lever and winding, performance of the high speed on/off valve was enhanced.This goal of this topic is promoting the development of the hydraulic control technology, making the fluid control technology and the computer control technology unified well, in order to adapt the technical trend of mechatronics.
Study on H13 Steel for Magnesium Alloy Die-casting Die Surface Strengthened by RE-B-N-C Multi-elements Penetrating
Study on H13 Steel for Magnesium Alloy Die-casting Die Surface Strengthened by RE-B-N-C Multi-elements Penetrating
H13 (4CrSMoSiV1), as a new model hot die steel, has excellenthardenability, quenching rigidity and good nature at room and hightemperature. Its service life is longer than the casting die steel(3Cr2W8V).The magnesium alloy casting die through routine heat treatment often showsinactivation of distress chap, severity erosion and mucosity to die in bad workcondition. Consequently, improvement of surface heat treatment technologyof H13 casting die is exigent with wide application of magnesium.The paper applied RE-B-N-C multi-element penetration technology andquenching+temper method to improve the resistance of abrasion, hightemperature oxidation and heat fatigue.
The penetration agents consisted ofadmixture of Char and activated carbon, urea and zala, and the activatorsconsisted of soda, ammonium chloride, sodium fluoride, aluminite powder,sodium chloride and creosote thulium. Several apparatus were Neodymium Magnets applied to testsamples, which were NIKO microscope for analysis of compound layer,M-400-H1microhardness instrument for test of penetration layer stiffness,M200 abrasion tester for attrition test of penetration layer, box type furnacefor high temperature oxidation resistant test. Moreover, heat fatigue control experiment were carried out among samples that were obtained through thedifferent methods included quenching+temper, quenching+temper+BNCmulti-element penetration, CrN vacuum ion metallic membrane plating,CrN/AlN vacuum ion metallic-membrane plating, vacuum ion NC multi-element penetration.The results showed that the methods, 930℃×4h (RE-BNC multi-elementpenetration)→1020℃×20min(quenching)→600℃×30min(temper)→550℃×4h(RE-NC multi-element penetration)→180℃×4h(aging treatment) areeffective in the surface strengthening. When the compound of carbonic acidwere put in by 10%, the compound layer thickness reached 95～105μm andthe case hardness reached HV1210 http://www.999magnet.com/ without soft band region. The surfaceattrition rate reduced to 0.028mg/min. The result of heat fatigue controlexperiment shows the surface cracks of RE-BNC multi-element penetrationsample had small changes, and no major cracks and dropped massive texturethrough 2000 tests from room temperature to 700℃. BNC multi-elementpenetration samples had radial cracks through 1500 tests, and had texturedesquamation through 2000 tests. Moreover, vacuum ion metallic-membraneplating and vacuum ion NC penetration samples had cracks and texturedesquamation at the different degree through 300～500 tests. Therefore,RE-BNC multi-element penetration technology is an effective method in thesurface treatment of H13 steel.
H13 (4CrSMoSiV1), as a new model hot die steel, has excellenthardenability, quenching rigidity and good nature at room and hightemperature. Its service life is longer than the casting die steel(3Cr2W8V).The magnesium alloy casting die through routine heat treatment often showsinactivation of distress chap, severity erosion and mucosity to die in bad workcondition. Consequently, improvement of surface heat treatment technologyof H13 casting die is exigent with wide application of magnesium.The paper applied RE-B-N-C multi-element penetration technology andquenching+temper method to improve the resistance of abrasion, hightemperature oxidation and heat fatigue.
The penetration agents consisted ofadmixture of Char and activated carbon, urea and zala, and the activatorsconsisted of soda, ammonium chloride, sodium fluoride, aluminite powder,sodium chloride and creosote thulium. Several apparatus were Neodymium Magnets applied to testsamples, which were NIKO microscope for analysis of compound layer,M-400-H1microhardness instrument for test of penetration layer stiffness,M200 abrasion tester for attrition test of penetration layer, box type furnacefor high temperature oxidation resistant test. Moreover, heat fatigue control experiment were carried out among samples that were obtained through thedifferent methods included quenching+temper, quenching+temper+BNCmulti-element penetration, CrN vacuum ion metallic membrane plating,CrN/AlN vacuum ion metallic-membrane plating, vacuum ion NC multi-element penetration.The results showed that the methods, 930℃×4h (RE-BNC multi-elementpenetration)→1020℃×20min(quenching)→600℃×30min(temper)→550℃×4h(RE-NC multi-element penetration)→180℃×4h(aging treatment) areeffective in the surface strengthening. When the compound of carbonic acidwere put in by 10%, the compound layer thickness reached 95～105μm andthe case hardness reached HV1210 http://www.999magnet.com/ without soft band region. The surfaceattrition rate reduced to 0.028mg/min. The result of heat fatigue controlexperiment shows the surface cracks of RE-BNC multi-element penetrationsample had small changes, and no major cracks and dropped massive texturethrough 2000 tests from room temperature to 700℃. BNC multi-elementpenetration samples had radial cracks through 1500 tests, and had texturedesquamation through 2000 tests. Moreover, vacuum ion metallic-membraneplating and vacuum ion NC penetration samples had cracks and texturedesquamation at the different degree through 300～500 tests. Therefore,RE-BNC multi-element penetration technology is an effective method in thesurface treatment of H13 steel.
Research of Key Technology of Ultra-short Yb～(3+) Doped Fiber Amplifier
Research of Key Technology of Ultra-short Yb～(3+) Doped Fiber Amplifier
Ultrashort pulse technology and lanthanon-doped fiber laser have become twoimportant fields in optics in recent years. High peak-power ultrashort pulses have asignificant value in high-precision industrial laser processing applications, scientificresearch, medical technology and so on. As an attractive gain medium, the Yb3+-dopedfiber has some better quality magnet lifter compared to other lanthanon-doped fiber, such as highersaturable power, higher optical conversion efficiency and broader gain spectrumbandwidth(which can support pulses as short as 30fs). In this paper the Yb3+-dopedfiber chirped pulse amplifier system is studied experimentally and theoretically.Firstly, the development history, recent achievement and perspective ofYb3+-doped fiber laser are summarized.Secondly, through numerical simulation and experiments the properties of thefigure-of-eight passively mode-locked fiber laser and Yb3+-doped fiber amplifier arestudied, the optimization of the parameters of amplifier is discussed. By using anYb3+-doped large-mode-area photonic crystal fiber amplifier, 356ps pulses with 100uJenergy are gained, and the average power achieves 3.1W.Thirdly, the characters http://www.999magnet.com/ of gratings compressor are studied experimentally andtheoretically. The principle of the gratings compressor design is concluded byanalyzing the parameters of grating. Finally, through optimization of the parameters ofgratings compressor, 716fs pulses with 20uJ energy are obtained.
Ultrashort pulse technology and lanthanon-doped fiber laser have become twoimportant fields in optics in recent years. High peak-power ultrashort pulses have asignificant value in high-precision industrial laser processing applications, scientificresearch, medical technology and so on. As an attractive gain medium, the Yb3+-dopedfiber has some better quality magnet lifter compared to other lanthanon-doped fiber, such as highersaturable power, higher optical conversion efficiency and broader gain spectrumbandwidth(which can support pulses as short as 30fs). In this paper the Yb3+-dopedfiber chirped pulse amplifier system is studied experimentally and theoretically.Firstly, the development history, recent achievement and perspective ofYb3+-doped fiber laser are summarized.Secondly, through numerical simulation and experiments the properties of thefigure-of-eight passively mode-locked fiber laser and Yb3+-doped fiber amplifier arestudied, the optimization of the parameters of amplifier is discussed. By using anYb3+-doped large-mode-area photonic crystal fiber amplifier, 356ps pulses with 100uJenergy are gained, and the average power achieves 3.1W.Thirdly, the characters http://www.999magnet.com/ of gratings compressor are studied experimentally andtheoretically. The principle of the gratings compressor design is concluded byanalyzing the parameters of grating. Finally, through optimization of the parameters ofgratings compressor, 716fs pulses with 20uJ energy are obtained.
2012年7月24日星期二
Microstructure and Mechanical Properties of Die-Cast Magnesium Alloys
Microstructure and Mechanical Properties of Die-Cast Magnesium Alloys
At present, the die casting technology has been widely used for the production of magnesium alloy structural components. However, due to low strength of magnesium alloys at high temperatures, how to improve both room temperature and high temperature strengths has become an important subject in development of magnesium alloys. In this dissertation, the influence of element Y on microstructure, tensile properties and low-cyclic fatigue behavior of die-cast Mg-Al-Y alloys has been studied by microstructure observation, tensile and low-cycle fatigue tests. Neodymium Magnets In addition, the effect of Ca on microstructure and mechanical properties of AE42 alloy have been investigated. The aim of this study is to provide a reliable theoretical reference for both development and engineering application of die-cast magnesium alloys containing RE elements.The observations on microstructure reveal that the grains in die-cast Mg-Al-Y alloys become finer with increasing the content of Y.
However, the coarse Al-Mg eutectic structures can be also observed in the microstructure of die-cast Mg-Al-Y alloys. It can be noted that the microstructure of die-cast AE42-Ca consists ofα-Mg, Al11RE3 and Al2Ca.The results of tensile tests indicate that the tensile properties of die-cast Mg-Al-Y alloys not only depend on experimental temperature, but also the content of rare element Y. At room temperature and 200℃, the ultimate tensile strength of the die-cast Mg-Al-0.5wt%Y alloy is the highest, while the die-cast Mg-Al-1.0wt%Y alloy shows the highest ultimate tensile strength at 150℃. At room and 150℃, the yield strength of the die-cast Mg-Al-1.0wt%Y alloy is the http://www.999magnet.com/ highest, while the die-cast Mg-Al-0.5wt%Y alloy shows the best yield strength at 200℃. It has been found that the die-cast AE42-0.8%Ca shows the best tensile strengths at room temperature, while the die-cast AE42-0.5%Ca and AE42-0.2%Ca alloys exhibit the best tensile properties at 150℃and 200℃respectively. In addition, aging treatment can further enhance the tensile properties of the die-cast AE42-Ca alloys.The results of low-cyclic fatigue tests show that the die-cast Mg-7%Al-0.5%Y alloy exhibits the same extent of cyclic strain hardening at various total strain amplitudes. For the die-cast Mg-7%A1-0.5%Y alloy, the relations between the elastic strain amplitude, plastic strain amplitude and reversals to failure can be described by the Basquin and Coffin-Manson equations, respectively. The SEM analysis on the fracture surfaces shows that the fatigue cracks initiate at the casting defects near the surface of the fatigue specimens, and propagate in a transgranular mode.
At present, the die casting technology has been widely used for the production of magnesium alloy structural components. However, due to low strength of magnesium alloys at high temperatures, how to improve both room temperature and high temperature strengths has become an important subject in development of magnesium alloys. In this dissertation, the influence of element Y on microstructure, tensile properties and low-cyclic fatigue behavior of die-cast Mg-Al-Y alloys has been studied by microstructure observation, tensile and low-cycle fatigue tests. Neodymium Magnets In addition, the effect of Ca on microstructure and mechanical properties of AE42 alloy have been investigated. The aim of this study is to provide a reliable theoretical reference for both development and engineering application of die-cast magnesium alloys containing RE elements.The observations on microstructure reveal that the grains in die-cast Mg-Al-Y alloys become finer with increasing the content of Y.
However, the coarse Al-Mg eutectic structures can be also observed in the microstructure of die-cast Mg-Al-Y alloys. It can be noted that the microstructure of die-cast AE42-Ca consists ofα-Mg, Al11RE3 and Al2Ca.The results of tensile tests indicate that the tensile properties of die-cast Mg-Al-Y alloys not only depend on experimental temperature, but also the content of rare element Y. At room temperature and 200℃, the ultimate tensile strength of the die-cast Mg-Al-0.5wt%Y alloy is the highest, while the die-cast Mg-Al-1.0wt%Y alloy shows the highest ultimate tensile strength at 150℃. At room and 150℃, the yield strength of the die-cast Mg-Al-1.0wt%Y alloy is the http://www.999magnet.com/ highest, while the die-cast Mg-Al-0.5wt%Y alloy shows the best yield strength at 200℃. It has been found that the die-cast AE42-0.8%Ca shows the best tensile strengths at room temperature, while the die-cast AE42-0.5%Ca and AE42-0.2%Ca alloys exhibit the best tensile properties at 150℃and 200℃respectively. In addition, aging treatment can further enhance the tensile properties of the die-cast AE42-Ca alloys.The results of low-cyclic fatigue tests show that the die-cast Mg-7%Al-0.5%Y alloy exhibits the same extent of cyclic strain hardening at various total strain amplitudes. For the die-cast Mg-7%A1-0.5%Y alloy, the relations between the elastic strain amplitude, plastic strain amplitude and reversals to failure can be described by the Basquin and Coffin-Manson equations, respectively. The SEM analysis on the fracture surfaces shows that the fatigue cracks initiate at the casting defects near the surface of the fatigue specimens, and propagate in a transgranular mode.
One-Step Synthesis of Ordered Mesoporous Carbon and Its Application in Supports of Catalysts
One-Step Synthesis of Ordered Mesoporous Carbon and Its Application in Supports of Catalysts
Ordered mesoporous carbon with 2D hexagonal structure derived from the co-assembly of F127 and resol had been successfully synthesized in one-step. The BET surface area, total pore volume, and pore diameter of the mesoporous carbon was 615.6 m2·g-1, 0.35 cm3·g-1, and 2.7 nm, respectively. Pt nanoparticles supported on the mesoporous carbon were fabricated by a facile CTAB assisted microwave synthesis process, wherein CTAB was expected to improve the wettability of carbon support as well as the dispersion of Pt nanoparticles.
