《牛津书虫系列汤姆索亚历险记》电子版英语教学
课外读物（含翻译）
1.Tom and his friends
'Tom! Tom! Where are you?'
No answer.
'Where is that boy? When I find him, I'm going to...'
Aunt Polly looked under the bed. Then she opened the door and looked out into the garden.
'Tom!'
She heard something behind her. A small boy ran past, but Aunt Polly put out her hand and stopped him.
'Ah, there you are! And what's that in your pocket?'
'Nothing, Aunt Polly.'
'Nothing! It's an apple! I can see it. Now listen, Tom. Those apples are not for you, and I -'
'Oh, Aunt Polly! Quick - look behind you!'
So Aunt Polly looked, and Tom was out of the house in a second. She laughed quietly. 'I never learn. I love that Tom, my dead sister's child, but he isn't an easy boy for an old lady. Well, it's Saturday tomorrow and there's no school, but it isn't going to be a holiday for Tom. Oh no! He's going to work tomorrow!'
* * *
Saturday was a beautiful day. It was summer and the sun was hot and there were flowers in all the gardens. It was a day for everybody to be happy.
Tom came out of his house with a brush and a big pot of white paint in his hand. He looked at the fence; it was three metres high and thirty metres long. He put his brush in the paint and painted some of the fence. He did it again. Then he stopped and looked at the fence, put down his brush and sat down. There were hours of work in front of him and he was the unhappiest boy in the village.
After ten minutes Tom had an idea, a wonderful idea. He took up the brush again and began work. He saw his friend Joe Harper in the street, but he didn't look at him. Joe had an apple in his hand. He came up to Tom and looked at the fence.
'I am sorry, Tom.'
Tom said nothing. The paint brush moved up and down.
'Working for your aunt?' said Joe. 'I'm going down to the river. I'm sorry you can't come with me.'
Tom put down his brush. 'You call this work?' he said.
'Painting a fence?' said Joe. 'Of course it's work!'
'Perhaps it is and perhaps it isn't. But I like it,' said Tom. 'I can go to the river any day. I can't paint a fence very often.'
Joe watched Tom for about five minutes. Tom painted very slowly and carefully. He often stopped, moved back from the fence and looked at his work with a smile. Joe began to get very interested, and said:
'Tom, can I paint a little?'
Tom thought for a second. 'I'm sorry, Joe. You see, my aunt wants me to do it because I'm good at painting. My brother Sid wanted to paint, too, but she said no.'
'Oh, please, Tom, just a little. I'm good at painting, too. Hey, do you want some of my apple?'
'No, Joe, I can't -'
'OK, you can have all my apple!'
Tom gave Joe the brush. He did not smile, but for the first time that day he was a very happy boy. He sat down and ate Joe's apple.
More friends came to laugh at Tom, but soon they all wanted to paint, too. By the afternoon Tom had three balls, an old knife, a cat with one eye, an old blue bottle, and a lot of other exciting things. He was the richest boy in St Petersburg, and the fence - all thirty metres of it - was a beautiful white. He went back to the house.
'Aunt Polly! Can I go and play now?'
Aunt Polly came out of the house to look. When she saw the beautiful white fence, she was very pleased. She took Tom into the house and gave him an apple.
'Well, you can go and play. But don't come home late.'
Tom quickly took a second apple and ran off.
* * *
On Monday morning Tom didn't want to go to school, but Aunt Polly got him out of bed, and then out of the house. In the street near the school he met his friend Huckleberry Finn. Huck had no mother, and his father drank whiskey all the time, so Huck lived in the streets. He didn't go to school, he was always dirty, and he never had a new shirt. But he was happy. The mothers of St Petersburg didn't like Huck, but Tom and his friends did.
'Hello, Huck!' said Tom. 'What have you got there?'
'A dead cat.'
'What're you going to do with it?' asked Tom.
'I'm going to take it to the graveyard tonight,' Huck said. 'At midnight. A dead cat can call ghosts out of their graves.' 'I never heard that,' said Tom. 'Is it true?'
'Well, I don't know,' said Huck. 'Old Mrs Hopkins told me. Come with me, and see. Or are you afraid of ghosts?'
