电气工程专业英语第2章
电气工程与自动化专业英语(第2版)Chapter02电子课件
1. 内容简介
本章主要介绍运算放大器、差分放大器、积分器、微分
器和有源滤波器等器件的工作原理。
2.文中涉及理论知识可参考《模拟电子学》中有关内 容。
3.生词与短语
▪ 1. analog electronics
模拟电子学
▪ 2. feedback
▪ 26. differential
adj. 差动的，微分的
▪ 27. rejection
n. 抑制, 衰减
▪ 28. integrator
n. 积分器
▪ 29. differentiator
n. 微分器
▪ 30. capacitor
n. 电容器
Chapter 2 Analog Electronics
Chapter 2 Analog Electronics
[2]Feedback is a technique by which gain of the analog system can be exchanged for other desirable qualities such as wider bandwi ▪ 32. bias ▪ 33. passive filter ▪ 34. active filter ▪ 35. implement ▪ 36. magnitude ▪ 37. cascade ▪ 38. cut-off
n. 常数 n. 偏置，偏压 n. 无源滤波器 n. 有源滤波器 v. 实现 n. 大小，幅度 v. 级联 adj. 截止的
集成电路 n. 放大器 n. 元件 v. 耦合 n. 晶体管 n. 硅 v. 封装 n. 增益 n. 性能
电气工程专业英语教程 (2)
Notes
[2] Electrons which are forced out of their orbits can result in a lack of electrons where they leave and an excess of electrons where they come to rest 本句中的主语是electrons，谓语是can result in， a lack of electrons where they leave and an excess of electrons where they come to rest是 宾语。这个宾语由and连接的名词短语a lack of electrons以及an excess of electrons组成，两个where引导地点状语，在理解时要分 清这里面的层次。 由于电子从轨道移走而造成该原子缺少电子，而移入电子的原子电子 过剩。使由于质子数多余电子数，缺少电子的成为正电荷。
参考译文
1.3 电荷之间的吸引和排斥 俗话说， 异性吸引” 处理电荷时是正确的。 俗话说 ， “ 异性吸引 ” ， 处理电荷时是正确的 。 每个 电荷四周有一个看不见的电场。 电荷四周有一个看不见的电场 。 当两个电性相同的电 荷靠近时电场将相斥， 荷靠近时电场将相斥 ， 当两个电性不同的电荷靠近时 电场将相吸。 电场将相吸 。 电荷周围的电场通过不可见的电力线表 示 ， 不可见的电力线表示引起吸引和排斥的不可见的 电场。 正电荷用离开的电力线表示、 电场 。 正电荷用离开的电力线表示 、 负电荷用进入的 电力线表示。 电力线表示。
Notes
[3] Trying to measure even small values of current would result in unimaginably large numbers. 本句的主语是一个动名词短语trying to measure even small values of current，谓语是动词词组result in，result in不能 机械地理解为“导致”，因为“导致”带有明显的感情 色彩，理解为“造成”更顺畅。 试图测量电流微小的值将产生难以想象的巨大的数字。
电气工程专业英语第2单元
2.Fundamentals of Solid-state Power Device2.1INTRODUCTIONIn this chapter we focus on solid-state power devices, or power semiconductors, only as they are being used in the power leads or power circuits to three-phase 460 V AC squirrel cage induction motors for either phase (voltage) control or frequency (speed) control.2.2 SOLID-STATE POWER DEVICESThe five major types of power semiconductors used in solid-state AC motor control are:(1)Diodes(2)Thyristors[e.g., silicon-controlled rectifiers (SCRs)](3)Transistors(4)Gate-turn-off thyristors(5)TriacsSCRs and triacs are commonly used for phase controls. Various combinations of diodes, SCRs, transistors, and GTOs are used for speed controls. The commonality of these devices is the use of crystals of silicon in the form of wafers that are layered so as to form various combinations of PN junction. The P junction is usually called the anode and N junction is usually called the cathode for diodes, SCRs, and GTOs; the corresponding terms for transistors are collector and emitter. The differences among these devices relate to how they go into and out of conduction and in their available ampere and voltage capabilities.Let’s take a brief look at each of these devices in terms of these parameters.2.2.1 DiodesFig.2.1 shows a single diode. The left portion shows a PN junction within the silicon crystal. The right portion shows the schematic symbol for a single diode.When the anode (P) is positive with respect to the cathode (N), forward current will flow, with a relatively low voltage drop in the diode itself. When the polarity is reversed, only a slight reverse leakage current will flow. This is illustrated in Fig.2.2. The forward voltage drop is usually about 1 V, independent of the currentrating.The forward current rating of a diode depends on its size and design, both of which are predicted on the need to dissipate the heat generated within the device so that the maximum junction temperature (usually 200。