Thereby, the electrocatalytic activity of Pt nanoparticles for adsorbed hydrogen was enhanced. The electrochemical active surface area of Pt nanoparticles prepared with CTAB (70.2 m2/g) was two times than that without CTAB.Carbon nanofiber was synthesized through a hard template of AAO (anodic aluminum oxide) membrane together with a rare earth magnets soft template of block copolymer surfactant F127. It exhibited hierarchical mesoporous structure combining regular spiral channels with round pores. Pt nanoparticles supported on the carbon nanofiber displayed superior performances in sulfuric acid. Its electrochemical active surface area for hydrogen oxidation was 181.1 m2/g, which was 5.5 times than that of Pt nanoparticles supported on mesoporous carbon powders.In order to reduce structural shrinkage during the carbonization, mesoporous carbon frameworks were reinforced by introducing silica into the nanocomposites. The mesoporous carbon, wherein the percentage of the carbon-compound content in the carbon-silica nanocomposite was 40%, possessed high BET surface area of 1330 m2/g, large pore diameter of 6.4 nm, and pore volume of 2.13 cm3/g. Pt nanoparticles supported on this carbon gave the excellent electrocatalytic activity for adsorbed hydrogen. Its electrochemical active surface area for hydrogen oxidation was 220.8 m2/g, which was 7 times than http://www.chinamagnets.biz/ that of Pt nanoparticles supported on carbon material without silica.Mesoporous carbon supports further modified by the rare earth oxides were expected to improve the utilization of noble metal while develop the synergetic catalysis. After modified by Pr2O3, mesoporous carbon loading with PtRu nanoparticles had the lowest charge transfer resistance and the highest Warburg coefficient of diffusion in the electrochemical reactions. In system of sulfuric acid, its electrochemical active surface area for hydrogen oxidation was 136.3 m2/g, which was 3.5 times than that of PtRu/C. In system of methanol, it showed high peak current density of 21.8 mA/cm2 for methanol oxidation, while presented the slower decay of current than PtRu/C, indicating the improved CO-tolerance.
Ordered mesoporous carbon with 2D hexagonal structure derived from the co-assembly of F127 and resol had been successfully synthesized in one-step. The BET surface area, total pore volume, and pore diameter of the mesoporous carbon was 615.6 m2·g-1, 0.35 cm3·g-1, and 2.7 nm, respectively. Pt nanoparticles supported on the mesoporous carbon were fabricated by a facile CTAB assisted microwave synthesis process, wherein CTAB was expected to improve the wettability of carbon support as well as the dispersion of Pt nanoparticles.
Thereby, the electrocatalytic activity of Pt nanoparticles for adsorbed hydrogen was enhanced. The electrochemical active surface area of Pt nanoparticles prepared with CTAB (70.2 m2/g) was two times than that without CTAB.Carbon nanofiber was synthesized through a hard template of AAO (anodic aluminum oxide) membrane together with a rare earth magnets soft template of block copolymer surfactant F127. It exhibited hierarchical mesoporous structure combining regular spiral channels with round pores. Pt nanoparticles supported on the carbon nanofiber displayed superior performances in sulfuric acid. Its electrochemical active surface area for hydrogen oxidation was 181.1 m2/g, which was 5.5 times than that of Pt nanoparticles supported on mesoporous carbon powders.In order to reduce structural shrinkage during the carbonization, mesoporous carbon frameworks were reinforced by introducing silica into the nanocomposites. The mesoporous carbon, wherein the percentage of the carbon-compound content in the carbon-silica nanocomposite was 40%, possessed high BET surface area of 1330 m2/g, large pore diameter of 6.4 nm, and pore volume of 2.13 cm3/g. Pt nanoparticles supported on this carbon gave the excellent electrocatalytic activity for adsorbed hydrogen. Its electrochemical active surface area for hydrogen oxidation was 220.8 m2/g, which was 7 times than http://www.chinamagnets.biz/ that of Pt nanoparticles supported on carbon material without silica.Mesoporous carbon supports further modified by the rare earth oxides were expected to improve the utilization of noble metal while develop the synergetic catalysis. After modified by Pr2O3, mesoporous carbon loading with PtRu nanoparticles had the lowest charge transfer resistance and the highest Warburg coefficient of diffusion in the electrochemical reactions. In system of sulfuric acid, its electrochemical active surface area for hydrogen oxidation was 136.3 m2/g, which was 3.5 times than that of PtRu/C. In system of methanol, it showed high peak current density of 21.8 mA/cm2 for methanol oxidation, while presented the slower decay of current than PtRu/C, indicating the improved CO-tolerance.
2012年7月16日星期一
Fabrication and Characterization of Ni-Based Fully Silicided Metal Gate
Fabrication and Characterization of Ni-Based Fully Silicided Metal Gate
The tunneling current through SiO2 or SiON increases exponentially as the dimension of complementary metal-oxide-semiconductor(CMOS) devices is scaling. As a result,SiO2 or SiON should be replaced by high-k gate dielectric.However,the conventional poly-Si gate has many problems,such as poly-Si depletion effects,and the imcompatibility with high-k dielectrics:Fermi-level pinning and charge-carrier-induced mobility degradation.Poly-Si gate must be replaced by metal gate with higher conductance.Fully silicided(FUSI) metal gate has been investigated extensively due to its large work function(WF) modulation range and excellent compatibility with the conventional CMOS field effect transistor process.This paper investigates the fabrication process,electric performance,WF modulation,SiO2/Si interface trap properties,and electrical characterization of FUSI metal Block Neodymium magnets gated MOS capacitor.Capacitance-voltage(C-V) measurement principle and analysis.By investigating the effects of measurement frequency and capacitor area on C-V measurement results, three or four element equivalent circuit model must be used,when the oxide leakage current is large(for example,in ultra thin gate oxide).The reduction of capacitor area can decrease dissipation factor D and therefore obtain reliable C-V characteristic curves.Pre-doping effects on Ni FUSI metal gate.First,the thesis investigated the fabrication process and characteristics of Ni FUSI metal gate formed from solid reaction of a-Si and Ni by sputtering on three different SiO2 thickness.The WF of the FUSI metal gate is 4.40 eV.Then,the thesis investigated the effects of ion implantation and spike activation anneal on the WF modulation of pre-doped Ni FUSI metal gate electrodes on SiO2 dielectrics,and the FUSI gated SiO2/Si(100) interface trap properties.
The interface trap properties were measured by using high-frequency C-V and photonic high-frequency C-V measurements.After fully silicidation anneal, the flatband voltage(VFB) of the Ni FUSI gated MOS capacitor shifts negatively or positively for As-doped or B-doped case,respectively.As-doped Ni FUSI gate may delaminate or peel off after forming gas anneal(FGA).Undoped NiSi FUSI gate has good thermal stability,and its WF before and after FGA is 4.75 eV and 4.74 eV, respectively.Interface trap density Dit calculated from the photonic high-frequency C-V curves is in good agreement with that calculated from the high-frequency and photonic high-frequency C-V curves.Before FGA,a characteristic Dit peak ranging from 5.7×1012 to 1.2×1013 cm- http://www.999magnet.com/ 2eV-1 was observed at approximately 0.63～0.74 eV above the valence band edge for As-doped and B-doped Ni FUSI gated capacitors which received a spike activation anneal after ion implantation.The characteristic peak,which may be related to Pb defects at the SiO2/Si(100) interface,could be eliminated after FGA.Ni(RE) FUSI metal gate.The thesis investigated the rare-earth(RE) metal alloying effects on the sheet resistance,the WF modulation of Ni(RE) FUSI gate electrodes.As the thickness percentage of Ho in the Ni(Ho) increases from 0 to 13%and 30%,the sheet resistance of the silicide increases from 1.4Ω/sq to 1.8Ω/sq and 3.1Ω/sq,and the VFB shift decreases from -0.31 to -0.50 and -0.58 V.The VFB shift can be attributed to the WF decrease due to Ho.As the thickness percentage of Er in the Ni(Er) increases from 0 to 10%and 32%,the sheet resistance of the silicide increases from 1.4Ω/sq to 2.1Ω/sq and 4.9Ω/sq.The WF is reduced approximately 0.17 eV due to the 10%Er thickness percentage in the Ni(Er).
The tunneling current through SiO2 or SiON increases exponentially as the dimension of complementary metal-oxide-semiconductor(CMOS) devices is scaling. As a result,SiO2 or SiON should be replaced by high-k gate dielectric.However,the conventional poly-Si gate has many problems,such as poly-Si depletion effects,and the imcompatibility with high-k dielectrics:Fermi-level pinning and charge-carrier-induced mobility degradation.Poly-Si gate must be replaced by metal gate with higher conductance.Fully silicided(FUSI) metal gate has been investigated extensively due to its large work function(WF) modulation range and excellent compatibility with the conventional CMOS field effect transistor process.This paper investigates the fabrication process,electric performance,WF modulation,SiO2/Si interface trap properties,and electrical characterization of FUSI metal Block Neodymium magnets gated MOS capacitor.Capacitance-voltage(C-V) measurement principle and analysis.By investigating the effects of measurement frequency and capacitor area on C-V measurement results, three or four element equivalent circuit model must be used,when the oxide leakage current is large(for example,in ultra thin gate oxide).The reduction of capacitor area can decrease dissipation factor D and therefore obtain reliable C-V characteristic curves.Pre-doping effects on Ni FUSI metal gate.First,the thesis investigated the fabrication process and characteristics of Ni FUSI metal gate formed from solid reaction of a-Si and Ni by sputtering on three different SiO2 thickness.The WF of the FUSI metal gate is 4.40 eV.Then,the thesis investigated the effects of ion implantation and spike activation anneal on the WF modulation of pre-doped Ni FUSI metal gate electrodes on SiO2 dielectrics,and the FUSI gated SiO2/Si(100) interface trap properties.
The interface trap properties were measured by using high-frequency C-V and photonic high-frequency C-V measurements.After fully silicidation anneal, the flatband voltage(VFB) of the Ni FUSI gated MOS capacitor shifts negatively or positively for As-doped or B-doped case,respectively.As-doped Ni FUSI gate may delaminate or peel off after forming gas anneal(FGA).Undoped NiSi FUSI gate has good thermal stability,and its WF before and after FGA is 4.75 eV and 4.74 eV, respectively.Interface trap density Dit calculated from the photonic high-frequency C-V curves is in good agreement with that calculated from the high-frequency and photonic high-frequency C-V curves.Before FGA,a characteristic Dit peak ranging from 5.7×1012 to 1.2×1013 cm- http://www.999magnet.com/ 2eV-1 was observed at approximately 0.63～0.74 eV above the valence band edge for As-doped and B-doped Ni FUSI gated capacitors which received a spike activation anneal after ion implantation.The characteristic peak,which may be related to Pb defects at the SiO2/Si(100) interface,could be eliminated after FGA.Ni(RE) FUSI metal gate.The thesis investigated the rare-earth(RE) metal alloying effects on the sheet resistance,the WF modulation of Ni(RE) FUSI gate electrodes.As the thickness percentage of Ho in the Ni(Ho) increases from 0 to 13%and 30%,the sheet resistance of the silicide increases from 1.4Ω/sq to 1.8Ω/sq and 3.1Ω/sq,and the VFB shift decreases from -0.31 to -0.50 and -0.58 V.The VFB shift can be attributed to the WF decrease due to Ho.As the thickness percentage of Er in the Ni(Er) increases from 0 to 10%and 32%,the sheet resistance of the silicide increases from 1.4Ω/sq to 2.1Ω/sq and 4.9Ω/sq.The WF is reduced approximately 0.17 eV due to the 10%Er thickness percentage in the Ni(Er).
Preparation of Hydroxide Nickel by Electrodeposition and Its Application in the Supercapacitors
Preparation of Hydroxide Nickel by Electrodeposition and Its Application in the Supercapacitors
Super-capacitor is a new kind of energy storage devices with remarkable advantages. Electrode material is an important factor that affects the ECs performances, among these, Ni(OH)2 appears to be a promising material. Ni(OH)2 was prepared by electrodeposit method, and doped with Co,Fe,La and Ce in our work. We planned to gain Ni(OH)2 electrode material with high specific surface area, excellent electrochemical performance, and high specific capacitance.The effect of electrodeposit parameters on the structure and electrochemical characteristics of Ni(OH)2 was studied using different experimental method, such as orthogonal experiment, single factor Alnico magnets experiment and contrast analysis. The structure and appearance of Ni(OH)2 were characterized using various techniques such as scanning electron microscopy(SEM) and X-ray diffraction(XRD). The electrochemical performance of Ni(OH)2 was discussed using kinds of measurements such as cyclic voltammetry and constant charging/discharging testing method.
The optimum Ni(OH)2 electrodeposit parameters were as the following:C(nickel nitrate)=0.5 mol·L-1, t=2 h,i=10 mA·cm-2,the reactive temperature is 30℃,V(ethanol):V(H2O)=1:1. The prepared Ni(OH)2 exhibited relatively lesser granularity, high specific surface area, eminent capacitive characteristics and excellent cycle life, the specific capacitance value was 550 F·g-1 at a discharging current of 5 mA. The structure of Ni(OH)2 prepared isβ-Ni(OH)2 by means of XRD.The super capacitance influences ofβ-Ni(OH)2 doped with other elements were also studied. http://www.999magnet.com/ The polarization of Lanthanum dopedβ-Ni(OH)2 was increased, it is advantageous to form particular films. Lanthanum existed in the crystal lattice of nickel hydroxide as ions. Nickel hydroxide electrode existed preferable capacitive characteristics and power performance after doped La,Ce,Co,Fe. With the increase of discharging current, specific capacitance appreciably decreased, and the performance of discharging at high current is also excellent.The corresponding grain size ofβ-Ni(OH)2 and La,Ce,Co,Fe dopedβ-Ni(OH)2 are respectively 15, 8, 14, 13, 10 nm calculated by Scherrer formula. Dopedβ-Ni(OH)2 electrode had better capacitive characteristics.
