专业外语单片机方向.pptVIP

专业英语概述;掌握专业外语技能是大学基础英语学习的主要目的之一，是一种素质上的提高，直接关系到学生的求职和毕业后的工作能力。 专业外语重要性体现在多个方面，大到日益广泛的国际间的科学技术交流，小到对产品说明书的翻译。在INTERNET查找资料。 专业外语具有与基础英语不同的特点和含义。; ; ; ;专业英语的基本特点 ; ; ; ;专业英语中的常用符号和数学式 ; ;专业英语的翻译标准 ; ; ; ; ; ; ; ; ;Unit1Electrical Networks;Unit1Electrical Networks;network n. 网络，电路 resistor n. 电阻器 inductor n. 电感器 capacitor n. 电容器 passive network 无源网络 active network 有源网络 characteristic adj. 特性(的)；n. 特性曲线 Ohm n. 欧姆 Faraday n. 法拉第 electric charge 电荷 integral n. 积分 increment n. 增量 armature n. 电枢，衔铁，加固 aforementioned adj. 上述的，前面提到的 ; An electrical circuit or network is composed of elements such as resistors, inductors, and capacitors connected together in some manner. If the network contains no energy sources, such as batteries or electrical generators, it is known as a passive network. On the other hand, if one or more energy sources are present, the resultant combination is an active network. In studying the behavior of an electrical network, we are interested in determining the voltages and currents that exist within the circuit. Since a network is composed of passive circuit elements, we must first define the electrical characteristic of these elements. ; In the case of a resistor, the voltage-current relationship is given by Ohm’s law, which states that the voltage across the resistor is equal to the current through the resistor multiplied by the value of the resistance. Mathematically, this is expressed as u=iR where u=voltage, V; i=current, A; R=resistance, ; The voltage across a pure inductor is defined by Faraday’s law, witch states that the voltage across the inductor is proportional to the rate of change with time of the current through the inductor. Thus we have where di/dt =rate of change of current, A/s; L= inductance , H.; The voltage developed across a capacitor is proportional to the electric charge q accumulating on the plates of the capacitor. Since the accumulation of charge ma