More precisely it tells you that what you might have learned about electric fields deriving from electric potential becomes false if you have a variable magnetic field.
更精确地说，电势产生电场，这一观点是错误的，如果忽略变化磁场的存在的话。
2
The computer PID control for electro hydraulic proportional constant presure variable displacement pump with electric feedback is introduced.
介绍了电反馈电液比例恒压变量泵的计算机PID控制。
3
The design of software is composed of the development of Virtual Panel Interface and the research of algorithm of measuring electricvariable.