Super-capacitor is a new kind of energy storage devices with remarkable advantages. Electrode material is an important factor that affects the ECs performances, among these, Ni(OH)2 appears to be a promising material. Ni(OH)2 was prepared by electrodeposit method, and doped with Co,Fe,La and Ce in our work. We planned to gain Ni(OH)2 electrode material with high specific surface area, excellent electrochemical performance, and high specific capacitance.The effect of electrodeposit parameters on the structure and electrochemical characteristics of Ni(OH)2 was studied using different experimental method, such as orthogonal experiment, single factor Alnico magnets experiment and contrast analysis. The structure and appearance of Ni(OH)2 were characterized using various techniques such as scanning electron microscopy(SEM) and X-ray diffraction(XRD). The electrochemical performance of Ni(OH)2 was discussed using kinds of measurements such as cyclic voltammetry and constant charging/discharging testing method.
The optimum Ni(OH)2 electrodeposit parameters were as the following:C(nickel nitrate)=0.5 mol·L-1, t=2 h,i=10 mA·cm-2,the reactive temperature is 30℃,V(ethanol):V(H2O)=1:1. The prepared Ni(OH)2 exhibited relatively lesser granularity, high specific surface area, eminent capacitive characteristics and excellent cycle life, the specific capacitance value was 550 F·g-1 at a discharging current of 5 mA. The structure of Ni(OH)2 prepared isβ-Ni(OH)2 by means of XRD.The super capacitance influences ofβ-Ni(OH)2 doped with other elements were also studied. http://www.999magnet.com/ The polarization of Lanthanum dopedβ-Ni(OH)2 was increased, it is advantageous to form particular films. Lanthanum existed in the crystal lattice of nickel hydroxide as ions. Nickel hydroxide electrode existed preferable capacitive characteristics and power performance after doped La,Ce,Co,Fe. With the increase of discharging current, specific capacitance appreciably decreased, and the performance of discharging at high current is also excellent.The corresponding grain size ofβ-Ni(OH)2 and La,Ce,Co,Fe dopedβ-Ni(OH)2 are respectively 15, 8, 14, 13, 10 nm calculated by Scherrer formula. Dopedβ-Ni(OH)2 electrode had better capacitive characteristics.
The Preparation and Vis-photocatalytic Activity of TiO2 Nanowires by Template Assembly Technology
The Preparation and Vis-photocatalytic Activity of TiO2 Nanowires by Template Assembly Technology
According to the current problems such as low quantum efficiency and limitedavailable visible light energy spectrum range in the titania photocatalytic field, theone-dimension titania nanoarrays were prepared via sol-electrophoretic andsol-dipping method combined with template technology. A wide range of testingtechniques was applied to characterize the influences of technological parameters onthe structure, morphology and photocatalytic performance of titania nanoarrays. Aseries of doped TiO2 nanowire arrays were prepared by adding different metal ions.Using this method, the self-immobilization of the titania photocatalyst can be easilyachieved and the visible photocatalytic activity can be effectively improved.Titania nanowire arrays with shape of string of candied haws were prepared inporous anodic alumina template (PAA) via sol-electrophoresis template method. Theeffects of electrophoretic voltage, polishing technology, post-treatment method andtime, sintering temperature on the morphology and UV-photocatalytic activity ofnanowires were studied in the experiment. Segment neodymium magnets The electrophoretic voltage was the maindriving force of the sol particles to move and form nanowires. The photocatalyticactivity of nanowires reached the best at the voltage of 4V. The study showed thatsodium hydroxide solution was a better post-treatment method than the mixed acidsolution and the most appropriate post-treatment time was 5min. The sinteringtemperature could affect the crystal phase and photocatalytic activity of the titaniananowires. The photocatalytic activity was the best when the content of rutile was10%. Titania nanowire arrays with shape of rod and titania nanotube arrays wereprepared by sol-dipping template method. As for dipping method, the one-dimensionnanoarrays cannot be obtained in normal pressure condition, but the regular titaniananowires and nanotubes could be obtained in a certain negative pressure condition.
The photocatalytic activity was characterized by the photocatalytic degradation ofmethyl orange solution under UV-light. The photocatalytic activity of nanowires withshape of string of candied haws was better than that of rod-shaped nanowires.Compared with the TiO2/glass film, the titania nanowire and nanotube arrays havemuch higher photocatalytic activity.A series of doped TiO2 nanowire arrays were prepared by adding different metalions (transition-metal ions, rare earth-metal ions). The photocatalytic activity of doped nanowires (M/TiO2) was measured under the visible light. As for the transition-metalions (Fe3+, Zn2+, Cr3+, Cu2+) and rare earth-metal ions (La3+, Ce3+, Nd3+) doped titaniananowires, the best dopping content of each ion was obtained via photocatalyticdegradation of methyl orange solution under visible light. In addition, La3+/Fe3+co-doped titania nanowires were prepared and the combined action of two types ofmetal ions could further improve the http://www.999magnet.com/ visible photocatalytic activity of titaniananowires. Through comparing the vis-photocatalytic activity of different ion-dopednanowires in the two systems, the metal ion doping mechanisms to achieve thevisible-light photocatalytic activities of the TiO2 nanowires are discussed fromdifferent views of doping energy level, ion radius, electron configuration and latticedilatation. The UV-vis absorption spectrums of M/TiO2 film samples showed that theabsorption edge of the UV-Vis spectra shift into visible light region and the band gapvalues were estimated via correlated formulas. In addition, compared with theTiO2/glass film, the titania nanowire arrays had more than 3 to 8 times higher visiblephotocatalytic activity and showed excellent aging performance. As a result, thetitania nanowire arrays have tremendous application prospect and predominanceunder visible light.
According to the current problems such as low quantum efficiency and limitedavailable visible light energy spectrum range in the titania photocatalytic field, theone-dimension titania nanoarrays were prepared via sol-electrophoretic andsol-dipping method combined with template technology. A wide range of testingtechniques was applied to characterize the influences of technological parameters onthe structure, morphology and photocatalytic performance of titania nanoarrays. Aseries of doped TiO2 nanowire arrays were prepared by adding different metal ions.Using this method, the self-immobilization of the titania photocatalyst can be easilyachieved and the visible photocatalytic activity can be effectively improved.Titania nanowire arrays with shape of string of candied haws were prepared inporous anodic alumina template (PAA) via sol-electrophoresis template method. Theeffects of electrophoretic voltage, polishing technology, post-treatment method andtime, sintering temperature on the morphology and UV-photocatalytic activity ofnanowires were studied in the experiment. Segment neodymium magnets The electrophoretic voltage was the maindriving force of the sol particles to move and form nanowires. The photocatalyticactivity of nanowires reached the best at the voltage of 4V. The study showed thatsodium hydroxide solution was a better post-treatment method than the mixed acidsolution and the most appropriate post-treatment time was 5min. The sinteringtemperature could affect the crystal phase and photocatalytic activity of the titaniananowires. The photocatalytic activity was the best when the content of rutile was10%. Titania nanowire arrays with shape of rod and titania nanotube arrays wereprepared by sol-dipping template method. As for dipping method, the one-dimensionnanoarrays cannot be obtained in normal pressure condition, but the regular titaniananowires and nanotubes could be obtained in a certain negative pressure condition.
The photocatalytic activity was characterized by the photocatalytic degradation ofmethyl orange solution under UV-light. The photocatalytic activity of nanowires withshape of string of candied haws was better than that of rod-shaped nanowires.Compared with the TiO2/glass film, the titania nanowire and nanotube arrays havemuch higher photocatalytic activity.A series of doped TiO2 nanowire arrays were prepared by adding different metalions (transition-metal ions, rare earth-metal ions). The photocatalytic activity of doped nanowires (M/TiO2) was measured under the visible light. As for the transition-metalions (Fe3+, Zn2+, Cr3+, Cu2+) and rare earth-metal ions (La3+, Ce3+, Nd3+) doped titaniananowires, the best dopping content of each ion was obtained via photocatalyticdegradation of methyl orange solution under visible light. In addition, La3+/Fe3+co-doped titania nanowires were prepared and the combined action of two types ofmetal ions could further improve the http://www.999magnet.com/ visible photocatalytic activity of titaniananowires. Through comparing the vis-photocatalytic activity of different ion-dopednanowires in the two systems, the metal ion doping mechanisms to achieve thevisible-light photocatalytic activities of the TiO2 nanowires are discussed fromdifferent views of doping energy level, ion radius, electron configuration and latticedilatation. The UV-vis absorption spectrums of M/TiO2 film samples showed that theabsorption edge of the UV-Vis spectra shift into visible light region and the band gapvalues were estimated via correlated formulas. In addition, compared with theTiO2/glass film, the titania nanowire arrays had more than 3 to 8 times higher visiblephotocatalytic activity and showed excellent aging performance. As a result, thetitania nanowire arrays have tremendous application prospect and predominanceunder visible light.
The Microstructure and Spectra of a Phosphor with Wider Excitation Bands for White LEDs
The Microstructure and Spectra of a Phosphor with Wider Excitation Bands for White LEDs
White LEDs (WLEDs) has become one of the key hi-technology world Wide due to its attractive advantages of energy consumption saving, environmental and lifetime long-lasting aspects. The YAG:Ce3+ phosphor puimped with chip blue light needs innovation to improve the properties. Of these, the silicate host phosphors with UV, nUV or blue-UV lights in wider excitation wavelength range for white-emitting is one of the innovative and competitive approaches.With the aim to the problems mentioned above, we investigated a new rare earth doped silicate base Magnetic lifter phosphor. The relationship between preparation, microstructure and luminescent properties presented experimentally and theoretically in detail. The important results we obtained are described as follows:A. A spray-pyrolysis procedure was employed to prepare phase-pure rare-earth doped silicate base phosphors. The measured wavelengths of these phosphors range from 350nm to 470nm. The typical emission wavelength lies at 567nm upon exited by 470nm light.B. The relationships between microstructure and luminescent properties of these silicate base phosphors are primarily obtained. The lower energy edge location of Eu2+ ion is found to correspond to a six-coordinated number by using Uiteret formula. Furthermore, the XRD ptterns, morphologies and spectra of SrxCa2-xSiO4、SrxMg2-xSiO4 and SrxBa2-xSiO4 phosphors were also characterized.C. A series of process parameters involved in spray-pyrolysis procedure, such as composition, sintering temperature were experimentally investigated.D. The as-received http://www.999magnet.com/ phosphor particles is self-assembled, loose, submicron sized,ball-mill free powders, resulting in improving the luminescent properties.E.We evaluate the stability of these phosphors, that is, chemical stability and thermal stability respectively.F. This process offers a resource saving, environmental-friendly and scalable competition capability to prepare the phosphors.
White LEDs (WLEDs) has become one of the key hi-technology world Wide due to its attractive advantages of energy consumption saving, environmental and lifetime long-lasting aspects. The YAG:Ce3+ phosphor puimped with chip blue light needs innovation to improve the properties. Of these, the silicate host phosphors with UV, nUV or blue-UV lights in wider excitation wavelength range for white-emitting is one of the innovative and competitive approaches.With the aim to the problems mentioned above, we investigated a new rare earth doped silicate base Magnetic lifter phosphor. The relationship between preparation, microstructure and luminescent properties presented experimentally and theoretically in detail. The important results we obtained are described as follows:A. A spray-pyrolysis procedure was employed to prepare phase-pure rare-earth doped silicate base phosphors. The measured wavelengths of these phosphors range from 350nm to 470nm. The typical emission wavelength lies at 567nm upon exited by 470nm light.B. The relationships between microstructure and luminescent properties of these silicate base phosphors are primarily obtained. The lower energy edge location of Eu2+ ion is found to correspond to a six-coordinated number by using Uiteret formula. Furthermore, the XRD ptterns, morphologies and spectra of SrxCa2-xSiO4、SrxMg2-xSiO4 and SrxBa2-xSiO4 phosphors were also characterized.C. A series of process parameters involved in spray-pyrolysis procedure, such as composition, sintering temperature were experimentally investigated.D. The as-received http://www.999magnet.com/ phosphor particles is self-assembled, loose, submicron sized,ball-mill free powders, resulting in improving the luminescent properties.E.We evaluate the stability of these phosphors, that is, chemical stability and thermal stability respectively.F. This process offers a resource saving, environmental-friendly and scalable competition capability to prepare the phosphors.
