Development of Automatic Locking Device for Magnetic Bearing Flywheel
Magnetic suspending is a technology, which utilizes magnetic power to make objects suspending without mechanical touching, it is also an all-around technology relating to several subjects. Nowaday, the controlling of a satellite stance is usually achieved by controlling the change of the angular momentum for a flywheel. The system of magnetic bearing flywheel has Block Neodymium magnets several characters, such as without friction, dispensing with lubrication and high-speed running, and it is applied in satellites very much.
During the satellite launching, the locking of Magnetic bearing flywheel is a key technology. In order to protecting flywheel from being damaged, the system of magnetic bearing flywheel, including the flywheel rotor, needs to be locking during the satellite launching, and in the orbiting of the satellite, it also needs to be loosing to make the rotor suspending. Although the static magnetic force of the magnetic bearing could maintain the rotor during the satellite launching, it utilizes additional locking device in many business applications of magnetic bearing flywheel. It can provide locking force for flywheel by locking device during launching to make the rotor fixing on the surface of the taper bush, and loose it in the satellite orbiting to make the rotor suspending as the free state.First, the motion mechanism is designed, which consists of power supply, transmission part, implement part and sustentation part, and a whole project of mechanism could be obtained according to this. In the locking project designing of the mechanism, several projects are enumerated, and an optimal one has been selected through comparing them with each other.
Then the motion control system is designed. In order to Block Neodymium magnets controlling the mechanism motion efficiently, a control system with an active feedback loop is chosen, which could ensure implement part working in its safe journey. Obviously, in order to making the mechanism automatic locking and loosing, a molectron, core of microcontroller, is designed, and a long-distance control is achieved by utilizing serial communication module, which could transfer the information between microcontroller and main computer.When the mechanism and its control system are designed, an experiment of the system could be maken on, and it could not only adjust the locking force of the mechanism efficiently, but also optimize the whole system and bring its capability reaching optimization level.At the end of this paper, it summarizes all of the development of the automatic locking system, and prospects the next further research.
2012年3月26日星期一
Particle Acceleration in Magnetic Reconnecting Current Sheets
Particle Acceleration in Magnetic Reconnecting Current Sheets
The sun is the most energetic particle accelerator in the solar system, producing ions of up to GeV and electrons of up to tens of MeV.Large solar flares are the most powerful explosions in the solar system,releasing up to 1032-1033ergs in -102-103s.The accelerated 20-100keV electrons and the sometimes greater than～1MeV ions appear to contain～10%-50%of this energy,indicating that the particle acceleration and energy release processes are intimately linked.Flare-accelerated electrons and ions colliding with the ambient solar atmosphere produce Magnetic lifter bremsstrahlung hard X-ray andγ-ray line emission.Hard X-rays can provides us with the most important information required for understanding the energy release process and the mechanism or mechanisms by which particles are energized during flare.So,one of the most fascinating aspects of solar flares is how the particles are accelerating to high energies.
This thesis is structured as follow:In chapter one,on the basis of surveying a number of references,we summarized the basic knowledge to flares and energy release mechanism.In chapter two,the acceleration mechanism for non-thermal is recommended.In chapter three,electron acceleration by a super-Dreicer electric field Ez is investigated in the reconnecting current Magnetic lifter sheet with a guiding magnetic field Bz by applying test particle simulation.The guiding field is assumed constant within an RCS,but it have different direction which change the test particle trajectories and lead to the particles which leave the current sheet following field lines close to the different separatrix.In the presence of Bz parallel to Ez,the pitch-angle of energed particle close to1800.In contrast,if Bz anti-parallel to Ez,the pitch-angle close to 00.The electric field will accelerate electron in different region due to the different direction of guiding field,but the effect to the distribution of electron energy is negligible.The Magnetic lifter energy spectrum of accelerated electron is universal with a power-law spectrum E-γ,and the value ofγhave the relation with the strength of the guiding field,the scale of the current sheet,and the strength of electric field.
The sun is the most energetic particle accelerator in the solar system, producing ions of up to GeV and electrons of up to tens of MeV.Large solar flares are the most powerful explosions in the solar system,releasing up to 1032-1033ergs in -102-103s.The accelerated 20-100keV electrons and the sometimes greater than～1MeV ions appear to contain～10%-50%of this energy,indicating that the particle acceleration and energy release processes are intimately linked.Flare-accelerated electrons and ions colliding with the ambient solar atmosphere produce Magnetic lifter bremsstrahlung hard X-ray andγ-ray line emission.Hard X-rays can provides us with the most important information required for understanding the energy release process and the mechanism or mechanisms by which particles are energized during flare.So,one of the most fascinating aspects of solar flares is how the particles are accelerating to high energies.
This thesis is structured as follow:In chapter one,on the basis of surveying a number of references,we summarized the basic knowledge to flares and energy release mechanism.In chapter two,the acceleration mechanism for non-thermal is recommended.In chapter three,electron acceleration by a super-Dreicer electric field Ez is investigated in the reconnecting current Magnetic lifter sheet with a guiding magnetic field Bz by applying test particle simulation.The guiding field is assumed constant within an RCS,but it have different direction which change the test particle trajectories and lead to the particles which leave the current sheet following field lines close to the different separatrix.In the presence of Bz parallel to Ez,the pitch-angle of energed particle close to1800.In contrast,if Bz anti-parallel to Ez,the pitch-angle close to 00.The electric field will accelerate electron in different region due to the different direction of guiding field,but the effect to the distribution of electron energy is negligible.The Magnetic lifter energy spectrum of accelerated electron is universal with a power-law spectrum E-γ,and the value ofγhave the relation with the strength of the guiding field,the scale of the current sheet,and the strength of electric field.
Research on Diagnosis Information Imaging for MCG-recordings
Research on Diagnosis Information Imaging for MCG-recordings
In 1972, D.Cohen detected human magnetic signal by using a SQUID in magnetic shield room, leading us to a new way of non-invasive heart measurement. The advantages of MCG measurement are completely non-invasive, non-contact, it needs no electrode, so the patient will not be affected by any radial, external magnetic field and nucleus trail injection. Neodymium Magnets Cardiac magnetic field of the ion moving between the cells of cardiac muscle can be recorded by superconductive technology, it can reveal the inbeing of cardiac bioelectricity. So MCG is one of the heart disease diagnosis methods which have bright future.This dissertation studies current density map of heart signals and chaos attractors, the followings are studied:1. Based on the former research, study the imaging methods of the heart current density map and composed current vectorgraph.
By drawing several patients current density map and composed current vectorgraph analyze the relationship between their diseases http://www.999magnet.com/ and magnetocarodigram. Develop the visual interface drawing both dynamic and static MCG.2. Based on the former research, study the relationship of medical information got from single point and composed current vectorgraph by drawing the chaos attractor map. If we find the right point, single point may contain diagnosis information we need.3. By accounting relative degree and relative matrix, study the relation between 36 heart signals and composed current vectorgraph which can reflect the characteristic of the heart. Although all the 36 signals are Neodymium Magnets relative to the compositive signal, the measure points near the middle of the heart have greater contribution to the general characteristic of the heart.4. Based on the former research, preprocess the heart signal, counterpoise the multi-period data into single-period data, and make a GUI module for this function by using MATLAB GUI.
In 1972, D.Cohen detected human magnetic signal by using a SQUID in magnetic shield room, leading us to a new way of non-invasive heart measurement. The advantages of MCG measurement are completely non-invasive, non-contact, it needs no electrode, so the patient will not be affected by any radial, external magnetic field and nucleus trail injection. Neodymium Magnets Cardiac magnetic field of the ion moving between the cells of cardiac muscle can be recorded by superconductive technology, it can reveal the inbeing of cardiac bioelectricity. So MCG is one of the heart disease diagnosis methods which have bright future.This dissertation studies current density map of heart signals and chaos attractors, the followings are studied:1. Based on the former research, study the imaging methods of the heart current density map and composed current vectorgraph.
By drawing several patients current density map and composed current vectorgraph analyze the relationship between their diseases http://www.999magnet.com/ and magnetocarodigram. Develop the visual interface drawing both dynamic and static MCG.2. Based on the former research, study the relationship of medical information got from single point and composed current vectorgraph by drawing the chaos attractor map. If we find the right point, single point may contain diagnosis information we need.3. By accounting relative degree and relative matrix, study the relation between 36 heart signals and composed current vectorgraph which can reflect the characteristic of the heart. Although all the 36 signals are Neodymium Magnets relative to the compositive signal, the measure points near the middle of the heart have greater contribution to the general characteristic of the heart.4. Based on the former research, preprocess the heart signal, counterpoise the multi-period data into single-period data, and make a GUI module for this function by using MATLAB GUI.
The Research of Electric Actuator of Valve Based on SRM
The Research of Electric Actuator of Valve Based on SRM
Electric actuator of valve is widely used in modern industry, and the controller is the core of the whole system. With the surge of foreign actuators rushing into China, it is necessary to develop products with independent copyright. With the analysis of the need of the products, an intelligent controller of a new motor is studied and a digital, intelligent, self-diagnosing actuator with field bus based on the former electric actuator is developed, which shorten the gap with the foreign magnet lifter actuators and will be a great benefit to our society.The key part of the paper is to develop a new kind of intelligent controller of valve actuator, using the switched reluctance motor as electric actuator, which is composed by a main controller, a detection circuit, a human-machine interface and a drive circuit of motor.
