自动化专业英语Unit 1 A1

1、 第第 2 / 61页页Linear Circuit Analysis 第第 3 / 61页页Gustav Robert Kirchhoff KVL KCL Georg Simon Ohm 欧姆欧姆.G.S.u(t)i(t)R=Ohms Law 第第 4 / 61页页 1Ohms Law Suppose that some material is connected to the terminals of an ideal voltage source u(t) as shown in Fig 1-1Suppose that u(t)=1 V , then the electric poten

2、tial at the top of the material is 1 V above the potential at the bottomSince an electron has a negative charge, electrons in the material will tend to flow from bottom to topTherefore，we say that a current tends to go from top to bottom through the material. Hence, for the given polarity, when u(t)

3、 is a positive number, i(t) will be a positive number with the direction indicated in Fig 1-1. 第第 5 / 61页页u(t)Ru(t)i(t) If u(t) =2V, again the potential at the top is greater 2V than at the bottom，so i(t) will again be positive. However，because the potential is now twice as large as before，the curre

4、nt i(t) be greater (If the material is a “linear” element，the current will be twice as great)If the resulting current i(t) is always directly proportional to the voltage for any function u(t)，the material is called a linear resistor To a linear resistor，we have： R= and i(t)= The unit of resistance (

5、volts per ampere) is referred to as Ohms and is denoted by the capital Greek letter omega Both equations above are also referred to as Ohms law 第第 6 / 61页页 2Kirchhoffs Current Law It is a consequence of the work of the German physicist (1824-1887) that enables us to analyze an interconnection of any

6、 number of elements (voltage sources，current sources，and resistors), as well as other electronic devicesWe will refer to any such interconnection as a circuit or a network For a given circuit a connection of two or more elements shall be called a node. We now present the first of Kirchhoffs two laws

7、，his current law (KCL)，which is essentially the law of conservation of electric charge： 第第 7 / 61页页ioutiini At any node of a circuit，at every instant of time, the sum of the currents into the node is equal to the sum of the currents out of the node. = An alternative, but equivalent，form of KCL can b

8、e obtained by considering currents directed into a node to be positive in sense and currents directed out of a node to be negative in sense. Under this circumstance，the alternative form of KCL can be stated as follows： = 0 At any node of a circuit，the currents algebraically sum to zero.ini 第第 8 / 61

9、页页 3. Kirchhoffs Voltage Law (KVL) We now present the second of Kirchhoffs lawsthe voltage law. To do this，we must introduce the concept of a “loop”. Starting at any node n in a circuit, we form a loop by traversing through elements and returning to the starting node n，and never encountering any oth

10、er node more than once. Kirchhoffs voltage law (KVL) is： + = - In traversing any loop in any circuit，at every instant of time，the sum of the voltages having one polarity equals the sum of the voltages having the opposite polarity. uu 第第 9 / 61页页 0u An alternative statement of KVL can be obtained by

11、considering voltages across elements that are traversed from plus to minus to be positive in sense and voltages across elements that are traversed from minus to plus to be negative in sense (or vice versa). Under this circumstance，KVL has the following alternative form. Around any loop in a circuit，

12、the voltages algebraically sum to zero. 第第 10 / 61页页 4. Circuit Analysis Techniques The process by which we determine a variable (either voltage or current) of a circuit is called analysis. Though：some simple single-stage amplifier circuits can be quite useful. We have already come across some simpl

13、e single-stage amplifier circuits whose analysis was accomplished by applying the basic principles converted to data-Ohms law, KCL and KVL. Nonetheless, we must also be able to analyze more complicated circuitsthose in which it is simply not possible to conveniently write and solve a set of linear a

14、lgebraic equations.1p 第第 11 / 61页页 There are several distinct approaches that we can take. In one we write a set of simultaneous equations in which the variables are voltage，this is known as nodal analysis. In another we write a set of simultaneous equations in which the variables are currents，this

15、is known as mesh analysis. Although nodal analysis can be used to all circuits, this is not the case for mesh analysis A class of circuits known as “nonplanar” networks cannot be handled with mesh analysis. However, a similar approachloop analysiscan be used. Here the variables are also current.1p 第