'Of course not!' said Tom. 'Come and meow for me at my window at eleven o'clock.'
After this, Tom was late for school, and the teacher looked at him angrily.
'Thomas Sawyer, why are you late again?' he said.
Tom began to speak, and then stopped. There was a new girl in the schoolroom - a beautiful girl with blue eyes and long yellow hair. Tom looked and looked.
Oh, how beautiful she was! And in two seconds Tom was in love! He must sit next to her. But how?
In the girls' half of the room there was only one empty chair, and it was next to the new girl. Tom thought quickly, and then looked at the teacher.
'I stopped to talk with Huckleberry Finn!' he said.
The teacher was very, very angry. Boys were often late for school. That was bad, but talking with Huckleberry Finn was worse, much worse! The teacher took his stick, and two minutes later Tom's trousers were very hot and the teacher's arm was very tired.
'Now, Tom Sawyer, you go and sit with the girls!'
Some of the children laughed. Tom walked to the chair next to the new girl, sat down and opened his book. The other children began to work again.
After ten minutes, the girl looked up. There was an apple on the table in front of her. She put it back on Tom's half of the table. A minute later the apple was in front of her again. Now it stayed. Next, Tom drew a picture of a house and put it in front of her.
'That's nice,' the girl said. 'Now draw a man.'
Tom drew a man next to the house. The man was taller than the house, and he had very big hands and very long legs. But the girl liked him.
'Can you draw me now?' she asked.
Tom drew a girl next to the man.
'You draw beautifully. I can't draw pictures.'
'I can teach you,' said Tom. 'After school.'
'Oh, please!'
'What's your name?' Tom asked.
'Becky. Becky Thatcher.'
Just then Tom felt a hand on his head. It was the teacher. He took Tom by the ear and moved him back to his chair in the boys' half of the room.
词汇
aunt n. the sister of your mother or father 姨母;姑母
pocket n. a small bag sewn into or on clothing, for carrying small articles 口袋
in a second in a very short period of time 片刻;瞬间
holiday n. a day or a period when no work needs to be done 假日;休息日
brush n. an object used for painting, cleaning, etc. 刷
子
fence n. usually a wood or wire barrier enclosing an area 栅栏
be good at to be skillful at something or doing something 擅长做某事
laugh at to treat someone or something as if they are stupid, by laughing and making funny remarks about them 嘲笑;取笑run off to suddenly leave a place or person 逃跑
whiskey n. a strong alcoholic drink 威士忌
ghost n. supposed apparition of a dead person or animal; disembodied spirit 鬼;幽灵
meow v. to make the crying sound a cat makes 喵喵叫
empty adj. with nothing in it 空的
stick n. a short slender length of wood 枝条;棍;棒
in front of ahead of; before 在前面
翻译
1.汤姆和他的伙伴们
"汤姆，汤姆，你在哪儿?"
没有人回答。
"这小鬼又跑哪儿去了，等我找到他，我要......"
波莉姨妈看了看床下，然后打开房门向花园望去。
"汤姆!"
她听到身后有动静。一个小男孩儿正要跑过，但是波莉姨妈伸出手把他拦住。
"哈，你在这儿!你的口袋里是什么?"
"什么都没有啊，波莉姨妈。"
"没有!那是个苹果!我看见了。现在听着，汤姆。这些苹果不是给你的，我要--"
"哎，波莉姨妈!快--看你后面!"
波莉姨妈看了一下，汤姆一转眼就跑出了屋子。她轻轻地笑了。"我又没长记性。我爱汤姆，我那死去的姐姐的孩子，但是我这个老太婆管不住他。明天是星期六，不用上学，但是汤姆不能放假。噢不!他明天可得要干活儿!"
* * *
星期六天气不错。夏天到了，艳阳高照，花园里繁花似锦。这是个人人都应该开心的好日子。
汤姆拿着一把刷子和一大桶白油漆从屋里走出来。他看着栅栏，栅栏足足有3米高、30米长。他把刷子蘸上油漆，开始刷栅栏，然后照旧这般。接着，他停了下来，看了看栅栏，放下刷子，坐了下来。他面前是好几个小时的工作呢，他是村庄里最不快乐的男孩儿了。
十分钟后，汤姆想出了一个主意，一个绝妙的主意。他重新把刷子拿起来，开始工作。他看到他的朋友乔·哈珀在街上，但是不去看他。乔手上拿着一个苹果。他走到汤姆面前，看着栅栏。
"我真为你难过，汤姆。"
汤姆不说话，拿着刷子刷上刷下。
"帮你姨妈干活儿呢?"乔问道，"我要去河边。真可惜你不能和我一起去。"
汤姆放下刷子。"你管这叫干活儿?"他说。
"刷栅栏?"乔说，"当然是干活儿啦!"