The work capability of SRM is mainly analyzed. The control mode is researched when the electric actuator of valve start and work. With the analysis of the use of the absolute value encoder in the control of SRM and the valve, a kind of absolute value encoder used in angle position control of SRM. Part of hardware of intelligent electric actuator controller is designed and controller software is compiled using C8051F020 MCU to replace PLC controller to reduce volum magnet lifter e and cost. The MCU is connected with PC by RS485. Industry configuration software KINGVIEW6.51 is used as upper computer monitor software, and friendly monitor picture is developed realizing long-distance setting, monitoring and fault diagnosis.Finally, the optimal switch-on angle and switch-off angle is got in experiments and the feasibility of the control scheme is proved.
Electric actuator of valve is widely used in modern industry, and the controller is the core of the whole system. With the surge of foreign actuators rushing into China, it is necessary to develop products with independent copyright. With the analysis of the need of the products, an intelligent controller of a new motor is studied and a digital, intelligent, self-diagnosing actuator with field bus based on the former electric actuator is developed, which shorten the gap with the foreign magnet lifter actuators and will be a great benefit to our society.The key part of the paper is to develop a new kind of intelligent controller of valve actuator, using the switched reluctance motor as electric actuator, which is composed by a main controller, a detection circuit, a human-machine interface and a drive circuit of motor.
The work capability of SRM is mainly analyzed. The control mode is researched when the electric actuator of valve start and work. With the analysis of the use of the absolute value encoder in the control of SRM and the valve, a kind of absolute value encoder used in angle position control of SRM. Part of hardware of intelligent electric actuator controller is designed and controller software is compiled using C8051F020 MCU to replace PLC controller to reduce volum magnet lifter e and cost. The MCU is connected with PC by RS485. Industry configuration software KINGVIEW6.51 is used as upper computer monitor software, and friendly monitor picture is developed realizing long-distance setting, monitoring and fault diagnosis.Finally, the optimal switch-on angle and switch-off angle is got in experiments and the feasibility of the control scheme is proved.
2012年3月18日星期日
A Research on Parameters Determination Method about Flux Observer
A Research on Parameters Determination Method about Flux Observer
Induction motor direct torque control technique has played an important role in variable frequency motor speed control field, as the promoting of automation degrade, man bring forward higher request toward the motor control system, the development and applying of new technique in industrial automation field inject new vigor for direct torque control technique, rare earth magnets inosculating new technique, upgrading the capability of control system will become the develop direction.Induction motor direct torque control method has the characters such as simple calculation, little dependence to motor parameters, excellent dynamic and static performance. But on the same time, it exists the problem of lower control precision, large influence suffer from motor parameters on the low speed stage, large concussion when motor exchanges between high speed and low speed. This paper discusses the construction method of direct torque control system, analysis flux observation tache, introduces conventional flux observation model and flux observation based on nerve network technique, compare the advantage and disadvantage each model.
The paper introduces the direct torque control system model and theory, then, introduces the flux observation model on the high speed stage and low speed stage, and adaptive flux observation model. Presents the parameter tuning method and Modeling rare earth magnets and Simulations. Gives the serving method aiming at the problem appearing on the simulation process, according to Lyapunov Stability theory, establish Lyapunov adaptive flux observation model, Particular introduces the tuning method of key parameter of these model. Applying the nerve network knowledge, simulation data of adaptive model, constructs the BP flux observation model http://www.chinamagnets.biz/ and speed observation model.This paper starts from flux observation, introduces the tuning method of model parameter, realizes the exchange between high-speed and low-speed under direct torque control arithmetic, constructs the direct torque control system, and inosculating NN technique on the construction process of flux observation model and speed observation model, improves the capability of control system.
Induction motor direct torque control technique has played an important role in variable frequency motor speed control field, as the promoting of automation degrade, man bring forward higher request toward the motor control system, the development and applying of new technique in industrial automation field inject new vigor for direct torque control technique, rare earth magnets inosculating new technique, upgrading the capability of control system will become the develop direction.Induction motor direct torque control method has the characters such as simple calculation, little dependence to motor parameters, excellent dynamic and static performance. But on the same time, it exists the problem of lower control precision, large influence suffer from motor parameters on the low speed stage, large concussion when motor exchanges between high speed and low speed. This paper discusses the construction method of direct torque control system, analysis flux observation tache, introduces conventional flux observation model and flux observation based on nerve network technique, compare the advantage and disadvantage each model.
The paper introduces the direct torque control system model and theory, then, introduces the flux observation model on the high speed stage and low speed stage, and adaptive flux observation model. Presents the parameter tuning method and Modeling rare earth magnets and Simulations. Gives the serving method aiming at the problem appearing on the simulation process, according to Lyapunov Stability theory, establish Lyapunov adaptive flux observation model, Particular introduces the tuning method of key parameter of these model. Applying the nerve network knowledge, simulation data of adaptive model, constructs the BP flux observation model http://www.chinamagnets.biz/ and speed observation model.This paper starts from flux observation, introduces the tuning method of model parameter, realizes the exchange between high-speed and low-speed under direct torque control arithmetic, constructs the direct torque control system, and inosculating NN technique on the construction process of flux observation model and speed observation model, improves the capability of control system.
2012年3月16日星期五
滇东南法郎组含锰地层沉积相及其锰矿成因研究
题名:滇东南法郎组含锰地层沉积相及其锰矿成因研究
作者:杜秋定
学位授予单位:成都理工大学
关键词:锰质核形石;;微生物成因;;沉积环境;;成矿模式;;中三叠统法郎组;;滇东南地区
摘要:
滇东南地区是我国南方优质富锰矿产区,锰矿床主要分布于东南部的建水——邱北一带,锰矿床产于中三叠世拉丁尼克期的法郎组地层中,为一套海相泥岩、粉砂岩、砂岩夹碳酸盐岩沉积。含锰地层产于上三叠统鸟格组碎屑Alnico magnets岩之下,中三叠统个旧组灰岩之上,它与上下两组之间有一沉积间断面存在。法郎组有两个含锰段,下含锰段位于法郎组的中下部,上含锰段位于法郎组中上部,除斗南外并非每个剖面上下含锰段的锰矿层同时并存,岩子脚剖面只有下部锰矿层,上部矿层尖灭,老乌剖面只有上部锰矿层,下部矿层尖灭。含矿层锰矿石以褐锰矿为主,含少量钙菱锰矿,胶结物以方解石为主,白云石,石英砂以及自生钠长石次之。
前人虽然对滇东南锰矿锰质来源及聚锰环境作了广泛研究。但是并未注意到矿石中出现的鲕、豆状结构以及这些构造的建造者——兰绿藻类微生物可能对锰质富集具有极为重要意义。产于滇东南中三叠世拉丁期法郎组地层中的Alnico magnets锰矿床,矿石中一般都可以观察到鲕状、豆状结构,具有同心环带构造。对采自这一地区斗南、岩子脚、老乌等典型矿床的锰矿石样品,进行了系统的薄片显微镜和扫描电镜观察,同时应用阴极发光技术对有代表性的样品进行了分析。根据对鲕、豆状结构矿石的显微结构特征的研究,发现这些矿石中的鲕、豆状结构是兰绿藻类微生物凝聚形成的显微叠层构造,具有核形石特有的核心和包壳,其明暗纹层相间的显微结构特征可以与现代深海大洋铁锰结核相类比,通过与现代深海锰结核结壳的叠层构造的对比结果,提出了滇东南地区锰矿石中锰质的富集过程可能与兰绿藻类微生物参与有密切的关系。
本文根据我们对滇东南一带的白显、汤得、岩子脚、老乌、斗南法郎组含锰地层野外考察和实测剖面的室内详细研究,结合前人的资料,调查区锰矿床(点)明显地受同期异相沉积的控制,通过微量元素和稀土元素(REE)数据,对Alnico magnets元素的相关性和配http://www.999magnet.com/分模式进行分析,在研究区应用合理的成矿模式,研究区的锰矿为氧化锰矿与碳酸盐锰矿混合存在,都是沉积成因,没有明显的变质现象。矿石一般都含有生物碎屑,因此可以判断锰矿形成是位于氧化还原界面附近,由于海平面的不断升降,氧化锰矿也随之不断的溶解沉淀,最终使得贫氧层孔隙水中锰离子的浓度达到最佳值,形成锰碳酸盐。由于氧化锰矿溶解不完全,形成氧化锰矿与碳酸盐锰矿混合存在现象。同时,滇东南地区锰矿床的形成,其空间分布明显受到层(Alnico magnets岩石地层)、相(岩相)、位(构造部位)控制,呈“三位一体”。
总之,对滇东南地区沉积建造,成矿环境,锰盆地分布规律等关键成矿地质问题的研究,有利于寻找并确定新的成锰盆地,预测优质锰矿的赋存位置,对建立一套新的,合理有效的沉积型锰矿和优质锰矿的找矿模式有借鉴意义。
学位年度:2009
作者:杜秋定
学位授予单位:成都理工大学
关键词:锰质核形石;;微生物成因;;沉积环境;;成矿模式;;中三叠统法郎组;;滇东南地区
摘要:
滇东南地区是我国南方优质富锰矿产区,锰矿床主要分布于东南部的建水——邱北一带,锰矿床产于中三叠世拉丁尼克期的法郎组地层中,为一套海相泥岩、粉砂岩、砂岩夹碳酸盐岩沉积。含锰地层产于上三叠统鸟格组碎屑Alnico magnets岩之下,中三叠统个旧组灰岩之上,它与上下两组之间有一沉积间断面存在。法郎组有两个含锰段,下含锰段位于法郎组的中下部,上含锰段位于法郎组中上部,除斗南外并非每个剖面上下含锰段的锰矿层同时并存,岩子脚剖面只有下部锰矿层,上部矿层尖灭,老乌剖面只有上部锰矿层,下部矿层尖灭。含矿层锰矿石以褐锰矿为主,含少量钙菱锰矿,胶结物以方解石为主,白云石,石英砂以及自生钠长石次之。
前人虽然对滇东南锰矿锰质来源及聚锰环境作了广泛研究。但是并未注意到矿石中出现的鲕、豆状结构以及这些构造的建造者——兰绿藻类微生物可能对锰质富集具有极为重要意义。产于滇东南中三叠世拉丁期法郎组地层中的Alnico magnets锰矿床,矿石中一般都可以观察到鲕状、豆状结构,具有同心环带构造。对采自这一地区斗南、岩子脚、老乌等典型矿床的锰矿石样品,进行了系统的薄片显微镜和扫描电镜观察,同时应用阴极发光技术对有代表性的样品进行了分析。根据对鲕、豆状结构矿石的显微结构特征的研究,发现这些矿石中的鲕、豆状结构是兰绿藻类微生物凝聚形成的显微叠层构造,具有核形石特有的核心和包壳,其明暗纹层相间的显微结构特征可以与现代深海大洋铁锰结核相类比,通过与现代深海锰结核结壳的叠层构造的对比结果,提出了滇东南地区锰矿石中锰质的富集过程可能与兰绿藻类微生物参与有密切的关系。
本文根据我们对滇东南一带的白显、汤得、岩子脚、老乌、斗南法郎组含锰地层野外考察和实测剖面的室内详细研究,结合前人的资料,调查区锰矿床(点)明显地受同期异相沉积的控制,通过微量元素和稀土元素(REE)数据,对Alnico magnets元素的相关性和配http://www.999magnet.com/分模式进行分析,在研究区应用合理的成矿模式,研究区的锰矿为氧化锰矿与碳酸盐锰矿混合存在,都是沉积成因,没有明显的变质现象。矿石一般都含有生物碎屑,因此可以判断锰矿形成是位于氧化还原界面附近,由于海平面的不断升降,氧化锰矿也随之不断的溶解沉淀,最终使得贫氧层孔隙水中锰离子的浓度达到最佳值,形成锰碳酸盐。由于氧化锰矿溶解不完全,形成氧化锰矿与碳酸盐锰矿混合存在现象。同时,滇东南地区锰矿床的形成,其空间分布明显受到层(Alnico magnets岩石地层)、相(岩相)、位(构造部位)控制,呈“三位一体”。
总之,对滇东南地区沉积建造,成矿环境,锰盆地分布规律等关键成矿地质问题的研究,有利于寻找并确定新的成锰盆地,预测优质锰矿的赋存位置,对建立一套新的,合理有效的沉积型锰矿和优质锰矿的找矿模式有借鉴意义。
学位年度:2009
陕西省青山金矿床地质地球化学特征初步研究
题名:陕西省青山金矿床地质地球化学特征初步研究
作者:陈兵
学位授予单位:成都理工大学
关键词:青山金矿床;;低温热水沉积;;热泉型金矿
摘要:
青山金矿床大地构造位置属扬子板块被动大陆边缘。地层属镇安-旬阳小区,出露泥盆系-石炭系地层,二者呈平行不整合接触。矿床处于小磨岭隆起南侧,区域性镇安-板岩、山阳-凤镇深大断裂旁侧,直接定位于海棠山-大坪复Special shape NdFeB magnets 向斜南翼下石炭统含矿岩系叠加的脆性断裂构造带内。
研究区内矿体主要赋存于界河街组与九里坪组的岩性接触面靠界河街组一侧;其顶板(底板)地层均不利于矿液交代,因其高C、S而作为良好的地球化学障,对矿液起了良好的遮拦作用,有利于矿质的富集与沉淀。
矿石分为原生金矿石和氧化金矿石。矿石金属矿物主要为热液期的菱铁矿、黄铁矿。矿石具有角砾状、微细浸染状、胶状、土状等构造及自形-半自形粒状、增生环带、草莓状、他形粒状、交代残余、假象等结构。矿石中金主要以次显微不可见形式赋存在黄铁矿和褐铁矿中。根据成矿地质背景、地http://www.999magnet.com/质地球化学特征,将该矿床的成矿作用演化划分为热水沉积期、热液期和表生期,其中热液期为矿床的主成矿期。
矿石中微量元素、稀土元素显示矿化组分对围岩具有继承性,成矿元素具有Au-Ag-As-Sb组合特征;氢氧同位素组成、碳同位素Special shape NdFeB magnets 分布和包体成分特征均显示成矿流体主要为受较强烈构造作用改造的大气降水;铅源具造山带铅同位素特征,显示其形成于造山带构造环境,成矿动力来自陆内造山作用;流体包裹体测温显示成矿温度为低温(153.6-335℃),成矿深度为浅成Special shape NdFeB magnets ,深度约为0.92km,成矿压力为270×105Pa;成矿流体低盐度(9.93-6.45%NaCl),高硫逸度(-11.25~ -16.96),低氧逸度(-36.97~-46.62),为相对还原环境(Eh为-018~-0.35)。金在成矿流体中主要以Au(HS)2-和Au2S(HS)22-络合物的形式进行迁移,并在温压条件改变时沉淀。
据上述地质地球化学特征,青山金矿床属浅成低温热液矿床的亚类—热泉型金矿床。
学位年度:2009
作者:陈兵
学位授予单位:成都理工大学
关键词:青山金矿床;;低温热水沉积;;热泉型金矿
摘要:
青山金矿床大地构造位置属扬子板块被动大陆边缘。地层属镇安-旬阳小区,出露泥盆系-石炭系地层,二者呈平行不整合接触。矿床处于小磨岭隆起南侧,区域性镇安-板岩、山阳-凤镇深大断裂旁侧,直接定位于海棠山-大坪复Special shape NdFeB magnets 向斜南翼下石炭统含矿岩系叠加的脆性断裂构造带内。
研究区内矿体主要赋存于界河街组与九里坪组的岩性接触面靠界河街组一侧;其顶板(底板)地层均不利于矿液交代,因其高C、S而作为良好的地球化学障,对矿液起了良好的遮拦作用,有利于矿质的富集与沉淀。
矿石分为原生金矿石和氧化金矿石。矿石金属矿物主要为热液期的菱铁矿、黄铁矿。矿石具有角砾状、微细浸染状、胶状、土状等构造及自形-半自形粒状、增生环带、草莓状、他形粒状、交代残余、假象等结构。矿石中金主要以次显微不可见形式赋存在黄铁矿和褐铁矿中。根据成矿地质背景、地http://www.999magnet.com/质地球化学特征,将该矿床的成矿作用演化划分为热水沉积期、热液期和表生期,其中热液期为矿床的主成矿期。
矿石中微量元素、稀土元素显示矿化组分对围岩具有继承性,成矿元素具有Au-Ag-As-Sb组合特征;氢氧同位素组成、碳同位素Special shape NdFeB magnets 分布和包体成分特征均显示成矿流体主要为受较强烈构造作用改造的大气降水;铅源具造山带铅同位素特征,显示其形成于造山带构造环境,成矿动力来自陆内造山作用;流体包裹体测温显示成矿温度为低温(153.6-335℃),成矿深度为浅成Special shape NdFeB magnets ,深度约为0.92km,成矿压力为270×105Pa;成矿流体低盐度(9.93-6.45%NaCl),高硫逸度(-11.25~ -16.96),低氧逸度(-36.97~-46.62),为相对还原环境(Eh为-018~-0.35)。金在成矿流体中主要以Au(HS)2-和Au2S(HS)22-络合物的形式进行迁移,并在温压条件改变时沉淀。
据上述地质地球化学特征,青山金矿床属浅成低温热液矿床的亚类—热泉型金矿床。
学位年度:2009
Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x系列合金磁热性能的研究
题名:Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x系列合金磁热性能的研究
作者:于越
学位授予单位:西华大学
关键词:磁热效应;;居里温度;;磁熵变;;磁相变;;稀土
摘要:
