本文介绍了采用新的脉宽调制原理和微电脑技术，研制出的25赫正弦波铃流源。
In this paper, using a new principle of PWM and the teehnique of storage system in a microcomputer are deseribed, and a 25Hz sinusidal bell current source has been developed.
根据非对称矩形同轴线原理研制了宽带吉赫横电磁波室。
A gigahertz TEM cell is developed according to the principle of asymmetric rectangular coaxial line.
论文采用统计求和法推导出系统自由能的表达式，利用系统自由能对粒子数取最小值的原理得到计算电离度的沙赫方程。
And the equation to calculate ionization rate is obtained at the base of the principle that the system free energy is the least versus the particle number.
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