电磁场

The reasons of our choice are:(1) the coupling of the electromagnetic field with the matter is universal and there is already some experiences with such a kind of field in the literature;(2) the pion is the lightest hadron and its interaction with other fields are known to some extent. The pion fields have been treated as external fields but the discussion is not comprehensive in the literature.

我们选取这样的外场的理由如下：(1)电磁场与物质相互作用的耦合常数是普适的，而且文献中已经有把电磁场当作外场来处理的经验；(2)π介子是最轻的强子，它与其它场的相互作用人们已经有所了解，文献中也有把π介子场当作外场来处理的例子，但讨论还不够深入。

Using the finitedifference timedomain electromagnetic method and c language program in the matlab software,the spatial electromagnetic field distribution radiation of photoconductive dipole antenna is calculated and displayed on the computer in a pseudocolor graph.

研究了光电导天线产生太赫兹波的辐射特性，利用麦克斯韦方程及其边界条件，计算了近远场的电场强度；采用电磁波时域有限差分方法，在Matlab系统软件中，用C语言编写程序计算光电导偶极天线的辐射太赫兹波的空间电磁场分布，并在计算机上以伪彩色图形显示，这种电磁场的可视化结果为天线的设计和改进提供了直观的物理依据。

From the Maxwell′s equation,the quasi static electromagnetic field equations in a perfect conductor have been deduced in this paper.The equations are used to analyze two eddy current field engineering problems,and good results are obtained.

本文从麦克斯韦方程出发，推导出良导体内的似稳电磁场方程，将导出的电磁场方程用于分析两个电磁工程实例，获得了两个工程问题的涡流场解析计算结果。

One of the major contributions of Maxwellian theory was that it set up an essential relation between the electromagnetic field and light in vacuum, and defined the speed of electromagnetic wave as the constant speed of light c , which implies a hypothesis that the rest mass of the photon should be zero exactly.

麦克斯韦电磁理论的一个重要贡献在于它将真空中的电磁场与光联系起来，并将电磁场的传播速度定义为真空的属性，即恒定的光速 c ，因而建立了电磁波与光之间的本质联系。

Electromagnetics course mainly including basic phenomena and laws of electro- magnetics, electrostatic field in vacuum, in conductor and in electric medium, electric energy, stabilized current, stabilized magnetic field and its basic laws, electric and magnetic fields caused by a moving chager in lower speed, the transform of electric and magnetic fields between different systems of coordinates, inductive laws, eddy field, self inductance, mutual inductance and transient, molecule current and magnetic substance, ferromagnet, boundary conditions, magnetic circuit theorem, energy of magnetic field and density of magnetic energy, displacement current, Maxwell's equation, electromagnetic wave, Poynting vector.

电磁学课程的主要内容包括：静电的基本现象和基本定律，真空中的静电场，导体和电介质中的静电场，电场的能量与电场能量密度，稳恒电流，稳恒电流磁场的基本定律，运动电荷的电磁场，不同参照系之间电磁场的变换，电磁感应定律，涡旋电场，互感，自感，暂态过程，分子电流与磁介质，铁磁体，边界条件，磁路定理，磁场的能量和磁能密度，位移电流， Maxwell 方程组，电磁波和玻印廷矢量等。

The influence of low-frequency electromagnetic field on microstructure and morphology of primary Si particles of Al-19.2% Si alloy ingot specimens prepared by semicontinuous casting process was investigated with electronic optical microscopy, where the specimens were taken from different parts of the cast to which different electromagnetic fields are applied.

采用低频电磁半连续铸造技术制备Al-19.2% Si合金铸锭，利用电子光学显微镜对铸锭的显微组织进行分析比较，研究了电磁场强度和频率对初生硅颗粒形貌的影响；利用测温技术对合金的凝固过程进行监测，研究低频电磁场对凝固前沿温度场的影响。

SUMMARY With many branches of learning, such as set theory and topology theory in mathematics, data structure and programming language in computer, and finite element method in numerical analysis of electromagnatic field, a new domain of FEM is studied in this thesis creatively.

本文综合使用数学中的集合论和图论、计算机科学中的数据结构和算法语言、以及物理学电磁场分支中电磁场数值分析的有限元理论等多门学科的知识，对有限元法的一个新领域进行了具有开创性的探讨。

Combining with the element-free method,a boundary element method without singular integration is presented by using non-singular fundamental solution to establish the boundary integral equation for electromagnetic field.

用非奇异基本解建立电磁场问题的边界积分方程，将其与无单元法相结合，提出了电磁场计算的无奇异积分的边界无单元法，编制了相应的计算程序，计算结果表明，方法合理可行。

In using DGF method, the first thing is to obtain the proper form of certain area. But the DGFs obtained now are all in achiral medium. So people are eager to know DGFs in spectral domain and space domain of chiral medium.

用解析的方法求解电磁场的边值问题主要依靠建立在经典电磁场理论基础上的并矢格林函数方法，应用DGF方法首先要找出适用于相应区域中的DGF形式，而现有的DGF形式都是基于非旋波媒质情形。

In the process of numerical computation of electromagnetic field, primary ending voltage is taken as constraint condition, primary starting current is iterated, and stating current and starting torque at rated voltage is obtained.

在电磁场的数值计算过程中，以初级端电压为约束条件，对初级起动电流进行了迭代计算，得到了额定电压下的起动电流和起动转矩，最后把正弦电磁场计算结果与实测结果进行了对比，表明直线感应电动机起动性能的计算结果满足工程实际的需要。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。