2012年7月10日星期二
Study on the Carrier and the New Catalyst to Remove Kitchen Cooking Oil Fume
Study on the Carrier and the New Catalyst to Remove Kitchen Cooking Oil Fume
We use catalysts in removing the kitchen cooking fumes before it came into the atmosphere.During this process,we try to reduce the volatile organic compounds(VOCs),the particulate matter(PM)and other pollutants.It is a very useful gas purification method.The current techniques are divided into physical and chemical.The physical methods are mainly by mechanical separation,filtration,absorption,washing and electrostatic law.The chemical methods commonly use thermal oxidation and catalytic combustion.We commonly use a catalyst for platinum,palladium and rhodium combination.By use of such precious metals as the main catalyst components,we can purify the volatile organic compounds(VOCs)and the particulate matter(PM),and other pollutants at the same time.However, precious metals are expensive,their resources are very limited,for these reasons,the use Magnetic lifter of precious metal as catalyst is not realistic.China is rich in Rare Earth,the reserves of rare earth are the first in the world.It has greater potential that Rare Earth may reduce the precious metal catalyst or even completely replace the precious metal in such areas.Our experimental group aimed at developing a kin of new catalyst for kitchen fume processor.In preparation of diatomite carrier,we used diatomite as the main raw material,then added wood chips and high-temperature adhesive.We did such tests as the X-ray diffraction(XRD),porosity and density,scanning electron microscopy(SEM)and EDAX Spectrum analysis to get the character of diatomite carrier including hole density,density and crystalline phase.The results showed that the porosity of structure relates to the sintering temperature.In 950℃,quartz has not yet begun the real sintering,the non-stereotyped SiO2 changes to quartz.In 1050℃and 1100℃quartz particles begin to sintering and begin the phase transition to quartz.In 950℃diatomite particles are many tubes.and there are distributed small holes in the tube wall.
But in 1050℃and 1100℃,it is difficult to find and we see the overall network.In this paper,we also selected nickel-chromium alloy as a carrier,and did pretreatments of sandblasting,acid washing and water washing.In order to increase the surface area,we use the sol-gel method,we coated it with a layer of glass coating,and then coating the catalyst on it.We compared this method to the method of diatomite,both of them can remove more than 90 percent of the fume.But diatomite costs more little,the preparation is more simple,so it has more practical value. http://www.999magnet.com/ Finally,the simulation system was used to test the catalyst,we added benzene instead of fumes,the test results showed that the benzene ignition temperature was below 200℃.in the low-temperature zone(0-200℃),the purification of benzene increased significantly with higher temperature.In high-temperature zone(200-500℃),with temperature rise,the rate of benzene purification increased very slowly and close to 100%.We can come into conclusion that,catalyst in heated condition has good effect.The results showed that the comprehensive utilization of catalyst can effectively remove fumes from the kitchen of volatile organic compounds (VOCs)with more than 90 percent.Metal carrier is expensive,and the preparation of catalyst coating is complex.On the other hand,the diatomite supported catalyst is prior in porosity,the number of holes,simple preparation,broad source of raw materials and low prices.So it has very good value and good prospect.
We use catalysts in removing the kitchen cooking fumes before it came into the atmosphere.During this process,we try to reduce the volatile organic compounds(VOCs),the particulate matter(PM)and other pollutants.It is a very useful gas purification method.The current techniques are divided into physical and chemical.The physical methods are mainly by mechanical separation,filtration,absorption,washing and electrostatic law.The chemical methods commonly use thermal oxidation and catalytic combustion.We commonly use a catalyst for platinum,palladium and rhodium combination.By use of such precious metals as the main catalyst components,we can purify the volatile organic compounds(VOCs)and the particulate matter(PM),and other pollutants at the same time.However, precious metals are expensive,their resources are very limited,for these reasons,the use Magnetic lifter of precious metal as catalyst is not realistic.China is rich in Rare Earth,the reserves of rare earth are the first in the world.It has greater potential that Rare Earth may reduce the precious metal catalyst or even completely replace the precious metal in such areas.Our experimental group aimed at developing a kin of new catalyst for kitchen fume processor.In preparation of diatomite carrier,we used diatomite as the main raw material,then added wood chips and high-temperature adhesive.We did such tests as the X-ray diffraction(XRD),porosity and density,scanning electron microscopy(SEM)and EDAX Spectrum analysis to get the character of diatomite carrier including hole density,density and crystalline phase.The results showed that the porosity of structure relates to the sintering temperature.In 950℃,quartz has not yet begun the real sintering,the non-stereotyped SiO2 changes to quartz.In 1050℃and 1100℃quartz particles begin to sintering and begin the phase transition to quartz.In 950℃diatomite particles are many tubes.and there are distributed small holes in the tube wall.
But in 1050℃and 1100℃,it is difficult to find and we see the overall network.In this paper,we also selected nickel-chromium alloy as a carrier,and did pretreatments of sandblasting,acid washing and water washing.In order to increase the surface area,we use the sol-gel method,we coated it with a layer of glass coating,and then coating the catalyst on it.We compared this method to the method of diatomite,both of them can remove more than 90 percent of the fume.But diatomite costs more little,the preparation is more simple,so it has more practical value. http://www.999magnet.com/ Finally,the simulation system was used to test the catalyst,we added benzene instead of fumes,the test results showed that the benzene ignition temperature was below 200℃.in the low-temperature zone(0-200℃),the purification of benzene increased significantly with higher temperature.In high-temperature zone(200-500℃),with temperature rise,the rate of benzene purification increased very slowly and close to 100%.We can come into conclusion that,catalyst in heated condition has good effect.The results showed that the comprehensive utilization of catalyst can effectively remove fumes from the kitchen of volatile organic compounds (VOCs)with more than 90 percent.Metal carrier is expensive,and the preparation of catalyst coating is complex.On the other hand,the diatomite supported catalyst is prior in porosity,the number of holes,simple preparation,broad source of raw materials and low prices.So it has very good value and good prospect.
Effects of Cadmium Stress and Cadmium/cerium Interaction Impact on Physiological Function of Misgurnus Anguillicaudatus
Effects of Cadmium Stress and Cadmium/cerium Interaction Impact on Physiological Function of Misgurnus Anguillicaudatus
Loach Misgurnus anguillicaudatus was exposed to Cd at 0.025, 0.25, 2.5mg/L and Cd supplied with Ce at 0.5mg/L. Poisonous effect of Cd and interactional impact of Cd/Ce on liver tissue of loach were investigate. The antioxidant enzyme activities and lipid peroxidation of liver tissue were maeasured after exposure of Cd and Cd/Ce. DNA damage of liver cell was examined by Single Cell Gel Assay (SCGE). Chang of component and structure for liver cell of loach was measurede by foruier transform infranred spectrum (FTIR) method. Following is result.1.The superoxide dismutase(SOD), catalase(CAT), peroxidase(POD), and malonyldialdehyde(MDA) of Misgurnus anguillicaudatus liver tissue were measured after treatment with Cd and Cd+Ce. Cd at concentration of less than 0.025mg/L slightly harms antioxidant enzyme activities and lipid peroxidation of magnet lifter Misgurnus anguillicaudatus liver tissue. Long time of exposure of Cd at concentration more than 0.25mg/L could significantly inhibit antioxidant enzyme activities and seriously harm lipid peroxidation of liver tissue. Supplement with 0.5mg/L Ce3+ can alleviate the lipid peroxidation damage when Cd level is form 0.025mg/L to 0.25mg/L. When Cd concertration is more than 2.5mg/L, Supplement with 0.5mg/L
Ce3+ can provide limited alleviation.2. Liver cell DNA damage Misgurnus anguillicaudatus treated with Cd and Cd+Ce was measured by Single Cell Gel Assay. It indicates that the comet tail DNA percentage, tail length/comet head diameter, and comet tail moment with treatment at concentration form 0.025mg/L to 0.25mg/L significantly increased compared with the control group. TL/D of treatment with Cd of 3 concentrations is more than 0.6 and cell DNA damage of 3 Cd treatments is greater than level three. It is suggested that Cd stress seriously harms the DNA integrity and affects genetic stability of liver cell. It is supposed that there is a dosage dependent effect of Cd on DNA damage of Misgurnus anguillicaudatus liver cell. Supplement of 0.5mg/L Ce with Cd stress at level of 0.025 mg/L and 0.25mg/L could significantly reduce DNA damage of liver cell including comet tail http://www.999magnet.com/ DNA percentage and TL/D (both P<0.05). 0.25mg/L Cd supplied with 0.5mg/L Ce can significantly reduce comet tail moment compared with the 0.25mg/L Cd treatment(P<0.01), while supplement of 0.5mg/L Ce to 2.5mg/L Cd2+ can’t significantly reduce it(P>0.05).3. Impact on liver tissue of Misgurnus anguillicaudatus by Cd and Cd+Ce was measured by foruier transform infranred spectrum. It indicates that Cd at 0.025 mg/L and 0.25mg/L could change nucleic acid conformation and reduce the structural stability. 2.5mg/L Cd could destroy protein secondary structure and reduce spatial structure stability of membrane protein and injure function of membrane. Supplement with 0.5mg/L Ce to treatment of Cd at 0.025 mg/L and 0.25mg/L could reduce negative effect on ingredient, conformation and content of moleculars. When treatment concentration of Cd reaches 2.5mg/L,0.5mg/L Ce can collaborate to destroyed conformation of each groups and to reduced stability of nucleic acid and protein spatial structure.
Loach Misgurnus anguillicaudatus was exposed to Cd at 0.025, 0.25, 2.5mg/L and Cd supplied with Ce at 0.5mg/L. Poisonous effect of Cd and interactional impact of Cd/Ce on liver tissue of loach were investigate. The antioxidant enzyme activities and lipid peroxidation of liver tissue were maeasured after exposure of Cd and Cd/Ce. DNA damage of liver cell was examined by Single Cell Gel Assay (SCGE). Chang of component and structure for liver cell of loach was measurede by foruier transform infranred spectrum (FTIR) method. Following is result.1.The superoxide dismutase(SOD), catalase(CAT), peroxidase(POD), and malonyldialdehyde(MDA) of Misgurnus anguillicaudatus liver tissue were measured after treatment with Cd and Cd+Ce. Cd at concentration of less than 0.025mg/L slightly harms antioxidant enzyme activities and lipid peroxidation of magnet lifter Misgurnus anguillicaudatus liver tissue. Long time of exposure of Cd at concentration more than 0.25mg/L could significantly inhibit antioxidant enzyme activities and seriously harm lipid peroxidation of liver tissue. Supplement with 0.5mg/L Ce3+ can alleviate the lipid peroxidation damage when Cd level is form 0.025mg/L to 0.25mg/L. When Cd concertration is more than 2.5mg/L, Supplement with 0.5mg/L
Ce3+ can provide limited alleviation.2. Liver cell DNA damage Misgurnus anguillicaudatus treated with Cd and Cd+Ce was measured by Single Cell Gel Assay. It indicates that the comet tail DNA percentage, tail length/comet head diameter, and comet tail moment with treatment at concentration form 0.025mg/L to 0.25mg/L significantly increased compared with the control group. TL/D of treatment with Cd of 3 concentrations is more than 0.6 and cell DNA damage of 3 Cd treatments is greater than level three. It is suggested that Cd stress seriously harms the DNA integrity and affects genetic stability of liver cell. It is supposed that there is a dosage dependent effect of Cd on DNA damage of Misgurnus anguillicaudatus liver cell. Supplement of 0.5mg/L Ce with Cd stress at level of 0.025 mg/L and 0.25mg/L could significantly reduce DNA damage of liver cell including comet tail http://www.999magnet.com/ DNA percentage and TL/D (both P<0.05). 0.25mg/L Cd supplied with 0.5mg/L Ce can significantly reduce comet tail moment compared with the 0.25mg/L Cd treatment(P<0.01), while supplement of 0.5mg/L Ce to 2.5mg/L Cd2+ can’t significantly reduce it(P>0.05).3. Impact on liver tissue of Misgurnus anguillicaudatus by Cd and Cd+Ce was measured by foruier transform infranred spectrum. It indicates that Cd at 0.025 mg/L and 0.25mg/L could change nucleic acid conformation and reduce the structural stability. 2.5mg/L Cd could destroy protein secondary structure and reduce spatial structure stability of membrane protein and injure function of membrane. Supplement with 0.5mg/L Ce to treatment of Cd at 0.025 mg/L and 0.25mg/L could reduce negative effect on ingredient, conformation and content of moleculars. When treatment concentration of Cd reaches 2.5mg/L,0.5mg/L Ce can collaborate to destroyed conformation of each groups and to reduced stability of nucleic acid and protein spatial structure.
Metallogenic Mechanism and Ore Forecasting of Huaixi Copper-gold Deposit, Pingyang Country, Zhejiang Province
Metallogenic Mechanism and Ore Forecasting of Huaixi Copper-gold Deposit, Pingyang Country, Zhejiang Province
The Huaixi copper-gold deposit,a hydrothermal vein filling-metasomatic type,is situated in Shanmen volcanic bottomland in Pingyan county,southeast depression of Zhejiang.Volcanic rocks occurred widely in the bottomland,which range from Late Jurassic to Early Cretaceous in Mesozoic.Host strata of ore-bodies are the Early Cretaceous Chaochuan Formation.27 Late Yanshanian intrsuions of quartz-diorite,K-feldspar granite and granite-porphyry have been identified and were controlled by NE basic structure.Volcanic apparatus and NW faults are prevalent in this area.Intersection parts of the former and locations of later faults crosscutting the former control the distribution of deposits.Attitude and shape of ore-bodies are consistent with the NW faulsts.Over 37 neodymium rare earth magnets mineral deposits have been investigated in studying area,including 11 mineral types of gold,silver,copper,lead,zinc,pyrite,alunite and pyrophyllite.The first(K1c1)and second(K1c2-1)segment of Chaochuan Formation outcropped broadly in the district and belong to continental intermediate-felsic and felsic volcanic lava,and volcaniclastic rock interbeding with minor sedimentary rocks.Faults are dominated by NW direction with subordinate NE,NNE NNW and NS ones.Intrusions are chiefly composed of quartz-diorite,K-feldspar granite-porphyry,with minor porphyritic alkali-feldspar granite and diabase dike.Lode ore bodies are controlled by the NW faults,and their occurrences are consistent with these faults.Gold mineralization upper and copper lower is obvious.Ore minerals are mainly consisted of chalcopyrite,galena,sphalerite,with minor native gold,jamesonit and chalcocite.Gangue minerals are quartz,pyrite,calcite,chlorite,epidotes.