16、第 12 / 61页页 5. Sinusoidal Circuits Step and impulse functions are useful in determining the responses of circuits when they are first turned on or when sudden or irregular changes occur in the input. This is called transient analysis. However, to see how a circuit responds to a regular or repetitive

17、 inputthe steady-state analysisfunction that is by far the most useful is the sinusoid.1p 第第 13 / 61页页 The sinusoid is an extremely important and ubiquitous function. To begin with the shape of ordinary household voltage is sinusoidal, consumer radio transmissions are either amplitude modulation (AM

18、)，in which the amplitude of a sinusoid is changed or modulated according some information signal，or frequency modulation (FM)，in which the frequency of a sinusoid is modulated. We have following conclusions about the sinusoid：1p 第第 14 / 61页页 1) If the input of a linear, time-invariant circuit is a s

19、inusoid, then the response is sinusoid of the same frequency. 2) Finding the magnitude and phase angle of a sinusoidal steady-state response can be accomplished with either real or complex sinusoids. 3) If the output of a sinusoidal circuit reaches its peak before the input, the circuit is a lead ne

20、twork. Conversely，it is a lag network. 4) Using the concepts of phasor and impedance，sinusoidal circuits can be analyzed in the frequency domain in a manner analogous to resistive circuits by using the phasor versions of KCL，KVL, nodal analysis, mesh analysis and loop analysis.1p 第第 15 / 61页页New wor

21、ds and phrasesadmittance dmitns n. 进入；入场权；通道；导纳 (即电阻的倒数)algebraical ,ldibreiikl adj. 代数学的（= algebraic）consequence knsikwns n. 结果，推理，推论，重要的地位polarity pulrti n. 两极；极性；对立depict dipikt vt. 描画；描述interconnection ,intknekn n. 互相连络；互连single-stage silsteid adj. 单级；单级的node nud n. 节点；瘤；结点 nodal adj. 节的；波节的；结点的

22、nonplanar adj. 非平面的；空间的（曲线的）impulse impls n. 冲动；脉冲；刺激；神经冲动 vt. 推动transient trnzint adj. 短暂的；路过的n. 瞬变现象；候鸟function fkn n. 功能；函数；盛大的集会vi. 行使职责；运行 omega umig n. 希腊字母的最后一个字；终了；最后 第第 16 / 61页页conservation ,knsvein n. 保存，保持；保护守恒encounter inkaunt vt. 遭遇，邂逅；遇到n. 遭遇，偶然碰见traverse trvs n. 横木；穿过vt. 穿过；详细研究vi. 横

23、越；旋转impedance impi:dns n. 阻抗 (包括电阻与电抗)loop lu:p vi. 打环；翻筋斗n. 环；圈；（闭合）回路mesh me n. 网络 网眼；网丝；圈套vi. 相啮合vt. 以网捕捉ubiquitous ju:bikwits adj. 普遍存在的；无所不在的modulate mdjuleit vt. 调节；调整；（信号）调制vi. 转调domain dumein n. 领域；产业；地产；计 域名phasor feiz(r) n. 相量相量图repetitive ripettiv adj. 重复，迭代sinusoid sainsid n. 正弦曲线，正弦refe

24、r to as 提到，作为，把称为analogous to 类似于 第第 17 / 61页页Technical Terms amplitude modulation (AM)调幅frequency modulation (FM)调频lag network 滞后网络 lead network 超前网络transient analysis 暂态分析 第第 18 / 61页页Language points 1. Gustav Kirchhoff人名，德同物理学家(1824-1887)，他给出了电路分析的两个基本定律 2. respond to 对响应；对作出反应；响应，回答 1）People res

25、pond to your warmth and curiosity now, and your world only gets better and better. 人们将会对妳的热情和好奇心给予汇报，妳的世界将会变得越来越好的！ 2）How to respond to a greeting?怎样回答别人的问候？ 第第 19 / 61页页 3）Legislators often respond to the quiet and professional pressure of lobbyists. 立法者通常回应平静和专业的说客的压力。 4）The X server will respond

