电偶极子

Analytical expressions for electromagnetic fields of a vertical or horizontal electric dipole over the finitely conducting plane are derived subject to the boundary conditions; Sommerfeld type integral contained in Hertz potential is expressed as the sum of two parts: zeroth order Hankel function and an absolutely convergent series of spherical Hankel function.

在此边界条件下，推导出有限导电平面上垂直和水平电偶极子电磁场的解析表达式；赫芝位函数中的索末菲型积分被表达成零阶汉克尔函数与绝对收敛的球汉克尔函数级数之和的形式。

This thesis contributed to the comprehensive study of the Finite-Difference Time-Domain method and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies. The work includes mainly three parts: the study on the performance of PML absorbing boundary condition applied to pseudo low frequency electromagnetic problems; the validation of the FDTD method with PML absorbing boundary conditions and the corresponding computer software based on the numerical study of the electromagnetic field of an electric dipole antenna, and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies; the development of an improved alternating direction implicit finite-difference time-domain method.

在综合前人工作基础上，本文对时域有限差分法及其在开关电源辐射电磁场数值计算中的应用进行了系统的分析和研究，其核心内容包括：伪低频电磁场数值计算中PML吸收边界条件性能的研究；基于基准问题—电偶极子天线三维辐射电磁场，验证了本文构造的基于PML吸收边界条件的三维FDTD法及其计算软件，并应用于高频开关电源辐射电磁场的数值分析；提出了一种改进的交替方向隐格式时域有限差分法。

In this thesis, the problem of simulating the effect on human body excited by anelectric dipole belongs to this category.

本文中极高频率的电偶极子在人体产生的效应的仿真属于这一类问题。

Goldberger AL, Bhargava V, West BJ, et al. On the mechanism of cardiac electrical stability: the fractal hypothesis, Biophys J.

按心电产生的瞬时空间电偶极子理论，各种导联的体表心电图信号是由瞬时空间电偶极子在各导联轴上的投影形成的。

The distribution of the electromagnetic field of an uniformly moving electric dipole is calculated by analyzing the electromagnetic potential of the electric dipole and making use of the covariability of electromagnetic field in different inertial frame under the theory of relativity.

本文通过对电偶极子电磁势的分析和相对论下电磁场在不同惯性系中的协变分布，计算了作匀速直线运动的电偶极子的电场和磁场的空间分布

The numerical results demonstrate that the MEI coefficients obtained using the technique,which takes dipole layer excitation as the "Metron" and the Green function in free space as the integral Kernel,are of higher precision over other techniques.

数值结果表明，利用电偶极子层激励作为测试子和自由空间格林函数作为积分核确定MEI系数的方法，比之其它方法具有更高的精度和明显的优点。

The article analyses angle distribution of radiant energy flow density and angle distribution of radiant power when an electric dipole is oscillating along polar axis in magnetic anisotropic medium,also compares them with the expression of that in isotropic medium;thereby,a theoretical basis for more effectly using electric isotropic and magnetic anisotropic medium is obtained.

分析振荡电偶极子在各向异性磁媒质中沿极轴振荡时其辐射能流密度的角分布和辐射功率的角分布情况，并与各向同性媒质中振荡电偶极子沿极轴振荡时辐射能流密度的角分布和辐射功率的角分布情况进行对比，得出更有效地利用电各向同性磁各向异性媒质的理论依据。y

When the magnitudes and directions of the electric and magnetic dipoles were matched, the radiation in backward and sideward direction was obviously restrained.

当TEM喇叭天线与低频补偿回路形成电偶极子和磁偶极子满足匹配条件时，天线低频辐射的单向性将得到提高。

deviation of the antenna radiation resistance seems larger in some textbooks about the electromagnetic theory for the editors have made some similar treatment when discussing the radiation power of short antenna.combining the concept of physical with mathematical tools and the precise results are gained,that is the real radiation resistance of electric dipole antenna is about ten times smaller than that of the approximate results in the actual literature by researching the electromagnetic field theory and average energy density.this offers evidence to grasp the radiated ability accurately.

小 摘要：在部分有关电磁场理论的教材中，编者讨论短天线的辐射功率时，由于作了某些近似处理而所得天线的辐射电阻值偏差较大。从天线辐射的电磁场理论和平均能流密度出发，使物理概念和数学工具相结合，运用矢量运算推导出精确的结果，即电偶极子天线的实际辐射电阻要比文献中的近似结果小数十倍，因而为准确把握天线的辐射能力提供了依据。

Global atmospheric electricity model is the circuit between atmosphere and surface. In lower atmosphere, the main sources of electric current within the model are thunderstorms, which are considered as vertical electric dipoles.

全球大气电模式是指大气和地表构成的闭合回路，其中考虑雷暴为主要充电电源，并将雷暴作为一个垂直电偶极子来考虑。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