Ore textures mainly have granular-euhedral pyrite,metasomatic,poikilitic ore texture.Wall alterations develop silicification,chloritization,ericitization,epidotization and argillation.Mineralization is divided into 4 phases in 2 stages.The first stage endogenetic stage is with 3 mineralization phases,while the second one is epidiagenetic stage.The quartz-diorite is characterized of high-K calc-alkaline metaluminous granite,and its CIPW standard minerals have high contents of diopside and magnetite,indicating a feature ofⅠ-type granite.The intrusion is enriched in LREE,Rb,Th,U,Pb,depleted in Nb,Ta,Ti and HREE and has the characteristics of syncollision granites.These results suggest the quartz-diorite intruded at the process of the collisional orogeny.K-feldspar granite porphyry is featured by calc-alkaline peraluminous granite with high kalium.It is depleted in Ca and Mg while enriched in Na,K,and high field strength elements(HFSE)such as Th,Ta,Hf.This porphyry exhibits features of A2-type granite and intruded at the end stage of the collisional orogeny.The consistent trace elements and rare elements distribution patterns,and similar Pb isotopic compositions between these rocks,indicate that both http://www.chinamagnets.biz/ of them came from a same deep source and were productions of comagmatic evolution of the same origin at different stages.The homogeneous temperature of fluid inclusions in quartz mostly clustered between 380-410℃,320-360℃and 230-300℃three interzones.Freezing point is from -6.8 to -8.2℃and salinity varies from 10.2 to 11.9ω(NaCl)%.The sphalerite fluid inclusions’ homogeneous temperature is 230-271℃,freezing point from -8.3 to -8.9℃and salinity between 12.0 and 12.7ω(NaCl)%.These suggest that metallogenic fluid is low-middle salinity.Based on detail estimation and calculation,the density of mineralization fluid is 0.68-0.91g/cm3 and depth is 0.51-1.67 km,indicating a supergene condition.Fractionation between LREE and HREE in quartz increase from 2.96 to 10.39.Hydrogen and oxygen isotopic compositions of quartz’s fluid inclusions are thatδD= -53.60‰tO -68.50‰andδ18OH2O=-6.88‰to -8.55‰,which located between the magmatic water and regional Mesozoic meteoric water(δD=-65‰,δ18O=-9.4‰)in the southeasten Zhejiang Province, indicating that ore-forming fluid was derived from mixing source of magmatic and meteoric. Eight pyrites’ sulfur isotopic compositions are from -2.14‰to +4.14‰,with mean of +1.67‰and range of 6.28‰.δ34S values of galena and sphalerite are 2.3‰and 2.2‰respectively,δ34S values of sulpur minerals are close to those of aerolite and granite,showing the sulfur of Huaixi copper-gold deposit from the deep magma.Value of initial Sr(Isr)of 5 quartzs’ fluid inclusions samples is 0.70938,which is similar with those of fluorite and calcite(0.70971 and 0.70927)and more than the upper mantle(0.702-0.706).However,it is close to the continental crust(0.710), indicating that metallogenic materials are dominantly from continental crust.Similar Pb isotopic compositions between ore sulfides and whole-rock intrusive rocks,which are all around the extended line of upper crust and orogenic belt,indicate the diagenetic and metallogenic materials are affinitative and dominantly from continental crust,probably inputted with some mantlederived materials.Cations in fluid inclusions are dominated by Ca2+,Na+ and K+ with minor Mg2+,
while anions are chiefly composed of HCO3- with subordinate Cl- and SO42-and minor F-.pH values of fluids are weak acid to approximately neutral.Copper and gold are transported in ore-forming fluids as chloride complex and sulfide complex respectively.Due to meteoric water inputting, fluid cooling and Cl- concentration deceasing result in the main mechanism of copper precipitation.Along with ore-bearing fluids ascending through fractures,water-rock interaction, Fe2+,Zn2+and Pb2+precipitation,and pH、fO2 and total sulfur concentration decreasing,involve in Au sulfide complex being destroyed and Au precipitated.The diagenesis age of quartz-diorite is 110Ma,and LA-ICPMS zircon U-Pb age of K-feldspar granite porphyry is(101.57±0.86)Ma(MSDW=1.3).Five quartz fluid inclusions samples yield a perfect Rb-Sr isochrone age of(101±1)Ma with ISr=0.70938±0.00001, repesenting the mineralization age.The similar diagenesis and minerogenetic ages suggest the genetic relationship between them.The tectonic setting of Huai-xi Cu-Au deposit is related to subduction of Pacific Ocean plate to Asia continent.During110-100Ma the dominant stress direction was SN lightly leaning to west,the syn-collisional granitoids and the compresso-twist faults of NE and NW occured.While 100Ma±the tectonic stress fields exchanged to extension, Caomen K-feldspar granite porphyry and other A2-type granites formed. http://www.chinamagnets.biz/ The intrusion of granitoids supply the metallogenic fluid and materials,which filled in NW faults to form ore-bodiesBased on comprehensive investigations of ore-body geology,mineralization mechanism and controlling factors,the metallogenic model and ore-body occurrence model of Huaixi Cu-Au deposit were established.With the help of geophysical exploring information,rock fracture geochemistry,primary halo and statistical character,granularity-thermoelectric properties-trace elements geochemistry of pyrites,six forecast targets in the deposit are pointed finally.
The Huaixi copper-gold deposit,a hydrothermal vein filling-metasomatic type,is situated in Shanmen volcanic bottomland in Pingyan county,southeast depression of Zhejiang.Volcanic rocks occurred widely in the bottomland,which range from Late Jurassic to Early Cretaceous in Mesozoic.Host strata of ore-bodies are the Early Cretaceous Chaochuan Formation.27 Late Yanshanian intrsuions of quartz-diorite,K-feldspar granite and granite-porphyry have been identified and were controlled by NE basic structure.Volcanic apparatus and NW faults are prevalent in this area.Intersection parts of the former and locations of later faults crosscutting the former control the distribution of deposits.Attitude and shape of ore-bodies are consistent with the NW faulsts.Over 37 neodymium rare earth magnets mineral deposits have been investigated in studying area,including 11 mineral types of gold,silver,copper,lead,zinc,pyrite,alunite and pyrophyllite.The first(K1c1)and second(K1c2-1)segment of Chaochuan Formation outcropped broadly in the district and belong to continental intermediate-felsic and felsic volcanic lava,and volcaniclastic rock interbeding with minor sedimentary rocks.Faults are dominated by NW direction with subordinate NE,NNE NNW and NS ones.Intrusions are chiefly composed of quartz-diorite,K-feldspar granite-porphyry,with minor porphyritic alkali-feldspar granite and diabase dike.Lode ore bodies are controlled by the NW faults,and their occurrences are consistent with these faults.Gold mineralization upper and copper lower is obvious.Ore minerals are mainly consisted of chalcopyrite,galena,sphalerite,with minor native gold,jamesonit and chalcocite.Gangue minerals are quartz,pyrite,calcite,chlorite,epidotes.
Ore textures mainly have granular-euhedral pyrite,metasomatic,poikilitic ore texture.Wall alterations develop silicification,chloritization,ericitization,epidotization and argillation.Mineralization is divided into 4 phases in 2 stages.The first stage endogenetic stage is with 3 mineralization phases,while the second one is epidiagenetic stage.The quartz-diorite is characterized of high-K calc-alkaline metaluminous granite,and its CIPW standard minerals have high contents of diopside and magnetite,indicating a feature ofⅠ-type granite.The intrusion is enriched in LREE,Rb,Th,U,Pb,depleted in Nb,Ta,Ti and HREE and has the characteristics of syncollision granites.These results suggest the quartz-diorite intruded at the process of the collisional orogeny.K-feldspar granite porphyry is featured by calc-alkaline peraluminous granite with high kalium.It is depleted in Ca and Mg while enriched in Na,K,and high field strength elements(HFSE)such as Th,Ta,Hf.This porphyry exhibits features of A2-type granite and intruded at the end stage of the collisional orogeny.The consistent trace elements and rare elements distribution patterns,and similar Pb isotopic compositions between these rocks,indicate that both http://www.chinamagnets.biz/ of them came from a same deep source and were productions of comagmatic evolution of the same origin at different stages.The homogeneous temperature of fluid inclusions in quartz mostly clustered between 380-410℃,320-360℃and 230-300℃three interzones.Freezing point is from -6.8 to -8.2℃and salinity varies from 10.2 to 11.9ω(NaCl)%.The sphalerite fluid inclusions’ homogeneous temperature is 230-271℃,freezing point from -8.3 to -8.9℃and salinity between 12.0 and 12.7ω(NaCl)%.These suggest that metallogenic fluid is low-middle salinity.Based on detail estimation and calculation,the density of mineralization fluid is 0.68-0.91g/cm3 and depth is 0.51-1.67 km,indicating a supergene condition.Fractionation between LREE and HREE in quartz increase from 2.96 to 10.39.Hydrogen and oxygen isotopic compositions of quartz’s fluid inclusions are thatδD= -53.60‰tO -68.50‰andδ18OH2O=-6.88‰to -8.55‰,which located between the magmatic water and regional Mesozoic meteoric water(δD=-65‰,δ18O=-9.4‰)in the southeasten Zhejiang Province, indicating that ore-forming fluid was derived from mixing source of magmatic and meteoric. Eight pyrites’ sulfur isotopic compositions are from -2.14‰to +4.14‰,with mean of +1.67‰and range of 6.28‰.δ34S values of galena and sphalerite are 2.3‰and 2.2‰respectively,δ34S values of sulpur minerals are close to those of aerolite and granite,showing the sulfur of Huaixi copper-gold deposit from the deep magma.Value of initial Sr(Isr)of 5 quartzs’ fluid inclusions samples is 0.70938,which is similar with those of fluorite and calcite(0.70971 and 0.70927)and more than the upper mantle(0.702-0.706).However,it is close to the continental crust(0.710), indicating that metallogenic materials are dominantly from continental crust.Similar Pb isotopic compositions between ore sulfides and whole-rock intrusive rocks,which are all around the extended line of upper crust and orogenic belt,indicate the diagenetic and metallogenic materials are affinitative and dominantly from continental crust,probably inputted with some mantlederived materials.Cations in fluid inclusions are dominated by Ca2+,Na+ and K+ with minor Mg2+,
while anions are chiefly composed of HCO3- with subordinate Cl- and SO42-and minor F-.pH values of fluids are weak acid to approximately neutral.Copper and gold are transported in ore-forming fluids as chloride complex and sulfide complex respectively.Due to meteoric water inputting, fluid cooling and Cl- concentration deceasing result in the main mechanism of copper precipitation.Along with ore-bearing fluids ascending through fractures,water-rock interaction, Fe2+,Zn2+and Pb2+precipitation,and pH、fO2 and total sulfur concentration decreasing,involve in Au sulfide complex being destroyed and Au precipitated.The diagenesis age of quartz-diorite is 110Ma,and LA-ICPMS zircon U-Pb age of K-feldspar granite porphyry is(101.57±0.86)Ma(MSDW=1.3).Five quartz fluid inclusions samples yield a perfect Rb-Sr isochrone age of(101±1)Ma with ISr=0.70938±0.00001, repesenting the mineralization age.The similar diagenesis and minerogenetic ages suggest the genetic relationship between them.The tectonic setting of Huai-xi Cu-Au deposit is related to subduction of Pacific Ocean plate to Asia continent.During110-100Ma the dominant stress direction was SN lightly leaning to west,the syn-collisional granitoids and the compresso-twist faults of NE and NW occured.While 100Ma±the tectonic stress fields exchanged to extension, Caomen K-feldspar granite porphyry and other A2-type granites formed. http://www.chinamagnets.biz/ The intrusion of granitoids supply the metallogenic fluid and materials,which filled in NW faults to form ore-bodiesBased on comprehensive investigations of ore-body geology,mineralization mechanism and controlling factors,the metallogenic model and ore-body occurrence model of Huaixi Cu-Au deposit were established.With the help of geophysical exploring information,rock fracture geochemistry,primary halo and statistical character,granularity-thermoelectric properties-trace elements geochemistry of pyrites,six forecast targets in the deposit are pointed finally.
Research on Doping Modification of BT/BST Series Capacitor Ceramics
Research on Doping Modification of BT/BST Series Capacitor Ceramics
BT(BaTiO3)/BST((BaSr)TiO3) ceramics have been becoming one of the highlights in the research on functional materials and devices for their potential applications in many fields. Most important of all is the combination of BT/BST ceramics with semiconductor integrated technique, and according to their effects of ferroelectric, piezoelectric, thermoelectric, dielectric, electro-optic and non-linear optical to realize their functions in signal memory, transition, modulation, switch, sensor and et al. For the limitation of sintering temperature and temperature stability have affected the properties of BT/BST ceramics and the practical applies in industries, in this dissertation, doped impurity to modify the properties and strcture of BT/BST have been presented. The main work is as the follows:1. The influence of the dopant BaSiO3 on the dielectric properties for BT ceramic capacitors has been discussed. It is found that doping BaSiO3 can improve the sintering and microstructure of the strong magnets capacitor ceramics. The results showed that the dielectric properties of doped BaSiO3 with 3mol% are as follows:εr=1792, tanδ=0.01,ρ= 6.1×1011Ω·cm,Eb=3.5 kV·mm-1,△C/C=18.0%(20～150℃),△C/C=-23.1%(-55～5℃), and the sintering temperature had decreased 40℃. SEM studies showed that doping BaSiO3 can suppress the grain to grow up for exception, and the structure of ceramic is compact with little pore. And XRD studies showed that there are a little SiO2 phases.2. The influence of doping rare-earth metal on the dielectric properties of BT series ceramic has been investigated by means of orthogonal design experiments. The major and secondary influencing factors and the influencing tendency of various factors’ levels for the dielectric properties of this ceramics have been obtained. The optimally compounding is BT+1%CeO2+1%Dy2O3+0.9%Y2O3+0.9%Yb2O3 (mole fraction) for dielectric constant and BT+1.5%CeO2+1.5%Dy2O3+0.6%Y2O3+0.6%Yb2O3 (mole fraction) for dielectric loss. The performance of the former ceramic which was sintering at 1280℃for 60 minutes isεr=6911, tanδ=0.0124; and the latter isεr=3800, tanδ= 0.0012.