近年来,稀土化合物GdCo_2、DyCo_2以其低廉的价格引起人们的关注,但GdCo_2居里温度远高于室温,相变类型为二级相变,磁熵变不高;DyCo_2居里温度远低于室温,相变类型为一级相变,具有较大的磁熵变,两者都不适合做Special shape NdFeB magnets室温磁制冷材料。为了利用GdCo_2和DyCo_2的各自优点,制备一种居里温度在室温附近,在低磁场下磁熵变有较高值且成本相对低廉的合金,本文在用部分Dy取代GdCo_2中Gd的基础上,再用部分Al来取代Co,用真空电弧熔炼炉制备Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x(X=0,0.05,0.1,0.15)两个系列合金,然后取铸态试样分别做温度为900℃4天、7天的热处理,运用SQUID量子磁强计,X射线衍射仪,扫描电镜,绝热温变测试系统等检测手段对铸态和热处理态的两系列合金进行性能测试,研究Al和Dy元素的加入对铸态和热处理态GdCo_2合金相结构、绝热温变、居里温度、磁熵变的影响。
室温粉末X射线衍射分析发现铸态、热处理4天Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金均属于GdCo_2和GdCo_3共存型晶体结构,而热处理7天Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金属于GdCo_2单相晶体结构。在1.4T磁场下,随着Al元素含量的增加,铸态、热处理7天Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金最大绝热温变值都减小,热处Special shape NdFeB magnets理4天Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金最大绝热温变值都先减小后增大,X=0.1时最大绝热温变值最小。对两组合金系来说,当铝的添加量相同时,都有同样的规律,即热处理7天的最大绝热温变值高于热处理4天的,热处理4天的最大绝热温变值高于铸态的。此外,在同一状态铝的添加量相同的情况下,Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x合金最大绝热温变值高于Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金。随着Al元素含量的增加,无论铸态还是热处理4天、7天,Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金居里温度都是先增大后减小,X=0.1时T_c值最大,这与预期的变化http://www.999magnet.com/规律相符。
由于进行了4天、7天900℃热处理,所以使得Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x系合金最大绝热温变值有所提高。特别是在7天900℃热处理后,由于Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x(X=0,X=0.1)合金的晶体结构由双相结构基本转变为单相结构,合金各元素分布也更均匀,合金的磁熵变在低磁场Special shape NdFeB magnets下(1T磁场下)仍保持较高的值,分别比铸态合金提高53.2%和33.1%。
以上工作表明:通过调节镝和铝的含量,可以使合金居里温度在室温附近变化。此外,镝和铝元素的加入降低了合金的成本,并没有改变GdCo_2合金的二级相变形式。在研究的合金中,Gd_(0.6)Dy_(0.4)Co_2合金居里温度在室温附近,成本低,在较小的外场下就能获得较高的磁熵变,因而有望成为较好的室温低场磁制冷工质。
学位年度:2009
作者:于越
学位授予单位:西华大学
关键词:磁热效应;;居里温度;;磁熵变;;磁相变;;稀土
摘要:
近年来,稀土化合物GdCo_2、DyCo_2以其低廉的价格引起人们的关注,但GdCo_2居里温度远高于室温,相变类型为二级相变,磁熵变不高;DyCo_2居里温度远低于室温,相变类型为一级相变,具有较大的磁熵变,两者都不适合做Special shape NdFeB magnets室温磁制冷材料。为了利用GdCo_2和DyCo_2的各自优点,制备一种居里温度在室温附近,在低磁场下磁熵变有较高值且成本相对低廉的合金,本文在用部分Dy取代GdCo_2中Gd的基础上,再用部分Al来取代Co,用真空电弧熔炼炉制备Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x(X=0,0.05,0.1,0.15)两个系列合金,然后取铸态试样分别做温度为900℃4天、7天的热处理,运用SQUID量子磁强计,X射线衍射仪,扫描电镜,绝热温变测试系统等检测手段对铸态和热处理态的两系列合金进行性能测试,研究Al和Dy元素的加入对铸态和热处理态GdCo_2合金相结构、绝热温变、居里温度、磁熵变的影响。
室温粉末X射线衍射分析发现铸态、热处理4天Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金均属于GdCo_2和GdCo_3共存型晶体结构,而热处理7天Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金属于GdCo_2单相晶体结构。在1.4T磁场下,随着Al元素含量的增加,铸态、热处理7天Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金最大绝热温变值都减小,热处Special shape NdFeB magnets理4天Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金最大绝热温变值都先减小后增大,X=0.1时最大绝热温变值最小。对两组合金系来说,当铝的添加量相同时,都有同样的规律,即热处理7天的最大绝热温变值高于热处理4天的,热处理4天的最大绝热温变值高于铸态的。此外,在同一状态铝的添加量相同的情况下,Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x合金最大绝热温变值高于Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金。随着Al元素含量的增加,无论铸态还是热处理4天、7天,Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x合金居里温度都是先增大后减小,X=0.1时T_c值最大,这与预期的变化http://www.999magnet.com/规律相符。
由于进行了4天、7天900℃热处理,所以使得Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x和Gd_(0.55)Dy_(0.45)Co_(2-x)Al_x系合金最大绝热温变值有所提高。特别是在7天900℃热处理后,由于Gd_(0.6)Dy_(0.4)Co_(2-x)Al_x(X=0,X=0.1)合金的晶体结构由双相结构基本转变为单相结构,合金各元素分布也更均匀,合金的磁熵变在低磁场Special shape NdFeB magnets下(1T磁场下)仍保持较高的值,分别比铸态合金提高53.2%和33.1%。
以上工作表明:通过调节镝和铝的含量,可以使合金居里温度在室温附近变化。此外,镝和铝元素的加入降低了合金的成本,并没有改变GdCo_2合金的二级相变形式。在研究的合金中,Gd_(0.6)Dy_(0.4)Co_2合金居里温度在室温附近,成本低,在较小的外场下就能获得较高的磁熵变,因而有望成为较好的室温低场磁制冷工质。
学位年度:2009
镁合金及其弱刚度结构件铣削加工试验研究
题名:镁合金及其弱刚度结构件铣削加工试验研究
作者:熊细文
学位授予单位:南京理工大学
关键词:镁合金;;弱刚度结构件;;铣削加工;;高速加工;;变形控制
摘要:
镁合金具有诸多优良的性能,被誉为“21世纪绿色工程材料”,在汽车、通信、航空航天及军工等领域具有广阔的应用前景。随着镁合金耐腐蚀、抗蠕变等性能的提高,一些有特殊应用要求的结构件已开始采用镁合金取代传统的金属结构材料,而对于镁合金薄壁等弱刚度结构件而言,加工时工件易发生较大变形,需Block Neodymium magnets要寻求有效的加工工艺与方法。本文依托国家科研项目,并结合高速加工技术,对稀土镁合金及其弱刚度结构件进行铣削加工试验研究,为其在相关领域上的应用提供技术支撑。
论文首先系统地阐述了镁合金切削加工的特点与存在的主要问题,对其在刀具、切削用量、切削液等方面的相关选用原则进行了总结。然后,以高强度新型稀土镁合金材料Mg-6Nd-4Gd-3Y为研究对象开展特征http://www.999magnet.com/结构铣削加工试验,对窄槽及薄壁加工过程中的切削温度、加工质量以及加工变形进行了相应研究,并分析了镁合金切屑的形状特征,获得了稀土镁合金的相关切削加工性能。接着,通过开展高速铣削析因试验与均匀试验系统地研究了铣削参数对高速铣削力的影响规律,得到了影响铣削力的显著性效应因素,并根Block Neodymium magnets据试验结果建立了铣削力的预测模型。最后,根据弱刚度结构件的加工变形控制措施以及上述试验研究的相关结论,并结合CAD/CAM/CAE技术对典型镁合金弱刚度结构件进行了加工工艺分析、加工变形数值模拟以及加工试验验证。试验结果初步达到预期目标,表明所用工艺是较合理可行的。
学位年度:2009
作者:熊细文
学位授予单位:南京理工大学
关键词:镁合金;;弱刚度结构件;;铣削加工;;高速加工;;变形控制
摘要:
镁合金具有诸多优良的性能,被誉为“21世纪绿色工程材料”,在汽车、通信、航空航天及军工等领域具有广阔的应用前景。随着镁合金耐腐蚀、抗蠕变等性能的提高,一些有特殊应用要求的结构件已开始采用镁合金取代传统的金属结构材料,而对于镁合金薄壁等弱刚度结构件而言,加工时工件易发生较大变形,需Block Neodymium magnets要寻求有效的加工工艺与方法。本文依托国家科研项目,并结合高速加工技术,对稀土镁合金及其弱刚度结构件进行铣削加工试验研究,为其在相关领域上的应用提供技术支撑。
论文首先系统地阐述了镁合金切削加工的特点与存在的主要问题,对其在刀具、切削用量、切削液等方面的相关选用原则进行了总结。然后,以高强度新型稀土镁合金材料Mg-6Nd-4Gd-3Y为研究对象开展特征http://www.999magnet.com/结构铣削加工试验,对窄槽及薄壁加工过程中的切削温度、加工质量以及加工变形进行了相应研究,并分析了镁合金切屑的形状特征,获得了稀土镁合金的相关切削加工性能。接着,通过开展高速铣削析因试验与均匀试验系统地研究了铣削参数对高速铣削力的影响规律,得到了影响铣削力的显著性效应因素,并根Block Neodymium magnets据试验结果建立了铣削力的预测模型。最后,根据弱刚度结构件的加工变形控制措施以及上述试验研究的相关结论,并结合CAD/CAM/CAE技术对典型镁合金弱刚度结构件进行了加工工艺分析、加工变形数值模拟以及加工试验验证。试验结果初步达到预期目标,表明所用工艺是较合理可行的。
学位年度:2009
褐飞虱胁迫下水稻、褐飞虱体内铕含量动态
题名:褐飞虱胁迫下水稻、褐飞虱体内铕含量动态
作者:杨敏
学位授予单位:扬州大学
关键词:褐飞虱;;水稻品种;;铕含量
摘要:
本文应用稀土元素铕标记方法研究了在褐飞虱胁迫下水稻不同品种、不同部位铕含量变化情况,主要结果如下:
1、土培条件下,申优1号和协优963分蘖后期接虫试验表明:在褐飞虱侵害下,申优1号水稻各部位铕含量变化比协优963更敏感,如30、60、120头/株褐飞虱侵害3天,水稻根、茎、叶铕含量都显著下降,且水稻各部位铕吸收量叶>根>茎;在不接虫情况下,协优963铕吸收量明显比申优1号铕含量要少;申优1号,随着褐飞虱密度的增加,水稻Alnico magnets各部位铕含量下降,根、叶铕含量对褐飞虱更敏感;协优963,受褐飞虱侵害后,水稻各部位铕吸收量变化趋势和申优1号很接近。30、60、120头/株褐飞虱侵害6天,水稻各部位铕含量明显下降,申优1号水稻品种根、茎、叶铕含量明显比协优963下降的快。
2、土培条件下,取食申优1号和协优963水稻的褐飞虱体内铕含量表明:褐飞虱取食申优1号水稻品种,体内铕吸收量明显比取食协优963水稻品种的要高;取食申优1号水稻的,60头/株的褐飞虱体内铕含量明显比30头/株的要高,而120头/株的则比30头/株的褐飞虱体内铕吸收量要低;取食协优963水稻品种的,随着褐飞虱密度的增加,褐飞虱体内铕吸收量反而减少。褐飞虱为害水稻6天的褐飞虱体内铕吸收量明显增加,且取食申优1号的比取食协优963的要增加的快。
3、水培条件下,申优1号和协优963分蘖后期接虫试验表明:在褐飞虱侵害下,申优1号水稻各部位铕含量变化比协优963更敏感,如30、Alnico magnets 60头/株褐飞虱侵害3天,水稻根、茎、叶铕吸收量都显著下降,且水稻各部位铕吸收量根>茎>叶。对照试验表明,在不接虫情况下,申优1号铕含量明显高于协优963;在30头/株情况下,申优1号和协优963受褐飞虱影响并没有显著差异,而60头/株时,申优1号水稻品种根、茎、叶受影响明显比协优963根、茎、叶大,这也说明了申优1号比协优963更敏感。
4、水培条件下,取食申优1号和协优963水稻的褐飞虱体内铕含量表明:褐飞虱取食申优1号水稻品种,体内铕吸收量明显比取食协优963水稻品种的要http://www.999magnet.com/高;取食申优1号水稻的,60头/株的褐飞虱体内铕吸收量明显比30头/株的要高,取食协优963水稻品种的,随着褐飞虱密度的增加,褐飞虱体内铕含量反而减少。
5、水培条件下,褐飞虱为害申优1号24h,在标记和未标记水稻上,褐飞虱分泌的蜜露量差异显著,而褐飞虱为害协优963 24h,标记水稻和未标记水稻上,褐飞虱分泌的蜜露量没有显著差异;褐飞虱为害不同水稻品种24h,褐飞虱分泌的蜜露量有显著差异。褐飞虱为害不同水稻品种24h,取食标记的不同品种水稻的褐飞虱体内铕含量Alnico magnets差异显著,取食未标记不同品种水稻的褐飞虱体内铕含量差异不显著;同一水稻品种上,标记和未标记水稻上褐飞虱铕含量有显著差异。
学位年度:2009
作者:杨敏
学位授予单位:扬州大学
关键词:褐飞虱;;水稻品种;;铕含量
摘要:
本文应用稀土元素铕标记方法研究了在褐飞虱胁迫下水稻不同品种、不同部位铕含量变化情况,主要结果如下:
1、土培条件下,申优1号和协优963分蘖后期接虫试验表明:在褐飞虱侵害下,申优1号水稻各部位铕含量变化比协优963更敏感,如30、60、120头/株褐飞虱侵害3天,水稻根、茎、叶铕含量都显著下降,且水稻各部位铕吸收量叶>根>茎;在不接虫情况下,协优963铕吸收量明显比申优1号铕含量要少;申优1号,随着褐飞虱密度的增加,水稻Alnico magnets各部位铕含量下降,根、叶铕含量对褐飞虱更敏感;协优963,受褐飞虱侵害后,水稻各部位铕吸收量变化趋势和申优1号很接近。30、60、120头/株褐飞虱侵害6天,水稻各部位铕含量明显下降,申优1号水稻品种根、茎、叶铕含量明显比协优963下降的快。
2、土培条件下,取食申优1号和协优963水稻的褐飞虱体内铕含量表明:褐飞虱取食申优1号水稻品种,体内铕吸收量明显比取食协优963水稻品种的要高;取食申优1号水稻的,60头/株的褐飞虱体内铕含量明显比30头/株的要高,而120头/株的则比30头/株的褐飞虱体内铕吸收量要低;取食协优963水稻品种的,随着褐飞虱密度的增加,褐飞虱体内铕吸收量反而减少。褐飞虱为害水稻6天的褐飞虱体内铕吸收量明显增加,且取食申优1号的比取食协优963的要增加的快。
3、水培条件下,申优1号和协优963分蘖后期接虫试验表明:在褐飞虱侵害下,申优1号水稻各部位铕含量变化比协优963更敏感,如30、Alnico magnets 60头/株褐飞虱侵害3天,水稻根、茎、叶铕吸收量都显著下降,且水稻各部位铕吸收量根>茎>叶。对照试验表明,在不接虫情况下,申优1号铕含量明显高于协优963;在30头/株情况下,申优1号和协优963受褐飞虱影响并没有显著差异,而60头/株时,申优1号水稻品种根、茎、叶受影响明显比协优963根、茎、叶大,这也说明了申优1号比协优963更敏感。
4、水培条件下,取食申优1号和协优963水稻的褐飞虱体内铕含量表明:褐飞虱取食申优1号水稻品种,体内铕吸收量明显比取食协优963水稻品种的要http://www.999magnet.com/高;取食申优1号水稻的,60头/株的褐飞虱体内铕吸收量明显比30头/株的要高,取食协优963水稻品种的,随着褐飞虱密度的增加,褐飞虱体内铕含量反而减少。
5、水培条件下,褐飞虱为害申优1号24h,在标记和未标记水稻上,褐飞虱分泌的蜜露量差异显著,而褐飞虱为害协优963 24h,标记水稻和未标记水稻上,褐飞虱分泌的蜜露量没有显著差异;褐飞虱为害不同水稻品种24h,褐飞虱分泌的蜜露量有显著差异。褐飞虱为害不同水稻品种24h,取食标记的不同品种水稻的褐飞虱体内铕含量Alnico magnets差异显著,取食未标记不同品种水稻的褐飞虱体内铕含量差异不显著;同一水稻品种上,标记和未标记水稻上褐飞虱铕含量有显著差异。
学位年度:2009
ZA73镁合金组织与性能研究
题名:ZA73镁合金组织与性能研究
作者:何曲波
学位授予单位:重庆大学
关键词:耐热镁合金;;ZA合金;;热处理;;稀土Er;;热模拟;;挤压加工
摘要:
Mg-Zn-Al(ZA)系列镁合金具有铸造性能优良、耐热性能好、成本低等特点,被认为是很有发展前途的镁合金系列。低合金化的ZA73镁合金除了具有ZA系列合金的优点外,还具有较低比重,深入研究ZA73镁合金组织Segment neodymium magnets与性能具有较强的实际意义。
本文通过金相(OM)、X-射线衍射分析(XRD)、差热分析(DSC)、扫描电镜(SEM+EDS)和透射电镜(TEM)等实验手段研究了ZA73及其改性合金铸态、热处理态、热模拟后和挤压态的显微组织,并结合力学性能试验、热模拟试验(Gleeble-1500)研究了显微组织、力学性能及成形行为间的关系。
研究结果表明,ZA73镁合金铸态组织中存在大量共晶组织,显微组织主要由α-Mg相和τ相[Mg32(Al,Zn)49]组成,大部分沿晶界半连续分布。经过固溶和时效处理后,合金中的主要第二相依然为τ相,但形态、数量和分布发生改变:固溶20h后,τ相几乎全部溶解,但时效后晶界析出较多τ相;固溶50h后时效,晶界析出τ相极少,大部分在晶内析出,且尺寸细小。固溶时效后,ZA73镁合金的室温力学性能提高,但高温力学性能降低。
添加稀土Er进行微合金化后,晶界半连续分布的τ相变为颗粒状或球状,并且合金中有细小颗粒状Er-Al化合物生成。半连续铸造ZA73镁合金的室Segment neodymium magnets温力学性能随着稀土Er含量的增加出现峰值,峰值时稀土Er含量为0.7%。金属型铸造ZA73镁合金的高温抗拉强度随着稀土Er含http://www.999magnet.com/量的增加而增加,伸长率在添加0.4%Er时出现峰值;高温下拉伸变形,合金的强度并不随温度的增高而连续降低,而是在温度为150℃拉伸变形时强度出现峰值。
变形温度和应变速率是影响ZA73及其改性合金流变应力和塑性的关键参数:应变速率一定时,流变应力随温度的增加而降低;温度一定时,流变应力随应变速率的提高而增加。稀土Er的加入可以提高合金低应变速率下变形的热塑性。在200~250℃范围内变形时,ZA73镁合金铸态枝晶网状组织特征消失,第二相化Segment neodymium magnets合物呈颗粒状弥散分布于基体中,尺寸明显细化;300℃变形时,低应变速率下合金组织明显粗化。细小第二相粒子增多和组织粗化导致合金热塑性降低。较高的应变速率和较高的温度有利于合金的热变形。
在350℃和较高应变速率(约0.1S~(-1))下顺利挤出了表面质量优良的棒材,其抗拉强度达355MPa,延伸率仍保持19%,晶粒尺寸细化至2～7μm。
学位年度:2009
作者:何曲波
学位授予单位:重庆大学
关键词:耐热镁合金;;ZA合金;;热处理;;稀土Er;;热模拟;;挤压加工
摘要:
Mg-Zn-Al(ZA)系列镁合金具有铸造性能优良、耐热性能好、成本低等特点,被认为是很有发展前途的镁合金系列。低合金化的ZA73镁合金除了具有ZA系列合金的优点外,还具有较低比重,深入研究ZA73镁合金组织Segment neodymium magnets与性能具有较强的实际意义。
本文通过金相(OM)、X-射线衍射分析(XRD)、差热分析(DSC)、扫描电镜(SEM+EDS)和透射电镜(TEM)等实验手段研究了ZA73及其改性合金铸态、热处理态、热模拟后和挤压态的显微组织,并结合力学性能试验、热模拟试验(Gleeble-1500)研究了显微组织、力学性能及成形行为间的关系。
研究结果表明,ZA73镁合金铸态组织中存在大量共晶组织,显微组织主要由α-Mg相和τ相[Mg32(Al,Zn)49]组成,大部分沿晶界半连续分布。经过固溶和时效处理后,合金中的主要第二相依然为τ相,但形态、数量和分布发生改变:固溶20h后,τ相几乎全部溶解,但时效后晶界析出较多τ相;固溶50h后时效,晶界析出τ相极少,大部分在晶内析出,且尺寸细小。固溶时效后,ZA73镁合金的室温力学性能提高,但高温力学性能降低。
添加稀土Er进行微合金化后,晶界半连续分布的τ相变为颗粒状或球状,并且合金中有细小颗粒状Er-Al化合物生成。半连续铸造ZA73镁合金的室Segment neodymium magnets温力学性能随着稀土Er含量的增加出现峰值,峰值时稀土Er含量为0.7%。金属型铸造ZA73镁合金的高温抗拉强度随着稀土Er含http://www.999magnet.com/量的增加而增加,伸长率在添加0.4%Er时出现峰值;高温下拉伸变形,合金的强度并不随温度的增高而连续降低,而是在温度为150℃拉伸变形时强度出现峰值。
变形温度和应变速率是影响ZA73及其改性合金流变应力和塑性的关键参数:应变速率一定时,流变应力随温度的增加而降低;温度一定时,流变应力随应变速率的提高而增加。稀土Er的加入可以提高合金低应变速率下变形的热塑性。在200~250℃范围内变形时,ZA73镁合金铸态枝晶网状组织特征消失,第二相化Segment neodymium magnets合物呈颗粒状弥散分布于基体中,尺寸明显细化;300℃变形时,低应变速率下合金组织明显粗化。细小第二相粒子增多和组织粗化导致合金热塑性降低。较高的应变速率和较高的温度有利于合金的热变形。
在350℃和较高应变速率(约0.1S~(-1))下顺利挤出了表面质量优良的棒材,其抗拉强度达355MPa,延伸率仍保持19%,晶粒尺寸细化至2～7μm。
学位年度:2009
乙氧基色酮希夫碱金属配合物的合成、表征及与DNA的作用研究
题名:乙氧基色酮希夫碱金属配合物的合成、表征及与DNA的作用研究
作者:王菊
学位授予单位:兰州大学
关键词:色酮类化合物;;希夫碱;;金属配合物;;荧光性质;;DNA结合
摘要:
本文主要报道了黄酮类希夫碱及其金属配合物的合成、表征及它们生物活性测定。共合成了四个希夫碱配体和十四个金属配合物。本论文由六章组成:
第一章,简要介绍了黄酮类化合Neodymium Magnets物药理作用的研究进展以及金属配合物与DNA的相互作用等。
第二章,介绍了6-乙氧基-3-醛基色酮(苯甲酰基)腙配体HL~1及其四种稀土金属(Sm,Eu,Gd,Tb),研究了铕、钐的配合物的荧光性质及与ct-DNA的相互作用,结果表明配合物均以插入方式与DNA结合。此外,稀土配合物都具有一定的清除OH·的作用。
第三章,介绍了6-乙氧基-3-醛基色酮(苯甲酰基)腙配体HL~1及过渡金属(Zn,Ni)配合物的合成、表征;锌的配合物在紫外灯下发出蓝光,测定了其固http://www.999magnet.com/体及液体荧光性质。与ct-DNA的相互作用的研究表明配体及锌配合物均能以插入方式与DNA结合。第四章,介绍了6-乙氧基-3-醛基色酮(对羟基苯甲酰基)腙配体H_2L~2及其两种稀土金属(La,Eu)配合物的合成、表征;研究了铕配合物固体及液体荧Neodymium Magnets光性质。与ct-DNA的相互作用的研究表明配体及配合物均能以插入方式与DNA结合,且配合物与DNA的结合能力比配体更强。第五章,介绍了6-乙氧基-3-醛基色酮(2,4-二羟基羟基苯甲酰基)腙配体H_3L~3及其四种稀土金属(La,SNeodymium Magnetsm,Dy,Eu)配合物的合成、表征;稀土金属镧的配合物在紫外灯下发出绿光,同时进行了镧、钐、铕配合物荧光性质研究。与ct-DNA的相互作用的研究表明所有的化合物均能以插入方式与DNA结合。
第六章,介绍了6-乙氧基-3-醛基色酮(氨基硫脲基)腙配体H_3L~4及其两种过渡金属(Zn,Cu)配合物的合成表征;进行了与ct-DNA的相互作用的研究。
学位年度:2009
作者:王菊
学位授予单位:兰州大学
关键词:色酮类化合物;;希夫碱;;金属配合物;;荧光性质;;DNA结合
摘要:
本文主要报道了黄酮类希夫碱及其金属配合物的合成、表征及它们生物活性测定。共合成了四个希夫碱配体和十四个金属配合物。本论文由六章组成:
第一章,简要介绍了黄酮类化合Neodymium Magnets物药理作用的研究进展以及金属配合物与DNA的相互作用等。
第二章,介绍了6-乙氧基-3-醛基色酮(苯甲酰基)腙配体HL~1及其四种稀土金属(Sm,Eu,Gd,Tb),研究了铕、钐的配合物的荧光性质及与ct-DNA的相互作用,结果表明配合物均以插入方式与DNA结合。此外,稀土配合物都具有一定的清除OH·的作用。
第三章,介绍了6-乙氧基-3-醛基色酮(苯甲酰基)腙配体HL~1及过渡金属(Zn,Ni)配合物的合成、表征;锌的配合物在紫外灯下发出蓝光,测定了其固http://www.999magnet.com/体及液体荧光性质。与ct-DNA的相互作用的研究表明配体及锌配合物均能以插入方式与DNA结合。第四章,介绍了6-乙氧基-3-醛基色酮(对羟基苯甲酰基)腙配体H_2L~2及其两种稀土金属(La,Eu)配合物的合成、表征;研究了铕配合物固体及液体荧Neodymium Magnets光性质。与ct-DNA的相互作用的研究表明配体及配合物均能以插入方式与DNA结合,且配合物与DNA的结合能力比配体更强。第五章,介绍了6-乙氧基-3-醛基色酮(2,4-二羟基羟基苯甲酰基)腙配体H_3L~3及其四种稀土金属(La,SNeodymium Magnetsm,Dy,Eu)配合物的合成、表征;稀土金属镧的配合物在紫外灯下发出绿光,同时进行了镧、钐、铕配合物荧光性质研究。与ct-DNA的相互作用的研究表明所有的化合物均能以插入方式与DNA结合。
第六章,介绍了6-乙氧基-3-醛基色酮(氨基硫脲基)腙配体H_3L~4及其两种过渡金属(Zn,Cu)配合物的合成表征;进行了与ct-DNA的相互作用的研究。
学位年度:2009
4-酰基吡唑啉酮类配合物的研究
题名:4-酰基吡唑啉酮类配合物的研究
作者:张慧慧
学位授予单位:兰州大学
关键词:4－酰基吡唑啉酮衍生物;;稀土离子及过渡金属离子;;F－B配合物;;晶体结构;;荧光性质
摘要:
含有酰肼或酰腙的化合物具有较强的配位能力和丰富多样的配位方式,而且在光、电、磁、生物等领域被广泛地应用。本文通Block Neodymium magnets过对一系列吡唑啉酮及其Shiff碱配体配合物超分子结构及性能的研究,对超分子自组装、功能配合物的设计合成及结构与性能的关系进行了探讨,合成了一系列具有应用前景的功能配合物,并对相关配合物的荧光、磁学性质进行了研究。全文共分为五部分:
1.介绍了本文的研究背景,重点介绍了与本文相关的吡唑啉酮衍生物的研究现状,以及荧光化学传感器的设计原理,并阐述了本论文的选题目的及意义。
