长余辉发光材料的制备与性能研究

题名:长余辉发光材料的制备与性能研究
作者:邱冬
学位授予单位:合肥工业大学
关键词:高温固相法;;稀土掺杂;;长余辉发光材料;;发光性能
摘要:

 绿色SrAl_2O_4: Eu~(2+), Dy~(3+)长余辉发光材料出现于二十世纪中期,并在九十年代得到迅速发展。它以铝酸盐原料为基质,以稀土材料作为掺杂元素形成发光中心和陷阱中心,激发光源可以是人造光源或者太阳光。它无毒、无放neodymium rare earth magnets射性、亮度高、余辉时间长、结构稳定,是一种高效节能的固体发光材料。近年来,该材料的应用日益广泛,其研究也受到国内外的广泛关注,单一的黄绿颜色已不能满足人们的需要。鉴于此,本论文采用高温固相法制备了SrAl_2O_4: Eu~(2+), Dy~(3+),CaAl_2O_4: Eu~(2+), Nd~(3+)和CaTiO_3: Pr~(3+)长余辉发光材料。利用XRD、荧光分光光度计、稳态/寿命荧光光谱议等研究手段,研究了助熔剂的种类及用量,激活剂Eu~(2+)的用量,辅助激活剂的种类及用量,焙烧温度,恒温的时间等因素对样品结构和性能的影响。最大发射峰波长分别位于510nm、440nm和618nm。衰减由初始的快衰减和其后的慢衰减两种衰减过程所组成,符合I=At-n规律。XRD分析表明,SrAl2O4: Eu~(2+), Dy3+材料和CaAl2O4: Eu~(2+), Nd3+材料在水浸后生成铝neodymium rare earth magnets酸盐的水化物,改变了材料的晶型,降低了材料的发光性能。

 在对发黄绿光和蓝光的稀土掺http://www.chinamagnets.biz/杂长余辉发光材料的研究取得一定进展的基础上,我们又以CaTiO_3: Pr~(3+)为基质,研究了性能优异的红色长余辉发光材料。用Zn~(2+)替代部分的Ca~(2+)离子,制备了Ca1-xZnxTiO3: Pr~(3+)样品。研究了掺入Zn~(2+)后样品的结晶物相和发光光谱。结果表明,用Zn~(2+)替代部分的Ca~(2+),能够提高样品的发光强度,改善了材料的发光性能。同时还发现,ZnO有一定的助熔作用,不能与H_3BO_3共用。另外,水浸对CaTiO_3: Pr~(3+)材料的发光性能影响不大。

 本论文通过对三种颜色长余辉发光材neodymium rare earth magnets料的研究,获得了这三种长余辉发光材料的制备工艺,结论对长余辉发光材料形成工业化生产有一定的指导意义。
学位年度:2009

The Analysis and Design of AC PMSM Servo Systems

The Analysis and Design of AC PMSM Servo Systems
　　The permanent magnet synchronous motor(PMSM), whose rotor is constructed by a kind of rare earth material, such as NdFeB, has appeared since early 1970’s. With the development of the technology of power electronics control, NdFeB material and motor design, permanent magnet synchronous motors get wide applications in many control systems, especially in the accurate servo control systems because they have excellent control capabilities, large torque neodymium rare earth magnets coefficient, small ripple torque, and many other good qualities.This thesis first introduced the development of PMSM and servo control system, and illuminated the mathematic model, rotor field orientation control (FOC) principle of PMSM and the space vector PWM(SVPWM) technology.
　　Then the current servo system and speed servo system were simulated by MATLAB/SIMULINK respectively. The simulation waveforms verified the validity of the entire system design. That supplied a good foundation for the following hardware design, software design and experiments analysis.On the base of principle analysis and simulation experiments, the thesis neodymium rare earth magnets particularly studied a digital AC servo system for PMSM based on DSP. The hardware structure of the system was introduced briefly and the key design method of software and controller were introduced in detail. Finally, the current, speed and position step response experiments were completed by a PMSM as control plant. The experiments showed the servo control system with good performance and could be applied to the practice.