用电介质镜像法计算线电荷与介质圆柱所形成的电场

利用电介质镜像法计算线电荷与介质圆柱体所形成的电场,给出电势与场强的解析表达式,进一步得出等势线与电场线方程,并利用软件MATLAB绘制出电场线和等势线(面)图予以验证.     

移动导体和电介质情况下的静电能公式推导

为了证明复杂带电系统的静电能与系统的建立过程无关,从库仑定律出发,运用数学方法,推导了以任意方式搬运自由电荷、导体和电介质时静电场做的功,得到普遍情况下的静电能公式.结果表明:对于线性电介质,静电能只与带电系统的最终分布状态有关.该结论为求解静电力的虚位移法提供了重要的理论依据.     

含共线刚性线夹杂压电介质的广义二维问题

基于Stroh理论，研究了含N个共线刚性线夹杂压电介质的广义二维问题，给出了介质内的复势函数、夹杂内的电场和夹杂尖端附近场奇异性系数的解析表达式。结果表明场奇异性系数取决于无限远处的应变。     

APPLICATION OF TREFFTZ BEM TO ANTI-PLANE PIEZOELECTRIC PROBLEM

Anti-plane electroelastic problems are studied by the Trefftz boundary elementmethod (BEM) in this paper. The Trefftz BEM is based on a weighted residual formulation andindirect boundary approach. In particular the point-collocation and Galerkin techniques, in whichthe basic unknowns are the retained expansion coefficients in the system of complete equations,are considered, Furthermore, special Trefftz functions and auxiliary functions which satisfy ex-actly the specified boundary conditions along the slit boundaries are also used to derive a specialpurpose element with local defects. The path-independent integral is evaluated at the tip of acrack to determine the energy release rate for a mode Ⅲ fracture problem. In final, the accuracyand efficiency of the Trefftz boundary element method are illustrated by an example and thecomparison is made with other methods.     

对数型非线性电介质中的一维空间亮孤子

研究了对数型非线性电介质中空间亮孤子，认为对数型电介质中可支持亮空间孤子，并对其束宽变化作了分析，指出其束宽变化与光源峰值功率成反比：当功率较低时，束宽随功率的增大而急剧减小，表现出良好的非线性效应；当功率不断增大时，束宽的减小趋势逐渐放慢直至停止，对数型材料呈现饱和特性。     

介质中电荷所受电场力的研究

在两个自由点电荷的电场中，两点电荷之间的相互作用力与点电荷所受的电场力是不同的，在真空中，这两种力是相似的，因为它们都满足这两点电荷之间相互作用的库仑定律，无论在真空中还是介质中，这两个点电荷之间的相互作用力都由它们相互作用的库仑力决定，但在一般情况下，在介质中，作用在点电荷上的电场力是不能由这两个点电荷之间的库仑力决定的，在电场中，如果让各向同性的均匀介质无限分布，作用在点电荷上的电场力仍可由两点电荷间的库仑力决定，本文研究了介质中点电荷所受的电场力等于两点电荷之间的库仑力的充要条件。     

Theoretical Studies on Expressions of Condensed-Phase Photoionization Cross Section

A set of general expressions for photoionization cross sections of atoms or molecules embedded in a medium and a dielectric influence function are derived based on Maxwell＇s equations and the Beer-Lambert＇s law in this work. The applications are performed for the photoionization process of solid gold both in the Clausius-Mossotti （virtual cavity） model and the Glauber-Lewenstein （real cavity） model firstly. The results show that the present theoretical expressions of photoionization cross section can be used to describe the photoionization process of atoms in condensed matter properly.     

Excel用于优化设计电容器尺寸

1 同轴柱形电容器的优化，设计两个同轴柱形导体构成了同轴柱形电容器．设电容器的内、外导体壳半径分别为r和R，长度为L(L≥R—r)，两导体壳层之间所填充电介质的介电常量为ε，其击穿场强为Emax(图1)．在外半径R一定的情况下，如何选择内圆筒导体半径r，使得设计出的电容器可以承受的电压最大?     

静电场中电介质的极化能

本文通过处于理想平板电容器中的一种电介质原子的极化模型，在经典物理范围内讨论了与电介质中静电场能量有关的问题．特别是关于静电场中电介质的极化能，说明它作为介质中静电场能量的组成部分在微观上的意义．     

Intrinsic Decoherence of Two Atoms System With Kerr Medium

We study the effect of Kerr medium on the intrinsic decoherence of a system which consists of two two-level atoms and a optical cavity. The entanglement of the system is calculated by making use of concurrence. Our results show that the intrinsic decoherence is very sensitive to the nonlinear coupling constant of Kerr medium. Both the oscillation period and the amplitude of the concurrence increase with the increasing nonlinear coupling constant.