2.合成了以1-苯基-3-甲基-4-苯甲酰基吡唑啉酮缩水杨酰肼为配体的五个稀土(Pr~(3+)、Sm~(3+)、Eu~(3+)、Gd~(3+)、Tb~(3+)配合物,并对其荧光性质进行了研究,对稀土配合物晶体结构的变化进行了详细的分析,发现吡唑啉酮Shiff碱中特有的氢键模式是中心金属离子配位方式的一个重要决定因素,从而进一步影响配体到稀土Block Neodymium magnets离子能量转移的有效程度。同时合成了一个双核Cu~(2+)配合物,通过对其晶体结构的分析以及与已报道的双核Cu~(2+)配合物的结构进行比较,预测了该配合物的磁性。
3.合成了以1-苯基-3-甲基-4-苯甲酰基吡唑啉酮缩肼为配体的Tb~(3+)配合物,四个过渡金属(Cu~(2+)、Co~(2+)、Mn~(2+)、Mn~(2+))配合物,分析讨论了配合物晶体结构的变化,发现除了中心金属离子的d电子构型和离子半径,吡唑啉酮Shiff碱与溶剂之间较强的氢键也影响着配体中心金属离子的配位方式。同时研究了双核Mn~(2 http://www.999magnet.com/
+)配合物的磁性以及Mn(OAc)_3促进的配体氧化偶联反应。
4.合成了以1-苯基-3-甲基-4-苯甲酰基吡唑啉酮缩苯甲酰腙为配体的Zn~(2+)配合物,对其晶体结构及氢键模式进行了分析,重点研究了该配合物对Ag~+离子的选择性识别。通过配合物的光物理性质以及电喷雾质谱、核磁共振谱等Block Neodymium magnets各种谱学数据,推测了Zn~(2+)配合物与Ag~+超分子自组装的方式。
5.合成了以1-苯基-3-甲基-4-酰基吡唑啉酮为配体的具有D-A(donor-acceptor)结构的三个F-B配合物,对其中的一个配合物的晶体结构及晶体内的堆积方式进行了分析,探讨了结构对它们发光性质的影响,发现吡唑啉分子的取代基变化影响固体中的堆积方式,从而进一步影响其分子间电荷转移的方式,造成了发射跃迁的明显不同。
学位年度:2009
作者:张慧慧
学位授予单位:兰州大学
关键词:4－酰基吡唑啉酮衍生物;;稀土离子及过渡金属离子;;F－B配合物;;晶体结构;;荧光性质
摘要:
含有酰肼或酰腙的化合物具有较强的配位能力和丰富多样的配位方式,而且在光、电、磁、生物等领域被广泛地应用。本文通Block Neodymium magnets过对一系列吡唑啉酮及其Shiff碱配体配合物超分子结构及性能的研究,对超分子自组装、功能配合物的设计合成及结构与性能的关系进行了探讨,合成了一系列具有应用前景的功能配合物,并对相关配合物的荧光、磁学性质进行了研究。全文共分为五部分:
1.介绍了本文的研究背景,重点介绍了与本文相关的吡唑啉酮衍生物的研究现状,以及荧光化学传感器的设计原理,并阐述了本论文的选题目的及意义。
2.合成了以1-苯基-3-甲基-4-苯甲酰基吡唑啉酮缩水杨酰肼为配体的五个稀土(Pr~(3+)、Sm~(3+)、Eu~(3+)、Gd~(3+)、Tb~(3+)配合物,并对其荧光性质进行了研究,对稀土配合物晶体结构的变化进行了详细的分析,发现吡唑啉酮Shiff碱中特有的氢键模式是中心金属离子配位方式的一个重要决定因素,从而进一步影响配体到稀土Block Neodymium magnets离子能量转移的有效程度。同时合成了一个双核Cu~(2+)配合物,通过对其晶体结构的分析以及与已报道的双核Cu~(2+)配合物的结构进行比较,预测了该配合物的磁性。
3.合成了以1-苯基-3-甲基-4-苯甲酰基吡唑啉酮缩肼为配体的Tb~(3+)配合物,四个过渡金属(Cu~(2+)、Co~(2+)、Mn~(2+)、Mn~(2+))配合物,分析讨论了配合物晶体结构的变化,发现除了中心金属离子的d电子构型和离子半径,吡唑啉酮Shiff碱与溶剂之间较强的氢键也影响着配体中心金属离子的配位方式。同时研究了双核Mn~(2 http://www.999magnet.com/
+)配合物的磁性以及Mn(OAc)_3促进的配体氧化偶联反应。
4.合成了以1-苯基-3-甲基-4-苯甲酰基吡唑啉酮缩苯甲酰腙为配体的Zn~(2+)配合物,对其晶体结构及氢键模式进行了分析,重点研究了该配合物对Ag~+离子的选择性识别。通过配合物的光物理性质以及电喷雾质谱、核磁共振谱等Block Neodymium magnets各种谱学数据,推测了Zn~(2+)配合物与Ag~+超分子自组装的方式。
5.合成了以1-苯基-3-甲基-4-酰基吡唑啉酮为配体的具有D-A(donor-acceptor)结构的三个F-B配合物,对其中的一个配合物的晶体结构及晶体内的堆积方式进行了分析,探讨了结构对它们发光性质的影响,发现吡唑啉分子的取代基变化影响固体中的堆积方式,从而进一步影响其分子间电荷转移的方式,造成了发射跃迁的明显不同。
学位年度:2009
1，3-丙二胺缩水杨醛金属配合物的合成、结构及性能研究
题名:1，3-丙二胺缩水杨醛金属配合物的合成、结构及性能研究
作者:李明杰
学位授予单位:黑龙江大学
关键词:Schiff碱;;合成;;结构;;磁性;;荧光
摘要:
Schiff碱金属配合物因其结构的多样性以及在发光、磁性、电化学和催化等功能材料领域具有潜在的应用价值而受到人们广泛的关注。人们对这类配合物的合成、表征、结构测定、光学、电化学、磁性和催化等方面进行Alnico magnets了富有成效的研究。
本文选取一种Schiff碱(1,3-丙二胺缩水杨醛(H2L))为配体与稀土盐反应合成出21种新的Schiff碱稀土配合物。对配合物分别进行了元素分析、差热失重、XRD、红外光谱、紫外光谱表征,并利用扩散的方法培养单晶,通过X–射线单晶衍射分析表征了5种配合物的分子结构,即配合物1、3、4、6和22。Schiff碱与水合硝酸稀土反应所得配合物的组成可表示为[Ln(H_2L)_2(NO_3)_3]n [Ln = La (1)],[Ln(H_2L)_2(NO_3)_3]2 [Ln = Pr (2), Nd (3), Eu (5), Gd (6), Tb (7) & Dy (8)] & [Ln(H2L)(NO_3)_3(CH_3OH)]2 [Ln = Sm (4) & Er (9)]。Schiff碱与水合氯化稀土反应所得配合物的组成可表示为[Ln(H_2L)_2Cl_3·2CH_3OH] [Ln = La (10), Pr (11), Nd (12), Sm (13), Eu (14), Gd (15), Tb (16), Er (17) & Lu (18)]。Schiff碱与无水氯化稀土反应所得配合物的组成可表示为[Ln(H_2L)_2Cl3·2CH_3OH] [Ln = La (19), Nd (20Alnico magnets) & Lu (21)]。Schiff碱与水合氯化锰反应所得配合物的组成可表示为[MnLCl] (22)。X–射线单晶衍射结构分析表明配合物1的结构为新颖的一维双链分子结构,配合物3、4和6为新颖的零维二聚体结构,配合物22为零维结构。
荧光光谱分析显示除配合物4、5和17是中心金属离子和配体发http://www.999magnet.com/光之外,其他配合物主要是配体发光。电导率数据表明配合物在甲醇和乙腈溶剂中为弱电解质溶液。乙烯及苯乙烯的催化聚合反应数据表明配合物19–21有催Alnico magnets化苯乙烯聚合的性能。在2–300 K温度范围内、500 Oe的场强下研究了配合物6的变温磁学性质。配合物6的金属离子间显示了反铁磁性相互作用。
学位年度:2009
作者:李明杰
学位授予单位:黑龙江大学
关键词:Schiff碱;;合成;;结构;;磁性;;荧光
摘要:
Schiff碱金属配合物因其结构的多样性以及在发光、磁性、电化学和催化等功能材料领域具有潜在的应用价值而受到人们广泛的关注。人们对这类配合物的合成、表征、结构测定、光学、电化学、磁性和催化等方面进行Alnico magnets了富有成效的研究。
本文选取一种Schiff碱(1,3-丙二胺缩水杨醛(H2L))为配体与稀土盐反应合成出21种新的Schiff碱稀土配合物。对配合物分别进行了元素分析、差热失重、XRD、红外光谱、紫外光谱表征,并利用扩散的方法培养单晶,通过X–射线单晶衍射分析表征了5种配合物的分子结构,即配合物1、3、4、6和22。Schiff碱与水合硝酸稀土反应所得配合物的组成可表示为[Ln(H_2L)_2(NO_3)_3]n [Ln = La (1)],[Ln(H_2L)_2(NO_3)_3]2 [Ln = Pr (2), Nd (3), Eu (5), Gd (6), Tb (7) & Dy (8)] & [Ln(H2L)(NO_3)_3(CH_3OH)]2 [Ln = Sm (4) & Er (9)]。Schiff碱与水合氯化稀土反应所得配合物的组成可表示为[Ln(H_2L)_2Cl_3·2CH_3OH] [Ln = La (10), Pr (11), Nd (12), Sm (13), Eu (14), Gd (15), Tb (16), Er (17) & Lu (18)]。Schiff碱与无水氯化稀土反应所得配合物的组成可表示为[Ln(H_2L)_2Cl3·2CH_3OH] [Ln = La (19), Nd (20Alnico magnets) & Lu (21)]。Schiff碱与水合氯化锰反应所得配合物的组成可表示为[MnLCl] (22)。X–射线单晶衍射结构分析表明配合物1的结构为新颖的一维双链分子结构,配合物3、4和6为新颖的零维二聚体结构,配合物22为零维结构。
荧光光谱分析显示除配合物4、5和17是中心金属离子和配体发http://www.999magnet.com/光之外,其他配合物主要是配体发光。电导率数据表明配合物在甲醇和乙腈溶剂中为弱电解质溶液。乙烯及苯乙烯的催化聚合反应数据表明配合物19–21有催Alnico magnets化苯乙烯聚合的性能。在2–300 K温度范围内、500 Oe的场强下研究了配合物6的变温磁学性质。配合物6的金属离子间显示了反铁磁性相互作用。
学位年度:2009
镇安卡林型金矿矿床类型及找矿方向探讨
题名:镇安卡林型金矿矿床类型及找矿方向探讨
作者:毛丽洪
学位授予单位:长安大学
关键词:卡林型金矿;;镇安;;矿床成因;;成矿预测
摘要:
本文选择镇安主要的卡林型金矿—二台子金矿以及金龙山矿带的东沟金矿作为研究对象,在充分整理和吸收前人大量研究成果的基础上,经过深入细致的野外地质调查,收集了大量的地质信息,采集了相关的岩石和矿物标本,并应用现代岩石学、矿物学、矿床学、地球化学、遥感地质学以及成矿预测等的理论和方Segment neodymium magnets法进行研究。本文在分析研究本区区域成矿地质背景、地质构造发展演化史的基础上,结合二台子、东沟等金矿的矿床地质特征、成矿特点等,分析探讨了http://www.999magnet.com/金矿的主要控矿因素与成矿条件,并从矿床矿石结构、构造、稳定同位素、微量与稀土元素以及包裹体测温等地球化学特征,分析探讨了矿床成因,认为该区金矿的形成与有利的地层、构造、成矿热液等关系密切,Segment neodymium magnets总结出了该区金矿的控矿因素和找矿标志,并用对比研究的思维和方法,对镇安地区金矿进行预测研究,提出找矿方向和重点靶区。
学位年度:2009
作者:毛丽洪
学位授予单位:长安大学
关键词:卡林型金矿;;镇安;;矿床成因;;成矿预测
摘要:
本文选择镇安主要的卡林型金矿—二台子金矿以及金龙山矿带的东沟金矿作为研究对象,在充分整理和吸收前人大量研究成果的基础上,经过深入细致的野外地质调查,收集了大量的地质信息,采集了相关的岩石和矿物标本,并应用现代岩石学、矿物学、矿床学、地球化学、遥感地质学以及成矿预测等的理论和方Segment neodymium magnets法进行研究。本文在分析研究本区区域成矿地质背景、地质构造发展演化史的基础上,结合二台子、东沟等金矿的矿床地质特征、成矿特点等,分析探讨了http://www.999magnet.com/金矿的主要控矿因素与成矿条件,并从矿床矿石结构、构造、稳定同位素、微量与稀土元素以及包裹体测温等地球化学特征,分析探讨了矿床成因,认为该区金矿的形成与有利的地层、构造、成矿热液等关系密切,Segment neodymium magnets总结出了该区金矿的控矿因素和找矿标志,并用对比研究的思维和方法,对镇安地区金矿进行预测研究,提出找矿方向和重点靶区。
学位年度:2009
新疆和硕县包尔图铜矿地质特征及成矿潜力分析
题名:新疆和硕县包尔图铜矿地质特征及成矿潜力分析
作者:李元元
学位授予单位:长安大学
关键词:地质特征;;成矿潜力;;包尔图;;新疆
摘要:
包尔图铜矿位于塔里木板块北缘南天山与中天山接触带的东段,乌瓦门-包尔图大断裂南侧,分布于艾木太乌拉背斜核部的一套变质Magnetic lifter岩中,是南天山-哈尔克-库米什金、铜、铅、锌多金属成矿带主要成矿区之一。
本文对该矿床基础地质特征和岩石学、矿床学、岩石地球化学以及矿床地球化学等方面进行研究,取得了以下认识:
(1)根据岩石变质程度和变质类型,初步提出矿区上志留-下泥盆统阿尔彼什麦布拉克组第一亚组的第一岩性段(Mi)和第二岩性段(Gn)的混合花岗岩、花岗质混合岩以及斜长片麻岩、角闪片麻岩应归为元古界星星峡群。
(2)矿区出露的变质岩主要为副变质岩,少量正变质岩,其原岩为沉积岩及少量火山岩;在不同构造环境判别图中,大部分样品均落在大陆岛弧区内,说明包尔图铜矿的赋矿围岩形成环境为大陆岛弧环境。
(3)通过岩/矿石稀土、微量元素地球化学研究,表明Magnetic lifter包尔图铜矿的成矿物质来源可能与混合花岗岩有关。
(4)包尔图铜矿目前已经发现六个铜矿化带31条铜矿化体,现发现的各个矿体规模虽都较小,但从成矿条件、区域成矿显示、区Magnetic lifter域构造背景及矿区勘查现状等分析,该区铜矿有一定的找矿潜力。
学位年度:2009
作者:李元元
学位授予单位:长安大学
关键词:地质特征;;成矿潜力;;包尔图;;新疆
摘要:
包尔图铜矿位于塔里木板块北缘南天山与中天山接触带的东段,乌瓦门-包尔图大断裂南侧,分布于艾木太乌拉背斜核部的一套变质Magnetic lifter岩中,是南天山-哈尔克-库米什金、铜、铅、锌多金属成矿带主要成矿区之一。
本文对该矿床基础地质特征和岩石学、矿床学、岩石地球化学以及矿床地球化学等方面进行研究,取得了以下认识:
(1)根据岩石变质程度和变质类型,初步提出矿区上志留-下泥盆统阿尔彼什麦布拉克组第一亚组的第一岩性段(Mi)和第二岩性段(Gn)的混合花岗岩、花岗质混合岩以及斜长片麻岩、角闪片麻岩应归为元古界星星峡群。
(2)矿区出露的变质岩主要为副变质岩,少量正变质岩,其原岩为沉积岩及少量火山岩;在不同构造环境判别图中,大部分样品均落在大陆岛弧区内,说明包尔图铜矿的赋矿围岩形成环境为大陆岛弧环境。
(3)通过岩/矿石稀土、微量元素地球化学研究,表明Magnetic lifter包尔图铜矿的成矿物质来源可能与混合花岗岩有关。
(4)包尔图铜矿目前已经发现六个铜矿化带31条铜矿化体,现发现的各个矿体规模虽都较小,但从成矿条件、区域成矿显示、区Magnetic lifter域构造背景及矿区勘查现状等分析,该区铜矿有一定的找矿潜力。
学位年度:2009
2-羟基喹啉-4-羧酸和1,2,3-三唑-4,5-二羧酸构筑的配位聚合物的合成、结构及性质
题名:2-羟基喹啉-4-羧酸和1,2,3-三唑-4,5-二羧酸构筑的配位聚合物的合成、结构及性质
作者:袁刚
学位授予单位:东北师范大学
关键词:氮杂环羧酸配体;;过渡金属;;稀土金属;;晶体结构;;配位聚合物
摘要:
配位聚合物不仅具有丰富的拓扑结构,而且在催化、分子导体、发光材料、分子磁体、非线性光学等领域有着广阔的应用前景。研究表明有机配体和金属离子的配位性质对配位聚合物结构和功能有着决定性的影响,其他影响因素如阴离子,模板剂、溶剂、反应物的摩尔比、反应体系的pH值等起协同调控作用Neodymium Magnets。因此,有目的的控制合成具有预期结构与性能的配位聚合物一直是化学家所追求的目标。近年来,人们利用含N杂环羧酸配体构筑出大量具有新颖拓扑结构的金属-有机配位聚合物。本论文采用水热法和溶剂法以2-羟基喹啉-4-羧酸(H_2hqc)和1,2,3-三唑-4,5-二羧酸(H_3tda)为主要的配体,辅以辅助配体与Zn~(2+),Cd~(2+)等过渡金属离子以及镧系金属离子构筑出了17个化合物,并对它们的晶体结构和性质进行了表征,进而探讨配体、金属离子对化合物结构的影响。
1.以2-羟基喹啉-4-羧酸为配体,分别在水热条件下和溶剂法合成条件下与过渡金属Zn~(2+) , Ni~(2+)离子反应合成了两个新颖的化合物,它们的分子式分别为[Zn_5(hqc)_4(μ3-OH)_2]_n (1)和[Ni(hqc)_2(H_2O)_2] (2)。探讨了金属离子的配位几何Neodymium Magnets以及反应条件对产物结构的影响。最后还对化合物的荧光性质进行了研究。
2.以1,2,3-三唑-4,5-二羧酸为配体,以2,2′-联吡啶(2,2′-bipy)等含氮的中性有机分子作为第二配体,在水热条件下分别与Zn~(2+),Cd~(2+),Co~(2+),Pb~(2+)等过渡金属离子构筑了8个新的配合物。配合物{[Cd_3(tda)_2(pyim)_3]·3H_2O}_n (7)为一维柱状结构, {[Zn_3(tda)_2(bipy)_2(H_2O)_2]·4H_2O}_n (3)和{[Cd_3(tda)_2(bipy)_3]·5H_2O}_n (4)为二维层状结构,其他的五个化合物[Zn_2(tda)(tz)(H_2O)_2]·H_2O (5) , [Zn_2(tda)(tz)(H_2O)_2]·H_2O (6) ,[Cd_7(tda)_4(pz)(Ac)(H_2O)_7]·3H_2O (8),[Co_5(tda)_4(H_2O)_8]_n (9),和[Pb(tda)]n (10)均为三维结构。同样探讨了金属离子的配位几何,以及配体的配位模式,同时对第二配体对结构的影http://www.999magnet.com/响进行了讨论,考察了配合物的荧光性质。
3.同样以1,2,3-三唑-4,5-二羧酸为Neodymium Magnets配体,与稀土金属离子反应,得到了7个同构的手性金属有机配合物[Ln(tda)(H_2O)]·2H_2O (Ln = La(11), Ce(12), Pr(13), Nd(14), Eu(15), Sm(16), Gd(17))。对配合物的手性结构特点进行了讨论,并对它们的荧光性质和磁学性质进行了研究。
学位年度:2009
作者:袁刚
学位授予单位:东北师范大学
关键词:氮杂环羧酸配体;;过渡金属;;稀土金属;;晶体结构;;配位聚合物
摘要:
配位聚合物不仅具有丰富的拓扑结构,而且在催化、分子导体、发光材料、分子磁体、非线性光学等领域有着广阔的应用前景。研究表明有机配体和金属离子的配位性质对配位聚合物结构和功能有着决定性的影响,其他影响因素如阴离子,模板剂、溶剂、反应物的摩尔比、反应体系的pH值等起协同调控作用Neodymium Magnets。因此,有目的的控制合成具有预期结构与性能的配位聚合物一直是化学家所追求的目标。近年来,人们利用含N杂环羧酸配体构筑出大量具有新颖拓扑结构的金属-有机配位聚合物。本论文采用水热法和溶剂法以2-羟基喹啉-4-羧酸(H_2hqc)和1,2,3-三唑-4,5-二羧酸(H_3tda)为主要的配体,辅以辅助配体与Zn~(2+),Cd~(2+)等过渡金属离子以及镧系金属离子构筑出了17个化合物,并对它们的晶体结构和性质进行了表征,进而探讨配体、金属离子对化合物结构的影响。
1.以2-羟基喹啉-4-羧酸为配体,分别在水热条件下和溶剂法合成条件下与过渡金属Zn~(2+) , Ni~(2+)离子反应合成了两个新颖的化合物,它们的分子式分别为[Zn_5(hqc)_4(μ3-OH)_2]_n (1)和[Ni(hqc)_2(H_2O)_2] (2)。探讨了金属离子的配位几何Neodymium Magnets以及反应条件对产物结构的影响。最后还对化合物的荧光性质进行了研究。
2.以1,2,3-三唑-4,5-二羧酸为配体,以2,2′-联吡啶(2,2′-bipy)等含氮的中性有机分子作为第二配体,在水热条件下分别与Zn~(2+),Cd~(2+),Co~(2+),Pb~(2+)等过渡金属离子构筑了8个新的配合物。配合物{[Cd_3(tda)_2(pyim)_3]·3H_2O}_n (7)为一维柱状结构, {[Zn_3(tda)_2(bipy)_2(H_2O)_2]·4H_2O}_n (3)和{[Cd_3(tda)_2(bipy)_3]·5H_2O}_n (4)为二维层状结构,其他的五个化合物[Zn_2(tda)(tz)(H_2O)_2]·H_2O (5) , [Zn_2(tda)(tz)(H_2O)_2]·H_2O (6) ,[Cd_7(tda)_4(pz)(Ac)(H_2O)_7]·3H_2O (8),[Co_5(tda)_4(H_2O)_8]_n (9),和[Pb(tda)]n (10)均为三维结构。同样探讨了金属离子的配位几何,以及配体的配位模式,同时对第二配体对结构的影http://www.999magnet.com/响进行了讨论,考察了配合物的荧光性质。
3.同样以1,2,3-三唑-4,5-二羧酸为Neodymium Magnets配体,与稀土金属离子反应,得到了7个同构的手性金属有机配合物[Ln(tda)(H_2O)]·2H_2O (Ln = La(11), Ce(12), Pr(13), Nd(14), Eu(15), Sm(16), Gd(17))。对配合物的手性结构特点进行了讨论,并对它们的荧光性质和磁学性质进行了研究。
学位年度:2009
Eu~(3+)掺杂BaTiO_3纳米纤维的制备及其发光性质研究
题名:Eu~(3+)掺杂BaTiO_3纳米纤维的制备及其发光性质研究
作者:薛红梅
学位授予单位:东北师范大学
关键词:BaTiO_3:Eu~(3+);;纳米纤维;;静电纺丝;;煅烧温度;;掺杂浓度;;发光性质
摘要:
一维半导体纳米结构在光学、光电器件及介电等领域有着广泛的应用前景。一维半导体纳米晶具有良好的限域、均匀的magnet lifter几何形状、结晶性易于控制等优点,使其成为近年来半导体研究中最活跃的领域。不同种类和形貌的一维半导体纳米材料不断地被合成出来,一维半导体纳米晶在向器件方向发展方面取得了突破性的进展。
BaTiO_3陶瓷由于其优越的光电特性得到了广泛的应用,BaTiO_3晶体的结构为立方相时是理想的钙铁矿型结构,它的晶格结构使得不同尺寸的施主离子(多为稀土离子)可以掺入到晶格中,掺杂稀土杂质后呈现出半导体性质,可用作半导体材料。稀土掺杂的钙钛矿结构的材料可应用于集成光发射器件、场致发射显示器、蓝绿全固态致密激光器和正温度系数电阻器等方面,引起了人们对它们的研究热潮。在含钛的半导体材料中,无论是实际应用还是理论深度,BaTiO_3都已达到较高的水平,并且具有一定的代表性。近年来一维BaTiO_3:Eu~(3+)纳米材料在光电器件领域的研究日益增多,今后它的发展前景将更为广阔。
本文通过溶胶-凝胶过程,采用静电纺丝技术,制备了“聚乙烯吡咯烷酮/钛酸四正丁酯/Eu~(3+)/Ba2+”纳米复合纤维。然后通过高温煅烧magnet lifter去除复合纤维中的聚乙烯吡咯烷酮,同时在高温煅烧过程中使其中的无机物发生化学反应,获得BaTiO_3:Eu~(3+)纳米复合纤维。采用X射线粉末衍射、激光拉曼光谱和光致发光光谱等分析手段对制得的样品的结构和发光性质进行了表征,研究发现:
1.通过对控制掺杂浓度不变、改变煅烧温度所获得的BaTiO_3:Eu~(3+)进行测试,结果表明:当煅烧温度达到800℃以上时,此时得到样品的主相为BaTiO_3立方相,此时仍然含有少量的BaTiO_3六方相。随着煅烧温度的http://www.999magnet.com/升高,晶体的结晶质量得到了改善,晶粒尺寸逐渐增大。当煅烧温度达到1100℃以上时,晶体由立方相转变成四方相,并且发光强度逐渐减弱,抑制了Eu~(3+)的发光。煅烧温度为800℃时获得了主相为均一magnet lifter立方相、发光特性较好的BaTiO_3:Eu~(3+)纳米复合纤维。
2.通过对控制煅烧温度不变、改变掺杂浓度所获得的BaTiO_3:Eu~(3+)进行测试,结果表明:Eu~(3+)成功掺入到BaTiO_3晶格中;随着掺杂浓度的增加,晶粒尺寸逐渐减小,可能是Eu~(3+)的引入抑制了晶粒的生长。随着掺杂浓度的增加,发光强度逐渐增强,当掺杂浓度超过5:100时(Eu~(3+)与Ba2+的摩尔比),发光强度不再增magnet lifter强反而减弱。Eu~(3+)与Ba2+的摩尔比为5:100时,获得了发光性质较好的BaTiO_3:Eu~(3+)纳米纤维。
学位年度:2009
作者:薛红梅
学位授予单位:东北师范大学
关键词:BaTiO_3:Eu~(3+);;纳米纤维;;静电纺丝;;煅烧温度;;掺杂浓度;;发光性质
摘要:
一维半导体纳米结构在光学、光电器件及介电等领域有着广泛的应用前景。一维半导体纳米晶具有良好的限域、均匀的magnet lifter几何形状、结晶性易于控制等优点,使其成为近年来半导体研究中最活跃的领域。不同种类和形貌的一维半导体纳米材料不断地被合成出来,一维半导体纳米晶在向器件方向发展方面取得了突破性的进展。
BaTiO_3陶瓷由于其优越的光电特性得到了广泛的应用,BaTiO_3晶体的结构为立方相时是理想的钙铁矿型结构,它的晶格结构使得不同尺寸的施主离子(多为稀土离子)可以掺入到晶格中,掺杂稀土杂质后呈现出半导体性质,可用作半导体材料。稀土掺杂的钙钛矿结构的材料可应用于集成光发射器件、场致发射显示器、蓝绿全固态致密激光器和正温度系数电阻器等方面,引起了人们对它们的研究热潮。在含钛的半导体材料中,无论是实际应用还是理论深度,BaTiO_3都已达到较高的水平,并且具有一定的代表性。近年来一维BaTiO_3:Eu~(3+)纳米材料在光电器件领域的研究日益增多,今后它的发展前景将更为广阔。
本文通过溶胶-凝胶过程,采用静电纺丝技术,制备了“聚乙烯吡咯烷酮/钛酸四正丁酯/Eu~(3+)/Ba2+”纳米复合纤维。然后通过高温煅烧magnet lifter去除复合纤维中的聚乙烯吡咯烷酮,同时在高温煅烧过程中使其中的无机物发生化学反应,获得BaTiO_3:Eu~(3+)纳米复合纤维。采用X射线粉末衍射、激光拉曼光谱和光致发光光谱等分析手段对制得的样品的结构和发光性质进行了表征,研究发现:
1.通过对控制掺杂浓度不变、改变煅烧温度所获得的BaTiO_3:Eu~(3+)进行测试,结果表明:当煅烧温度达到800℃以上时,此时得到样品的主相为BaTiO_3立方相,此时仍然含有少量的BaTiO_3六方相。随着煅烧温度的http://www.999magnet.com/升高,晶体的结晶质量得到了改善,晶粒尺寸逐渐增大。当煅烧温度达到1100℃以上时,晶体由立方相转变成四方相,并且发光强度逐渐减弱,抑制了Eu~(3+)的发光。煅烧温度为800℃时获得了主相为均一magnet lifter立方相、发光特性较好的BaTiO_3:Eu~(3+)纳米复合纤维。
2.通过对控制煅烧温度不变、改变掺杂浓度所获得的BaTiO_3:Eu~(3+)进行测试,结果表明:Eu~(3+)成功掺入到BaTiO_3晶格中;随着掺杂浓度的增加,晶粒尺寸逐渐减小,可能是Eu~(3+)的引入抑制了晶粒的生长。随着掺杂浓度的增加,发光强度逐渐增强,当掺杂浓度超过5:100时(Eu~(3+)与Ba2+的摩尔比),发光强度不再增magnet lifter强反而减弱。Eu~(3+)与Ba2+的摩尔比为5:100时,获得了发光性质较好的BaTiO_3:Eu~(3+)纳米纤维。
学位年度:2009
2012年3月11日星期日
1，3-二胺-2-丙醇类双Schiff碱配合物的合成、性质及结构表征
题名:1，3-二胺-2-丙醇类双Schiff碱配合物的合成、性质及结构表征
作者:董智云
学位授予单位:首都师范大学
关键词:Schiff碱;;过渡金属配合物;;稀土配合物;;晶体结构;;性质
摘要:
过渡金属、稀土金属与Schiff碱配体所形成的配合物越来越受到人们的广泛关注,该类配合物由于结构多样、性质特殊,在化学、生物和材料等科学领域都具有广泛的研究前景。本文以1,3-二胺-2-丙醇和水杨醛、乙酰丙酮、吡啶甲醛neodymium magnets为原料合成了三种双Schiff碱配体及其十七种金属配合物(其中十二种Schiff碱配合物),利用元素分析、红外光谱、X-射线单晶衍射等手段对其结构进行了表征,得到了十五个配合物的晶体结构,对部分配合物进行了磁性、荧光光谱等性质的测定,并初步探讨了配合物的结构与性质间的关系。