"也许是，也许不是。但是我喜欢。"汤姆说，"我哪天去河边都成，但并不总是有机会刷栅栏啊。"
乔盯着汤姆看了差不多有五分钟。汤姆非常认真地慢慢刷着油漆。他时不时停下来，后退两步，看着自己的杰作微笑。乔开始感兴趣了，他问道：
"汤姆，我能刷一会儿吗?"
汤姆想了一下。"对不起，乔。你知道吗，我姨妈让我来干这活儿是因为我刷得好。我弟弟锡德也想刷呢，但她不同意。"
"哦，求求你，汤姆，就一点儿成吗?我也刷得挺好的。嗨，你想来点儿我的苹果吗?"
"不行，乔，我不能--"
"好吧，我把整个苹果都给你!"
汤姆把刷子递给乔。他没有笑，但那是他那天第一次非常开心。他坐了下来，吃着乔的苹果。
更多的伙伴过来嘲笑汤姆，但不久他们就都想要刷油漆了。到下午时，汤姆已经有了三个球、一把旧的小刀、一只独眼猫、一个旧的蓝瓶子和其他许多稀奇玩意儿。现在他是圣彼得斯堡最富有的男孩儿了，而那道栅栏--整整30米长的栅栏--被涂上了美丽的白色。他走回屋子。
"波莉姨妈!现在我能出去玩了吗?"
波莉姨妈走出屋来检查，当她看到漂亮的白色栅栏时，非常满意。她把汤姆带回屋里，给了他一个苹果。
"好，你现在可以去玩了，但是别回来得太晚。"
汤姆飞快地又拿了一个苹果，跑出去了。
* * *
星期一的早上，汤姆不想去上学，但是波莉姨妈把他揪下床，丢出了门。在学校附近的街上，他遇到了好朋友哈克贝利·费恩。哈克没有母亲，父亲成天喝酒，所以哈克就露宿街头了。他不上学，总是脏兮兮的，从来没穿过新衣服，但是他很快乐。圣彼得斯堡的妈妈们不喜欢他，但是汤姆和伙伴们都喜欢他。
"你好啊，哈克!"汤姆说，"你那是弄了个什么?"
"一只死猫。"
"你要把它怎么样?"汤姆问。
"我打算今晚把它拿到坟场去。"哈克说，"在午夜的时候，一只死猫能把坟墓里的鬼魂召出来。"
"我从来没听说过。"汤姆说，"是真的吗?"
"哦，我不知道。"哈克说，"是老霍普金斯太太告诉我的。跟我来看看吧，你就能知道了。你不会害怕鬼吧?"
"当然不!"汤姆说，"11点钟到我窗口学猫叫叫我。"
这之后，汤姆上学迟到了，老师生气地看着他。
"托马斯·索亚，你怎么又迟到了?"他说。
汤姆开始讲话，然而又停住了。教室里有个新来的女生--一个有着蓝眼睛、黄色长发的漂亮女孩子。汤姆打量个不停。
哦，她长得多漂亮啊!短短两秒钟内，汤姆恋爱了!他必须坐在她旁边。但怎么做呢?
