氧化铝填料电导率对浇注体性能影响的研究

从电导率技术参数角度出发,研究了电导率40μS·cm-1的氧化铝填料对标准试样的电气性能和力学性能的影响。研究结果表明,电导率在40~79μS·cm-1之间变化时,其电气性能和机械性能与≤40μS·cm-1浇注的样条相比相近。     

稳恒磁场处理对聚乙烯/炭系填料复合材料电导特性的影响

在聚乙烯(PE)、低密度聚乙烯(LDPE)/炭黑、LDPE/石墨、LDPE/碳纳米管的热压成型过程中施加稳恒磁场,研究了磁场处理对聚乙烯/炭系填料复合材料电导特性的影响。研究结果表明:磁场处理能导致聚乙烯的结晶度提高,聚乙烯和LDPE/炭黑复合材料的体积电阻率增加;磁场在石墨片层内和碳纳米管中"诱导"形成感应磁矩,使得石墨片层和碳纳米管分别沿垂直于磁场方向和平行于磁场方向在LDPE中取向,从而导致LDPE/石墨复合材料沿平行于磁场方向的电导率减小,而LDPE/碳纳米管复合材料沿平行于磁场方向的电导率增加。     

填料表面状态对聚合物复合材料动态力学性能的影响

本文采用动态力学分析研究了填料表面状态对复合材料动态力学性能的影响。研究结果表明，填料表面状态对复合材料的动态力学性能影响很大。填料表面的偶联剂处理显著增强了复合材料中两相间的相互作用，并使复合材料的力学损耗峰值（tanβcmax）明显降低，峰半宽（△W）变宽，玻璃化转变表观活化能（△W）增大。     

Al（OH）3颗粒分散状态对EPDM／Al（OH）3复合材料电导率影响的研究

本文用扫描电子显微镜（ＳＥＭ）观察了无机填料Ａｌ（ＯＨ）３颗粒在ＥＰＤＭ基体中的分散状态,并根据Ｍｘｗｅｌｌ理论和Ｙａｍａｄａ推导的方法计算了Ａｌ（ＯＨ）３颗粒的分散因子,研究了Ａｌ（ＯＨ）３颗粒的分散状态对复合材料电导率的影响。     

电场强度对变压器绝缘油电导率的影响研究

本文中作者以几种常用的变压器油为测试对象,在不同温度和场强下对各种绝缘油的电导率进行了测试和分析,总结出了电导率变化规律。     

功能填料高填充聚合物基复合材料绝缘性能研究进展

综述了功能填料高填充聚合物基复合材料(HFPCs)在埋入式器件、高能存储、导热、封装等方面的应用情况,探讨了不同因素对HFPCs介电强度的影响及其研究进展,并对该材料的应用前景进行了展望。     

Al(OH)_3颗粒分散状态对EPDM/Al(OH)_3复合材料电导率影响的研究

本文用扫描电子显微镜（SEM）观察了无机填料Al（OH）3颗粒在EPDM基体中的分散状态,并根据Maxwell理论和Yamada推导的方程计算了Al（OH）3颗粒的分散因子,研究了Al（OH）3颗粒的分散状态对复合材料电导率的影响。     

环氧灌封料中无机填料的研究

简述了环氧灌封料中无机填料的使用种类和性能,分析了纳米TiO2、SiO2等粒子对材料性能的影响。同时利用双层模型和公式模型解释了颗粒含量、颗粒大小等影响材料性能的原因。     

温度对超纯水电导率测量的影响及其对策

分析了影响超纯水电导率测量的主要原因是水样纯度达到一定程度后，其理化特性发生了变化，温度系数不再是一个常数而是一个变量，其值从２％～９％间随温度和溶液纯度不同而发生连续变化。故此不能采用常规的温度补偿方法进行仪器定。介绍了国内外进行温度补偿的三种方法：样品恒温法、手动调整补偿法、自动温度补偿法。     

制备方法对复合触头材料导电特性的影响

根据复合材料制备方法的各自特点 ,建立了计算复合触头材料电导率的三维单元网络模型。应用该模型研究了制备方法对材料电导率的影响 ,并与测量值进行了比较。结果表明了这种模型的可行性。     

铜—金刚石电接触复合材料的导电性

本文通过对铜－金刚石系列电接触材料导电性的测量，分析了该体系材料中合金化元素和组元相－金刚石，铌和镉等含量对材料电阻率的影响，分析和测量结果表明，在所研究成分范围内，添加成分对铜基体的导体电性影响很小，材料电阻率均可以满足电器地材料性能的要求。     