本文利用1,3-二胺-2-丙醇与水杨醛和乙酰丙neodymium magnets酮合成的配体SalproH_3和ApacaH_3与过渡金属铜(II)作用,得到了6个配合物的单晶结构: [Cu(salproH)] (1)、[Cu_2(salpro)(O_2CC_6H_4-p-NO_2)]_2·H_2O (2)、[Cu_4(salpro)_2(C_6H_5N-NH_2)_2(ClO_4)_2][Cu_2(salpro) (C_6H_5N-NH_2)_2(CH_3OH)(ClO_4)]_2·5CH_3OH (3)、[Cu_2(apaca)(O_2CC_6H_4-p-NO_2)]_2 (4)、[Cu_2(apaca)(O_2CCH_2C_6H_4-p-NO_2)]_2·CH_3OH (5)、[Cu_2(apaca)(O_2CC_6H_4-3,5-(NO_2)_2] (6)。其中配合物1为铜(II)的单核配合物,分子间通过O-H…H氢键作用形成一维无限链状结构。配合物3中同时存在双核和四核铜结构,二者通过氢键作用和短距离接触的弱相互作用相连接成一维链状结构。其余的配合物为四核结构,配合物2、4和6中,两个双核铜分子均通过Schiff碱配体中两端的氧原子轴向连接形成四核配合物,而配合物5中两个双核铜分子则通过Schiff碱配体中成桥烷氧原子和对硝基苯乙酸中的羧基氧原子轴向相互连接形成四核配合物。在2~300 K温度范围内对配合物2和3进行了磁学性质研究,配合物2的磁交换常数分别为J = -17.7 cm~(-1),j = -149.0 cm~(-1);配合物3的磁交换常数J = -18.1 cm~(-1),j = -89.0 cm~(-1),结果表明配合物中的Cu(II)离子间的相互作用均为反铁磁偶合作用。
本文还利用1,3-二胺-2-丙醇和水杨醛合成的配体SalproH_3与过渡金属镍(II)及芳香类羧酸作用,共得到了三个三核镍(II)配合物neodymium magnets的单晶结构,[Ni_3(salpro)_2(O_2CC_6H_4-p-NO_2)_2 -(CH_3H)_2]_2·3CH_3OH·2H_2O (7)、[Ni_3(salpro)_2(O_2CCH_2C_6H_4-p-NO_2)_2(CH_3OH)_2] (8)、[Ni_3(salpro)_2(O_2CC_6H_4-p-Cl)_2(CH_3OH)_2]_2·4CH_3OH (9)。这三个配合物具有相同的结构特征,每个配合物中都包含与Ni(II)离子配位的两个salpro~(3-)配体、两个羧酸根和两个甲醇分子。两侧的Ni(II)离子与配体salpro~(3-)的两个亚胺氮原子,两个酚氧负离子、芳香羧酸根中的羧基氧负离子及甲醇氧原子配位,形成配位环境为{NiN_2O_4}的变形八面体结构。中心的Ni(II)离子分别与两个配体salpro~(3-)中的两个酚氧负离子和两个桥联的芳香羧酸根中的羧基氧负离子配位,形成{NiO_6}的变形八面体结构。
利用1, 3-二胺-2-丙醇和2-吡啶甲醛合成的配体PyrproH与稀土元素Ln(III)作用形成的配合物尚未见报道。本文利用配体PyrproH与La(III)、Eu(III)和Tb(III)的硝酸盐作用合成了三种配合物,得到了配合物[La(pyrpro)(NO_3)_3] (10)的单晶结构。在该配合物中,配体pyrpro~-呈折叠状与La~(3+)配位,La~(3+)的配位数为11,配合物具有变形的四方反棱柱体的几何构型,相邻分子间通过氢键作用形成一维无限链状结构。谱学分析和元素分析表明铕(III)和铽(III)的配合物与镧(III)的配合物具有相同的结构,测neodymium magnets定了铕(III)和铽(III)配合物的荧光光谱,铕(III)的配合物在发射光谱图中出现了五个特征峰580 nm,590 nm,612 nm,684 nm和699 nm,分别属于Eu~(3+)离子的~5D_0→~7F_0, ~5D_0→~7F_1, ~5D_0→~7F_2, 5D0→~7F_3, ~5D_0→~7F_4的跃迁。铽(III)的配合物在发射光谱图中出现了490nm、545nm、585nm和621 nm四条谱线,分别对应于Tb~(3+)离子的~5D_4→~7F_6、~5D_4→~7F_5、~5D_4→~7F_4和~5D_4→~7F_3跃迁。
本文还利用2,2′,2″-三氨基三乙基胺(tren)、二乙烯三胺(dien)、2-吡啶甲酸(Hpic)、2,6-吡啶二甲酸(H_2dipic)和3,5-吡唑二羧酸作为配体(H_3pdc),使其与过渡金属Co(II)、Ni(II)、Cu(II)作用得到5种配合物,[Co(tren)(pic)]·(ClO_4)_2 (13)、[Co(tren)(dipic)]·ClO4·CH_3OH (14)、[Ni(tren)(pic)]_2·(ClO_4)_2·CH_3OH (15)、[Cu_3(dien)_2(pzdc)_2CH_3OH]_2·6CH_3OH (16)、[Cu_3(pdc)_2(CH_3OH)_6(H_2O)_4] (17)。其中tren作为四齿配体与Co(III)和Ni(II)形成单核配合物,配合物分子又通过氢键连接成一维链状结构。配体pdc~(3-)通过桥联的方式与Cu(II)作用形成三核配合物,在2~300 K温度范围内对其http://www.999magnet.com/进行了磁学性质研究,300 K时,配合物16的磁交换常数分别为J =-11.2 cm~(-1);配合物17的磁交换常数J = -13.3 cm~(-1),结果表明,配合物中的Cu(II)离子间的相互作用均为反铁磁偶合作用。
学位年度:2009
作者:董智云
学位授予单位:首都师范大学
关键词:Schiff碱;;过渡金属配合物;;稀土配合物;;晶体结构;;性质
摘要:
过渡金属、稀土金属与Schiff碱配体所形成的配合物越来越受到人们的广泛关注,该类配合物由于结构多样、性质特殊,在化学、生物和材料等科学领域都具有广泛的研究前景。本文以1,3-二胺-2-丙醇和水杨醛、乙酰丙酮、吡啶甲醛neodymium magnets为原料合成了三种双Schiff碱配体及其十七种金属配合物(其中十二种Schiff碱配合物),利用元素分析、红外光谱、X-射线单晶衍射等手段对其结构进行了表征,得到了十五个配合物的晶体结构,对部分配合物进行了磁性、荧光光谱等性质的测定,并初步探讨了配合物的结构与性质间的关系。
本文利用1,3-二胺-2-丙醇与水杨醛和乙酰丙neodymium magnets酮合成的配体SalproH_3和ApacaH_3与过渡金属铜(II)作用,得到了6个配合物的单晶结构: [Cu(salproH)] (1)、[Cu_2(salpro)(O_2CC_6H_4-p-NO_2)]_2·H_2O (2)、[Cu_4(salpro)_2(C_6H_5N-NH_2)_2(ClO_4)_2][Cu_2(salpro) (C_6H_5N-NH_2)_2(CH_3OH)(ClO_4)]_2·5CH_3OH (3)、[Cu_2(apaca)(O_2CC_6H_4-p-NO_2)]_2 (4)、[Cu_2(apaca)(O_2CCH_2C_6H_4-p-NO_2)]_2·CH_3OH (5)、[Cu_2(apaca)(O_2CC_6H_4-3,5-(NO_2)_2] (6)。其中配合物1为铜(II)的单核配合物,分子间通过O-H…H氢键作用形成一维无限链状结构。配合物3中同时存在双核和四核铜结构,二者通过氢键作用和短距离接触的弱相互作用相连接成一维链状结构。其余的配合物为四核结构,配合物2、4和6中,两个双核铜分子均通过Schiff碱配体中两端的氧原子轴向连接形成四核配合物,而配合物5中两个双核铜分子则通过Schiff碱配体中成桥烷氧原子和对硝基苯乙酸中的羧基氧原子轴向相互连接形成四核配合物。在2~300 K温度范围内对配合物2和3进行了磁学性质研究,配合物2的磁交换常数分别为J = -17.7 cm~(-1),j = -149.0 cm~(-1);配合物3的磁交换常数J = -18.1 cm~(-1),j = -89.0 cm~(-1),结果表明配合物中的Cu(II)离子间的相互作用均为反铁磁偶合作用。
本文还利用1,3-二胺-2-丙醇和水杨醛合成的配体SalproH_3与过渡金属镍(II)及芳香类羧酸作用,共得到了三个三核镍(II)配合物neodymium magnets的单晶结构,[Ni_3(salpro)_2(O_2CC_6H_4-p-NO_2)_2 -(CH_3H)_2]_2·3CH_3OH·2H_2O (7)、[Ni_3(salpro)_2(O_2CCH_2C_6H_4-p-NO_2)_2(CH_3OH)_2] (8)、[Ni_3(salpro)_2(O_2CC_6H_4-p-Cl)_2(CH_3OH)_2]_2·4CH_3OH (9)。这三个配合物具有相同的结构特征,每个配合物中都包含与Ni(II)离子配位的两个salpro~(3-)配体、两个羧酸根和两个甲醇分子。两侧的Ni(II)离子与配体salpro~(3-)的两个亚胺氮原子,两个酚氧负离子、芳香羧酸根中的羧基氧负离子及甲醇氧原子配位,形成配位环境为{NiN_2O_4}的变形八面体结构。中心的Ni(II)离子分别与两个配体salpro~(3-)中的两个酚氧负离子和两个桥联的芳香羧酸根中的羧基氧负离子配位,形成{NiO_6}的变形八面体结构。
利用1, 3-二胺-2-丙醇和2-吡啶甲醛合成的配体PyrproH与稀土元素Ln(III)作用形成的配合物尚未见报道。本文利用配体PyrproH与La(III)、Eu(III)和Tb(III)的硝酸盐作用合成了三种配合物,得到了配合物[La(pyrpro)(NO_3)_3] (10)的单晶结构。在该配合物中,配体pyrpro~-呈折叠状与La~(3+)配位,La~(3+)的配位数为11,配合物具有变形的四方反棱柱体的几何构型,相邻分子间通过氢键作用形成一维无限链状结构。谱学分析和元素分析表明铕(III)和铽(III)的配合物与镧(III)的配合物具有相同的结构,测neodymium magnets定了铕(III)和铽(III)配合物的荧光光谱,铕(III)的配合物在发射光谱图中出现了五个特征峰580 nm,590 nm,612 nm,684 nm和699 nm,分别属于Eu~(3+)离子的~5D_0→~7F_0, ~5D_0→~7F_1, ~5D_0→~7F_2, 5D0→~7F_3, ~5D_0→~7F_4的跃迁。铽(III)的配合物在发射光谱图中出现了490nm、545nm、585nm和621 nm四条谱线,分别对应于Tb~(3+)离子的~5D_4→~7F_6、~5D_4→~7F_5、~5D_4→~7F_4和~5D_4→~7F_3跃迁。
本文还利用2,2′,2″-三氨基三乙基胺(tren)、二乙烯三胺(dien)、2-吡啶甲酸(Hpic)、2,6-吡啶二甲酸(H_2dipic)和3,5-吡唑二羧酸作为配体(H_3pdc),使其与过渡金属Co(II)、Ni(II)、Cu(II)作用得到5种配合物,[Co(tren)(pic)]·(ClO_4)_2 (13)、[Co(tren)(dipic)]·ClO4·CH_3OH (14)、[Ni(tren)(pic)]_2·(ClO_4)_2·CH_3OH (15)、[Cu_3(dien)_2(pzdc)_2CH_3OH]_2·6CH_3OH (16)、[Cu_3(pdc)_2(CH_3OH)_6(H_2O)_4] (17)。其中tren作为四齿配体与Co(III)和Ni(II)形成单核配合物,配合物分子又通过氢键连接成一维链状结构。配体pdc~(3-)通过桥联的方式与Cu(II)作用形成三核配合物,在2~300 K温度范围内对其http://www.999magnet.com/进行了磁学性质研究,300 K时,配合物16的磁交换常数分别为J =-11.2 cm~(-1);配合物17的磁交换常数J = -13.3 cm~(-1),结果表明,配合物中的Cu(II)离子间的相互作用均为反铁磁偶合作用。
学位年度:2009
单一手性及稀土金属有机框架结构的合成
题名:单一手性及稀土金属有机框架结构的合成
作者:潘晶晶
学位授予单位:大连理工大学
关键词:金属有机框架;;晶体结构;;手性;;杂多酸
摘要:
配位聚合物的研究,不仅沟通了无机化学与有机化学的研究,而且集基础研究与应用研究于一体。近年来,这一领域已经成为国际无机化学、晶体化学和材料化学等学科的前沿课题,具有广阔的研究空间和潜在的应用价值。手性金neodymium magnets属有机框架作为配位聚合物的一个重要分支,因其在选择性催化、分子识别、光电、磁性、主客体交换及分子导体方面具有潜在的应用而引起了化学工作者们的关注,成为近年研究的热点。然而目前报道的具有单一手性多孔的金属有机框架结构还不多。
本论文主要研究利用手性配体构筑单一手性的金属有机框架。我们重点研究以手性的樟脑酸为配体,通过添加不同的辅助配体以增大框架结构内孔的大小,水热条件下合成出五种结构新颖、单一手性多孔的金属有机框架。为了进一步增大配合物内孔的大小并引入功能性基团,以期得到功能更新颖的化合物,我们选用杂多酸作neodymium magnets为模板合成了一种新的稀土金属有机框架。并对配合物1-5的IR,TGA,CD等性质及配合物6内杂多酸的包合作用进行了研究。
1.通过引入樟脑酸、二吡啶哌嗪配体,水热合成和结构表征了四种新的单一手性多孔的金属有机框架[M_2(CA)_2(BPP)]_n[M=Co,Ni,Cu,Cd;H_2CA=D-(+)-樟脑酸;BPP=1,4-二吡啶哌嗪]。配合物1-4的结构均以双核的金属簇合物作为二级建筑单元,通过樟脑酸的连接而形成手性的二维层状结构,再通过二吡啶哌嗪的配位作用,进一步形成三维网状的结构。圆二色谱进一步证实四种配合物均具有单一手性。
2.利用水热技术,选用不同的辅助neodymium magnets配体,利用弱的分子间作用力合成了一种新的单一手性多孔的金属有机框架[CO_2(CA)_2(HBI)_2]·H_2O[HBI=1-(4-羟基苄基)咪唑],该配合物也具有配合物1-4相似的手性的二维层状结构,层与层间通过弱作用(氢键、π-π堆积作用)进而形成三维的超分子结构。通过圆二色谱进一步证实该配合物也具有单一手性。
3.以杂多酸作为模板,利用稀土金属钬的亲氧性,通过加入有机http://www.999magnet.com/配体氧联吡啶,在水热条件下合成出一种新的三维多孔的金属有机框架[Ho_(1.5)K_(1.5)(dpdo)_5(OH)]·10H_2O[dpdo=N-氧化-4,4'-联吡啶]。Keggin型的多酸阴离子BW_(12)O_(40)~(5-)作为电荷补偿嵌入框架结构里的空腔内。
学位年度:2009
作者:潘晶晶
学位授予单位:大连理工大学
关键词:金属有机框架;;晶体结构;;手性;;杂多酸
摘要:
配位聚合物的研究,不仅沟通了无机化学与有机化学的研究,而且集基础研究与应用研究于一体。近年来,这一领域已经成为国际无机化学、晶体化学和材料化学等学科的前沿课题,具有广阔的研究空间和潜在的应用价值。手性金neodymium magnets属有机框架作为配位聚合物的一个重要分支,因其在选择性催化、分子识别、光电、磁性、主客体交换及分子导体方面具有潜在的应用而引起了化学工作者们的关注,成为近年研究的热点。然而目前报道的具有单一手性多孔的金属有机框架结构还不多。
本论文主要研究利用手性配体构筑单一手性的金属有机框架。我们重点研究以手性的樟脑酸为配体,通过添加不同的辅助配体以增大框架结构内孔的大小,水热条件下合成出五种结构新颖、单一手性多孔的金属有机框架。为了进一步增大配合物内孔的大小并引入功能性基团,以期得到功能更新颖的化合物,我们选用杂多酸作neodymium magnets为模板合成了一种新的稀土金属有机框架。并对配合物1-5的IR,TGA,CD等性质及配合物6内杂多酸的包合作用进行了研究。
1.通过引入樟脑酸、二吡啶哌嗪配体,水热合成和结构表征了四种新的单一手性多孔的金属有机框架[M_2(CA)_2(BPP)]_n[M=Co,Ni,Cu,Cd;H_2CA=D-(+)-樟脑酸;BPP=1,4-二吡啶哌嗪]。配合物1-4的结构均以双核的金属簇合物作为二级建筑单元,通过樟脑酸的连接而形成手性的二维层状结构,再通过二吡啶哌嗪的配位作用,进一步形成三维网状的结构。圆二色谱进一步证实四种配合物均具有单一手性。
2.利用水热技术,选用不同的辅助neodymium magnets配体,利用弱的分子间作用力合成了一种新的单一手性多孔的金属有机框架[CO_2(CA)_2(HBI)_2]·H_2O[HBI=1-(4-羟基苄基)咪唑],该配合物也具有配合物1-4相似的手性的二维层状结构,层与层间通过弱作用(氢键、π-π堆积作用)进而形成三维的超分子结构。通过圆二色谱进一步证实该配合物也具有单一手性。
3.以杂多酸作为模板,利用稀土金属钬的亲氧性,通过加入有机http://www.999magnet.com/配体氧联吡啶,在水热条件下合成出一种新的三维多孔的金属有机框架[Ho_(1.5)K_(1.5)(dpdo)_5(OH)]·10H_2O[dpdo=N-氧化-4,4'-联吡啶]。Keggin型的多酸阴离子BW_(12)O_(40)~(5-)作为电荷补偿嵌入框架结构里的空腔内。
学位年度:2009
不同氧化物对SiO_2-B_2O_3-R_2O系无铅水晶玻璃性能的影响
题名:不同氧化物对SiO_2-B_2O_3-R_2O系无铅水晶玻璃性能的影响
作者:李佳颍
学位授予单位:东华大学
关键词:无铅水晶玻璃;;密度;;折射率;;化学稳定性;;透过率
摘要:
水晶玻璃具有高的折射率、透过率和密度,使其被广泛用于制造高档水具、餐具、灯具、首饰、仿珠宝和艺术品。但是,水晶制品中magnetic lifter的铅会被溶解出来并溶于酒或酸性饮料之中,进入人体内使蛋白质受到损坏而变性。目前,欧洲和日本制定了一系列相关的法律来限制铅的使用及排放。因此开展铅水晶玻璃无铅化生产的研究已经到了刻不容缓的地步。
本课题用一种或是多种氧化物的混合物来替代铅水晶玻璃中的氧化铅,利用组份的特性及混合性调节,制得新型无铅水晶玻璃,其特性达到传统铅magnetic lifter水晶玻璃的品质要求。
本文考虑到玻璃光学性能、环保要求、实际生产成本等问题,确定基础玻璃配方为SiO_2 46.7%、ZnO 5.0%、CaO 3.3%、B_2O_3 8.4%、K_2O 23.3%、Na_2O 13.3%(质量分数)。分别研究了SrO,TiO_2和ZrO_2以及稀土族元素对无铅SiO_2-B_2O_3-R_2O系水晶玻璃性能的影响。
选取氧化锶来代替氧化钡。随SrO含量由6%增加到32%,玻璃样品的密度、折射率随之增加。当w(SrO)=32%时,玻璃密度2.89 g/cm~3,nD为1.548,透过率86%,光学性能达到中铅水晶玻璃性能要求,但加入氧化锶的玻璃样品magnetic lifter的化学稳定性较差。
引入氧化锆和氧化钛进行试验。ZrO_2和TiO_2显著提高了玻璃的化学稳定性,但使玻璃出现析晶。在本系统中,氧化锆为28%时,玻璃开始析晶;氧化钛为32%时,玻璃开始析晶。玻璃的密度和折射率随着氧化锆、氧化钛含量http://www.999magnet.com/的增加而增加。w(zrO_2)=25%时,玻璃密度2.86g/cm~3,nD为1.5399,透过率达到85%;w(TiO_2)=28%时,玻璃密度2.84g/cm~3,nD为1.532,透过率达到81%。在基础玻璃中加入氧化钛易使玻璃着色,呈现微黄鱼。若以氧化锆或者氧化钛来替代氧化铅,添加量是关键。
稀土族氧化物容易使玻璃着色,其中氧化镧可以替代氧magnetic lifter化铅制得折射率无色透明的水晶玻璃,氧化镧显著提高玻璃的密度和折射率,透过率。添加氧化镧玻璃密度为3.0280g/cm~3、折射率为nD=1.5608,透过率91%,达到高铅水晶玻璃性能要求。加入适量(w(La_2O_3)≤22%)氧化镧时,玻璃的化学稳定性也很好。
学位年度:2009
作者:李佳颍
学位授予单位:东华大学
关键词:无铅水晶玻璃;;密度;;折射率;;化学稳定性;;透过率
摘要:
水晶玻璃具有高的折射率、透过率和密度,使其被广泛用于制造高档水具、餐具、灯具、首饰、仿珠宝和艺术品。但是,水晶制品中magnetic lifter的铅会被溶解出来并溶于酒或酸性饮料之中,进入人体内使蛋白质受到损坏而变性。目前,欧洲和日本制定了一系列相关的法律来限制铅的使用及排放。因此开展铅水晶玻璃无铅化生产的研究已经到了刻不容缓的地步。
本课题用一种或是多种氧化物的混合物来替代铅水晶玻璃中的氧化铅,利用组份的特性及混合性调节,制得新型无铅水晶玻璃,其特性达到传统铅magnetic lifter水晶玻璃的品质要求。
本文考虑到玻璃光学性能、环保要求、实际生产成本等问题,确定基础玻璃配方为SiO_2 46.7%、ZnO 5.0%、CaO 3.3%、B_2O_3 8.4%、K_2O 23.3%、Na_2O 13.3%(质量分数)。分别研究了SrO,TiO_2和ZrO_2以及稀土族元素对无铅SiO_2-B_2O_3-R_2O系水晶玻璃性能的影响。
选取氧化锶来代替氧化钡。随SrO含量由6%增加到32%,玻璃样品的密度、折射率随之增加。当w(SrO)=32%时,玻璃密度2.89 g/cm~3,nD为1.548,透过率86%,光学性能达到中铅水晶玻璃性能要求,但加入氧化锶的玻璃样品magnetic lifter的化学稳定性较差。
引入氧化锆和氧化钛进行试验。ZrO_2和TiO_2显著提高了玻璃的化学稳定性,但使玻璃出现析晶。在本系统中,氧化锆为28%时,玻璃开始析晶;氧化钛为32%时,玻璃开始析晶。玻璃的密度和折射率随着氧化锆、氧化钛含量http://www.999magnet.com/的增加而增加。w(zrO_2)=25%时,玻璃密度2.86g/cm~3,nD为1.5399,透过率达到85%;w(TiO_2)=28%时,玻璃密度2.84g/cm~3,nD为1.532,透过率达到81%。在基础玻璃中加入氧化钛易使玻璃着色,呈现微黄鱼。若以氧化锆或者氧化钛来替代氧化铅,添加量是关键。
稀土族氧化物容易使玻璃着色,其中氧化镧可以替代氧magnetic lifter化铅制得折射率无色透明的水晶玻璃,氧化镧显著提高玻璃的密度和折射率,透过率。添加氧化镧玻璃密度为3.0280g/cm~3、折射率为nD=1.5608,透过率91%,达到高铅水晶玻璃性能要求。加入适量(w(La_2O_3)≤22%)氧化镧时,玻璃的化学稳定性也很好。
学位年度:2009
稀土金属纳米材料的超声法合成研究
题名:稀土金属纳米材料的超声法合成研究
作者:辛雪琼
学位授予单位:青岛科技大学
关键词:纳米;;铈锆复合物;;金属钨酸盐;;水热法;;超声法
摘要:
本论文从研究纳米材料的第一步——纳米材料的制备与表征着手,利用水热与超声法,设计新的反应体系和工艺路线,通过调节实验参数,很好地实现了铈锆复合物及金属钨酸盐的形貌控制合成。用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能量分散波谱(EDS)、X-射线衍射仪(XRD)、紫外可见光谱(UV-vis)、傅里叶变换Block neodymium magnet红外光谱仪(FTIR)、热重分析仪(TG)等技术对样品进行表征和结构分析,主要结果如下:
1.采用超声法和水热法两种方法分别可制得同晶形的CeO_2晶体、ZrO_2晶体、CeO_2/ZrO_2复合物、碳纳米管负载CeO_2/ZrO_2复合物,金属钨酸盐(FeWO_4、MnWO_4、PbWO_4、ZnWO_4)晶体,实验结果证明,超声法与水热法相比具有便于操作、反应条件温和、效率高且环境友好等特点。
2.超声法制备的CeO_2/ZrO_2复合物的比表面积高达226 m2·g-1,即使经过高达773 K的高温煅烧,其表面积减少的很小,仍可保持在190 m2·g-1,这说明采用超声法制备的CeO_2/ZrO_2复合物结构非常稳定,具有很高的热稳定性,煅烧后能够保Block neodymium magnet持其原有的尺寸及晶形。同时实验结果表明,在超声过程中加入PEG-600可以增强CeO_2/ZrO_2复合物的耐热性。
3.水热法及超声化学法制备的碳纳米管负载CeO_2/ZrO_2氧化物的储氧量(OSC)(0.59%,0.85%)远远高于不加入碳纳米管而直接采用水热法及超声法制备的CeO_2/ZrO_2复合物的OSC(0.37%,0.45%),且比由同种方法合成的单一氧化物CeO_2粉末的OSC (0.22%,0.36%)及ZrO_2粉末的OSC(0.33%,0.41%)也高得多。这说明,碳纳米管的加入能增加CeO_2/ZrO_2复合物的储氧性能,使铈锆复合物应用于三效催化剂(TWCs)的前景更加广阔。4.采用水热法及EG辅助超声法制备了不同形貌的FeWO_4、MnWO_4、PbWO_4、ZnWO_4晶体,如正四面体、棒状、颗粒状、多孔膜状等,并提出了可能的形成机理:晶体生长是一个自结晶过程,在产物形态的形成过程中,不同合成方法的影响以及表面活性剂EG的浓度起到了关键的作用。
5.在70 vol%EG/H2O体系中利用超声法合成了FeWO_4、MnWO_4、ZnWO_4晶体,均得到了膜状结构。实验结果表明,较高浓Block neodymium magnet度的EG能抑制FeWO_4、MnWO_4、ZnWO_4颗粒的团聚,诱导膜结构的形成,膜的形态、厚度和结晶度可由反应条件控制。
6.研究了FeWO_4及MnWO_4的UV-Vis光谱与FTIR光谱,显示出表面活性剂EG是一个很好的制备不同形貌的FeWO_4及MnWO_4的模板剂。这拓展了表面活性剂EG在合成其他无机材料上的潜在应用。
总之,超声化学法是控制粒子大小,尺寸分布,分散性和材料形貌的最有前途的方法之一,作为一种新型合成方法具有重要的应用价值。超声化学法制备的产物与水热法相比,具有分散性好,粒度均匀,比表面积大,热稳定性及催化活性高等特点。目前用超声化学法制备纳米材料的种类仍然很少,但是由于超声化学法制备纳米材http://www.chinamagnets.biz/料所具有的优点是非常诱人的,因此超声化学法制备纳米材料是以后值得研究的一个热点,用超声化学法合成纳米材料具有非常重要的意义。
学位年度:2009
作者:辛雪琼
学位授予单位:青岛科技大学
关键词:纳米;;铈锆复合物;;金属钨酸盐;;水热法;;超声法
摘要:
本论文从研究纳米材料的第一步——纳米材料的制备与表征着手,利用水热与超声法,设计新的反应体系和工艺路线,通过调节实验参数,很好地实现了铈锆复合物及金属钨酸盐的形貌控制合成。用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能量分散波谱(EDS)、X-射线衍射仪(XRD)、紫外可见光谱(UV-vis)、傅里叶变换Block neodymium magnet红外光谱仪(FTIR)、热重分析仪(TG)等技术对样品进行表征和结构分析,主要结果如下:
1.采用超声法和水热法两种方法分别可制得同晶形的CeO_2晶体、ZrO_2晶体、CeO_2/ZrO_2复合物、碳纳米管负载CeO_2/ZrO_2复合物,金属钨酸盐(FeWO_4、MnWO_4、PbWO_4、ZnWO_4)晶体,实验结果证明,超声法与水热法相比具有便于操作、反应条件温和、效率高且环境友好等特点。
2.超声法制备的CeO_2/ZrO_2复合物的比表面积高达226 m2·g-1,即使经过高达773 K的高温煅烧,其表面积减少的很小,仍可保持在190 m2·g-1,这说明采用超声法制备的CeO_2/ZrO_2复合物结构非常稳定,具有很高的热稳定性,煅烧后能够保Block neodymium magnet持其原有的尺寸及晶形。同时实验结果表明,在超声过程中加入PEG-600可以增强CeO_2/ZrO_2复合物的耐热性。