电气工程专业英语
电气工程师专业英语词汇10kV distribution substation 10kV配电所abrupt change of voltage 电压突变accumulation of electric energy 电能存储actuating coil 动作线圈adjustment diagram 调整图alarm 报警alarm signal 报警信号alternating light 变光灯ammeter 电流表apparent energy consumption unit 单位视在能耗arc furnace 电弧炉armature 电枢arrester; lighting arrester; surge diverters 避雷器automatic voltage regulator 电压自动调整器backlighting; background illumination 背景照明battery box 电池箱battery charger 电池充电器battery contactor 电池接触器battery fuse 电池保险丝battery resistor 电池电阻器blow-out coil 磁吹线圈boom 吊杆bracket (OCS) 底座（接触网）；支架；托架bracket for headspan wire 定位索底座bridge 电桥brush 电刷built-in wardrobe; built-in closet; closet 壁灯bulb; light(lamp) bulb; electric bulb 灯泡butterfly valve with electric actuator 电动蝶阀button 电钮cable and accessories 电缆及附件cable armour 电缆铠装cable bays 电缆电线间隔cable box 电缆箱cable bracket; cable tray 电缆托架cable continuity test 电路复测cable differential protection 电缆差动保护cable distribution cabinets （CDCs）电缆分线箱（电缆分歧箱）cable drum 电缆盘cable duct cable conduit 电缆管道cable duct; cable trench 电缆沟cable end; cable lug 电缆端头cable fault locator 电缆故障探测仪cable gallery 电缆廊道cable hanger; cable suspender 电缆吊架cable laying laying of cables 电缆敷设cable marking 电缆标志cable rack 电缆架cable shaft 电缆竖井cable sleeve; electrical wire conduit 电缆套管cable support 电缆支架cable tapping box 电缆分接箱cable terminal 电缆终端cable terminal box 电缆盒cable tray 电缆托架cable trenches with chequer plates 带方形盖板的电缆沟槽cable trough 电缆沟槽cable trough; trough 电缆槽cable tunnel; cable-subway 电缆隧道cable vault 电缆室cable work 电缆厂capacitance 电容capacitance compensation 电容补偿capacitive charges 电容电荷capacitive voltage transformer 电容式电压互感器capacitor 电容器capacitor bank 电容器组capacitor compensator 电容补偿器capacitor coupling 电容耦合capacitor filtering 电容滤波catenary/messenger 承力索catenary; messenger wire; catenary wire 承力索ceiling lamp ceiling light 顶灯ceramic wall bushings 穿墙套管changeover box 电源切换箱changeover box for smoke curtain 挡烟垂幕电源切换箱circuit 电路circuit connection 电路接线circuit diagram 电路图circuit diagrams 电路图circuit diagrams 电路图circuit parameter 电路参数circuit-breaker unit 断路器单元closed circuit 闭路closed circuit TV (CCTV) 闭路电视code for electrical design and installation 电气设计安装规范coefficient of resistivity 电阻系数compensation 补偿compensation reactor 补偿电抗器concealed piping; concealed pipe 暗管concealed wiring; concealed electric wiring 暗线condenser 电容器condenser bank(block) 电容器组condenser charge 电容器充电condenser discharge 电容器放电condenser reactance 电容器电抗conductor 导线conductor rail 导电轨conductor resistance 导体电阻contact 触头continuous carrying capacity 持续载流能力corona 电晕cross-span drop bracket 定位索定位支座current & voltage transducer 电流电压变换器current amplification 电流放大current relay 电流继电器current relay 电流继电器current transformer (CT) 电流互感器de-energize 断电diesel generator; diesel dynamo 柴油发电机diesel power plant; diesel generating station 柴油发电站differential protection 差动保护differential