在女生坐的那半边教室，只有一个空座位，就在那个新来女孩儿旁边。汤姆的脑筋转得飞快，然后他看着老师。
"我停下来和哈克贝利·费恩聊天了!"他说。
老师非常非常气愤。男孩子上学经常迟到，这当然不对，但是和哈克贝利·费恩讲话就更有错，大错特错!老师拿起了教鞭，两分钟后，汤姆的裤子都热辣辣的了，老师的胳膊也累得打不动了。
"现在，汤姆·索亚，你去和女生坐在一起。"
有几个孩子笑了起来。汤姆走到新来的女生旁边的座位，坐下来，把书打开。其他的孩子也重新开始学习。
十分钟后，那女孩儿抬起头。她面前的桌上多了个苹果。她把苹果放回汤姆那边的桌上。很快，苹果又出现在她面前。这一次苹果没被推回去。接下来，汤姆画了一座房子，摆在她面前。
"画得真好。"女孩儿说，"再画个男人吧。"
汤姆在房子旁边画了个男人，人比房子还高，两手大大，双腿长长，但是那女孩儿喜欢。
"你能画个我吗?"她问。
汤姆在男人的旁边加上那女孩儿。
"你画得真漂亮，我就不会画画。"
"我教你吧。"汤姆说，"等放了学。"
"噢，好啊!"
"你叫什么名字?"汤姆问。
"贝姬，贝姬·撒切尔。"
就在这时，汤姆感觉到一只手落到他头上，是老师的手!他拧着汤姆的耳朵，把他拖回到了男生那半边他自己的座位上。
电子信息工程专业课程名称中英文翻译对照 （2009级培养计划）
实践环节翻译 高等数学Advanced Mathematics
大学物理College Physics 线性代数Linear Algebra 复变函数与积分变换Functions of Complex Variable and Integral Transforms 概率论与随机过程Probability and Random Process 物理实验Experiments of College Physics 数理方程Equations of Mathematical Physics 电子信息工程概论Introduction to Electronic and Information Engineering 计算机应用基础Fundamentals of Computer Application 电路原理Principles of Circuit 模拟电子技术基础Fundamentals of Analog Electronics 数字电子技术基础Fundamentals of Digital Electronics C语言程序设计The C Programming Language 信息论基础Fundamentals of Information Theory 信号与线性系统Signals and Linear Systems 微机原理与接口技术Microcomputer Principles and Interface Technology 马克思主义基本原理Fundamentals of Marxism 思想、理论和“三个代表” 重要思想概论 Thoughts of Mao and Deng 中国近现代史纲要Modern Chinese History 思想道德修养与法律基 础 Moral Education & Law Basis 形势与政策Situation and Policy 英语College English 体育Physical Education 当代世界经济与政治Modern Global Economy and Politics 卫生健康教育Health Education 心理健康知识讲座Psychological Health Knowledge Lecture 公共艺术课程Public Arts 文献检索Literature Retrieval 军事理论Military Theory 普通话语音常识及训练Mandarin Knowledge and Training 大学生职业生涯策划 （就业指导） Career Planning (Guidance of Employment ) 专题学术讲座Optional Course Lecture 科技文献写作Sci-tech Document Writing 高频电子线路High-Frequency Electronic Circuits 通信原理Communications Theory 数字信号处理Digital Signal Processing 计算机网络Computer Networks 电磁场与微波技术Electromagnetic Field and Microwave Technology 现代通信技术Modern Communications Technology
1.This electron beam sweeps across each line at a uniform rate，then flies back to scan another line directly below the previous one and so on，until the horizontal lines into which it is desired to break or split the picture have been scanned in the desired sequence． 电子束以均匀的速率扫描每一行，然后飞速返回去扫描下一行，直到把被扫描的图像按所希望的顺序分割成行。 2.The technical possibilities could well exist，therefore，of nation-wide integrated transmission network of high capacity，controlled by computers，interconnected globally by satellite and submarine cable，providing speedy and reliable communications throughout the word 因此，在技术上完全可能实现全国性的集成发送网络。这种网络容量大，由计算机控制，并能通过卫星和海底电缆实现全球互联，提供世界范围的高速、可靠的通信。 3.Transit time is the primary factor which limits the ability of a transistor to operate at high frequency． 渡越时间是限制晶体管高频工作能力的主要因素 4.The intensity of sound is inversely proportional to the square of the distance measured from the source of the sound. 声强与到声源的距离的平方成反比。 5.The attenuation of the filter is nearly constant to within 0.5 dB over the entire frequency band． 该滤波器的衰减近于恒定, 整个频带内的变化在0.5 dB以内。 