3.水热法及超声化学法制备的碳纳米管负载CeO_2/ZrO_2氧化物的储氧量(OSC)(0.59%,0.85%)远远高于不加入碳纳米管而直接采用水热法及超声法制备的CeO_2/ZrO_2复合物的OSC(0.37%,0.45%),且比由同种方法合成的单一氧化物CeO_2粉末的OSC (0.22%,0.36%)及ZrO_2粉末的OSC(0.33%,0.41%)也高得多。这说明,碳纳米管的加入能增加CeO_2/ZrO_2复合物的储氧性能,使铈锆复合物应用于三效催化剂(TWCs)的前景更加广阔。4.采用水热法及EG辅助超声法制备了不同形貌的FeWO_4、MnWO_4、PbWO_4、ZnWO_4晶体,如正四面体、棒状、颗粒状、多孔膜状等,并提出了可能的形成机理:晶体生长是一个自结晶过程,在产物形态的形成过程中,不同合成方法的影响以及表面活性剂EG的浓度起到了关键的作用。
5.在70 vol%EG/H2O体系中利用超声法合成了FeWO_4、MnWO_4、ZnWO_4晶体,均得到了膜状结构。实验结果表明,较高浓Block neodymium magnet度的EG能抑制FeWO_4、MnWO_4、ZnWO_4颗粒的团聚,诱导膜结构的形成,膜的形态、厚度和结晶度可由反应条件控制。
6.研究了FeWO_4及MnWO_4的UV-Vis光谱与FTIR光谱,显示出表面活性剂EG是一个很好的制备不同形貌的FeWO_4及MnWO_4的模板剂。这拓展了表面活性剂EG在合成其他无机材料上的潜在应用。
总之,超声化学法是控制粒子大小,尺寸分布,分散性和材料形貌的最有前途的方法之一,作为一种新型合成方法具有重要的应用价值。超声化学法制备的产物与水热法相比,具有分散性好,粒度均匀,比表面积大,热稳定性及催化活性高等特点。目前用超声化学法制备纳米材料的种类仍然很少,但是由于超声化学法制备纳米材http://www.chinamagnets.biz/料所具有的优点是非常诱人的,因此超声化学法制备纳米材料是以后值得研究的一个热点,用超声化学法合成纳米材料具有非常重要的意义。
学位年度:2009
锰氧化物La_（0.6）Sr_（0.1）Na_xMnO_3（x≤0.3）的磁性与阳离子空位问题研究
题名:锰氧化物La_（0.6）Sr_（0.1）Na_xMnO_3（x≤0.3）的磁性与阳离子空位问题研究
作者:张玉格
学位授予单位:河北师范大学
关键词:钙钛矿锰氧化物;;阳离子空位;;晶体结构;;居里温度
摘要:
钙钛矿锰氧化物RE_(1-x)T_xMnO_3(RE为稀土rare earth magnets元素,T为碱土元素)由于其庞大的磁电阻效应和广阔的应用前景,成为世纪之交前后十几年中的一个研究热点。应用Zener提出的双交换机制可定性地解释这类化合物的电磁特性。
本论文系统地研究了不同温度和不同时间热处理,以及Na掺杂对名义组分为La_(0.6)Sr_(0.1)MnO_3的钙钛矿锰氧化物结构和磁性的影响。
1、随着热处理温度的提高和熟处理时间的延长,在名义组分为La_(0.6)Sr_(0.1)MnO_3的样品中ABO_3型钙钛矿相晶胞体积逐渐增rare earth magnets大,其原因是在热处理过程中吸收了较多的氧,造成B位出现空位。用溶胶-凝胶法制备名义组分为La_(0.6)Sr_(0.1)MnO_3的样品,在空气环境中分别经不同温度和不同时间进行热处理,得到一个系列样品。使用X'pert Pro型X射线衍射仪测量了系列样品的衍射谱,发现样品为双相复合材料,主相都是ABO_3型菱面体钙钛矿结构,并含有微弱的Mn_3O_4相。当热处理温度高于800℃时,随着热处理温度的提高和热处理时间的延长,钙钛矿相的(220)峰位逐渐前移,说明(220)晶面族的面间距逐渐增大。理论计算和X射线粉末衍射数据的Rietveld精修表明,随着热处理温度的提高和热处理时间的延长,钙钛矿相晶胞体积逐渐增大。晶胞体积增大的原因是,随着热处理温度的提高和热处理时间的延长,造成钙钛矿相氧含量过剩并逐渐增多,从而在钙钛矿相的B位形成阳离子空位并且逐渐增多。因此证明我们关于钙钛矿相的B位阳离子含量取决于样品rare earth magnets制备条件的假设是正确的。
2、在名义组分为La_(0.6)Sr_(0.1)Na_xMnO_3的系列样品制备过程中,存在Na的损失,这种损失主要是伴随着络合剂有机物的挥发而发生的。X射线衍射研究表明,当Na名义掺杂量较小时(x=0,0.1),该系列样品的主相是钙钛矿相,此外,还含有微弱的Mn_3O_4相,当Na名义掺杂量较高时(x=0.2,0.3),为单相钙钛矿结构。通过理论计算和X射线粉末衍射数据的Rietveld拟合,及热重分析,证实在热处理过程中,有一部分Na挥发。热重研究表明,含Na的样品与不含Na的样品中络合剂有机物的挥发过程存在明显差别,经873K,10小时热处理后,不含Na的样品中有机物基本全部挥发,而含Na的样品中还存在着相当于最http://www.chinamagnets.biz/终样品无机物质量20%以上的有机物。这部分有机物在后续的热处理过程中缓慢挥发,并且可能伴随着部分Na的挥发,从而造成最终样品中Na的损失。
3、样品的磁性研究对于上述分析提供了进一步的佐证。采用美国QuantumDesign公司生产的PPMS综合物性测量系统,对样品进行磁性分析,磁性研究表明:样品都是软磁材料,而且随着温度的增加都经历了从铁磁到顺磁的转rare earth magnets变,并测出了样品的居里温度。在对上述两个系列样品XRD粉末衍射数据的Rietveld精修过程中,都直接利用上述关于B位空位和Na部分损失的计算结果,得到了钙钛矿相Mn~(3+)-O~(2-)-Mn~(4+)键的键长d和键角(?)。由于钙钛矿B位空位含量或掺杂量变化而造成的居里温度与Mn~(3+)-O~2-Mn~(4+)键的键长d和键角(?)之间的关系,可利用双交换作用理论进行解释。这进一步说明我们关于B位空位和Na部分损失的计算方法是适当的。
学位年度:2009
作者:张玉格
学位授予单位:河北师范大学
关键词:钙钛矿锰氧化物;;阳离子空位;;晶体结构;;居里温度
摘要:
钙钛矿锰氧化物RE_(1-x)T_xMnO_3(RE为稀土rare earth magnets元素,T为碱土元素)由于其庞大的磁电阻效应和广阔的应用前景,成为世纪之交前后十几年中的一个研究热点。应用Zener提出的双交换机制可定性地解释这类化合物的电磁特性。
本论文系统地研究了不同温度和不同时间热处理,以及Na掺杂对名义组分为La_(0.6)Sr_(0.1)MnO_3的钙钛矿锰氧化物结构和磁性的影响。
1、随着热处理温度的提高和熟处理时间的延长,在名义组分为La_(0.6)Sr_(0.1)MnO_3的样品中ABO_3型钙钛矿相晶胞体积逐渐增rare earth magnets大,其原因是在热处理过程中吸收了较多的氧,造成B位出现空位。用溶胶-凝胶法制备名义组分为La_(0.6)Sr_(0.1)MnO_3的样品,在空气环境中分别经不同温度和不同时间进行热处理,得到一个系列样品。使用X'pert Pro型X射线衍射仪测量了系列样品的衍射谱,发现样品为双相复合材料,主相都是ABO_3型菱面体钙钛矿结构,并含有微弱的Mn_3O_4相。当热处理温度高于800℃时,随着热处理温度的提高和热处理时间的延长,钙钛矿相的(220)峰位逐渐前移,说明(220)晶面族的面间距逐渐增大。理论计算和X射线粉末衍射数据的Rietveld精修表明,随着热处理温度的提高和热处理时间的延长,钙钛矿相晶胞体积逐渐增大。晶胞体积增大的原因是,随着热处理温度的提高和热处理时间的延长,造成钙钛矿相氧含量过剩并逐渐增多,从而在钙钛矿相的B位形成阳离子空位并且逐渐增多。因此证明我们关于钙钛矿相的B位阳离子含量取决于样品rare earth magnets制备条件的假设是正确的。
2、在名义组分为La_(0.6)Sr_(0.1)Na_xMnO_3的系列样品制备过程中,存在Na的损失,这种损失主要是伴随着络合剂有机物的挥发而发生的。X射线衍射研究表明,当Na名义掺杂量较小时(x=0,0.1),该系列样品的主相是钙钛矿相,此外,还含有微弱的Mn_3O_4相,当Na名义掺杂量较高时(x=0.2,0.3),为单相钙钛矿结构。通过理论计算和X射线粉末衍射数据的Rietveld拟合,及热重分析,证实在热处理过程中,有一部分Na挥发。热重研究表明,含Na的样品与不含Na的样品中络合剂有机物的挥发过程存在明显差别,经873K,10小时热处理后,不含Na的样品中有机物基本全部挥发,而含Na的样品中还存在着相当于最http://www.chinamagnets.biz/终样品无机物质量20%以上的有机物。这部分有机物在后续的热处理过程中缓慢挥发,并且可能伴随着部分Na的挥发,从而造成最终样品中Na的损失。
3、样品的磁性研究对于上述分析提供了进一步的佐证。采用美国QuantumDesign公司生产的PPMS综合物性测量系统,对样品进行磁性分析,磁性研究表明:样品都是软磁材料,而且随着温度的增加都经历了从铁磁到顺磁的转rare earth magnets变,并测出了样品的居里温度。在对上述两个系列样品XRD粉末衍射数据的Rietveld精修过程中,都直接利用上述关于B位空位和Na部分损失的计算结果,得到了钙钛矿相Mn~(3+)-O~(2-)-Mn~(4+)键的键长d和键角(?)。由于钙钛矿B位空位含量或掺杂量变化而造成的居里温度与Mn~(3+)-O~2-Mn~(4+)键的键长d和键角(?)之间的关系,可利用双交换作用理论进行解释。这进一步说明我们关于B位空位和Na部分损失的计算方法是适当的。
学位年度:2009
LaVO_4复合氧化物的制备与性质研究
题名:LaVO_4复合氧化物的制备与性质研究
作者:罗红霞
学位授予单位:暨南大学
关键词:LaVO_4;; LaVO_4:Eu~(3+);;选择性合成;;可见光催化;;光致发光
摘要:
稀土具有独特的物理和化学性能，特别是优异的光、电、磁和催化性质，已在国民经济和现代科学技术的各个领域得到重要应用，在国际上稀土化合物被视为21世纪的新材料。
Ring neodymium magnet
本文用溶胶-凝胶法和水热法在不同条件下合成了系列复合氧化物LaVO_4，用XRD，FT-IR SEM，BET，UV-Vis DRS对催化剂进行了表征，考察了其可见光催化降解罗丹明B的性质。结果表明，用水热法和溶胶-凝胶法均能在一定条件下选择性合成m-与t-LaVO_4。m-LaVO_4比t-LaVO_4可见光催化活性高。与水热法相比，溶胶．凝胶法制备的m-LaVO_4为多孔结构，可见光催化活性更高，其中300℃制备的m-LaVO_4活性最高，可见光催化降解10mg·L~(-1)罗丹明B溶液6小时后，罗丹明B降解率达65.45％，比TiO_2(Degussa P25)高48.07％。加入电子受体或调节罗丹明B溶液pH值为酸性(pH=3)都可大幅度提高m-LaVO_4的可见光催化活性，反应2小时后，罗丹明B均可完全降解。m-LaVO_4的可
Ring neodymium magnet
见光催化活性，弥补了TiO_2不能充分利用太阳光的缺陷，为其在光催化领域的应用打下了基础。
不采用添加剂，用水热法和沉淀法在不同pH值下选择性合成了m-和t-LaVO_4:Eu~(3+)，考察了样品的光致发光性质。实验证明，pH值是选择性合成m-和t-LaVO_4:Eu~(3+)的关键，在pH值6-9之间可合成t-LaVO_4:Eu~(3+)，pH值4-5之间可合成m-LaVO_4:Eu~(3+)。样品在280 nm紫外光激发下能发射600-620 nm窄带红光，t-LaVO_4:Eu~(3+)发光性能远比m-LaVO_4:Eu~(3+)优越。形貌对光致发光性质有重要影响，沉淀法所得到的t-LaVO_4:Eu~(3+)具有规则的形貌，尺寸为亚微米级。延长陈化时间可增强样品发光强度，常温下陈化12 h所得样品的发光强度与180℃水热2 h样品相近。Eu~(3+)掺杂量也是影响样品发光性质重要因素，其最佳掺杂浓度为摩尔百分数5％。t-LaVO_4:Eu~(3+)结构稳定，在60
Ring neodymium magnet
0℃以下煅烧后样品发光强度不会下降。
学位年度:2009
作者:罗红霞
学位授予单位:暨南大学
关键词:LaVO_4;; LaVO_4:Eu~(3+);;选择性合成;;可见光催化;;光致发光
摘要:
稀土具有独特的物理和化学性能，特别是优异的光、电、磁和催化性质，已在国民经济和现代科学技术的各个领域得到重要应用，在国际上稀土化合物被视为21世纪的新材料。
Ring neodymium magnet
本文用溶胶-凝胶法和水热法在不同条件下合成了系列复合氧化物LaVO_4，用XRD，FT-IR SEM，BET，UV-Vis DRS对催化剂进行了表征，考察了其可见光催化降解罗丹明B的性质。结果表明，用水热法和溶胶-凝胶法均能在一定条件下选择性合成m-与t-LaVO_4。m-LaVO_4比t-LaVO_4可见光催化活性高。与水热法相比，溶胶．凝胶法制备的m-LaVO_4为多孔结构，可见光催化活性更高，其中300℃制备的m-LaVO_4活性最高，可见光催化降解10mg·L~(-1)罗丹明B溶液6小时后，罗丹明B降解率达65.45％，比TiO_2(Degussa P25)高48.07％。加入电子受体或调节罗丹明B溶液pH值为酸性(pH=3)都可大幅度提高m-LaVO_4的可见光催化活性，反应2小时后，罗丹明B均可完全降解。m-LaVO_4的可
Ring neodymium magnet
见光催化活性，弥补了TiO_2不能充分利用太阳光的缺陷，为其在光催化领域的应用打下了基础。
不采用添加剂，用水热法和沉淀法在不同pH值下选择性合成了m-和t-LaVO_4:Eu~(3+)，考察了样品的光致发光性质。实验证明，pH值是选择性合成m-和t-LaVO_4:Eu~(3+)的关键，在pH值6-9之间可合成t-LaVO_4:Eu~(3+)，pH值4-5之间可合成m-LaVO_4:Eu~(3+)。样品在280 nm紫外光激发下能发射600-620 nm窄带红光，t-LaVO_4:Eu~(3+)发光性能远比m-LaVO_4:Eu~(3+)优越。形貌对光致发光性质有重要影响，沉淀法所得到的t-LaVO_4:Eu~(3+)具有规则的形貌，尺寸为亚微米级。延长陈化时间可增强样品发光强度，常温下陈化12 h所得样品的发光强度与180℃水热2 h样品相近。Eu~(3+)掺杂量也是影响样品发光性质重要因素，其最佳掺杂浓度为摩尔百分数5％。t-LaVO_4:Eu~(3+)结构稳定，在60
Ring neodymium magnet
0℃以下煅烧后样品发光强度不会下降。
学位年度:2009
纳米晶SmCo二元系永磁体的制备与研究
题名:纳米晶SmCo二元系永磁体的制备与研究
作者:许刚
学位授予单位:北京工业大学
关键词:SmCo;;放电等离子烧结(SPS);;高温磁性能;;非晶;;纳米晶
摘要:
稀土永磁材料是一种重要的基础功能材料,广泛应用于计算机、网络、通信、航空航天、交通、办公自动化、家电、医疗保健的高新技术领域。现代工业的发展以及航空航天事业的突飞猛进将稀土永磁材料推向更广阔的strong magnets使用场合,使用条件也越来越高,因而对高磁性能、高使用温度的永磁体有越来越强烈的需求。虽然SmCo系二元合金1:5,2:17二元相已经早已有所研究,但是研究的范围大多是在微米尺度下的结构及其磁性能,而在进入纳米尺度条件下,它们的结构和磁性能将有别于以往的研究;并且希望通过改良制备工艺获得较好性能的纳米晶烧结磁体。另外,传统的制备工艺下较难获得亚稳相,随着人们对亚稳相的认识进一步的深入,以及对亚稳相特殊功能的需求,越来越多的研究者投入对亚稳相的研究,例如:SmCo系1:7,1:13相; 1:13相被预测在SmCo系具有最高磁晶各向异性场strong magnets及最高的居里温度,将是永磁材料的一大突破。
新的放电等离子烧结技术(SPS)具有烧结速度快,烧结温度低(比传统烧结温度低几百度),能效比率高,环保等特点,利用低温烧结抑制晶粒长大,可加压使材料高致密化,从而获得高致密的烧结块体。SPS快速非平衡烧结技术为Sm-Co体系高温永磁体的研究带来了新气象。本文应用SPS特殊的烧结工艺,结合通过快淬-高能球磨法制备的非晶粉末,在680-720℃、500MPa、保温3分钟的工艺条件下原位烧结,较好控制了strong magnets非晶晶化的成相过程,成功制备了纳米晶SmCo二元系SmCo_5、Sm_2Co_(17)以及SmCo_(13)等烧结磁体。
使用XRD衍射分析了化合物SmCo_5、Sm_2Co_(17)、SmCo_(13)的晶体结构,并确定烧结磁体晶粒尺寸以及分析晶体结构和性能的影响。采用透射电子显微镜(TEM)观察了磁体的微观结构。采用物理性质测量系统(PPMS)测试磁体的磁滞http://www.chinamagnets.biz/回线,确定磁体的饱和磁化强度、剩磁、矫顽力等性能,观察到纳米晶磁体的剩磁增强效应;并通过剩磁曲线δM-T的变化趋势,表现出纳米晶间强交换耦合作用。测得室温下SmCo_5磁体具有高矫顽力2.85T,Sm_2Co_(17)磁体有0.87T的矫顽力,SmCo_(13)具有高达0.9T的剩磁及0.39T的矫顽力。使用振动样品磁强计(VSM)测试磁体在不同温度下的磁滞回线,计算其矫顽力温度系数。结果表明,SmCo_5磁体的矫顽力温度系数为-0.146%/℃,说明SmCo_5纳米晶烧结strong magnets磁体具有良好的高温磁性能。
学位年度:2009
作者:许刚
学位授予单位:北京工业大学
关键词:SmCo;;放电等离子烧结(SPS);;高温磁性能;;非晶;;纳米晶
摘要:
稀土永磁材料是一种重要的基础功能材料,广泛应用于计算机、网络、通信、航空航天、交通、办公自动化、家电、医疗保健的高新技术领域。现代工业的发展以及航空航天事业的突飞猛进将稀土永磁材料推向更广阔的strong magnets使用场合,使用条件也越来越高,因而对高磁性能、高使用温度的永磁体有越来越强烈的需求。虽然SmCo系二元合金1:5,2:17二元相已经早已有所研究,但是研究的范围大多是在微米尺度下的结构及其磁性能,而在进入纳米尺度条件下,它们的结构和磁性能将有别于以往的研究;并且希望通过改良制备工艺获得较好性能的纳米晶烧结磁体。另外,传统的制备工艺下较难获得亚稳相,随着人们对亚稳相的认识进一步的深入,以及对亚稳相特殊功能的需求,越来越多的研究者投入对亚稳相的研究,例如:SmCo系1:7,1:13相; 1:13相被预测在SmCo系具有最高磁晶各向异性场strong magnets及最高的居里温度,将是永磁材料的一大突破。
新的放电等离子烧结技术(SPS)具有烧结速度快,烧结温度低(比传统烧结温度低几百度),能效比率高,环保等特点,利用低温烧结抑制晶粒长大,可加压使材料高致密化,从而获得高致密的烧结块体。SPS快速非平衡烧结技术为Sm-Co体系高温永磁体的研究带来了新气象。本文应用SPS特殊的烧结工艺,结合通过快淬-高能球磨法制备的非晶粉末,在680-720℃、500MPa、保温3分钟的工艺条件下原位烧结,较好控制了strong magnets非晶晶化的成相过程,成功制备了纳米晶SmCo二元系SmCo_5、Sm_2Co_(17)以及SmCo_(13)等烧结磁体。
使用XRD衍射分析了化合物SmCo_5、Sm_2Co_(17)、SmCo_(13)的晶体结构,并确定烧结磁体晶粒尺寸以及分析晶体结构和性能的影响。采用透射电子显微镜(TEM)观察了磁体的微观结构。采用物理性质测量系统(PPMS)测试磁体的磁滞http://www.chinamagnets.biz/回线,确定磁体的饱和磁化强度、剩磁、矫顽力等性能,观察到纳米晶磁体的剩磁增强效应;并通过剩磁曲线δM-T的变化趋势,表现出纳米晶间强交换耦合作用。测得室温下SmCo_5磁体具有高矫顽力2.85T,Sm_2Co_(17)磁体有0.87T的矫顽力,SmCo_(13)具有高达0.9T的剩磁及0.39T的矫顽力。使用振动样品磁强计(VSM)测试磁体在不同温度下的磁滞回线,计算其矫顽力温度系数。结果表明,SmCo_5磁体的矫顽力温度系数为-0.146%/℃,说明SmCo_5纳米晶烧结strong magnets磁体具有良好的高温磁性能。
学位年度:2009
2012年3月8日星期四
Research on the Switched Reluctance Generator Control System
Research on the Switched Reluctance Generator Control System
As the representative of modern electrical machines, switched reluctance machine combines the electrical machine theories with the modern power electronics technique and the advanced microprocessor control technique, which not only has low-cost strong structure, good fault-tolerant and heat-resistant capability but also has excellent controllability. Thus, switched reluctance machine as motor is widely used in drive and speed regulation field. In these ten years, more and more attention is also paid to its application in generation field, which interests many specialists neodymium magnets and scholars.This paper mainly focuses on the application of switched reluctance generator, and has done some further theoretic research as well as experimental research.Firstly, this paper summarized and analyzed the present and the prospective of wind generation and relative techniques based on a large number of referenced materials, presented the several advantages of SRG generation http://www.999magnet.com/ system, further made the significance of developing this kind of system clear.
Secondly, how switched reluctance generator works and how to control it are explained from a new view, which separated the switched reluctance generator from switched reluctance motor and clarified the performance characters of SRG.. The linear and nonlinear mathematical model of SRG inductance was produced.Thirdly, in this chapter, the linear and nonlinear mathematic models of SRG were discussed in details. Simulation of SRG using MATLAB software and a neodymium magnets series of qualitative analysis were conducted. Some instructive theoretic conclusions were drawn from the above work.Fourthly, a set of practical SRG system is developed, which based on DSP control technique and power electronics converting technique. The reasonable design of this system fully displayed the flexibility of SRG control.Finally, experiments have been done on this practical system. The experimental results validated and deepened the conclusions drawn neodymium magnets from theoretical research. The compare between the results from experiments and simulation also testified the practicability of the mathematical models presented in this paper.
As the representative of modern electrical machines, switched reluctance machine combines the electrical machine theories with the modern power electronics technique and the advanced microprocessor control technique, which not only has low-cost strong structure, good fault-tolerant and heat-resistant capability but also has excellent controllability. Thus, switched reluctance machine as motor is widely used in drive and speed regulation field. In these ten years, more and more attention is also paid to its application in generation field, which interests many specialists neodymium magnets and scholars.This paper mainly focuses on the application of switched reluctance generator, and has done some further theoretic research as well as experimental research.Firstly, this paper summarized and analyzed the present and the prospective of wind generation and relative techniques based on a large number of referenced materials, presented the several advantages of SRG generation http://www.999magnet.com/ system, further made the significance of developing this kind of system clear.