26、to certain X client requests that require a reply. As noted, not all requests require a reply. 服务器会对某个需要响应的特定的X客户端产生回应。注意，并不是所有的请求都需要回应的。 第第 20 / 61页页 3 . vice versa 反之亦然，反过来也一样反之亦然，反过来也一样 1) Ultimately, it is the individual stocks those determine the market, not vice versa. 说到底，是一支支股票决定了股市走向，而否则相反。

27、 2) You can open an account using the desktop client terminal and then control it using a mobile terminal and vice versa. 你可以使用桌面客户端开立账户，然后再用移动终端加以控制，反之亦然。 3) A man of high birth may be of low worth and vice versa.出身高贵者，其人或者低；出身卑陋者，其人或可仰。 4) The Core will allow small companies with small application

28、s to integrate into much larger networks of systems, and vice versa. 核心将允许有小型应用的小公司集成进系统的更大网络，反之亦然。 第第 21 / 61页页 4. time-invariant adj.不变时的；不随时间改变的不随时间改变的n. 时间不变量time-invariant circuit 时不变电路 (稳态电路) .Linear time-invariant systems线性非时变系统； 1) We start with time-invariant filters and basic wavelets. 从时不

29、变滤波器和基本小波开始课程。 2) Cant Apply the Superposition Theorem for the Power of the Linear Time-Invariant Sinusoidal Steady State Circuit? 线性非时变正弦稳态电路的功率不能用迭加原理吗? 3) The state-space representation and the transfer function representation of fractional order linear time-invariant systems are introduced. 介绍了分

30、数阶线性定常系统的状态方程描述和传递函数描述。 第第 22 / 61页页 5. ubiquitous ju:bikwits adj. 普遍存在的；无所不在的 1) The ubiquitous mouse input device is not metaphoric of anything, but rather is learned idiomatically. 无所不在的鼠标输入设备没有任何隐喻；相反，是习惯用法的学习。 2) In many ways, the timing of his career and life explains why Rawlings is at once a

31、 hidden and ubiquitous influence. 在许多年里，他的职业生涯和生活方式只是作为一种隐藏的但是无处不在的影响。 3) In a satellite-based Internet system, satellites are used to interconnect various networks and to provide ubiquitous Internet access to homes and businesses. 在基于卫星的互联网系统中,卫星用来实现各种网络的互联,为家庭和商业提供互联网的接入服务。 第第 23 / 61页页 6. modulat

32、e vt. 调节；调整；（信号）调制vi.转调modulation n. 1) related phrases：modulate types调制类型 modulate curriculum 模块课程modulate mode调制方式 frequency modulate调频 2) Emotions may absolutely dictate a type of response, but people do modulate the size of that response (usually!). 情绪必然会促发某种响应，但人们会适时调整反应的烈度（而且一贯如此）。 3) Research

33、ers would also like to study other treatments that directly modulate immune system responses in flu patients. 研究人员也希望能测试直接调整流感病患免疫系统的方法。 第第 24 / 61页页 7. alternative :lt:ntiv adj. 供选择的；交替的n. 二中择一 1) You have the alternative of riding or walking. 你可以在坐车和步行中选择一种。 2) Behavior modification could be an al

34、ternative, he says. 行为改变是一种可能的选择，他说。 3) When would a retail salesperson offer an alternative sale to a customer? 在什么情况下，销售人员需要提供替代产品给顾客？ 4) Is it better to provide all the customers with the same level of service or is there an alternative? 是否最好是向所有客户提供同样的服务水平，还是有其他的选择方案？ 第第 25 / 61页页 8. considering

35、 prep. 考虑到；就而论conj. 考虑到 1) I have no time considering all issue or recall my memory. 我没有时间考虑种种问题或者随意翻开记忆。 2) Considering the ponderance of the problem, effective measures must be adopted before it has been worsen. 考虑到问题的严重性，在事态进一步恶化之前，必须采取有效的措施。 第第 26 / 61页页 9. refer to as 提到，作为，把称为 1) related phras