6.At present, the state of most semiconductor device technology is such that the device design and process technology must be supplemented by screening and inspection procedures, if ultimate device reliability is to be obtained and controlled． 目前, 大多数半导体器件的技术尚未十分完善, 以至若要获得并控制器件最终的可靠性, 就必须辅以筛选和检验, 以弥补设计和工艺技术之不足 7.Bandwidth of transistor amplifiers vary from about 250 MHz in the L band to 1000 MHz in the X band． 晶体管放大器的带宽在L波段约为250 MHz, 在X波段为1000 MHz。 8.The output of the differential amplifier is fed to the circuit’s output stage via an offset-compensation network, which causes the op-amp’s output to center at zero volts. The output stage takes the form of a complementary emitter follower, and provides a low-impedance output. 差动放大级的输出通过一个失调补偿网络与输出级相连, 目的是使运放的输出以0 V为中心。输出级采用互补的射极跟随器的形式以使输出阻抗很低 9.Because of the very high open-loop voltage gain of the op-amp, the output is driven into positive saturation (close to +V) when the sample voltage goes slightly above the reference voltage, and driven into negative saturation (close to-V) when the sample voltage goes slightly below the reference voltage. 由于运放的开环电压增益很高, 当取样电压略高于参考电压时, 输出趋向于正向饱和状态(接近+V)。当取样电压低于参考电压时, 输出趋向于负向饱和状态(接近-V)。 10.If the signal source were direct connected instead of capacitor coupled, there would be a low resistance path from the base to the negative supply line, and this would affect the circuit bias conditions. 如果信号源和电路不是用电容耦合而是直接相连，从基极到负电源线就会一个低阻通路，并且这将影响到电路偏置状态 11.The differential amplifier has a high-impedance (constant-current)“tail”to give it a high input impedance and a high degree of common-mode signal rejection. It also has a high-impedance collector (or drain) load, to give it a large amount of signal-voltage gain (typically about 100 dB). 差动放大极有一个高阻抗的“尾巴”（恒流源）以提供高输入阻抗和对共模信号的深度抑制，同时，它还具有一个高阻抗和集电极或漏极负载以提供高的信号电压增益（典型的数据是100dB). 12.On the other hand, a DC negative-logic system, as in Figure 3.6(b), is one which designates the more negative voltage state of the bit as the 1 level and the more positive as the 0 level. 另一方面, 如图3.6(b)所示, 把比特的较低的电压状态记为1电平, 较高的电压状态记为0电平, 这样的系统称为直流负逻辑系统。 13.For example, to represent the 10 numerals (0, 1, 2, …, 9) and the 26 letters of the English alphabet would require 36
电子技术英文自我介绍带翻译 I am 26 years old,born in shandong province . I was graduated from qingdao university. my major is electronic.and i got my bachelor degree after my graduation in the year of 2003. I spend most of my time on study,i have passed CET4/6 . and i have acquired basic knowledge of my major during my school time. In July 2003, I begin work for a small private company as a technical support engineer in QingDao city.Because I'm capable of more responsibilities, so I decided to change my job. And in August 2004,I left QingDao to BeiJing and worked for a foreign enterprise as a automation software test engineer.Because I want to change my working environment, I'd like to find a job which is more challenging. Morover Motorola is a global company, so I feel I can gain the most from working in this kind of company ennvironment. That is the reason why I come here to compete for this position. I think I'm a good team player and I'm a person of great honesty to others. Also I am able to work under great pressure. 我26岁,出生在山东省。 我毕业于青岛大学。我的专业是电子。我毕业后,我得到了我的学士学位在2003年。