Secondly, how switched reluctance generator works and how to control it are explained from a new view, which separated the switched reluctance generator from switched reluctance motor and clarified the performance characters of SRG.. The linear and nonlinear mathematical model of SRG inductance was produced.Thirdly, in this chapter, the linear and nonlinear mathematic models of SRG were discussed in details. Simulation of SRG using MATLAB software and a neodymium magnets series of qualitative analysis were conducted. Some instructive theoretic conclusions were drawn from the above work.Fourthly, a set of practical SRG system is developed, which based on DSP control technique and power electronics converting technique. The reasonable design of this system fully displayed the flexibility of SRG control.Finally, experiments have been done on this practical system. The experimental results validated and deepened the conclusions drawn neodymium magnets from theoretical research. The compare between the results from experiments and simulation also testified the practicability of the mathematical models presented in this paper.
The Design and Simulation Research of AC PMSM Servo System
The Design and Simulation Research of AC PMSM Servo System
This thesis particularly described the design of full digital AC servo system based on the PMSM(Permanent Magnet Synchronous Motor). With discussing the difference among several control strategies and analyzing mathematical model of PMSM, the id = 0 vector control for the SPMSM had been chosen to be the strategy of this servo system. The theory of SVPWM and the ways of locating the PMSM’s rotor pole had been presented in this thesis. The establishing of the three loops servo system of PMSM which is based on the id = 0 vector control by use of magnetic lifter the Saber Designer had also been introduced.The design of three loops servo system’s controllers was the key point of this thesis. With analyzing the function requirement of three loops servo system, as for the current loop, the author adopted PI controller to ensure the performance of speediness and anti-disturbance; Considering the performance criterion of the velocity controller such as overshoot, regulating time, disturbance and precision, and the advantages and disadvantages of several kinds of controllers;As for the position loop,we chose the proportion and feedforward controller to satisfy the performance magnetic lifter criterion of the locating precision , tracking precision and the range of overshoot.
Then by the use of Saber Designer, we proved the arithmetic of controllers that we finally determined to be right.On the basis of the analysis of the theory and result of simulation, we designed the hardware and software of the full digital AC servo http://www.999magnet.com/ system. The hardware of the servo system could be divided into two parts, the first was the control circuit part and the other was the power circuit part. And the design of the galvanometry and photoelectric-encoder was the key point,While the content of software described the key design method and the flowchart of the software magnetic lifter designing. The last paragraph of this thesis referred to the experiments of three loops of the servo system, the results of the experiment proved that the performance of the control system was satisfying, and validated the strategy that we had designed.
This thesis particularly described the design of full digital AC servo system based on the PMSM(Permanent Magnet Synchronous Motor). With discussing the difference among several control strategies and analyzing mathematical model of PMSM, the id = 0 vector control for the SPMSM had been chosen to be the strategy of this servo system. The theory of SVPWM and the ways of locating the PMSM’s rotor pole had been presented in this thesis. The establishing of the three loops servo system of PMSM which is based on the id = 0 vector control by use of magnetic lifter the Saber Designer had also been introduced.The design of three loops servo system’s controllers was the key point of this thesis. With analyzing the function requirement of three loops servo system, as for the current loop, the author adopted PI controller to ensure the performance of speediness and anti-disturbance; Considering the performance criterion of the velocity controller such as overshoot, regulating time, disturbance and precision, and the advantages and disadvantages of several kinds of controllers;As for the position loop,we chose the proportion and feedforward controller to satisfy the performance magnetic lifter criterion of the locating precision , tracking precision and the range of overshoot.
Then by the use of Saber Designer, we proved the arithmetic of controllers that we finally determined to be right.On the basis of the analysis of the theory and result of simulation, we designed the hardware and software of the full digital AC servo http://www.999magnet.com/ system. The hardware of the servo system could be divided into two parts, the first was the control circuit part and the other was the power circuit part. And the design of the galvanometry and photoelectric-encoder was the key point,While the content of software described the key design method and the flowchart of the software magnetic lifter designing. The last paragraph of this thesis referred to the experiments of three loops of the servo system, the results of the experiment proved that the performance of the control system was satisfying, and validated the strategy that we had designed.
2012年3月7日星期三
Magnetoelectric Properties of the Multiferroic Materials
Magnetoelectric Properties of the Multiferroic Materials
Ferroelectric/Ferromagnetic composite is a novel functional material, which possesses not only ferroelectric and ferromagnetic properties but also magnetoelectric coupling effect, so that it has very broad range potential applications. In this thesis, the magnetoelectric effect of the multiferroic material was studied by developing several popular models of micro-mechanics, which can enable us to analyze the macroscopical behavior from the micro-structure of the neodymium rare earth magnets composition. We mostly consider matrix-based two-phase multiferroic composites, matrix-based three-phase multiferroic composites and magnetoelectric polycrystals. These numerical results provide guidelines for the experimental design of the multiferroic material.A mean field Mori-Tanaka model was used to calculate the effective magnetoelectroelastic moduli of matrix-based two-phase multiferroic composites, emphasizing the effects of particular shape of second phase particles. The results show a strong influence of shape aspect ratios of constituent phases on the effective magnetoelectric coefficients, while the orientation is parallel and perpendicular about the pole polarization of matrix and magnetization of the second phase particles. A mean field Mori-Tanaka model was developed to calculate the neodymium rare earth magnets effective magnetoelectroelastic moduli of matrix-based three-phase multiferroic composites.
The change trend of magnetoelectric coefficients in the three-phase particulate composites which are made of rare-earth-iron alloys, piezoelectric ceramics and polymer (Terfenol-D/PZT/PVDF) were obtained. The variations of magnetoelectric coefficients of the composites with respect to the microstructural features have been investigated. The results show a strong influence of volume fraction and shape aspect ratios of constituent phases on the effective magnetoelectric coefficients. The optimal volume fraction and shape aspect ratios of particles for the strongest magnetoelectric coupling are identified. It is observed that lamellar particles are optimal for ME coefficient a11, while fibrous particles are optimal for a33.we developed an effective medium approximation to calculate the macroscopic effective coefficients of magnetoelectric polycrystals, which are annealed in perpendicular electric and magnetic fields, and emphasized the effects of temperature as well as shape and orientation distribution of grains on the macroscopic magnetoelectric coefficients of polycrystalline Cr2O3.
Through a systematic study, it is observed that the effective magnetoelectric coefficients on the diagonal of magnetoelectric coefficient moduli are zero, neodymium rare earth magnets and only non-diagonal magnetoelectric coefficients appear, and that calculated from the effective medium approximation is higher than simple volume averaging and agrees with experimental data better. It is also noted that polycrystals with randomly oriented grains are optimal for a12 while those with appropriate texture coefficients can cause nonzero a13 and with texture coefficient around 0.5 are optimal for this.
Ferroelectric/Ferromagnetic composite is a novel functional material, which possesses not only ferroelectric and ferromagnetic properties but also magnetoelectric coupling effect, so that it has very broad range potential applications. In this thesis, the magnetoelectric effect of the multiferroic material was studied by developing several popular models of micro-mechanics, which can enable us to analyze the macroscopical behavior from the micro-structure of the neodymium rare earth magnets composition. We mostly consider matrix-based two-phase multiferroic composites, matrix-based three-phase multiferroic composites and magnetoelectric polycrystals. These numerical results provide guidelines for the experimental design of the multiferroic material.A mean field Mori-Tanaka model was used to calculate the effective magnetoelectroelastic moduli of matrix-based two-phase multiferroic composites, emphasizing the effects of particular shape of second phase particles. The results show a strong influence of shape aspect ratios of constituent phases on the effective magnetoelectric coefficients, while the orientation is parallel and perpendicular about the pole polarization of matrix and magnetization of the second phase particles. A mean field Mori-Tanaka model was developed to calculate the neodymium rare earth magnets effective magnetoelectroelastic moduli of matrix-based three-phase multiferroic composites.
The change trend of magnetoelectric coefficients in the three-phase particulate composites which are made of rare-earth-iron alloys, piezoelectric ceramics and polymer (Terfenol-D/PZT/PVDF) were obtained. The variations of magnetoelectric coefficients of the composites with respect to the microstructural features have been investigated. The results show a strong influence of volume fraction and shape aspect ratios of constituent phases on the effective magnetoelectric coefficients. The optimal volume fraction and shape aspect ratios of particles for the strongest magnetoelectric coupling are identified. It is observed that lamellar particles are optimal for ME coefficient a11, while fibrous particles are optimal for a33.we developed an effective medium approximation to calculate the macroscopic effective coefficients of magnetoelectric polycrystals, which are annealed in perpendicular electric and magnetic fields, and emphasized the effects of temperature as well as shape and orientation distribution of grains on the macroscopic magnetoelectric coefficients of polycrystalline Cr2O3.
Through a systematic study, it is observed that the effective magnetoelectric coefficients on the diagonal of magnetoelectric coefficient moduli are zero, neodymium rare earth magnets and only non-diagonal magnetoelectric coefficients appear, and that calculated from the effective medium approximation is higher than simple volume averaging and agrees with experimental data better. It is also noted that polycrystals with randomly oriented grains are optimal for a12 while those with appropriate texture coefficients can cause nonzero a13 and with texture coefficient around 0.5 are optimal for this.