The optimiallyρ=7.8×1011Ω·cm of 3 sample and the optimially Eb=8.2 kV·mm-1 of 8 sample,△C/C= 61.8% (20～80℃)of 5 sample. Studied by SEM found that the grain size small and uniform when the samples had high dielectric properties, and the crystal grains ranged compaction with little pore when the samples had low dielectric loss. SEM studies showed that the samples all formed perovskite structure (ABO3), but there were some SiO2 phases at about 2θ=29°.3. The influence of the doping Bi4Ti3O12 on the dielectric properties and sintering temperature for (Ba0.71Sr0.29TiO3 (BST) ceramic capacitors has been discussed. It is found that http://www.chinamagnets.biz/ when w(Bi4Ti3O12)=10%, the dielectric properties are as follows:εr=2558, tanδ=0.0050,△C/C=-39.2%(20～150℃),△C/C=12.21%(-55～5℃), and the sintering temperature decreased to 1180℃, when w(Bi4Ti3O12)=8%,ρ=6.2×1011Ω·cm, Eb=7.4 kV·mm-1 which are the maximal value; when w(Bi4Ti3O12)=50%, the dielectric properties are as follows:εr=1045, tanδ=0.0040,△C/C =-13.2%(20～150℃),△C/C= 1.22%(-55～5℃),ρ=1.24×1011Ω·cm, Eb=4.7kV·mm-1, and the sintering temperature decreased to 1090℃.The change of C and tanδof BST ceramic capacitors followed frequency became small when doping Bi4Ti3O12 in BST ceramic. But when vv(Bi4Ti3O12)≥10wt%, the effect was small for C. Doping high content of Bi4Ti3O12 can make the curve of tanδ-f flater. The influence of various Bi4Ti3O12 additive amounts on microstructure and phases compositions of BST ceramics http://www.chinamagnets.biz/ were studied by SEM and XRD. The result shows that Bi4Ti3O12 additives influence the properties and microstructure of BST ceramics by means of forming defect solid solution, strong segregation in crystal boundary, suppress the grain’s growth and fine crystal grains. But when w(Bi4Ti3O12)≥46wt %, there appeared banding Bi in the microstructure, and the diffracting intensity of main phases became larger, the crystal grains began bigger, the doping Bi4Ti3O12 can’t fine crystal grains go on.
BT(BaTiO3)/BST((BaSr)TiO3) ceramics have been becoming one of the highlights in the research on functional materials and devices for their potential applications in many fields. Most important of all is the combination of BT/BST ceramics with semiconductor integrated technique, and according to their effects of ferroelectric, piezoelectric, thermoelectric, dielectric, electro-optic and non-linear optical to realize their functions in signal memory, transition, modulation, switch, sensor and et al. For the limitation of sintering temperature and temperature stability have affected the properties of BT/BST ceramics and the practical applies in industries, in this dissertation, doped impurity to modify the properties and strcture of BT/BST have been presented. The main work is as the follows:1. The influence of the dopant BaSiO3 on the dielectric properties for BT ceramic capacitors has been discussed. It is found that doping BaSiO3 can improve the sintering and microstructure of the strong magnets capacitor ceramics. The results showed that the dielectric properties of doped BaSiO3 with 3mol% are as follows:εr=1792, tanδ=0.01,ρ= 6.1×1011Ω·cm,Eb=3.5 kV·mm-1,△C/C=18.0%(20～150℃),△C/C=-23.1%(-55～5℃), and the sintering temperature had decreased 40℃. SEM studies showed that doping BaSiO3 can suppress the grain to grow up for exception, and the structure of ceramic is compact with little pore. And XRD studies showed that there are a little SiO2 phases.2. The influence of doping rare-earth metal on the dielectric properties of BT series ceramic has been investigated by means of orthogonal design experiments. The major and secondary influencing factors and the influencing tendency of various factors’ levels for the dielectric properties of this ceramics have been obtained. The optimally compounding is BT+1%CeO2+1%Dy2O3+0.9%Y2O3+0.9%Yb2O3 (mole fraction) for dielectric constant and BT+1.5%CeO2+1.5%Dy2O3+0.6%Y2O3+0.6%Yb2O3 (mole fraction) for dielectric loss. The performance of the former ceramic which was sintering at 1280℃for 60 minutes isεr=6911, tanδ=0.0124; and the latter isεr=3800, tanδ= 0.0012.
The optimiallyρ=7.8×1011Ω·cm of 3 sample and the optimially Eb=8.2 kV·mm-1 of 8 sample,△C/C= 61.8% (20～80℃)of 5 sample. Studied by SEM found that the grain size small and uniform when the samples had high dielectric properties, and the crystal grains ranged compaction with little pore when the samples had low dielectric loss. SEM studies showed that the samples all formed perovskite structure (ABO3), but there were some SiO2 phases at about 2θ=29°.3. The influence of the doping Bi4Ti3O12 on the dielectric properties and sintering temperature for (Ba0.71Sr0.29TiO3 (BST) ceramic capacitors has been discussed. It is found that http://www.chinamagnets.biz/ when w(Bi4Ti3O12)=10%, the dielectric properties are as follows:εr=2558, tanδ=0.0050,△C/C=-39.2%(20～150℃),△C/C=12.21%(-55～5℃), and the sintering temperature decreased to 1180℃, when w(Bi4Ti3O12)=8%,ρ=6.2×1011Ω·cm, Eb=7.4 kV·mm-1 which are the maximal value; when w(Bi4Ti3O12)=50%, the dielectric properties are as follows:εr=1045, tanδ=0.0040,△C/C =-13.2%(20～150℃),△C/C= 1.22%(-55～5℃),ρ=1.24×1011Ω·cm, Eb=4.7kV·mm-1, and the sintering temperature decreased to 1090℃.The change of C and tanδof BST ceramic capacitors followed frequency became small when doping Bi4Ti3O12 in BST ceramic. But when vv(Bi4Ti3O12)≥10wt%, the effect was small for C. Doping high content of Bi4Ti3O12 can make the curve of tanδ-f flater. The influence of various Bi4Ti3O12 additive amounts on microstructure and phases compositions of BST ceramics http://www.chinamagnets.biz/ were studied by SEM and XRD. The result shows that Bi4Ti3O12 additives influence the properties and microstructure of BST ceramics by means of forming defect solid solution, strong segregation in crystal boundary, suppress the grain’s growth and fine crystal grains. But when w(Bi4Ti3O12)≥46wt %, there appeared banding Bi in the microstructure, and the diffracting intensity of main phases became larger, the crystal grains began bigger, the doping Bi4Ti3O12 can’t fine crystal grains go on.
Hydrogen Permeation Behavior and Embrittlement of Hot-dip Coated Steels Exposed to Seawater
Hydrogen Permeation Behavior and Embrittlement of Hot-dip Coated Steels Exposed to Seawater
The security of hot-dip coated steels was imperiled by the synergy of hydrogen permeation and stress in marine environment. In this thesis, three kinds of hot-dip coated steels (Galvanized, Galfan and Galvalume) were used as investigative object. Self hydrogen permeation curves of three hot-dip coated steels were measured using a Devanathan-Stachurski bipolar cell. The effect of the ratio of the area of the exposed steel substrate versus coating surface was investigated. Hydrogen permeation resistance and self hydrogen permeablity when defect existed were compared among three materials. Also, the hydrogen permeation mechanism was analyzed rare earth magnets combined with these coatings’chemical composition and structure and their corrosion mechanism in seawater.
The stress-strain curves of these materials with different hydrogen charging conditions were obtained by SSRT, and their mechanical properties was compared. Fractography were also carried out to investigate the effect of hydrogen permeation on the mechanical properties of steel substrate. The results showed that:(1) Hydrogen permeation resistance of Galvanized coating is the lowest, and that of Galfan coating is higher. And when these two kinds of coating have defect, hydrogen absorption and permeation were accelerated. On the contrary, Galvalume coating showed excellent hydrogen permeation resistance, and showed almost no self hydrogen permeation even with defect. Hydrogen permeation flux decreased with the ratio of the area of the exposed steel substrate versus coating surface. With the higher content of aluminum and compacter structure and better corrosion resistance, the coating showed better hydrogen permeation resistance and less self hydrogen permeability. http://www.chinamagnets.biz/ (2) Self hydrogen permeation of Galvanized and Galfan coating in seawater reduced their percentage elongation after fracture and density energy and shift their fracture characteristics from ductile to quasicleavage. The percentage elongation after fracture and density energy of Galvalume coating were also reduced and its fracture characteristics was shift from ductile to locally quasicleavage. With longer hydrogen charging time, the materials showed higher susceptibility to hydrogen embrittlement. With higher content of aluminum and better corrosion resistance, the coating showed lower susceptibility to hydrogen embrittlement in seawater.
The security of hot-dip coated steels was imperiled by the synergy of hydrogen permeation and stress in marine environment. In this thesis, three kinds of hot-dip coated steels (Galvanized, Galfan and Galvalume) were used as investigative object. Self hydrogen permeation curves of three hot-dip coated steels were measured using a Devanathan-Stachurski bipolar cell. The effect of the ratio of the area of the exposed steel substrate versus coating surface was investigated. Hydrogen permeation resistance and self hydrogen permeablity when defect existed were compared among three materials. Also, the hydrogen permeation mechanism was analyzed rare earth magnets combined with these coatings’chemical composition and structure and their corrosion mechanism in seawater.
The stress-strain curves of these materials with different hydrogen charging conditions were obtained by SSRT, and their mechanical properties was compared. Fractography were also carried out to investigate the effect of hydrogen permeation on the mechanical properties of steel substrate. The results showed that:(1) Hydrogen permeation resistance of Galvanized coating is the lowest, and that of Galfan coating is higher. And when these two kinds of coating have defect, hydrogen absorption and permeation were accelerated. On the contrary, Galvalume coating showed excellent hydrogen permeation resistance, and showed almost no self hydrogen permeation even with defect. Hydrogen permeation flux decreased with the ratio of the area of the exposed steel substrate versus coating surface. With the higher content of aluminum and compacter structure and better corrosion resistance, the coating showed better hydrogen permeation resistance and less self hydrogen permeability. http://www.chinamagnets.biz/ (2) Self hydrogen permeation of Galvanized and Galfan coating in seawater reduced their percentage elongation after fracture and density energy and shift their fracture characteristics from ductile to quasicleavage. The percentage elongation after fracture and density energy of Galvalume coating were also reduced and its fracture characteristics was shift from ductile to locally quasicleavage. With longer hydrogen charging time, the materials showed higher susceptibility to hydrogen embrittlement. With higher content of aluminum and better corrosion resistance, the coating showed lower susceptibility to hydrogen embrittlement in seawater.
化学成分对AerMet100钢组织和性能的影响
化学成分对AerMet100钢组织和性能的影响
This paper shows the results of research on the microstructure and mechanical properties due to adding RE and the different content of composition of AerMetlOO, known as the secondary hardening ultra-high strength steel. In this study, the mechanical properties were test. In additional, the microstructure of the alloy was analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).Through research found that the influence of carbon content is remarkable to the mechanical properties of experimental steel. With the increase of carbon content the strength and hardness of experimental steel gradually improved and the Segment neodymium magnet impact toughness and fracture toughness gradually decreased. Some quasi-cleavage morphologies appear in impact fracture with the increase of the carbon content in the experimental steel, while the aging peak increase gradually, but its position unchangeable.With the increase of chromium content the strength and toughness of steel did not change significantly and the age-hardening peak shifts to lower temperature. With the aging temperature increased the high-chromium steel strength decline faster. The increase of chromium content cause faster over-aging.
The chromium addition makes cementite unstable, which promotes the M2C carbides formed and increases the rate of over-aging in the materials.With the increase of molybdenum content the strength and hardness of steel gradually improved, but the toughness gradually decreased, quasi-cleavage morphologies increase. Increasing the molybdenum content of the alloy would be increase the driving force for M2C precipitation, and increase the peak hardness, while reverted austenite reduced, therefore reducing the plasticity and toughness of the steel.The influence of cobalt is relatively remarkable to the mechanical properties of experimental steel. With the increase of cobalt content the strength and hardness of steel gradually improved, while the toughness decreased, and quasi-cleavage morphologies increase in impact fracture. The cobalt addition promotes austenite http://www.chinamagnets.biz/ change to martensite and the formation of the M2C carbides. Thus the strength of steel increase, toughness reduces with the increase of cobalt content.With the increase of nickel content the toughness of steel gradually raised, dimples increase, quasi-cleavage reduces. The aging curve of strength shifts to lower temperature with the nickel content increase. That is, the nickel increases result in earlier over-aging in experimental steel. The nickel addition promotes the dissolution of M3C cementite and thus makes fine M2C carbides formed at lower temperatures.The addition of RE causes the inclusion modification, formed the round or oval-shaped RE inclusion. And it has changed the distribution of inclusions, makes mean spacing of inclusions increases. Therefore the toughness of steel will be improved.