Lesson eight 第八课 Ⅱ.翻译句子，并注意remain和above的词类和词义 2. In this case the voltage applied must remain unchanged. 在这种情况下，那个应用电压必须保持不变 4. If you take 3 from 8, 5 remain. 如果从8中拿走3，剩5. 6. The above property was discovered by Faraday. 法拉第发现以上性质。 8. Lenz states that the self-induced emf impedes any change of current and tends to support the former current value. The above is known as Lenz’s law. 楞茨陈述自感电动势阻止电流的变化而保持先前电流的值。上面就是我们所知的楞 次定律。 Ⅲ.翻译句子，注意some的词义 2. That radio receiver weighs some five kilograms. 那个无线接收器重五公斤。 4. Some element in the substance is not known. 物质中的一些元素是人们不知道的。 Ⅳ.翻译句子，注意句中one 的不同用法和词义。 2. This concept was discussed in Chapter One. 这个概念在第一张讨论过。 4. No one can lift this equipment. 没人能举起这件设备。 6. This chapter will deal with one of the three functions of a turning circuit. 这章我们将介绍螺旋电路三个功能中的一个。 8. Before one studies a system, it is necessary to define and discuss some important terms. 在研究一个系统之前，确定且讨论一些重要的术语是有必要的。 Ⅴ.画出句中的名词从句，说明其种类，并将句子译成汉语。 2. These experiments do not show which particles. 这些实验不能显示他们的粒子结构。 4. The operating point is determined by how much bias is used. 操作要点是被用多少偏压决定的。 6. It is not important how this voltage is produced. 这个电压是怎么产生的并不重要。 8. It may be questioned whether this approach is the best for the physicist. 这种方式最适合于医生可能会被质疑。 10. This ball may be used to determine whether that body is charged. 这个球可能用于检测是否身体是带电的。 12. It is known that charged particles emit electromagnetic waves whenever they are accelerated. 众所周知的当电子被加速他们就会发射电磁波。 14. The value of this factor determines how fast the amplitude of the current
基于单片机控制的光收发器设计 1 引言 在“三网合一”的推动下,光纤到户等光纤接入方案的应用日益广泛。在光进铜退的呼声下,光网络迅速发展。光收发器在光通信中起到光电、电光转换的作用，是光通信必不可少的器件。由于涉及到高速电路设计、精密机械加工和光学设计,光收发器的成本占据了光纤通信系统和的重要部分,而较高的光收发器价格成了制约光纤接入推广的瓶颈。进一步降低光收发器的成本将有利于光接入的应用推广，加快光进铜退的步伐。 光收发器主要由电路部分、光发送组件和光接收组件组成。其中电路部分又包括激光驱动、光接收信号放大和控制部分。目前市场上的光收发器的电路部分使用的是三个专用芯片。一直有公司在研究把激光驱动和接收信号放大电路集成在一个器件上,控制器使用普通的嵌入式处理器的方案。由于只使用一个专用芯片和一个通用芯片，这样就可以大幅降低电路部分的成本。ＰHYWORＫS 公司研制的PＨＹ1０76芯片就是一款这样的芯片。它主要针对1.２５Ｇｂpｓ到２.5Ｇbps的光收发器,具有外围电路简单，控制电路只需要普通的8位单片机就可以实现的特点。本文主要研究了PHY１076 的性能，选择了ATMEL 公司的ATＭEＧA88 单片机进行控制,设计出光收发器样品，并进行了性能测试,最终成功设计了1.25G 光收发器。 ２光收发器设计方案及工作原理讨论 光收发器在发展的过程中,有许多种不同的外形封装。ＳＦＰ(小型化可热插拔光收发一体模块）是目前在5Ｇｂpｓ以下速率中最先进的一种封装形式,具有小型化、可热插拔、功耗小、系统可集成度高以及能够进行数字诊断功能等特点。 本设计中使用激光驱动电路和光接收放大电路集成的PHY１076 作为专用芯片，使用ＡＴＭEL 的AVR 单片机ATＭEGA88 进行控制和实现DDＭ功能,加上相应的TOＳA(光发射组件）,ROSA(光接收组件)和结构件，设计了一款工作在1.25Gｂpｓ传输距离为10km 的ＳFP 光收发器。系统方框图如图1所示：
果粒橙 图解:译文“蓝色” Unit 6 The Principle of PCM PCM原理 Pcm is dependent on three separate operations, sampling, quantizing, and coding. Many different schemes for performing these three functions have evolved during recent years, and we shall describe the main ones. In these descriptions we shall see how a speech channel of telephone quality may be conveyed as a series of amplitude values, each value being represented, that is, coded as a sequence of 8 binary digits. Furthermore, we shall prove that a minimum theoretical sampling frequency of order 6.8 kilohertz(khz) is required to convey a voice channel occupying the range 300 HZ to 3.4 Khz. Practical equipments, however, normally use3 a sampling rate of 8 khz, and if 8-digits per sample value are used, the voice channel becomes represented by a stream of pulses with a repetition rate of 64khz. Fig .1-1 illustrates the sampling, quantizing, and coding processes. PCM的构成依赖于三个环节，即采样、量化和编码。