36、es：refer to A as B把A称作B refer to sth as把看作、称作 refer to sb as把称做，把当做 2) This is what most scientists refer to as “cloning”. 这就是科学家们所说的“克隆”。 3) In the United States today, nearly half of us live in areas that we refer to as the suburbs. 今天，在美国，我们之中有近乎一半的人生活在被称之为郊区的地方。 4) That kind of stupid action-mak

37、ing something worse that is already bad-is what we refer to as adding fuel to the fire. 那种愚蠢的行为把已经够遭的事情弄的无法收拾就是我们所说的“往火上浇油”。 第第 27 / 61页页ExercisesI. Answer the following questions according to the text. What is Kirchhoffs Current Law?2. What is Kirchhoffs Voltage Law? At any node of a circuit，at eve

38、ry instant of time, the sum of the currents into the node is equal to the sum of the currents out of the node. In traversing any loop in any circuit，at every instant of time，the sum of the voltages having one polarity equals the sum of the voltages having the opposite polarity. 第第 28 / 61页页3. What i

39、s called a circuit analysis?4. Why the sinusoid is an extremely important function? The process by which we determine a variable (either voltage or current) of a circuit is called analysis. To begin with the shape of ordinary household voltage is sinusoidal, consumer radio transmissions are either a

40、mplitude modulation (AM)，in which the amplitude of a sinusoid is changed or modulated according some information signal，or frequency modulation (FM)，in which the frequency of a sinusoid is modulated. 第第 29 / 61页页1. be directly proportional to the voltage 2. percentage of modulation3. introduce the c

41、oncept of a “loop” 4. the phasor versions of KCL5. present the second of Kirchhoffs laws 6. time-invariant circuit7sinusoidal steady-state response 8. ordinary household voltage II. Put the following phrases into Chinese. 与电压成正比调整的百分数 引入闭合回路的概念 基尔霍夫电流定律的相量变化 介绍基尔霍夫的第二定律 时不变回路 正弦稳态响应 一般家庭的电压 第第 30 /

42、61页页v求解线性代数方程组并不容易。2. 每一瞬时的正电压和等于负电压和。3. 我们必须学会分析比较复杂的电路。4. 回路电流法却可适用于任何电路。5. 每一瞬时流入结点的电流和总是等于流出结点的电流和。 Translate the following into EnglishIn complicated circuits it is simply not possible to conveniently write and solve a set of linear algebraic equations. The sum of the voltages having one polari

43、ty equals the sum of the voltages having the opposite polarity. We must also be able to analyze more complicated circuits.Loop analysis can be used to all circuits. At every instant of time, the sum of the currents into the node is equal to the sum of the currents out of the node. 第第 31 / 61页页 翻译是一种

44、再创造，即译者根据原作者的思想翻译是一种再创造，即译者根据原作者的思想，用另一种语言表达出来。这就是要求译者必须，用另一种语言表达出来。这就是要求译者必须确切理解和掌握原作的内容与含意，在确切理解确切理解和掌握原作的内容与含意，在确切理解的基础上，很好地运用译文语言把原文内涵通顺的基础上，很好地运用译文语言把原文内涵通顺流畅地再现给读者。流畅地再现给读者。 Translating Skills 科技英语翻译的标准与方法科技英语翻译的标准与方法 第第 32 / 61页页 一、翻译的标准 科技英语的翻译标准可概括为“忠实、通顺忠实、通顺”四个字。 忠实，首先指忠实于原文内容忠实，首先指忠实于原文内

45、容，译者必须把原作的内容完整而准确的表达出来，不得任意发挥或增删；忠实忠实还指保持原作风格，尽量表现其本来面目还指保持原作风格，尽量表现其本来面目。 通顺，即指译文语言必须通俗易懂，符合规范通顺，即指译文语言必须通俗易懂，符合规范。忠实与通顺是相辅相成的，缺一不可。忠实而不通顺，读者会看不懂；通顺而不忠实，脱离原作的内容与风格，通顺就失去了意义。例如： Translating Skills 第第 33 / 61页页 Translating Skills1. The electric resistance is measured in ohms. 误译：电的反抗是用欧姆测量的。误译：电的反抗是用