This paper shows the results of research on the microstructure and mechanical properties due to adding RE and the different content of composition of AerMetlOO, known as the secondary hardening ultra-high strength steel. In this study, the mechanical properties were test. In additional, the microstructure of the alloy was analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).Through research found that the influence of carbon content is remarkable to the mechanical properties of experimental steel. With the increase of carbon content the strength and hardness of experimental steel gradually improved and the Segment neodymium magnet impact toughness and fracture toughness gradually decreased. Some quasi-cleavage morphologies appear in impact fracture with the increase of the carbon content in the experimental steel, while the aging peak increase gradually, but its position unchangeable.With the increase of chromium content the strength and toughness of steel did not change significantly and the age-hardening peak shifts to lower temperature. With the aging temperature increased the high-chromium steel strength decline faster. The increase of chromium content cause faster over-aging.
The chromium addition makes cementite unstable, which promotes the M2C carbides formed and increases the rate of over-aging in the materials.With the increase of molybdenum content the strength and hardness of steel gradually improved, but the toughness gradually decreased, quasi-cleavage morphologies increase. Increasing the molybdenum content of the alloy would be increase the driving force for M2C precipitation, and increase the peak hardness, while reverted austenite reduced, therefore reducing the plasticity and toughness of the steel.The influence of cobalt is relatively remarkable to the mechanical properties of experimental steel. With the increase of cobalt content the strength and hardness of steel gradually improved, while the toughness decreased, and quasi-cleavage morphologies increase in impact fracture. The cobalt addition promotes austenite http://www.chinamagnets.biz/ change to martensite and the formation of the M2C carbides. Thus the strength of steel increase, toughness reduces with the increase of cobalt content.With the increase of nickel content the toughness of steel gradually raised, dimples increase, quasi-cleavage reduces. The aging curve of strength shifts to lower temperature with the nickel content increase. That is, the nickel increases result in earlier over-aging in experimental steel. The nickel addition promotes the dissolution of M3C cementite and thus makes fine M2C carbides formed at lower temperatures.The addition of RE causes the inclusion modification, formed the round or oval-shaped RE inclusion. And it has changed the distribution of inclusions, makes mean spacing of inclusions increases. Therefore the toughness of steel will be improved.
2012年7月6日星期五
Synthesis of NdB6 and Fabrication Technique of in Situ (TiB+TiC+Nd2O3)/Ti Composites by Powder Metallurgy
Synthesis of NdB6 and Fabrication Technique of in Situ (TiB+TiC+Nd2O3)/Ti Composites by Powder Metallurgy
Recently, titanium matrix composites (TMCs) attracted more and more attention and are considered technically superior and cost-effective owning to their high strength and elastic module compared to their weight, especially their good mechanical properties at elevated temperature and wide potential application in the field of aviation and aerospace. A novel method to prepare particulate-reinforced TMCs has been developed—in situ technology where the reinforcements Block Neodymium magnets are synthesized in metallic matrices by chemical reactions between elements or between elements and compound during the fabrication, which eliminates the incompatibility on interface between matrix and reinforcement based on their nucleation and growth from parent matrix phase. Compared to conventional TMCs, in situ method has attracted much more attention due to their ease of fabrication and low cost as well as high mechanical properties.For developing particulate reinforced TMCs, it’s very important to use compatible reinforcements. Many reinforcements are used in TMCs, including SiC, Al2O3, TiC, TiB, TiB2 and rare earth oxide. In this paper, NdB6 and B4C were chosen to be raw materials to structure the reinforcements. However, we were facing another question, where http://www.999magnet.com/ could we get the pure NdB6 which was not available in Chinese market. After do a large amount of studies on the production of NdB6 and YB6 powder, the decision of synthesizing NdB6 powder by ourselves was finally made. The main results of this paper can be described as follow:1. After a series of pretreatments, NdB6 powders are fabricated from 说
Recently, titanium matrix composites (TMCs) attracted more and more attention and are considered technically superior and cost-effective owning to their high strength and elastic module compared to their weight, especially their good mechanical properties at elevated temperature and wide potential application in the field of aviation and aerospace. A novel method to prepare particulate-reinforced TMCs has been developed—in situ technology where the reinforcements Block Neodymium magnets are synthesized in metallic matrices by chemical reactions between elements or between elements and compound during the fabrication, which eliminates the incompatibility on interface between matrix and reinforcement based on their nucleation and growth from parent matrix phase. Compared to conventional TMCs, in situ method has attracted much more attention due to their ease of fabrication and low cost as well as high mechanical properties.For developing particulate reinforced TMCs, it’s very important to use compatible reinforcements. Many reinforcements are used in TMCs, including SiC, Al2O3, TiC, TiB, TiB2 and rare earth oxide. In this paper, NdB6 and B4C were chosen to be raw materials to structure the reinforcements. However, we were facing another question, where http://www.999magnet.com/ could we get the pure NdB6 which was not available in Chinese market. After do a large amount of studies on the production of NdB6 and YB6 powder, the decision of synthesizing NdB6 powder by ourselves was finally made. The main results of this paper can be described as follow:1. After a series of pretreatments, NdB6 powders are fabricated from 说
Synthesis and Characterization of New Nano-luminescent Labels Used in Immunoassay
Synthesis and Characterization of New Nano-luminescent Labels Used in Immunoassay
This paper aims at controllable preparation technology, characterization technology, and biomarker technology of functional lanthanide fluorescence nanoparticles, based on developments of lanthanide luminescent material. Several kinds of lanthanide nanoprecursors were synthesized with gel-network precipitation technique. After calcining these precursors, we get highperformance fluorescent nanocompounds, which are well dispersed and Alnico magnets sphere-like with an average diameter of less than 100nm. The luminescent properties were investigated by the fluorescence spectrophotometer. The results show that luminescent features of the products synthesized by the gel-network precipitation technique are similar to those by solid-state reaction, while the calcining temperature is reduced about 200℃-400℃. The conditions of the preparation process were also studied systematically and the optimal conditions were concluded.
Then nanophosphors were wrapped with TEOS hydrolyzation, and the nucleocapsid nanoparticles have steady-going luminescence and disperse well.There are six chapters in this magisterial dissertation.In the first chapter, this paper briefly introduces the classification and application of immunoassay and nanophosphor labels, as well as the characteristic and the current development situation of lanthanide fluorescence material.In the second chapter, we used gelatin as the disperser, and successfully prepared Eu3+-doped LaPO4 nanoparticles, which are basically monodisperse, have smaller particle size and better homogeneity. According to our measurements with http://www.999magnet.com/ XRD: the products belong to monoclinic monazite type, and the optimum condition for heat-treatment of the sample was at 600℃ for 2 hours. The emission spectra of LaPO4: Eu consists of the sharp line emissions in the range of 500～720nm from the transitions of electrons. The excitation spectra have two parts, the wide band at 270nm and the sharp line at 396nm.In the third chapter, Ce,Tb-doped LaPO4 nanoparticles were successfully
This paper aims at controllable preparation technology, characterization technology, and biomarker technology of functional lanthanide fluorescence nanoparticles, based on developments of lanthanide luminescent material. Several kinds of lanthanide nanoprecursors were synthesized with gel-network precipitation technique. After calcining these precursors, we get highperformance fluorescent nanocompounds, which are well dispersed and Alnico magnets sphere-like with an average diameter of less than 100nm. The luminescent properties were investigated by the fluorescence spectrophotometer. The results show that luminescent features of the products synthesized by the gel-network precipitation technique are similar to those by solid-state reaction, while the calcining temperature is reduced about 200℃-400℃. The conditions of the preparation process were also studied systematically and the optimal conditions were concluded.
Then nanophosphors were wrapped with TEOS hydrolyzation, and the nucleocapsid nanoparticles have steady-going luminescence and disperse well.There are six chapters in this magisterial dissertation.In the first chapter, this paper briefly introduces the classification and application of immunoassay and nanophosphor labels, as well as the characteristic and the current development situation of lanthanide fluorescence material.In the second chapter, we used gelatin as the disperser, and successfully prepared Eu3+-doped LaPO4 nanoparticles, which are basically monodisperse, have smaller particle size and better homogeneity. According to our measurements with http://www.999magnet.com/ XRD: the products belong to monoclinic monazite type, and the optimum condition for heat-treatment of the sample was at 600℃ for 2 hours. The emission spectra of LaPO4: Eu consists of the sharp line emissions in the range of 500～720nm from the transitions of electrons. The excitation spectra have two parts, the wide band at 270nm and the sharp line at 396nm.In the third chapter, Ce,Tb-doped LaPO4 nanoparticles were successfully
2012年7月3日星期二
溶剂萃取稀土的热动力学及萃取剂性质的研究
溶剂萃取稀土的热动力学及萃取剂性质的研究
Solvent extraction is an important and useful analytic technology. Due to the good effect, easy manipulation and easy massive production, it is popularizing in the fields of chemistry, environment protection and industry -agriculture. The thermokinetic property of solvent extraction is an important aspect of solvent extractant chemistry and is mainly Cube neodymium magnet about the study of extraction equilibrium, reaction rate and thermokinetic parameters. Microcalorimetric method is a new method to study the thermokinetic property of solvent extraction and the property of extractant. The thermokinetic data will supply a theory basis for ion extraction system and will propel the development of extraction separation technology.In this paper, the solvent extraction of Pr3+、Gd3+、Tb3+、Dy3+ 、Ho3+ with l-phenyl-3-methyl-4-benzoyl-pyrazolane-5 has been studied. The composure of extracted compound, the equilibrium constants, the reaction rate constants and the thermodynamic functions have been obtained. The reaction mentioned above and the extractant’s properties have been studied by the microcalorimetric method.1. The chief contents and conclusions1.1 Study of the extraction thermokinetic propertyIn this paper, these ions (Pr3+、Gd3+、Tb3+、Dy3+、Ho3+) were extracted.
The equilibrium equations are:Pr3++3 HPMBPo = Pr(PMBP)3(o)+3H+ Gd3++3 HPMBPo = Gd(PMBP)3(o)+3H+ Tb3++3 HPMBPo = Tb(PMBP)3(o)+3H+Dy3++3 HPMBPo = Dy(PMBP)3(o)+3H+ Ho3++3 HPMBPo = Ho(PMBP)3(o)+3H+The reaction rate constant, reaction rate equation and activity energy were obtained and △rHθm was calculated.The thermodynamic function △rHmθ was measured by microcalorimetric method. The determined △rHθm was compared with the calculated results. 1.2 Study of the extractant’s propertySaponification-extractant has the structure of surfactant, the property of surfactant, so it is not in the present of unimolecuar in the organic phase, but easy to form revered micelles.The thermodynamic property of the micelle’s formation procession has been studied by the microcalorimetric method with the mass action model of the surfactant.In the paper, saponificcation-salts of HPMBP have been made first. It was diluted by acetone. The property of this system was studied by the microcalorimetric method. The cirtical micelle http://www.chinamagnets.biz/ concentration(CMC), aggregation number(n), formation constant of micelle(Km) and the thermodynamic function(△rHmθ、△rHmθ、△rHmθ) were calculated. Under the condition of identical alcohol’s concentration, the values of CMC and △rHmθ decrease with the increment of alcohol’s carbon number, otherwise the values of the n, Km, △rHmθ, △rHmθ increase with the increnment of alcohol’s carbon number. Under the condition of the identical alcohol, the values of the n, △rHmθ decrease with the increment of the alcohol’s concentration, and the values of CMC, △rHmθ, △rHmθ increase with the increment of the alcohol’s concentration. This result is identical to the thermodynamic theory.2. The main innovative points(1) Microcalorimetric method is a new method to determine the reaction heat of solvent extraction process quickly and correctly.(2) The CMC and the thermodynamic functions determined by microcalorimetric method establish theoretical basis to understand the surfactant’s property in non-aqueous solutions.
Solvent extraction is an important and useful analytic technology. Due to the good effect, easy manipulation and easy massive production, it is popularizing in the fields of chemistry, environment protection and industry -agriculture. The thermokinetic property of solvent extraction is an important aspect of solvent extractant chemistry and is mainly Cube neodymium magnet about the study of extraction equilibrium, reaction rate and thermokinetic parameters. Microcalorimetric method is a new method to study the thermokinetic property of solvent extraction and the property of extractant. The thermokinetic data will supply a theory basis for ion extraction system and will propel the development of extraction separation technology.In this paper, the solvent extraction of Pr3+、Gd3+、Tb3+、Dy3+ 、Ho3+ with l-phenyl-3-methyl-4-benzoyl-pyrazolane-5 has been studied. The composure of extracted compound, the equilibrium constants, the reaction rate constants and the thermodynamic functions have been obtained. The reaction mentioned above and the extractant’s properties have been studied by the microcalorimetric method.1. The chief contents and conclusions1.1 Study of the extraction thermokinetic propertyIn this paper, these ions (Pr3+、Gd3+、Tb3+、Dy3+、Ho3+) were extracted.
