Giant magnetoresistance:history,development and beyond

With the discovery of giant magnetoresistance(GMR),research effort has been made to exploiting the influence of spins on the mobility of electrons in ferromagnetic materials and/or artificial structures,which has lead to the idea of spintronics.A brief introduction is given to GMR effects from scientific background to experimental observations and theoretical models.In addition,the mechanisms of various magnetoresistance beyond the GMR are reviewed,for instance,tunnelling magnetoresistance,colossal magnetoresistance,and magnetoresistance in ferromagnetic semiconductors,nanowires,organic spintronics and non-magnetic systems.     

二维相变系统Collins模型的统计理论

Kawamura曾利用Collins模型,在忽略4-原子存在的情况下,研究了二维系统的相变。本文进一步考虑4-原子的存在,计算了有空格点存在时系统的吉布斯自由能,研究了4-原子所占百分数对三相点t_t,P_t值以及临界点t_c,p_c值的影响,获得了具有三相点和临界点的完整相图。本文还讨论了相变时各相的面积与温度之间的关系。所得结果与通常的三维物质非常相似。 关键词：     

THE TIME RESPONSE OF THE FERRITE LOADED CAVITY AND STABILITY OF BIAS AUTOTUNING SYSTEM

A state space model is described, the time response of ferrite loaded cavity is proposed and a new digital measuring method devised.
Results of actual measurement on model cavity are given. On these bases the stability of stationary state of bias autotuning system to fast external perturbation is discussed.     

Memory Effect in Ceramic Superconductors

We measured the time decay of the magnetic moment of high T_c superconductors YBa₂Cu₃O_7-δ ceramic samples and found the memory effect which has hitherto been reported only in single crystals. The temperature and field ranges, especially the memory phenomenon in ceramic samples at liquid nitrogen temperature can only be understood in a combined picture of both flux creep and glass behaviour     

电热原子吸收光谱法中原子形成机理的热力学和动力学研究

本文对电热原子吸收光谱法（ＥＴＡＡＳ）中气态原子形成机理的热力学和动力学研究状况进行了评述，引用文献６２篇。     

碱金属掺杂富勒烯超导体的临界温度和约化能隙研究

碱金属掺杂富勒烯与传统的超导体情况不同，它有一个很宽区域的声子谱，其最高频率和最低频率分别与费密能Ｅ_F和零温超导能隙△₀为同一数量级，这必将导致对原来强耦合超导电性理论的修正。本文在此情况下求解Ｅｌｉａｓｈｂｅｒｇ方程，得到Ｔ_c和△₀的表达式。结果表明，分子间的低频振动模和分子上的高频振动模同样参与电声耦合，Ｔ_c主要取决于声子谱中高频成份的贡献，而△₀的增加主要取决于声子谱中 关键词：     

反散射理论导出极低能量下的e-He相互作用势

以入射能量为２ｅｙ的ｅ－Ｈｅ弹性散射微分截面的实验数据为基础，运用反散射方法，理论上导出了ｅ－Ｈｅ的相互作用势。用这样的相互作用势计算能量为２和５ｅｖ时的弹性微分截面。所得结果表明，ＷＫＢ反散射方法对极低能情况是失效的，但量子反散射方法仍然非常成功。在极低能情况下，量子反散射方法得到的ｅ－Ｈｅ相互作用势是实数和定域的，呈现出强Vａｎ ｄｅｒ Ｗａａｌｓ势的特征，能给出符合实验数据的结果。     

关于5-正则图的强协调性

构造了若干个 5 -正则图的强协调值 ,从而证明它们都是强协调的     

Lie Symmetrical Hojman Conserved Quantity of Relativistic Mechanical System

In this paper, we study the Lie symmetrical Hojman conserved quantity of a relativistic mechanical system under general infinitesimal transformations of groups in which the time parameter is variable. The determining equation of Lie symmetry of the system is established. The theorem of the Lie symmetrical Hojman conserved quantity of the system is presented. The above results are generalization to Hojman's conclusions, in which the time parameter is not variable and the system is non-relativistic. An example is given to illustrate the application of the results in the last.