Research on Effective Organizational Form of Private Enterprises of China-Industrial Alliance from the Perspective of Shanxi Magnetism Material Alliance
Research on Effective Organizational Form of Private Enterprises of China-Industrial Alliance from the Perspective of Shanxi Magnetism Material Alliance
Private enterprises have obtained considerable development and already become a major constituent part of national economy and important power to impel social and economic development of China since reform and opening up. However, there are inevitably many difficulties of private enterprises which have grown in the period of reforming in the course of development, such as funds insufficiency, small scale, lower technical level, weaker innovation ability, strong magnets talent shortage and higher flow rate. There are enormous challenges for the survival and development of private enterprises which are generally at the inferior position in domestic and international competition due to the congenital difficulties with the change of social and economic environment, especially the rapid development of science and technologies, entering into WTO as well as the integration of international economy. Therefore, how to get rid of the difficult position and how to grow stronger are always the puzzle of private enterprises, and also the focus of government and all walks of life of the society. Private enterprises of Shanxi magnetism material industry as a part of private enterprises of China, which have started since 1986, have strong magnets also experienced the difficult period which China’s private enterprises went through.
There are also congenital difficulties in their developing process, and they are also in inferior position in domestic and international competition. Nevertheless, they have gained great achievements in 7 years after they took the path of common development through building magnetism material alliance, whose member has developed from the initial 18 magnetism material enterprises to 102 members until 2007containing 100 private enterprises, involving different industrial chains such as raw materials, manufacture, processing, trade, and equipments and so on. Moreover, Shanxi magnetism material alliance has already become the largest industrial organization of China to be engaged in agglutination, processing neodymium iron boron and special equipments. The success of Shanxi magnetism material alliance has given the enlightenment about how to get rid of the difficult position of private enterprises of strong magnets China especially small ones through building industry alliance. This graduation thesis conducts the research precisely for this goal.
This paper analyzes the ecological background and build-up types and characteristics of the current international industrial alliance on the basis of "management ecology". It holds that the international industrial alliance has provided the platform to enhance competitive advantages for large enterprises or enterprises with powerful technology, but it has exclusiveness for small and medium-sized enterprises. Then, it comprehensively analyzes the independent development characteristics, familial characteristics, regional characteristics and authority pursue characteristics under the special situation of China from the historical and ecological perspective. Furthermore, comparing with the path of funds and talents introduction, the path of merge and collectivization development, the path of international industrial alliance pattern development as well as the path of Shanxi magnetism material alliance pattern development under the congenital difficult conditions of funds insufficiency and small strong magnets scale, it believes that Shanxi magnetism material alliance as an organization form among enterprises is suitable and effective for private enterprises of China. Thus, its experience can be drawn for that of China. At last, the paper suggests some countermeasures and suggestions for developing industrial alliance of private enterprises in China on the analysis of the success and existent questions of Shanxi magnetism material alliance.There is certain guiding sense of this paper to the current development of private enterprises of China, which can help China to realize innovative country and give some enlightenment to the regional policy-makers.
Private enterprises have obtained considerable development and already become a major constituent part of national economy and important power to impel social and economic development of China since reform and opening up. However, there are inevitably many difficulties of private enterprises which have grown in the period of reforming in the course of development, such as funds insufficiency, small scale, lower technical level, weaker innovation ability, strong magnets talent shortage and higher flow rate. There are enormous challenges for the survival and development of private enterprises which are generally at the inferior position in domestic and international competition due to the congenital difficulties with the change of social and economic environment, especially the rapid development of science and technologies, entering into WTO as well as the integration of international economy. Therefore, how to get rid of the difficult position and how to grow stronger are always the puzzle of private enterprises, and also the focus of government and all walks of life of the society. Private enterprises of Shanxi magnetism material industry as a part of private enterprises of China, which have started since 1986, have strong magnets also experienced the difficult period which China’s private enterprises went through.
There are also congenital difficulties in their developing process, and they are also in inferior position in domestic and international competition. Nevertheless, they have gained great achievements in 7 years after they took the path of common development through building magnetism material alliance, whose member has developed from the initial 18 magnetism material enterprises to 102 members until 2007containing 100 private enterprises, involving different industrial chains such as raw materials, manufacture, processing, trade, and equipments and so on. Moreover, Shanxi magnetism material alliance has already become the largest industrial organization of China to be engaged in agglutination, processing neodymium iron boron and special equipments. The success of Shanxi magnetism material alliance has given the enlightenment about how to get rid of the difficult position of private enterprises of strong magnets China especially small ones through building industry alliance. This graduation thesis conducts the research precisely for this goal.
This paper analyzes the ecological background and build-up types and characteristics of the current international industrial alliance on the basis of "management ecology". It holds that the international industrial alliance has provided the platform to enhance competitive advantages for large enterprises or enterprises with powerful technology, but it has exclusiveness for small and medium-sized enterprises. Then, it comprehensively analyzes the independent development characteristics, familial characteristics, regional characteristics and authority pursue characteristics under the special situation of China from the historical and ecological perspective. Furthermore, comparing with the path of funds and talents introduction, the path of merge and collectivization development, the path of international industrial alliance pattern development as well as the path of Shanxi magnetism material alliance pattern development under the congenital difficult conditions of funds insufficiency and small strong magnets scale, it believes that Shanxi magnetism material alliance as an organization form among enterprises is suitable and effective for private enterprises of China. Thus, its experience can be drawn for that of China. At last, the paper suggests some countermeasures and suggestions for developing industrial alliance of private enterprises in China on the analysis of the success and existent questions of Shanxi magnetism material alliance.There is certain guiding sense of this paper to the current development of private enterprises of China, which can help China to realize innovative country and give some enlightenment to the regional policy-makers.
2012年3月4日星期日
Role of Magnetic Resonance Imaging in Estimating the Response
Role of Magnetic Resonance Imaging in Estimating the Response of Breast Cancer to Neoadjuvant Chemotherapy & Role of the ADC Value in Estimating and Predicting the Response of Breast Cancer to Neoadjuvant Chemotherapy: A Pilot Study with Diffusion-Weighte
Part One:Role of Magnetic Resonance Imaging in Estimating the Response of Breast Cancer to Neoadjuvant ChemotherapyBackground:Neoadjuvant chemotherapy has become one of the most important parts of treatment in breast cancer.But to date,there is still short of a method which can accurately and efficiently assess the response to neoadjuvant magnet lifter chemotherapy.Recently, a series of studies conducted in the western countries documented that magnetic resonance imaging(MRI) can accurately evaluate chemotherapeutic response,while there were still few studies conducted in our country.However,many studies indicated that MRI may overestimate or underestimate the residual disease in patients receiving neoadjuvant chemotherapy.The role of MRI in assessing the response of breast cancer to neoadjuvant chemotherapy needs further study.Objective:①To approach the value of MRI in estimating the morphology of the tumor in breast cancer patients receiving magnet lifter neoadjuvant chemotherapy.②To compare the accuracy of MRI with sonography and clinical assessment in assessing the residual disease,and to compare the accuracy of MRI with sonography in assessing the response of breast cancer to neoadjuvant chemotherapy.Methods:A total of 22 breast cancer patients participated in this prospective study on neoadjuvant chemotherapy.They were examined by MRI and sonography before chemotherapy,after the second cycle and after the fourth cycle of chemotherapy.
The shrinkage patterns of the tumor appeared on MRI and their relationship with histological type,ER/PR expression with IHC,Her2 status with IHC,treatment regimen was examined.We also investigated the relative value of MRI,sonography and clinical assessment in assessing the residual disease and the relative value of MRI and sonography in assessing the response compared with pathological examination, and the relationship between the treatment regimen and the accuracy of MRI in estimating the residual disease in patients receiving neoadjuvant magnet lifter chemotherapy.Results:There were two shrinkage patterns.12 of 22 breast cancers(54.5%) showed a concentric shrinkage pattern while 10 cases(45.5%) showed a dendritic shrinkage pattern.ER and PR negative tumors,tumors with Her2 high expression(++～+++), invasive ductal carcinoma and tumors treated with anthracyclines tended to show concentric shrinkage while ER and/or PR positive tumors,tumors with Her2 low expression(-～+),mucinous carcinoma,invasive lobular carcinoma and tumors treated with taxanes or vinorelbine tended to show dendritic shrinkage.
A strong correlation(r=0.781,P<0.001) was observed between the longest diameter of residual disease measured on MRI and pathology while the longest diameter measured on sonography(r=0.574,P=0.005) and clinical assessment(r=0.450,P=0.036) only showed moderate correlation with pathologic results.The error of the longest diameter measured on MRI compared with pathologic results(0.51±0.55cm) was also less than that measured on sonography(0.73±0.78cm) and clinical assessment (1.27±0.93cm) compared with pathologic results.There was no significant difference between sonography and MRI in assessing the response(CR,PR,SD,PD) to neoadjuvant chemotherapy(P=0.754).The sensitivity,specificity,positive predictive value and negative predictive value of MRI in magnet lifter diagnosis of pathologic complete response(pCR) were higher than those of sonography(83.3%,100.0%, 100.0%,94.1%vs.66.7%,93.8%,80.0%,88.2%),and the false positive rate and false negative rate of MRI in diagnosis of pCR were lower than those of sonography(0.0%,16.7%vs.6.2%,33.3%).The overall agreement of response as measured on MRI and sonography compared with pathology was 95.5%and 86.4%, respectively.MRI underestimated the residual disease in 2 cases and overestimated the residual disease in 4 cases.
The correlation between MRI after chemotherapy and histology was 0.868(P=0.005) in anthracyclines treated group,which was higher than that in taxanes(r=0.777,P=0.008) or vinorelbine(r=0.594,P=0.406) treated group.Conclusions:MRI is a useful modality for evaluating the morphology of the tumor in breast cancer patients receiving neoadjuvant chemotherapy.MRI can estimate the residual tumor extent after neoadjuvant chemotherapy more accurately than sonography and clinical assessment,and MRI also can estimate the response to neoadjuvant chemotherapy more accurately than sonography. Part Two.Role of the ADC Value in Estimating and Predicting the Response of Breast Cancer to Neoadjuvant Chemotherapy:a Pilot Study with Diffusion-Weighted MRIBackground:Neoadjuvant chemotherapy has been accepted as the standard treatment of locally advanced breast cancer.But to date,there is still short of a method which can accurately assess and early predict response to neoadjuvant chemotherapy.A number of recent preclinical animal studies and cell models have indicated the potential magnet lifter usefulness of diffusion-weighted imaging(DWI) in predicting response to the treatment of cancers.Till now,few papers demonstrating the similar results in human studies have been published.However,DWI has been utilized to assess response to treatment in brain tumors,metastatic liver lesions and rectal carcinomas. The role of diffusion-weighted magnetic resonance imaging in assessing the response of breast cancer to neoadjuvant chemotherapy needs further study.Objective:To approach the ADC value obtained on DWI in estimating and predicting the response of breast cancer to neoadjuvant chemotherapy. Methods:A total of 35 breast cancer cases participated in this prospective study on neoadjuvant chemotherapy.12 cases of them who have finished neoadjuvant chemotherapy underwent surgery,and were examined by DWI before chemotherapy, after the second cycle of chemotherapy and before surgery(1 case of them was excluded because there was no residual disease showed on MRI before surgery).23 cases who have not finished neoadjuvant chemotherapy were examined by DWI before chemotherapy and after the first cycle of chemotherapy.We assessed the appearances of tumor on DWI.Of the 11 patients,we assessed the relationship between the degree of the changes in ADC value and the degree of the changes in the longest diameter of tumor measured on MRI and the relationship between the changes in ADC values and age,ER/PR expression with IHC,Her2 status with IHC and the response to neoadjuvant chemotherapy.We also assessed whether the ADC value before neoadjuvant chemotherapy could predict the response of breast cancer and the degree of the changes in the longest diameter of tumor.We estimated the relationship between the size reduction in neoadjuvant treatment of breast cancer and the changes in ADC value after the magnet lifter first cycle or the second cycle of chemotherapy.
Results:Of the 11 cases,a strong negative correlation was observed between the degree of the changes in ADC value and the degree of the changes in the longest diameter of tumor measured on MRI(r=-0.729,P=0.011).Age and Her2 status were not significantly associated with the changes in ADC value,but both ER and PR negative patients were likely to have greater changes in ADC value than ER and/or PR positive patients(-0.14±0.13 vs.-0.50±0.28,P=0.027).This phenomenon was also seen in the changes in the longest diameter(P=0.011).9 of 11 cases were diagnosed partial disease(PR) by MRI and 2 of 11 cases were diagnosed stable disease(SD) by MRI after chemotherapy.The mean ADC value of the posttreatment was increased more significantly in the PR group(0.41±0.26,P=0.002) than in the SD group(0.02±0.01,P=0.205).A strong negative correlation was also observed between the ADC values,measured prior to treatment,and the degree of the changes in the longest diameter after therapy(r=-0.793,P=0.004).A significant difference between the mean ADC value of PR group and SD group was shown before chemotherapy(1.00±0.10 vs.1.27±0.10,P=0.006).Of the 11 cases,both the increase in the ADC value(P=0.002,P=0.002) and the decrease in the longest magnet lifter diameter(P=0.001,P<0.001) were significant after the second cycle of neoadjuvant chemotherapy and before surgery.It was noted that of the 23 cases,there was a significant increase in the ADC value at the first cycle time point(P<0.001),while the decrease in the longest diameter was not significant(P=0.103).Conclusions:The ADC value obtained on Diffusion-weighted MR imaging is potentially useful in detecting the response of breast cancer to neoadjuvant chemotherapy,and the ADC value before chemotherapy can predict the response of breast cancer and the degree of the changes in the longest diameter http://www.999magnet.com/ of tumor.The increase in the ADC value at the first cycle time point may predict the early response of breast cancer to neoadjuvant chemotherapy.
Part One:Role of Magnetic Resonance Imaging in Estimating the Response of Breast Cancer to Neoadjuvant ChemotherapyBackground:Neoadjuvant chemotherapy has become one of the most important parts of treatment in breast cancer.But to date,there is still short of a method which can accurately and efficiently assess the response to neoadjuvant magnet lifter chemotherapy.Recently, a series of studies conducted in the western countries documented that magnetic resonance imaging(MRI) can accurately evaluate chemotherapeutic response,while there were still few studies conducted in our country.However,many studies indicated that MRI may overestimate or underestimate the residual disease in patients receiving neoadjuvant chemotherapy.The role of MRI in assessing the response of breast cancer to neoadjuvant chemotherapy needs further study.Objective:①To approach the value of MRI in estimating the morphology of the tumor in breast cancer patients receiving magnet lifter neoadjuvant chemotherapy.②To compare the accuracy of MRI with sonography and clinical assessment in assessing the residual disease,and to compare the accuracy of MRI with sonography in assessing the response of breast cancer to neoadjuvant chemotherapy.Methods:A total of 22 breast cancer patients participated in this prospective study on neoadjuvant chemotherapy.They were examined by MRI and sonography before chemotherapy,after the second cycle and after the fourth cycle of chemotherapy.
The shrinkage patterns of the tumor appeared on MRI and their relationship with histological type,ER/PR expression with IHC,Her2 status with IHC,treatment regimen was examined.We also investigated the relative value of MRI,sonography and clinical assessment in assessing the residual disease and the relative value of MRI and sonography in assessing the response compared with pathological examination, and the relationship between the treatment regimen and the accuracy of MRI in estimating the residual disease in patients receiving neoadjuvant magnet lifter chemotherapy.Results:There were two shrinkage patterns.12 of 22 breast cancers(54.5%) showed a concentric shrinkage pattern while 10 cases(45.5%) showed a dendritic shrinkage pattern.ER and PR negative tumors,tumors with Her2 high expression(++～+++), invasive ductal carcinoma and tumors treated with anthracyclines tended to show concentric shrinkage while ER and/or PR positive tumors,tumors with Her2 low expression(-～+),mucinous carcinoma,invasive lobular carcinoma and tumors treated with taxanes or vinorelbine tended to show dendritic shrinkage.
A strong correlation(r=0.781,P<0.001) was observed between the longest diameter of residual disease measured on MRI and pathology while the longest diameter measured on sonography(r=0.574,P=0.005) and clinical assessment(r=0.450,P=0.036) only showed moderate correlation with pathologic results.The error of the longest diameter measured on MRI compared with pathologic results(0.51±0.55cm) was also less than that measured on sonography(0.73±0.78cm) and clinical assessment (1.27±0.93cm) compared with pathologic results.There was no significant difference between sonography and MRI in assessing the response(CR,PR,SD,PD) to neoadjuvant chemotherapy(P=0.754).The sensitivity,specificity,positive predictive value and negative predictive value of MRI in magnet lifter diagnosis of pathologic complete response(pCR) were higher than those of sonography(83.3%,100.0%, 100.0%,94.1%vs.66.7%,93.8%,80.0%,88.2%),and the false positive rate and false negative rate of MRI in diagnosis of pCR were lower than those of sonography(0.0%,16.7%vs.6.2%,33.3%).The overall agreement of response as measured on MRI and sonography compared with pathology was 95.5%and 86.4%, respectively.MRI underestimated the residual disease in 2 cases and overestimated the residual disease in 4 cases.
The correlation between MRI after chemotherapy and histology was 0.868(P=0.005) in anthracyclines treated group,which was higher than that in taxanes(r=0.777,P=0.008) or vinorelbine(r=0.594,P=0.406) treated group.Conclusions:MRI is a useful modality for evaluating the morphology of the tumor in breast cancer patients receiving neoadjuvant chemotherapy.MRI can estimate the residual tumor extent after neoadjuvant chemotherapy more accurately than sonography and clinical assessment,and MRI also can estimate the response to neoadjuvant chemotherapy more accurately than sonography. Part Two.Role of the ADC Value in Estimating and Predicting the Response of Breast Cancer to Neoadjuvant Chemotherapy:a Pilot Study with Diffusion-Weighted MRIBackground:Neoadjuvant chemotherapy has been accepted as the standard treatment of locally advanced breast cancer.But to date,there is still short of a method which can accurately assess and early predict response to neoadjuvant chemotherapy.A number of recent preclinical animal studies and cell models have indicated the potential magnet lifter usefulness of diffusion-weighted imaging(DWI) in predicting response to the treatment of cancers.Till now,few papers demonstrating the similar results in human studies have been published.However,DWI has been utilized to assess response to treatment in brain tumors,metastatic liver lesions and rectal carcinomas. The role of diffusion-weighted magnetic resonance imaging in assessing the response of breast cancer to neoadjuvant chemotherapy needs further study.Objective:To approach the ADC value obtained on DWI in estimating and predicting the response of breast cancer to neoadjuvant chemotherapy. Methods:A total of 35 breast cancer cases participated in this prospective study on neoadjuvant chemotherapy.12 cases of them who have finished neoadjuvant chemotherapy underwent surgery,and were examined by DWI before chemotherapy, after the second cycle of chemotherapy and before surgery(1 case of them was excluded because there was no residual disease showed on MRI before surgery).23 cases who have not finished neoadjuvant chemotherapy were examined by DWI before chemotherapy and after the first cycle of chemotherapy.We assessed the appearances of tumor on DWI.Of the 11 patients,we assessed the relationship between the degree of the changes in ADC value and the degree of the changes in the longest diameter of tumor measured on MRI and the relationship between the changes in ADC values and age,ER/PR expression with IHC,Her2 status with IHC and the response to neoadjuvant chemotherapy.We also assessed whether the ADC value before neoadjuvant chemotherapy could predict the response of breast cancer and the degree of the changes in the longest diameter of tumor.We estimated the relationship between the size reduction in neoadjuvant treatment of breast cancer and the changes in ADC value after the magnet lifter first cycle or the second cycle of chemotherapy.
Results:Of the 11 cases,a strong negative correlation was observed between the degree of the changes in ADC value and the degree of the changes in the longest diameter of tumor measured on MRI(r=-0.729,P=0.011).Age and Her2 status were not significantly associated with the changes in ADC value,but both ER and PR negative patients were likely to have greater changes in ADC value than ER and/or PR positive patients(-0.14±0.13 vs.-0.50±0.28,P=0.027).This phenomenon was also seen in the changes in the longest diameter(P=0.011).9 of 11 cases were diagnosed partial disease(PR) by MRI and 2 of 11 cases were diagnosed stable disease(SD) by MRI after chemotherapy.The mean ADC value of the posttreatment was increased more significantly in the PR group(0.41±0.26,P=0.002) than in the SD group(0.02±0.01,P=0.205).A strong negative correlation was also observed between the ADC values,measured prior to treatment,and the degree of the changes in the longest diameter after therapy(r=-0.793,P=0.004).A significant difference between the mean ADC value of PR group and SD group was shown before chemotherapy(1.00±0.10 vs.1.27±0.10,P=0.006).Of the 11 cases,both the increase in the ADC value(P=0.002,P=0.002) and the decrease in the longest magnet lifter diameter(P=0.001,P<0.001) were significant after the second cycle of neoadjuvant chemotherapy and before surgery.It was noted that of the 23 cases,there was a significant increase in the ADC value at the first cycle time point(P<0.001),while the decrease in the longest diameter was not significant(P=0.103).Conclusions:The ADC value obtained on Diffusion-weighted MR imaging is potentially useful in detecting the response of breast cancer to neoadjuvant chemotherapy,and the ADC value before chemotherapy can predict the response of breast cancer and the degree of the changes in the longest diameter http://www.999magnet.com/ of tumor.The increase in the ADC value at the first cycle time point may predict the early response of breast cancer to neoadjuvant chemotherapy.
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