46、欧姆测量的。 正译：电阻的测量单位是欧姆。正译：电阻的测量单位是欧姆。 2. All metals do not conduct electricity equally well. 误译：全部金属不导电得相等好。误译：全部金属不导电得相等好。 正译：并非所有的金属都同样好地导电。正译：并非所有的金属都同样好地导电。 3. The moment the circuit is completed, a current will start flowing the coil. 正译：电路一旦接通，电流开始流向线圈。正译：电路一旦接通，电流开始流向线圈。 4. Some special alloy s

47、teels should be used for such parts because the alloying elements make them tougher, stronger, or harder than carbon steels. 正译：对这类零件可采用某些特殊的合金钢，因为合金元素能提高钢正译：对这类零件可采用某些特殊的合金钢，因为合金元素能提高钢的韧性、强度、硬度。的韧性、强度、硬度。 从以上例句可以清楚的看到，不能任意删改，并不是逐词死译；汉语从以上例句可以清楚的看到，不能任意删改，并不是逐词死译；汉语译文规范化，并非是离开原文随意发挥。此外，还应注意通用术语的译文规范

48、化，并非是离开原文随意发挥。此外，还应注意通用术语的译法。比如，例译法。比如，例1中的中的“电阻电阻”已成为固定词组，不能用别的译法。已成为固定词组，不能用别的译法。 第第 34 / 61页页Translating Skills 二、翻译的方法二、翻译的方法翻译的方法一般来说有直译翻译的方法一般来说有直译 (literal translation) 和意译和意译 (free translation)。直译，即指。直译，即指“既忠实于原文内容，又既忠实于原文内容，又忠忠实于原文的形式实于原文的形式”的翻译。意译，就是指忠实于原文的内容，的翻译。意译，就是指忠实于原文的内容，但不拘泥于原文的形式。

49、但不拘泥于原文的形式。 翻译时，我们应灵活运用上述两种方法，能直译的就直译，需翻译时，我们应灵活运用上述两种方法，能直译的就直译，需 要意译的就意译。因为对同一个句子来说，有时并非只能用一要意译的就意译。因为对同一个句子来说，有时并非只能用一 种方法，所以我们可以交替使用或同时并用以上两种方法。种方法，所以我们可以交替使用或同时并用以上两种方法。 请看下面的句子请看下面的句子: 第第 35 / 61页页 Translating Skills1. Milky Way 银河银河 (意译意译) (不可直译为：牛奶路不可直译为：牛奶路) 2. bulls eye 靶心靶心 (意译意译) (不可直译为：

50、牛眼睛不可直译为：牛眼睛) 3. New uses have been found for old metals, and new alloys have been made to satisfy new demands. 老的金属有了新用途，新的金属被冶炼出来，以满足新的需要老的金属有了新用途，新的金属被冶炼出来，以满足新的需要(本句前本句前半部分用了意译法，后半部分用了直译法半部分用了意译法，后半部分用了直译法)4. The ability to program these devices will make a student an invaluable asset to the gro

51、wing electronic industry. 对这些器件编程的能力将使学生成为日益增长的电子工业领域中的无对这些器件编程的能力将使学生成为日益增长的电子工业领域中的无价人才（这里价人才（这里asset 原意为资产，我们根据上下文意译成原意为资产，我们根据上下文意译成“人才人才”）。）。 第第 36 / 61页页Translating Skills 三、翻译中的专业性特点三、翻译中的专业性特点 科学技术本身的性质要求科技英语与专业内容相科学技术本身的性质要求科技英语与专业内容相互配合，相互一致，这就决定了专业英语与普通互配合，相互一致，这就决定了专业英语与普通英语有很大的差异。专业英语以其

