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1、As the voltage varies with time, the displacement of charge also varies with time, causing what is known as the displacement current. 当电压随时间的变化、位移电荷也随时间的变化而变化,造成所谓的位移电流。The device capable of doing this is called a capacitor. The ability of a capacitor to store electrical energy is termed capacitance
2、.该装置能做这项被称为电容。电容器的能力储存电能被称为电 容。Resistance is the capacity of materials to impede the flow of current or, more specifically, the flow of electric charge.电阻是材料的能力来阻碍电流的流动,或者更确切地说,电荷的流动。Second, a current cannot change instantaneously in an inductor, that is, the current cannot change by a finite amount
3、 in zero time. 第二,电流不能改变瞬间在一个电感,也就是说,当前无法改变由有限零时间。Inductance is the property of oppsing any change of a current flowing through a coil.电感的属性相对任何一个线圈通过电流的变化。Oppsing:adj.反对的;相对的;对面的 | v.反对Note from Eq(1.4) that the voltage across the terminals of an inductor is proportional to the time rate of change
4、of the current inthe inductor.注意从式(1.4)的电压,一个电感的连接端子是成正比的变率的电 感电流。They occur in many, many applications and make possible circuits and subsystems that perform very useful functions.他们出现在许多,许多的应用,使可能的电路和子系统,执行非 常有用的功能。The cascaded gain and loss through the amplifier/feedback network must be greater t
5、han unity级联增益,并通过放大器/反馈网络的损失必须大于1In most oscillator circuits, oscillation builds up from zero when power is first applied, under linear circuit operation.在大多数振荡器电路,建立了振动从零功率时首次应用,在线性电 路的操作。It is often encountered in engineering systems and commonly produced by the unbalance in rotating machinery, is
6、olation, earthquakes, bridges, buildings, control and automatization devices, just for naming a few examples.这是经常遇到在工程系统和普遍的不平衡产生的旋转机械、隔离、地震、桥梁、建筑、控制和自动化设备,只是为了命名的一些例子。A relaxation oscillator is an oscillator in which a capacitor is charged gradually and then discharged rapidly.一个弛张振荡器是其中一个电容充电逐步然后迅
7、速排出的振荡器。The capacitor is charged through the resistor, causing the voltage across the capacitor to approach the charging voltage on an exponential curve.电容器充电通过电阻器,引起的电压,电容器充电电压的方法在一 个指数曲线。This field, also called a RF field or radio wave, can be used for wireless broadcasting and communications over
8、 a significant portion of the electromagnetic radiation spectrumfrom 9 Khz to thousands of Ghz.这一领域,也称为射频场或无线电波,可用于无线广播通讯的一个 重要部分,电磁辐射频谱从9千赫至成千上万的阻抗特性。Each of these bands, other than the lowest frequency segment, represents an increase of frequency corresponding to an order of magnitude (powe of ten
9、).这些频段,最低的频率段以外,代表频率的增加,相应的一个量 级(十鲍威)。The Decibel is the unit used to express relative differences in signal strength.分贝是单位用来表达相对差异的信号强度Since power is proportional to the square of a signal s amplitude(e.g., a power ratio of 100 is equivalent to an amplitude ratio of 10).因为电力的平方成正比,信号的振幅(例句。,一个功率比10
10、0就相 当于一个振幅比10)。For example, suppose that a signal that passes through two channel segments is first attenuated in the ratio of 20 to 1 on the first leg and 7 to 1 on the second.例如,假设一个信号,经过两个通道衰减段第一比率的20到1在第一回合7 - 1的第二个.By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT
11、89C51 is a powerful microcontroller(自微控制 器)which provides a highly-flexible and cost-effective solution to many embedded control applications.结合一个多才多艺的8位CPU与一闪一闪的单一晶片、爱特梅尔 是一个功能强大的单片机AT89C51为我们提供了一个高度灵活的和精打细算的解决许多嵌入式控制应用。In addition, the AT89C51 is designed with static logic for operation down to ze
12、ro frequency and supports two software selectable power saving modes.此外,以AT89C51单片机为核心设计了静态逻辑操作降至零频率 和支持两种软件可节电模式。Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink 8 TTL inputs. When 1s are written to Port 0 pins , the pins can be used as high impedance inpu
13、ts.端口 0是一个8位漏极开路的端双向I / O端口。作为一个输出 端口,每个引脚可以吸收8个TTL输入。当1秒是写给端口 0针、 针可作为高阻抗输入。21)By the summer of 1973, Kahn and Cerf had worked out a fundamental reformulation, where the differences between network protocols were hidden by using a common internetwork 互联网络) protocol and instead of the network being
14、responsible for reliability, as in the ARPANET, the hosts became responsible.在1973年夏天,卡恩以及现想出了一个基本收入,在网络协议之 间的差别是被使用了一个公共的网际协议 ,而网络负责可靠性,如 在阿帕网,东道主成为负责任的Cerf credits Hubert Zimmerman and Louis Pouzin, designer of the CYCLADES network, with important influences on this design.?瑟夫归功于休伯特齐默尔曼和路易普赞,的基克拉泽
15、斯网 络设计师,这种设计上的重要影响。two tin cans and a stringOne popular saying has it that TCP/IP, the eventual product ofCerf and Kahn s work, will run over 一个流行的说法,TCP /IP,最终产品的现和卡恩的工作,要超出 两 个罐头和一个字符串工There is even a implementation designed to run using homing pigeons, IP over Avian Carriers.甚至有设计运行使用信鸽,超过禽流运营商的IP推行。Today sP networking represents a synthesis of several developments that began to evolve in the 1960s and 19
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