protection cables 差动保护电缆differential relay 差动继电器digital format 电子文档direct feeding system with return cable 带回流线的直接供电方式（TRNF供电方式）directional coil 定向线圈directional coupler 定向耦合器directional lighting 定向照明dispatching centre; load dispatching centre; control调度中心centredisplay lighting 陈列品照明district transformer station and distribution center 地区变、配电所drawer 抽屉柜drawout design 抽出式设计drop bracket 吊架drop bracket 定位单环, 定位支座electric coupler 电器连接electric displacement 电位移electric equipment inspection railcar 电气检测车electric hoist (block) 电动葫芦electric horn 电喇叭electric installation drawing 电气图纸electric joint 电气分断点electric potential 电势electric power fitting 电力金具electric railway 电气铁道electric resistance; resistivity 电阻率electric siren 电笛electric system 电气系统electric traction 电力牵引electric traction feeding system 电力牵引供电系统electric traction telemechanical system 电力牵引远动系统electrical apparatus for explosive atmospheres 爆炸环境用电气设备electrical design 电气设计electrical diagrams 电气图electrical energy 电能electrical equipment (appliance) 电器electrical experimental equipment 电工实验设备electrical installation; electrical fitting 电气安装electrical lamp; electric light 电灯electrical maintenance case 电器维修箱electrical outlet 电气出线口electrical rating 电气额定值electrician 电工electrification 电气化electrification interference 电气化干扰electrification interference 电气化干扰electrified railway 电气化铁路electrified railway remodeling 电气化铁道改造,电气化铁路改造electrified track 电气化铁道electromaginetic induction 电磁感应electromagnetic relay 电磁继电器electronic AC stabilizer 电子交流稳压器electronic information processing 电子信息处理electroplated coating of zinc 电镀锌emergency battery 备用电池energy transmission 电能传输factory site; location of factory 场致发光灯fall of current 电流下降fall of voltage 电压下降fastening blacket 抱箍fiber glass steel 玻璃钢floor special purpose receptacle 地面专用插座fluorescent lamp ballast with emergency function 带应急功能的荧光灯镇流器fly light gallery 灯光天桥frequency-modulated, digital telegram 调频数字电报galvanized iron wire strands 镀锌钢绞线galvanized steel sheet 镀锌钢管galvanometer; rheometer; current meter 电流计glass reinforced plastic 玻璃纤维加劲塑料ice 冰雪impulse current 冲击电流incandescent lamp base 白炽灯灯头incandescent lamp; incandescent filament lamp 白炽灯incandescent lighting 白炽灯照明inductance 电感inductance-capacitance meter 电感器industrial frequency AC electric traction system 单相工频交流电力牵引制inner covering 电缆内护层inner covering; bedding sheath 电缆内套insulation window 保温窗intensity of current 电流强度interrupter; circuit breaker; breaker 断路器，续断器interruption of current 断路isolux curve 等照度曲线kilowatt-hour meter; watt-hour meter; electric meter 电能表lamination 叠片lamp bridge 灯桥lamp socket; lamp holder; lamp base 灯座lamp; light; lantern 灯lamplight; lighting 灯光lamps; lighting fixtures 灯具lampshade lamp cover 灯罩leading 超前lead-out 出线life terminal 带电端子light control 灯光控制light trough; light slot; troffer 灯槽lighthouse beacon; pharos 灯塔lighting standard; lighting post; lighting pole 灯柱lightning protection 避雷（防雷）lightning rod，lightning conductor 避雷针little poisonous 低毒little poisonous 低毒live 带电live 带电live equipment 带电设备live working 带电作业local power supply 地方电源low frequency 低频low smoke zero halogen cable 低烟无卤电缆low -voltage cable 低压电缆low voltage circuit 低压电路low -voltage control 低压控制low -voltage power distribution box 低压配电箱low -voltage protection 低压保护low -voltage switch 低压开关low -voltage switch cabinet 低压开关柜low-term overvoltage 短时过电压low-voltage switchgear 低压成套开关magnetic switch 磁力开关magnitude of voltage 电压值mains side 电流侧mains switch 电源开关mains transformer 电源变压器mains voltage 电源电压making capacity 闭合容量marker lamp 标志灯mild steel conduct rail; mild steel third rail 低碳钢接触轨modulator-demodulator (modem) 调制解调器motor-generator set 电动发电机组moving contact 动触头network command centre (NCC) 电网指挥中心nominal value 标称值nominal voltage 标称电压notch-off 断电ohmic loss 电阻损失one-way circuit 单相电路one-way feeding 单边供电open circuit breaker; cutout; circuit breaker (CB) 断路器open-circuit arc 断路电弧open-delta connection V形接法open-phase protection 断相保护装置operating system (OS) 操作系统operation of network 电网运行管理operation passageway 操作走廊outlet 出线口outlet 出线口outlet box 出线盒outlet box 出线盒overhead illumination; overhead lighting; top lighting 顶部照明panel; board 电屏parallel circuit; shunt circuit 并联电路parallel connection; shunt connection 并联parallel resistance 并联电阻patch board; patch 插头板PE (protective earth) 保护地pendant continuous row fluorescent fixture 吊装荧光灯带pendent(pendant) lamp ; drop light 吊灯permanent lighting 常设照明phasing device 定相器point to point configuration 点对点配置point welding machine 点焊机port 端口potential 电位potential difference 电位差potential fall; voltage drop 电压降potential rise 电压升potential transformer; inductive voltage transformer 电压互感器potential transformer; pressure transformer; voltage电压互感器transformerpower administration 电业管理局power cable 电力电缆power cable well 电力电缆井power car 动力车辆power control box 动力控制箱power dispatch 电力调度power dispatcher 电调power lighting transformer feeder cubicle 动力变压器馈电柜power line harmonic current interference 电力线谐波干扰power source 电源power source bay 电源间隔power source for indication lamp 表示灯电源power supply cabinet 动力柜power supply cable 电力供电电缆power supply cable 电源线power supply of electric traction system 电力牵引供电系统电源power supply panel 电源屏power supply plug 电源插头power supply room 电源室power transformer substation; substation (SS) 动力变电所power transformers energy saving operation 电力变压器经济运行power transmission 电能输送power-line carrier channel; PLC-channel 电力线载波通道principle of superposition 叠加原理private wire 测试线protection panel 保护屏protective cable 保护电缆protective circuit 保护电路protective equipment of secondary circuit of power system 电力系统二次回路控制装置protective?wire 保护线push button switch; push button; button switch 按钮开关push-button 按钮push-button control; button control 按钮控制reactance 电抗reactive current 电抗性电流reactive drop 电抗性电压降Reactors 电抗器reference electrode 参考电极registration device 定位装置registration wire 定位索resistance 电阻resistance value 电阻值resistivity 电阻率rheostatic control 变阻调速safety lighting 安全照明safety voltage 安全电压SCA (supervisory control and data acquisition) 电力监控系统sectioning 电分段sectioning 电分段sectioning?point 电分段装置semi-autotensioned catenary equipment 半补偿链形悬挂semidirect lighting 半直接照明series battery 串联电池组series circuit 串联电路series connection 串联series-parallel circuit 串并联short circuit 短路short circuit calculation 短路计算short circuit detection transformer 短路监视互感器short-circuit current 短路电流short-circuit current 短路电流short-circuit current capacity 短路载流量short-circuit current setting calculation 短路电流整定计算short-circuit failure 短路故障short-circuit impedance 短路阻抗short-circuit loss 短路损耗short-circuit protection 短路保护装置short-circuiter 短路器short-time load 短时负载show-window