近年来，人们对这三个环节的实现提出了许多不同的方案，我们将对其中的一些主要的方案进行讨论。在这些讨 论中，我们会看到话路中的语声信号是如何转换成幅值序列的，而每个幅值又被编码，即以8位二进制数的序列表示。而且，我们将证明，为了转换频率范围为300HZ— 3.4KHZ的话路信号，理论上最小采样频率须为6.8khz。但是，实际设备通常用8khz 的采样速率，而如果每个样值用8位码的话，则话路是由一个重复速率为64khz的脉 冲流来表示的。图1-1表示了采样、量化、编码的过程。 Reexamination of our simple example shows us that the speech signal of maximum frequency 3.4khz has been represented by a signal of frequency 64khz. However, if only 4-digits per sample value had been used, the quality of transmission would drop, and the repetition rate of the pulses would be reduced to 32khz. Thus the quality of transmission is dependent on the pulse repetition rate, and for digital communication systems these two variables may be interchanged most efficiently. 让我们再研究一下上面提到的简单例子。可以看出，最高频率为3.4khz的话音信号适用64khz的（脉冲流）信号来表示的。但是，如果每个样值中用4位（码）表示，则传输质量会下降，而脉冲的重复速率也将减小到32khz。因而传输质量是取决于脉 冲重复速率的。对于数字通信系统，这两个量之间极明显的互相影响着。 Digital transmission provides a powerful method for overcoming noisy environments. Noise can be introduced into transmission patch in many different ways : perhaps via a nearby lightning strike, the sparking of a car ignition system, or the thermal low-level noise within the communication equipment itself. It is the relationship of the true signal to the noise signal, known as the signal-to-noise ratio, which is of the most interest to the communication engineer.Basically, if the signal is very large compared to the noise level, then a perfect message can take place; however, this is not always the case. For example, the signal received from a
A business survives and thrives on information: information within the organization and information changed with suppliers, customers,and regulators. Moreover, the information needs to be consistent, accessible, and at the right location. We consider information in four forms-voice, data, image, and video-and the implications of distributed requirements. The term voice communications refers primarily to telephone related communications. By far the most common form of communication in any organization and for most personnel is direct telephone conversation. The telephone has been a basic tool of business for decades. Telephone communications has recently been enhanced by a variety of computer-based services, including voice mail and computerized telephone exchange systems. V oice mail provides the ability to send, forward , and reply to voice messages nonsimultaneously , and it has become a cost-efficient tool even for many midsize organizations. It provides saving on answering machines and services as well as more responsive service to customers and suppliers. Advances have also been made in computerized telephone exchange systems, including in-house digital private branch exchanges(PBX) and Centrex systems provided by the local telephone company. These new systems provide a host of features, including call