The equilibrium equations are:Pr3++3 HPMBPo = Pr(PMBP)3(o)+3H+ Gd3++3 HPMBPo = Gd(PMBP)3(o)+3H+ Tb3++3 HPMBPo = Tb(PMBP)3(o)+3H+Dy3++3 HPMBPo = Dy(PMBP)3(o)+3H+ Ho3++3 HPMBPo = Ho(PMBP)3(o)+3H+The reaction rate constant, reaction rate equation and activity energy were obtained and △rHθm was calculated.The thermodynamic function △rHmθ was measured by microcalorimetric method. The determined △rHθm was compared with the calculated results. 1.2 Study of the extractant’s propertySaponification-extractant has the structure of surfactant, the property of surfactant, so it is not in the present of unimolecuar in the organic phase, but easy to form revered micelles.The thermodynamic property of the micelle’s formation procession has been studied by the microcalorimetric method with the mass action model of the surfactant.In the paper, saponificcation-salts of HPMBP have been made first. It was diluted by acetone. The property of this system was studied by the microcalorimetric method. The cirtical micelle http://www.chinamagnets.biz/ concentration(CMC), aggregation number(n), formation constant of micelle(Km) and the thermodynamic function(△rHmθ、△rHmθ、△rHmθ) were calculated. Under the condition of identical alcohol’s concentration, the values of CMC and △rHmθ decrease with the increment of alcohol’s carbon number, otherwise the values of the n, Km, △rHmθ, △rHmθ increase with the increnment of alcohol’s carbon number. Under the condition of the identical alcohol, the values of the n, △rHmθ decrease with the increment of the alcohol’s concentration, and the values of CMC, △rHmθ, △rHmθ increase with the increment of the alcohol’s concentration. This result is identical to the thermodynamic theory.2. The main innovative points(1) Microcalorimetric method is a new method to determine the reaction heat of solvent extraction process quickly and correctly.(2) The CMC and the thermodynamic functions determined by microcalorimetric method establish theoretical basis to understand the surfactant’s property in non-aqueous solutions.
Research on the Luminescent Properties of High-lying Excited States of Pr～(3+) and Nd～(3+)
Research on the Luminescent Properties of High-lying Excited States of Pr～(3+) and Nd～(3+)
High-lying excited states of Pr3+ are with unique luminescence properties. The highest state of 4f2 configuration is 1S0. In certain hosts, 1S0 is located below the lowest state of 4f5d configuration, quantum cutting process may take place after vacuum UV excitation. In other hosts, 1S0 is above the bottom of the 4f5d configuration, and 4f5d-4f2 emission Block neodymium magnet may be observed. Thus Pr doped materials may be applied as the UVU excited phosphors, tunable laser of lasers and scintillators.In the thesis, we have prepared Pr and Nd doped materials and investigated their spectroscopic properties especially in the UVU region, and got the following conclusions:1. In SrAl12O19: Pr3+ both 4f2 1S0 and 4f5d emissions can be observed at high temperature under VUV excitation. Relative intensity of the broad band 4f5d emission increases with temperature increasing. The temperature dependence of the relative intensity may be well fitted with the model that the population of 4f5d is from thermal excitation of 4f2 1S0. This process further reduces the efficiency of visible emission in quantum cutting, and it must be considered in developing quantum cutting materials.2. http://www.chinamagnets.biz/ In KLu3F10:Pr3+ and NH4Lu2F7:Pr3+, Pr3+ ions may occupy two different types of sites. They are distinguished both by the emission and decay properties. One may be excited by 182 nm and with both 4f5d and 4F2(1S0) emissions, while the other may be excited by 209nm and with only 4f5d and 4f2(1S0) emission. With 193 nm laser pulse excitation, both sites can be excited. The decay curve can be fitted with a sum of two exponential decay functions.3. Host absorption and Nd3+ 4f3-4f25d absorption bands can be observed in YAG: Nd3+ excitation spectrum monitoring at 398 nm, where both the self trapped exciton (STE) emission and Nd3+ emission exist. After host excitation, electrons and holes are either be trapped forming STE or transfer energy to Nd3+, resulting subsequently in STE emission and Nd3+ emission. With Nd concentration increases, concentration quenching takes place and Nd3+ 4f3-4f25d absorption bands in the excitation spectrum decrease, while the STE emission related host excitation band keeps almost constant.
High-lying excited states of Pr3+ are with unique luminescence properties. The highest state of 4f2 configuration is 1S0. In certain hosts, 1S0 is located below the lowest state of 4f5d configuration, quantum cutting process may take place after vacuum UV excitation. In other hosts, 1S0 is above the bottom of the 4f5d configuration, and 4f5d-4f2 emission Block neodymium magnet may be observed. Thus Pr doped materials may be applied as the UVU excited phosphors, tunable laser of lasers and scintillators.In the thesis, we have prepared Pr and Nd doped materials and investigated their spectroscopic properties especially in the UVU region, and got the following conclusions:1. In SrAl12O19: Pr3+ both 4f2 1S0 and 4f5d emissions can be observed at high temperature under VUV excitation. Relative intensity of the broad band 4f5d emission increases with temperature increasing. The temperature dependence of the relative intensity may be well fitted with the model that the population of 4f5d is from thermal excitation of 4f2 1S0. This process further reduces the efficiency of visible emission in quantum cutting, and it must be considered in developing quantum cutting materials.2. http://www.chinamagnets.biz/ In KLu3F10:Pr3+ and NH4Lu2F7:Pr3+, Pr3+ ions may occupy two different types of sites. They are distinguished both by the emission and decay properties. One may be excited by 182 nm and with both 4f5d and 4F2(1S0) emissions, while the other may be excited by 209nm and with only 4f5d and 4f2(1S0) emission. With 193 nm laser pulse excitation, both sites can be excited. The decay curve can be fitted with a sum of two exponential decay functions.3. Host absorption and Nd3+ 4f3-4f25d absorption bands can be observed in YAG: Nd3+ excitation spectrum monitoring at 398 nm, where both the self trapped exciton (STE) emission and Nd3+ emission exist. After host excitation, electrons and holes are either be trapped forming STE or transfer energy to Nd3+, resulting subsequently in STE emission and Nd3+ emission. With Nd concentration increases, concentration quenching takes place and Nd3+ 4f3-4f25d absorption bands in the excitation spectrum decrease, while the STE emission related host excitation band keeps almost constant.
Mineralogical and Geochemical Characteristics of Massive Sulfides in the Okinawa Through
Mineralogical and Geochemical Characteristics of Massive Sulfides in the Okinawa Through
Along with the deeper understanding of ocean, hydrothermal fluids activity have drawn more and more attention; the research of the global distribution, scale, chemical components and mechanism on modern hydrothermal fluid massive sulfides, can provide profound ground work to mineralization theory and hydrothermal fluids massive sulfides. Recently, the hydrothermal fluids zone in Okinawa Through has been widely focused, although some conclusions have been drawn according to the mineralogical and geochemical analysis of sediments in Okinawa Ball Neodymium Magnets Through conducted by some scholars, the problems in the mode of occurrence of metal elements, the regularity of minerogenetic enrichment, the division of mineral stages and the origin of mineral materials are still there unsolved. This paper mainly analyzes mineral components and zonal characteristics of massive sulfides in Okinawa Through by means of polished section identification, X-ray diffraction, etc; meanwhile, the testing analysis in macro-elements and trace elements is also conducted to analyze the Black Smoker samples using chemical analysis and inductively coupled plasma mass spectrometry (ICP-MS). Based on the analysis conducted above, this paper also discusses the patterns like transportation, activation and precipitation of various kinds of elements during the revolution of Black Smoker.Based on the analysis from polished section, the dominant mineral materials on the Black Smoker are Sphalerite, Chalcopyrite and pyrrhotite. Sample Sk1031-1 comes from Black Smoker nozzle, which is a classical pathway structural, has the obvious zonal distribution from outer wall to inner wall.; the change from Sphalerite to Chalcopyrite; the ratio Cu/Zn in Black Smoker massive sulfides has been widely known that it’s controlled by the thermal history of hydrothermal fluids, rich Zn zone is formed when temperature is below 300 degrees centigrade,
whereas rich Cu zone is formed when temperature is above 300 degrees centigrade.According to the chemical testing, analysis to the samples, this massive sulfide is obviously rich in Cu, Fe and Zn, which all have the correlation coefficient larger than 0.8. This means they have obvious concomitance relationship; Au, Ag have lower relativity with dominant mineral material, which means they can exist as independent minerals. The reason why Cu, Fe and Zn in basalt around http://www.chinamagnets.biz/ research zone are lower than the average content in Earth Crust is maybe the extraction resulted from the long-term hydrothermal fluids recycling. The REE content in Black Smoker massive sulfides are relatively low, ranging from 4.45×10-6 to 39.15×10-6, and LREE is richer compared to HREE, where Eu(δEu=5.05-82.01)、Ce(δCe=2.89-9.17)has positive anomaly, (Only Sample Sk1030-4a has negative anomaly:δCe=0.76). The conclusion drawn above slightly varies from the former investigators’one which is Element Eu has relative lower negative anomaly. The REE distribution pattern in Black Smoker massive sulfides is very different from the one in sedimentary rock, volcanic rock and ocean water in our research zone, which indicates the multi-origins of massive sulfide materials, and the complexity of fluids system. The REE distribution patterns in massive sulfides can reflect the revolution characteristics of hydrothermal fluids to some extent.
Along with the deeper understanding of ocean, hydrothermal fluids activity have drawn more and more attention; the research of the global distribution, scale, chemical components and mechanism on modern hydrothermal fluid massive sulfides, can provide profound ground work to mineralization theory and hydrothermal fluids massive sulfides. Recently, the hydrothermal fluids zone in Okinawa Through has been widely focused, although some conclusions have been drawn according to the mineralogical and geochemical analysis of sediments in Okinawa Ball Neodymium Magnets Through conducted by some scholars, the problems in the mode of occurrence of metal elements, the regularity of minerogenetic enrichment, the division of mineral stages and the origin of mineral materials are still there unsolved. This paper mainly analyzes mineral components and zonal characteristics of massive sulfides in Okinawa Through by means of polished section identification, X-ray diffraction, etc; meanwhile, the testing analysis in macro-elements and trace elements is also conducted to analyze the Black Smoker samples using chemical analysis and inductively coupled plasma mass spectrometry (ICP-MS). Based on the analysis conducted above, this paper also discusses the patterns like transportation, activation and precipitation of various kinds of elements during the revolution of Black Smoker.Based on the analysis from polished section, the dominant mineral materials on the Black Smoker are Sphalerite, Chalcopyrite and pyrrhotite. Sample Sk1031-1 comes from Black Smoker nozzle, which is a classical pathway structural, has the obvious zonal distribution from outer wall to inner wall.; the change from Sphalerite to Chalcopyrite; the ratio Cu/Zn in Black Smoker massive sulfides has been widely known that it’s controlled by the thermal history of hydrothermal fluids, rich Zn zone is formed when temperature is below 300 degrees centigrade,
whereas rich Cu zone is formed when temperature is above 300 degrees centigrade.According to the chemical testing, analysis to the samples, this massive sulfide is obviously rich in Cu, Fe and Zn, which all have the correlation coefficient larger than 0.8. This means they have obvious concomitance relationship; Au, Ag have lower relativity with dominant mineral material, which means they can exist as independent minerals. The reason why Cu, Fe and Zn in basalt around http://www.chinamagnets.biz/ research zone are lower than the average content in Earth Crust is maybe the extraction resulted from the long-term hydrothermal fluids recycling. The REE content in Black Smoker massive sulfides are relatively low, ranging from 4.45×10-6 to 39.15×10-6, and LREE is richer compared to HREE, where Eu(δEu=5.05-82.01)、Ce(δCe=2.89-9.17)has positive anomaly, (Only Sample Sk1030-4a has negative anomaly:δCe=0.76). The conclusion drawn above slightly varies from the former investigators’one which is Element Eu has relative lower negative anomaly. The REE distribution pattern in Black Smoker massive sulfides is very different from the one in sedimentary rock, volcanic rock and ocean water in our research zone, which indicates the multi-origins of massive sulfide materials, and the complexity of fluids system. The REE distribution patterns in massive sulfides can reflect the revolution characteristics of hydrothermal fluids to some extent.
Synthesis, Characterization of Titanium (IV) and Lanthanide(III) Complexes Containing Pyrrolyl-Functionalized Ligands
Synthesis, Characterization of Titanium (IV) and Lanthanide(III) Complexes Containing Pyrrolyl-Functionalized Ligands
Using N,N-Di(pyrrolyl-α-methyl)-N-methylamine(H2dpma) and N1,N3- [bis (Pyrrole-2-yl)methylene)] diethylenetriamine (H3dpda) neodymium magnets as ligands, under an atmosphere of dry Nitrogen with the rigid exclusion of air and moisture and aided by Schlenk techniques, we have synthesizes five organolanthanide complexes and six titanium complexes. The crystal structures of three complexes were determined by X-ray diffraction. All these complexes were well characterized by elemental analysis and NMR.The structures of Ln(dpma)(N(TMS)2) indicated they are potencial catalysts for intramolecular hydroamination of alkynes. By analysis the http://www.chinamagnets.biz/ ligand system, we proposed the pyrrolyl contained titanium dichloride complexe TiCl2(dpma)Py are active catalyst for the olefin polymerization.
Using N,N-Di(pyrrolyl-α-methyl)-N-methylamine(H2dpma) and N1,N3- [bis (Pyrrole-2-yl)methylene)] diethylenetriamine (H3dpda) neodymium magnets as ligands, under an atmosphere of dry Nitrogen with the rigid exclusion of air and moisture and aided by Schlenk techniques, we have synthesizes five organolanthanide complexes and six titanium complexes. The crystal structures of three complexes were determined by X-ray diffraction. All these complexes were well characterized by elemental analysis and NMR.The structures of Ln(dpma)(N(TMS)2) indicated they are potencial catalysts for intramolecular hydroamination of alkynes. By analysis the http://www.chinamagnets.biz/ ligand system, we proposed the pyrrolyl contained titanium dichloride complexe TiCl2(dpma)Py are active catalyst for the olefin polymerization.
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