52、独特的语体，英语有很大的差异。专业英语以其独特的语体，明确表达作者在其专业方面的见解，其表达方式明确表达作者在其专业方面的见解，其表达方式直截了当，用词简练。即使同一个词，在不同学直截了当，用词简练。即使同一个词，在不同学科的专业英语中，其涵义也是不同的。例如：科的专业英语中，其涵义也是不同的。例如： 第第 37 / 61页页 Translating Skills1. The computer took over an immense range of tasks from workers muscles and brains. 误译：计算机代替了工人大量的肌肉和大脑。误译：计算机代替了工人大

53、量的肌肉和大脑。 正译：计算机取代了工人大量的体力和脑力劳动。正译：计算机取代了工人大量的体力和脑力劳动。 （这里（这里muscles and brains 引申为引申为“体力和脑力劳动体力和脑力劳动”。）。） 2. Vibration has worked some connection lose. 误译：震动影响了一些连接的松弛。误译：震动影响了一些连接的松弛。 正译：震动使一些接线松了。（专业知识使我们通过正译：震动使一些接线松了。（专业知识使我们通过connection联想到联想到“接线接线”或或“连接线连接线”。）。） 3. In any case work doesnt inclu

54、de time, but power does. 正译：在任何情况下，功不包括时间，但功率包括时间。正译：在任何情况下，功不包括时间，但功率包括时间。 （这里（这里work，power在物理专业分别译为在物理专业分别译为“功功”、“功率功率”。）。） 4Like charges repel each other while opposite charges attracted. 正译：同性电荷相排斥，异性电荷相吸引。正译：同性电荷相排斥，异性电荷相吸引。 charge含义有含义有“负载、充电、充气、电荷负载、充电、充气、电荷”，按专业知识理解为，按专业知识理解为“电荷电荷”。 从以上例句可知，

55、专业英语专业性强，逻辑性强，翻译要力求准确、精练、从以上例句可知，专业英语专业性强，逻辑性强，翻译要力求准确、精练、正式。这不仅要求我们能熟练地运用汉语表达方式，还要求具有较高的专业正式。这不仅要求我们能熟练地运用汉语表达方式，还要求具有较高的专业水平。水平。 第第 38 / 61页页 外特性等效外特性等效 第第 39 / 61页页 Suppose that a load resistor RL is connected to an arbitrary (in the sense that it contains only linear elements) circuit as shown i

56、n Fig 6-2 (a).What value of the load RL will absorb the maximum amount of power? Knowing the particular circuit, we can use nodal or mesh analysis to obtain an expression for the power absorbed by RL，then take the derivative of this expression to determine what value of RL results in maximum powerTh

57、e effort required for such an approach can be quite great. Fortunately，though, a remarkable and important circuit theory concept states that as far as RL is concerned，the arbitrary circuit shown in Fig 6-2(a) behaves as though it is a single independent voltage source in series with a single resista

58、nce (Fig 6-2(c). Reading More 第第 40 / 61页页戴维南定理戴维南定理 假定一个负载电阻RL与任意一个电路(这个电路中只含有线性元件)相连接，如图1-2(a)所示，那么电阻取何值时可以消耗的电功率最大？对于一个具体的电路，我们可以用结点分析法或网孔分析法来求出RL所消耗功率的表达式。然后根据这个表达式求出电阻为多大值时消耗的功率最大。但用这种方法来求解，计算量比较大，然而一个著名的、重要的电路理论概念指出：如果只求RL的话，图1-2(a)中的任意电路可用一个独立电压源串联一个电阻来表示(图1-2(c)。 第第 41 / 61页页 Once we determi

59、ne the values of this source and this resistance，we simply apply the results on maximum power transfer. Suppose we are given an arbitrary circuit containing any or all of the following elements resistors，voltage sources，current sources. (The sources can be dependent as well as independent.) Let us i

60、dentify a pair of nodes，say node a and node b，so that the circuit can be partitioned into two pars as shown in Fig 6-2 (b). Furthermore suppose that circuit A contains no dependent source that independent on a variable in circuit B, and vice versa. 第第 42 / 61页页 只要求出了这个电压源和这个电阻的值，我们就能够很方便地分析电阻消耗的最大功率