lighting 橱窗照明shunt capacitors 并联电容sign illumination system 标志照明系统simple (catenary) equipment system with single contact wire 单接触线的简单链形悬挂single arm pantograph 单臂受电弓single core cable PVC jacket 单芯电缆PVC套single power supply 单电源single-phase motor 单相电动机single-phase system 单相系统single-phase two-wire system 单相两线制single-throw switch 单投开关slide-in (unit) 抽屉式socket; outlet; receptacle 插座spare fuses 备用保险丝spotlight; spot lamp 点光源stainless steel running face 不锈钢化性接触面standard light source 标准光源stand-by generator; reserved generator 备用发电机stand-by lighting 备用照明stand-by power source 备用电源star-delta connection Y-△接线start pulse 触发脉冲stitched catenary suspensic 弹性链形悬挂stitched catenary suspension 弹性链形悬挂stitched tramway type equipment 弹性简单悬挂strong current test panel (including rectifying and voltage regulating) 大电流测试 (含整流; 高压) 电源屏sub-distribution box 动力配电箱sub-distribution box for elevator 电梯配电箱superimposed load 超载superimposed load 叠加荷载supper-low voltage circuit 超低压电路surge arrester 电涌放电器switching-surge 操作过电压tagging 标签telephone interference 电话干扰tensioning equipment/tensioning device/tensioner 补偿器terminal 端子terminal block 端子板terminal block 端子排terminal box 端子箱terminal box 端子箱terminal insulator 端子绝缘terminal linkage board 端子连接板terminal of the cable linking box 电缆连接箱端子terminal point gun 端子连接器terminals for power supply 电源端子The trigger contains materials and equipment that are considered to be controlled commodities that either cannot be exported or that require an expert license. The list is an up-to date database maintained by Oak Ride National Laboratory (ORNZ) and has interactive search capacities. The list contains brief subject identifiers; you can “click” on a particular item to acquire detailed 出口材料和商品受控单specifications.time switch 定时开关traction transformer for single-phase V，V．connection 单相V，V．结线牵引变压器traction transformer of single-phase connection 单相结线牵引变压器transformer 动力变压器transformer bank 变压器组transformer box 变压器箱transformer capacity 变压器容量transformer coupling 变压器耦合transformer pole 变压器杆transformer protection panel 变压器保护屏transformer station; substation 变电所transmitting relay 传输继电器twin bracket 定位双环underground cable terminal box 地中电缆盒underground cable; ground cable 地下电缆uninterrupted power supply (UPS) 不间断电源(UPS) valve amplifier 电子管放大器vital aspect 安全显示voltage amplification 电压放大voltage below level 电压过低voltage distortion 电压畸变率voltage drop 电压损失voltage limiter 电压限制器(限压器）voltage regulator 调压器voltage unbalance 电压不平衡度voltmeter 电压表wall lamp; bracket light 壁灯washer 垫圈watt-hour meter; kilowatt-hour meter; electric meter 电表workshop power supply 车间电源workshop power supply 车间供电zinc-clad steel strand wire 镀锌钢绞线。
电气工程专业英语+unt1参考文档
Unit 1 Fundamentals of Electronic Circuits
1.1 Introduction to Circuit Theory 1.2 Analog and Digital Circuits 1.3 Three-Phase Circuits 1.4 Further Reading
Notice that the three points that form node b ① are connected by perfectly conducting wires and therefore constitute a single point.
Note:① "three points that form node b "表示"形成节点
b的3个点".此句可译为:注意到形成节点b的3个点是通过理
elements or devices, whereas a circuit is a network
providing one or more closed paths③.
Note：②：regard … as表示“把…认为” NNoottee：：③①：：pdrioffveirtfherse为ntiate nbeettwwoerekn的A后an置d 定B表语示。区分A和B；To differentiate between a circuit and a network是目的状语从句.