聚全氟乙丙烯/氮化铝高导热绝缘复合材料的研究

采用聚全氟乙丙烯(FEP)为基体,偶联处理的氮化铝(AlN)为填料,通过共混、模压等方法制备了高导热、高绝缘的FEP/AlN复合材料。结合材料导热计算模型,分析了AlN含量对材料热导率、体积电阻率、力学以及流变性能的影响。结果表明:随AlN填充量的增加,复合材料的热导率呈近线性增加,当填加AlN的质量百分率为30%时,材料的热导率可达2.22 W/(m.K),体积电阻率可达1.5×1013Ω.m,并具有较好的力学性能和流变性能。     

Numerical Calculation of Electrical Conductivity of Porous Electroceramics

A numerical method for the calculation of the electrical conductivity of porous ceramics for gas sensing applications is developed, which takes into account detailed microstructural features by mapping a mesoscopic irregular resistor network onto the microstructure. The overall conductance of the ceramic sample is obtained by solving the Kirchhoff equations for the irregular network using an efficient iterative algorithm. The method is designed to handle the widely varying conductivities of different microstructural components present in ceramic gas sensors. The evolution of the macroscopic conductance of the model systems during a phase field simulation of sintering is obtained and several characteristic stages are distinguished. The potential applications of the method in computer aided microstructural optimization for ceramic gas sensors is discussed.     

Electrical Conductivity of CeO2 Prepared from Nanosized Powders

Nanosized powders of cerium dioxide with controlled physical properties were prepared by the precipitation technique using ammonium hydroxide or oxalic acid as precipitating agent. The calcined precursors were studied by nitrogen adsorption to determine the specific surface area, X-ray diffraction for phase characterization and crystallite size determination, and by laser scattering for particle size distribution. The morphology of powder particles was observed by scanning electron microscopy. It is shown that both precipitating materials may be used for the preparation of nanocrystalline powders (< 10 nm) with high values of specific surface area (> 90 m² g^{– 1}). The observed differences between powders prepared from hydroxides or oxalates rely on the distribution of particle sizes and in the morphology of the agglomerated particles. Impedance spectroscopy experiments were carried out in the 5 Hz–13 MHz frequency range under controlled partial pressure of oxygen from 10 ppm to 1 atm. The analysis of these results allowed for the determination of the charge carriers responsible for the electrical transport in the ceria sintered pellets.     

Analytical Functions for the dc and ac Conductivity of Conductor-Insulator Composites

The Maxwell-Wagner and the Bruggeman Symmetric and Asymmetric Media equations are introduced and the well defined microstructures for which these effective media equations apply are emphasized. The microstructures characterising percolation systems and the resultant critical volume fractions are then discussed. After this the concept of scaling, the percolation expressions and a new two exponent analytical phenomenological equation are introduced and their interrelationship is examined. The information obtainable from dc measurements is investigated and then simulations of impedance and modular spectra obtained from the effective media equations are given and the implications of these results discussed. Followed this, results for the complex ac conductivity of a nearly ideal continuum systems are given and it is shown that the conductivity above and the dielectric term below the critical volume fraction can be scaled onto analytical curves, using parameters obtained from dc conductivity measurements. Lastly simulations of the type of impedance spectra and dispersion relations that might be observed for systems with a percolation microstructure but non ideal insulating and conducting components are given and discussed.     

固体电绝缘材料导热系数的测定方法

简要介绍了几种测定固体电绝缘材料导热系数的方法,重点讨论了保护热流计法测定固体电绝缘材料导热系数的方法原理、导热仪的结构、影响测试结果的因素。     

Electrical Conductivity Studies of AgCl:KCl (RbCl, CsCl) Composites and a Novel Method of Obtaining Highly Porous Materials

Two phase systems consisting of AgCl and KCl (or RbCl, CsCl) have been studied with respect to morphology and electrical properties. As expected from the contact of such Frenkel and Schottky disordered ionic conductors, substantial enhancement effects were not observed. In the case of AgCl:KCl, eutectic lamellar structures have been obtained and their conductivities measured using both macroscopic electrodes as well as microelectrodes. Leaching the alkali chloride out of the lamellar composite leads to a porous solid network. Potential applications of such microporous ionic silver halides as a gas sensor as well as a solid envelope for liquid electrolytes are considered.     

钛酸铜钙-氮化硼掺杂EPDM复合介质的电学和力学性能研究

非线性电导材料的应用是解决高压直流电缆附件内部电场集中问题的一种有效方案.因此,通过掺杂钛酸铜钙(calcium copper titanate,CCTO)纳米填料对三元乙丙橡胶(ethylene-propylene-diene monomer,EPDM)进行改性,在较低的掺杂体积分数(2％CCTO)下,复合介质展现出...