电磁继电器触点参数的测试

本文介绍了电磁继电器触点电参数的测试方法，包括接触电阻、绝缘电阻参数测试。     

2003年的诺贝尔物理奖

2003年的诺贝尔物理奖授予了低温物理领域的三位物理学家，他们是Alexei A、Abrikosov(阿布里柯索夫)，Vitaly L．Ginzburg(京茨堡)以及Anthony J．Leggett(莱格特),此奖用以表彰前两者在超导电性方面的贡献，后者为在超流方面作出的贡献.大家知道，自然界中的微观粒子服从量子力学规律；     

Electrical Resistance Measurement of an Individual Carbon Nanotube

Aiming at the difficulty in the electrical resistance measurement, we develop a simple statistical model for the carbon nanotubes adequately dispersed in available insulated liquid and introduce the concept of “the most probability”. Based on this model, we obtain the function between macroscopic resistance R and resistance of an individual nanotube, Ro, from which one can calculate the resistance of an individual nanotube by measuring the macroscopic resistance. By computational simulation, we prove the reliability of the model. Then, we analyse the feasibility of the model when applied to experiment.     

三嗪类光学探针与标记分析

评述了以三聚氰氯作桥联剂或骨架而合成的三嗪类衍生物、特别是其光学标记探针的研究进展及分析应用。     

YBa2Cu3O7-δ体系在B∥I∥c下磁场引起的电阻耗散

基于最近提出的平面外电阻耗散模型,计算了YBa_2Cu_3O_(7-8),体系在平行于c轴的磁场下不同温度时的平面外磁阻率ρ-B和不同磁场时的平面外电阻转变ρ-T.该模型预言了文献上普遍报道的该体系在外加磁场下的Lorentz力无关的耗散行为.为确信这一点,作为例子,特别将由该模型预言的理论结果与在YBa_2Cu_5O(7-8)体系中在B//I//c下测得的电阻转变曲线进行了定量地比较. 关键词：     

WO3掺杂的La2/3Sr1/3MnO3电输运与磁电阻特性

通过溶胶-凝胶法制备了La2／3Sr1／3MnO3＋xWO3（x=0～25％）系列多晶陶瓷样品．结果表明。随着WO3掺杂量的增加，样品的电阻率增大，金属-绝缘体相变温度（Tp）值下降．在1．4T磁场下，当0≤x≤12．5％时，样品的室温磁电阻值从5％增大到15％，提高了200％．当12．5％〈x≤25％时，室温磁电阻值从15％降低到0．这对磁电阻材料在室温下的应用提供实验依据．     

Pseudo-Spin-Valve Trilayer Using Amorphous CoNbZr Layer： Giant Magnetoresistance, Domain Structures and Potentials for Spin-Electronic Devices

We propose a pseudo-spin-valve (PSV) trilayer using amorphous CoNbZr Mloy for soft magnetic layers. The giant magnetoresistance (GMR), domain structures and their variation upon thermal annealing are investigated. The GMR effect is not only stable up to 300℃ but also enhanced due to the improvement of the interfaces between Cu and magnetic layers. With high annealing temperature, the magnetoresistance (MR) ratio decreases rapidly as a result of serious layer interdiffusion. Dense stripe domains, which disappear after annealing at 300℃ for 1h, are observed in the sandwiched films. It is found that after patterning to elliptic stripe with aspect ratio of 6:1, the trilayers have a single domain and their MR ratio increases. The dynamic MR behaviour under an ac magnetic field indicates that the patterned stripes have good linear MR responses. Therefore, it is believed that the CoNbZr/Cu/Co PSV trilayers have strong potentials for spin-electronic devices including magnetic random access memory.     

硬盘驱动器巨磁电阻(GMR)磁头:从微米到纳米

近年来电脑硬盘存储密度的飞速增长(年增长100％)已超出摩尔定律的预言．这种惊人的高速增长中，最关键的因素是自旋阀纳米多层膜结构，即巨磁电阻(GMR)读传感器磁头的应用．事实上，巨磁电阻磁头读传感器(reader sensor)已经实现由微电子器件向纳米电子器件转化，并且形成大规模产业．这一过程包含了自旋电子学、材料科学、微电子工程学、化学、微机械力学和工程学等诸学科和相关微加工技术综合性挑战极限，进入纳米科技领域实质性进步．     

用实验室常用电表测量电感线圈和直流电阻箱的交流损耗电阻

1引言在RIAf串联iff振实验中，由于电感线圈和直流电阻箱（因高频电阻箱价格高、取材困难，众多教科书上往往以直流电阻箱取代）所引起的交流损耗电阻的影响，使Q的计算值总是大于它的测量值，如何克服交流损耗电阻所带来的不可忽略的影响，已有许多文献介绍了他们的尝试．以厂是我们对这些问题的看法和探讨；其一，“替代法””‘是在电路谐振时，用一个直流电阻箱替代原谐振电路，选择某一阻值，使电阻箱端电压恢复到原电路谐振状态时的数值，则电阻箱示值即为电路总损耗电阻．实验中我们发现，受电表灵敏度的限制，在替代过程中有数欧…