series
n. 连续；系列；级数；串联
parallel
adj. 平行的；并联的 n. 平行线；平
行面；v. 相应；平行
impedance
n. [电]阻抗；全电阻；[物]阻抗
theorem
n. [数]定理；法则
电气工程及其自动化专业英语
time-invariant 时不变的
self-(or mutual-)induction 自（互）感
displacement current 位移电流 conductance 电导
voltage drop 电压降 volt-ampere characteristics 伏安特性
metal-filament lamp 金属丝灯泡
seen, increase of current from zero to
I≈I1 causes the terminal voltage of the source to decrease linearly
V12=V=E－VS=E－RSI
Fig.1.3
In other words, the voltage drop VS across the source resistance rises in proportion to the current. This goes on until
(完整版)电气工程及其自动化专业英语第二章课文翻译
第二章第一篇To say that we live in an age of electronics is an understatement. From the omnipresent integrated circuit to the equally omnipresent digital computer, we encounter electronic devices and systems on a daily basis. In every aspect of our increasingly technological society— whether it is science, engineering, medicine, music, maintenance, or even espionage—the role of electronics is large, and it is growing.谈论关于我们生活在一个电子学时代的论调是一种空泛的论调。
从无处不在的集成电路到同样无处不在的数字计算机，我们在日常活动中总会遇到电子设备和电子系统。
在我们日益发展的科技社会的方方面面——无论是在科学、工程、医药、音乐、维修方面甚至是在谍报方面——电子学的作用是巨大的，而且还将不断增强。
In general, all of the tasks with which we shall be concerned can be classified as "signal-processing“tasks. Let us explore the meaning of this term一般说来，我们将要涉及到的工作被归结为“信号——处理”工作，让我们来探究这个术语的含义吧。
A signal is any physical variable whose magnitude or variation with time contains information. This information might involve speech and music, as in radio broadcasting, a physical quantity such as the temperature of the air in a room, or numerical data, such as the record of stock market transactions. The physical variables that can carry information in an electrical system are voltage and current. When we speak of "signals", therefore, we refer implicitly to voltages or currents. However, most of the concepts we discuss can be applied directly to systems with different information-carrying variables. Thus, the behavior of a mechanical system (in which force and velocity are the variables) or a hydraulic system (in which pressure and flow rate are the variables) can often be modeled or represented by an equivalent electrical system. An understanding of the behavior of electrical systems, therefore, provides a basis for understanding a much broader range of phenomena. 信号就是其与时间有关的量值或变化包含信息的任何物理变量。
电气工程专业英语section 4-2
Section 2
Performance Characteristics of Induction Motors
region. Slip values for speeds above synchronous speed are negative, as is evident from Eq.(4-3). Operation in the generating region results from overhauling loads or from the motor being driven by a prime mover. For induction generating action to occur, the machine must have a source of leading exciting current. This leading excitation can be supplied from the power system if the motor is connected to such a system, or it can be provided by capacitors of appropriate value connected across the motor terminals. In recent years, induction
风力发电机
Return
Addition or Omission of Words
3. 增加表示动词时态的词 汉语中动词没有时态变化，需要在译文中增加时 间副词或助词来表示英语里的不同时态。通常在翻译 现在时，可增添“能”、“可”、“会”等字；译将 来时可增添“将”、“要”、“会”等字；译过去时 可增添“已”、“曾”、“过”、“了”、“以前”、 “当时”、“过去”等词；译完成式可增添“已 （经）”、“曾（经）”、“了”、“过”、“一直” 等词；译进行时可增添“正（在）”、“在”等词。 (1) Scientists are working to develop new ways to make the semiconductor material used in computers and other modern electronic devices. 科学家们正在研 究新的方法制造用于计算机和其他现代电子仪器中的
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This number can be simplified using mathematical exponents. 这个数字可以用数学的指数形式来化简， Instead of writing 24 zeros after the number 1,write1024.用1024来代 替24个零。 Trying to measure even small values of current would result in unimaginably large numbers. 试图测量如此微小的电流将产生难以想象的巨大的数字。 For this reason current is measured in amperes which is abbreviated ”amp”. 所以，电流用安培数来度量，安培可以简写为“amps”。 The symbol for amp is the letter: A”.安培可以用符号“A”来表示。 A current of one amp means that in one second about 6.24×1018electrons move through a cross-section of conductor. 一安培的电流意味着在一秒中之内有6.24×1018个电子流过导体的截面。 These numbers are given for information only and you do not need to be concerned with them. 这些数字只是信息，并不需要去关心。 It is important, that the concept of current flow be understood. 但是重要的是理解电流的概念。
