PbNb2O6基压电陶瓷的高温介电性能研究

本文在PbNb2O6基础上采用Ba^2＋取代Pb^2＋离子,并通过添加Cr2O3、Y2O3、Sm2O3、Nd2O3和CeO2等氧化物进行掺杂改性,研究不同掺杂剂对PbNb2O6陶瓷材料结构的影响,寻找提高压电性能及居里温度的途径.试验结果表明,掺杂后的偏铌酸铅显微结构发生了变化,适量的掺杂可获得压电性能和工艺稳定性能很好,且居里温度较高（420℃～600℃）的改性PbNb2O6系压电陶瓷,可分别满足350℃和500℃以上高温应用环境的要求.     

压电陶瓷变压器材料PMMN-PZT的研究

研究了一种四元系压电陶瓷变压器材料PMMN -PZT。XRD分析证明 ,采用二步法预合成的PMMN -PZT粉料不如一步法 ;SEM分析进一步证实了一步法预合成的粉料能制成性能更好的陶瓷样品。造粒工艺对陶瓷样品的显微结构和压电性能也有重要的影响。最后制得了性能较好的PMMN -PZT压电陶瓷材料 ,其Kp=0 .5 18,Qm=3887,tanδ =0 .71% ,εT3 3 /ε0 =70 1,d3 3 =2 0 3,基本上能满足压电变压器的要求     

Intrinsic Elastic, Dielectric, and Piezoelectric Losses in Lead Zirconate Titanate Ceramics Determined by an Immittance-Fitting Method

The material coefficients of "soft" and "hard" lead zirconate titanate (PZT) ceramics were determined as complex values by the nonlinear least-squares-fitting of immittance data measured for length-extensional bar resonators. The piezoelectric d -constant should be a complex value to obtain a best fitting between observed and calculated results. Because the elastic, dielectric, and piezoelectric losses determined in this process were not "intrinsic" losses, a calculation process to evaluate the "intrinsic" losses was proposed. It was confirmed that the intrinsic losses were smaller than the corresponding extrinsic losses. The intrinsic piezoelectric loss existed in both soft and hard PZTs; ∼50% of the loss of piezoelectric d -constant was derived from the elastic and dielectric losses. The most notable difference between the soft and hard PZTs was observed in their elastic losses.     

准同型相界附近(Na1-xKx)0.5Bi0.5TiO3的制备及性能研究

利用固相法制备了（Na1-xKx）0.5Bi0.5TiO3系压电陶瓷，XRD分析表明所得陶瓷样品为纯的钙钛矿结构，其准同型相界在x=0．18～0．22之间；电子探针显微分析显示所做陶瓷样品晶粒发育良好，具有规则的外形和明显的晶界；实验所得陶瓷样品损耗tanδ最大不超过5％，最好的压电常数d33=153 pC／N，平面机电耦合系数kp=0．299，它们分别出现在x=0．22和0．20处。     

压挤成形--固化法制备0-3型压电复合材料的性能研究

详细地叙述了室温压挤成形———固化工艺制备 0 -3型压电复合材料工艺 ,使用XRD、SEM和HP42 94测试并分析了样品的结构和性能 ,并与压电陶瓷性能参数进行了对比 ;同时用这种工艺制备可以获得介电损耗小、机电耦合系数为 2 5 .11%、压电应变常数为 3 2PC N和机电品质因数可达到 3 0 2的 0— 3型压电复合材料。     

压电双晶片型旋转精密驱动器动态特性和控制

提出了以自由端带有集中质量的悬臂式压电双晶片为驱动单元的新型冲击式旋转精密驱动器.制作了驱动器样机,建立了基于Lugre摩擦模型的驱动器动力学模型.对驱动器动态特性进行了仿真分析和实验对比研究.根据驱动器的动态特性,提出了冲击式压电双晶片型精密驱动器特定的定频调压控制方法.仿真分析结果和实验结果吻合较好,表明该动力学模型符合驱动器的动态特性,可用于对冲击式压电双晶片型旋转精密驱动器的理论分析.     

Alkaline treatment kinetics of calcium phosphate by piezoelectric quartz crystal impedance

Calcium phosphate film was prepared by electrochemical deposition technology. Subsequently, the alkaline treatment process of calcium phosphate film in 0.1 mol/L NaOH solution was monitored on real time by the piezoelectric quartz crystal impedance (PQCI) technique. The variations of morphology and composition for the alkaline treatment products were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) and X-ray diffraction (XRD), respectively. The dynamic variations of calcium phosphate can be characterized by the change of equivalent circuit parameters. The results show that the forming process of hydroxyapatite (HA) is composed of three stages: (1) acidic calcium phosphate dissolution; (2) phase transformation; and (3) HA formation. Furthermore, the correlative kinetic equations and parameters are obtained by fitting the static capacitance (C _s)—time curves. Foundation item: Project(2005CB623901) supported by the Major State Basic Research and Development Program of China     

智能材料二维问题的状态空间解

抛弃任何有关位移或应力模式的人为假设,引入状态空间理论,从压电、压磁智能材料和电磁耦合弹性介质材料二维问题的基本方程出发,建立了压电、压磁智能材料和弹性介质二维问题的状态变量方程,得到状态变量空间解,此解形式简单、便于应用.     

压电层合板多场耦合有限元分析及其优化设计

从压电本构方程出发,采用高阶位移场,高阶电势分布和线性温度分布假设,借助Hamilton原理推导了压电层合板结构的力-电-热场耦合的高阶有限元模型.应用ANSYS/APDL语言,编写了热载荷作用下压电层合悬臂板的有限元分析程序.在此基础上,采用零阶优化方法和一阶优化方法对比分析了四边简支板的形状最优控制设计.两种方法吻合良好,验证了程序的正确性.     

新型乙肝压电免疫传感器的研制

通过自组装半胱胺在压电石英金电极上,用缩合剂（EDC和NHS）将羧基化碳纳米管和乙肝表面抗体连接到半胱胺膜,构建乙肝表面抗原的一种新的生物压电免疫传感器。传感器的灵敏度为17.268 Hz/（μg/mL）,线性范围为0.05μg/mL-15μg/mL,并能实时检测。