A=cos(pi*x-pi/2)i+sin(pi*x)j 正电荷形成的电场 负电荷形成的电场   正负电荷形成的电场 无限长导线上均匀分布的正电荷 电场 均匀分布电荷的平面 电场 电荷均匀分布的球面形成的电场 磁铁的磁场 均匀电流导线上的磁场 电流环形成的磁场  …

[转载请注明出处]http://www.cnblogs.com/mashiqi 2016/12/12 以下会用高中的物理知识和大学微积分的数学知识对麦克斯韦方程组进行一个简单的解释.希望大家都能看得懂Maxwell's equations大概说了什么.至少了解个大概吧. 1.高斯定律 (Gauss's law):电场 电荷(electic charges)产生静电场(static electric field).静电场线始于正电荷,指向负电荷.任意区域内的电荷总量正比于相应的电场在此区域表面的第…

电磁场理论中存在四个基本物理量,电场强度E,磁场强度H,电场通量密度D,磁场通量密度B. E:其中E和H最简单,电场中的电荷受到电场力的作用,单位电荷受的力称为电场强度,这种定义得到E的单位为N/C,牛顿/每库仑.另一种单位的定义引入了电位(电势),电位指电场强度的变化,其数值等于电荷从该处经过任意路径移动到无穷远处所做的功(人为假定无穷远处的势能为零)与电荷量的比值.电势常用的符号为U或φ,在国际单位制中的单位是伏特(V).由E=-▽U得到电场强度,所以得到电场强度的另一个单位V/m. H:磁…

Radio Basics for RFID The following is excerpted from Chapter 3: Radio Basics for UHF RFID from the Book, The RF in RFID: Passive UHF RFID in Practice by Daniel M. Dobkin. Order a copy of The RF in RFID: Passive UHF RFID in Practice before December 3…

https://www.ted.com/talks/stephen_hawking_asks_big_questions_about_the_universe/transcript00:13There is nothing bigger or older than the universe. The questions I would like to talk about are: one, where did we come from? How did the universe come in…

align是输入多行公式中最好用的环境,仅仅是个人浅见,因为他的对齐非常灵活,如果大家需要非常灵巧的对齐方式的多行公式,建议使用align环境,对应的也还有align*和aligned等等类似的环境,这里不再详述.下文提供代码,尽展其风姿绰约.演示效果图: 演示代码:\documentclass{article}\pagestyle{empty}\setcounter{page}{6}\setlength\textwidth{266.0pt}\usepackage{CJK}\usepackage…

Stephen Hawking: Questioning the universe 1. 第一段: There is nothing bigger or older than the universe. The questions I would like to talk about are: one, where did we come from? How did the universe come into being? Are we alone in the universe? Is th…

Autoconf Autoconf Creating Automatic Configuration Scripts Edition 2.13, for Autoconf version 2.13 December 1998 by David MacKenzie and Ben Elliston 目录 介绍 创建configure脚本 编写`configure.in' 用autoscan创建`configure.in' 用ifnames列举条件 用autoconf创建configure 用aut…

Obtaining an intuitive idea for why antennas radiate is helpful in understanding the fundamentals of antennas. On this page, I'll attempt to give a low-key explanation with no regard to mathematics on how and why antennas radiate electromagnetic fiel…

Autoconf Creating Automatic Configuration Scripts Edition 2.13, for Autoconf version 2.13 December 1998 by David MacKenzie and Ben Elliston -------------------------------------------------------------------------------- Permission is granted to make…