–attract
v.吸引
• attraction
– repel v.sites attract 异性吸引
• repulsion
n.排斥
–magnetic
有吸引力的
adj. 磁的, 有磁性的,
–magnetic field 磁场
–electric field
–current flow
电场
–lines of force 力线 电流
–electromotive force=EMF 电动势 –counter- electromotive
force=CEMF 反电动势
–potential adj.势的, 位的 • (electric) potential difference
电位差 • a difference by potential
2.1units of measurement for current测量电流的单位 The following chart reflects special prefixes that are used when dealing with very small or large value of current:下面的图表反映了处 理很小和很大的电流时的计量单位的词头： Prefix 词头 symbol 符号 decimal 十进制 1kiloampere1千安 1KA 1000A 1milliampere1毫安 1mA 1/1000A 1microamoere1微安 1μA 1/1000000A 2.2 direction of current flow电流的方向 Some authorities distinguish between electron flow and current flow. 一些权威将电子流和电流区分， Conventional current flow theory ignores the flow of electrons and states that current flows from positive to negative. 传统上电流理论忽略电子流，而认为电流是从正极流向负极。 To avoid confusion ,we will use the electron flow concept which states that electrons flow from negative to positive. 为了避免混淆，我们使用电子流概念是电子从负极流向正极。
的百万分之一)
1.Electric charge 电荷 1.1neutral state of an atom 1.1 中性的原子 Elements are often identified by the number of electrons in orbit around the nucleus of the atoms making up the element and by the number of protons in the atom. 元素是通过组成该原子的核子轨道上的电子数及核子中的质子数来区分 的。 A hydrogen atom, for example, has only one electron and one proton. 例如，一个氢原子只有一个电子和一个质子。 An aluminum atom（illustrated）has 13 electrons and 13 protons. 一个铝原子有13个电子和13个质子（如图）。 An atom with an equal number of electrons and protons is said to be electrically neutral. 一个有相同数目的电子和质子数的原子电性呈中性。
中性状态,
[nju:'trælət • electroneutrality n.电中性 i]
• be electrically neutral电性呈中 性
–orbit
n.轨道；轨迹
• orbital electron 轨道电子
–gravity
n. 地心引力, 重力
• acceleration of gravity 重力加速度 • the centre of gravity 重心，重点
1.3 attraction and repulsion of electric charge电荷之间的吸引和排斥 The old saying, ”opposites attract” is true when dealing with electric charges. 俗话说，“异性吸引”，处理电荷时是正确的。 Charged bodies have an invisible electric field around them. 每个电荷四周有一个看不见的电场。 When two like-charged bodies are brought together, their electric field will work to repel them.当两个电性相同的电荷靠近时电场将相斥， When two unlike-charged bodies are brought together, their electric field will work to attract them.当两个电性不同的电荷靠近时电场将相吸。 The electric field around a charged body is represented by invisible lines of force. 电荷周围的电场通过不可见的电力线表示， The invisible lines of force represent an invisible electric field that causes the attraction and repulsion. 不可见的电力线表示引起吸引和排斥的不可见的电场。 Lines of force are shown leaving a body with a positive charge and entering a body with a negative charge. 正电荷用离开的电力线表示、负电荷用进入的电力线表示。
1.2positive and negative charges 正负电荷 Electrons in the outer band of an atom are easily displaced by the application of some external force. 原子的外圈的电子很容易由于受到外力的作用而被移走。 Electrons which are forced out of their orbits can result in a lack of electrons where they leave and an excess of electrons where they come to rest. 由于电子从轨道移走而造成该原子缺少电子，而移入电子的原子电子 过剩。 The lack of electrons is called a positive charge because ther are more protons than electrons. 使由于质子数多于电子数，缺少电子的成为正电荷。 The excess of electrons has a negative charge.电子过剩的称为负 电荷。 A positive or negative charge is caused by an absence or excess of electrons. 电子不足或过剩产生正或负电荷。 The number of protons remains constant. 质子数始终是恒定不变的。
Electric Basic Concept
–nucleus
n.核子['nju:kli:əs]
–atom
–proton
n. 原子['ætəm]
n.质子['prəu,tɒn] n.电子
–electron
• free electron
自由电子
• electrochemical adj. 电气化学的