forwarding, call waiting, least-cost routing of long-distance calls, and a variety of accounting and auditing features. The term data communications is sometimes used to refer to virtually any form of information transfer other than voice. It is sometimes convenient to limit this term to information in the form of text(such as reports, memos, and other documents) and numerical data(such as accounting files). The rapid changes in technology have created fresh challenges for management in making effective use of data communications. We will briefly outline the changes in technology in transmission, networks, and communications software that present the manager with new powerful business tools but also the necessity of making choices among complex alternatives. 一个企业生存和蓬勃发展的信息：在改变与供应商，客户和监管机构的组织和信息的信息。此外，对信息的需求是一致的，访问，并在合适的位置。我们认为，在四种形式的语音，数据，图像，视频和分布式需求的影响的信息。 长期的语音通信，主要是指以电话相关的通讯。迄今为止最常见的沟通形式中的任何组织和大多数工作人员是直接的电话交谈。电话已几十年来的基本的业务工具。电话通讯最近已加强各种以计算机为基础的服务，包括语音邮件和程控电话交换系统。语音信箱提供的能力，发送，转发和回复语音邮件nonsimultaneously，它已成为一个成本效益的工具，甚至许多中小型组织。提供节省答录机和服务，以及更快捷的服务客户和供应商。程控电话交换系统，包括内部数字专用分支交换机（PBX）和本地电话公司提供的Centrex系统也取得了进展。这些新系统提供主机的功能，包括呼叫转接，呼叫等待，长途电话的最低成本路由，各种会计和审计功能。 长期的数据通信有时被用来指几乎任何其他信息传输比语音形式。有时可以很方便限制这个术语在文本形式的信息（如报告，备忘录和其他文件）和数字数据（如会计档案）。已创建管理新的挑战，在有效地利用数据通信技术的迅速变化。我们将简要概述在传输技术的变化，网络和通信软件，经理提出新的强大的商业工具，但也使复杂的替代品之间的选择的必要性。
（电子行业企业管理）电子专业中英文词汇翻 译
有功功率activepower 无功功率reactivepower 视在功率apparentpower 功率因数powerfactor 功率因数补偿 power-factorpensation 串联谐振seriesresonance 并联谐振parallelresonance 谐振频率resonancefrequency 频率特性frequencycharacteristic 幅频特性 amplitude-frequencyresponsechar acteristic 相频特性 phase-frequencyresponsecharacte ristic 截止频率cutofffrequency 品质因数qualityfactor 通频带pass-band 带宽bandwidth(BW) 滤波器filter 一阶滤波器first-orderfilter 二阶滤波器second-orderfilter 低通滤波器low-passfilter 高通滤波器high-passfilter 带通滤波器band-passfilter 带阻滤波器band-stopfilter 转移函数transferfunction 波特图Bodediagram 傅立叶级数Fourierseries 三相电路 三相电路three-phasecircuit 三相电源three-phasesource 对称三相电源symmetricalthree-phasesource 对称三相负载symmetricalthree-phaseload 相电压phasevoltage 相电流phasecurrent 线电压linevoltage 线电流linecurrent 三相三线制 three-phasethree-wiresystem 三相四线制 three-phasefour-wiresystem 三相功率three-phasepower 星形连接 starconnection(Y-connection) 三角形连接triangularconnection(D-connectio n,deltaconnection) 中线neutralline 电路的暂态过程分析 暂态transientstate 稳态steadystate 暂态过程，暂态响应transientresponse 换路定理lowofswitch 一阶电路first-ordercircuit 三要素法three-factormethod 时间常数timeconstant 积分电路integratingcircuit 微分电路differentiatingcircuit 磁路与变压器 磁场magneticfield 磁通flux
Unit 12 生物识别技术 Unit 12-1 第一部分：指纹识别 在所有的生物技术中，指纹识别是最早期的一种技术。我们知道，每个人都有自己独特的、不可变更的指纹。指纹是由手指表皮上的一系列峰谷组成的。指纹的独特性是由这些峰谷的形状以及指纹的细节点所决定的。指纹的细节点是指纹局部凸起处的一些特性，这些特性出现在凸起的分叉处或是凸起的截止处。 指纹匹配技术可以被分为两类：基于细节的指纹匹配技术和基于相关性的指纹匹配技术。基于细节的指纹匹配首先要找出细节点，然后在手指上对应出与它们相关的位置，如图12.1所示。但是，使用这种方法存在一些困难。要精确地提取指纹的细节点是很困难的。而且，这种方法不能很好地考虑指纹峰谷的整体形状。基于相关性的指纹匹配技术可以解决部分基于细节的指纹匹配方法存在的问题，但它也存在一些自身的缺陷。基于相关性的匹配技术需要给出已注册过的特征点的精确位置，并且该方法会受图像平移和旋转的影响。 图12.1 基于细节的指纹匹配 基于细节的指纹匹配技术在匹配不同大小的细节模型时（未注册过的）会存在一些问题。指纹上局部的凸起结构不能完全由指纹细节实现特征化。我们可以尝试另一种表达指纹的方法，它可以获得更多的指纹局部信息并且得到固定长度的指纹编码。于是，我们只需要计算两个指纹编码之间的欧几里得距离，匹配过程有望变得相对简单。 研发对于指纹图像中噪声更稳健并能实时提供更高精度的算法是重要的。商用指纹（身份）认证系统对给定的错误接受率要求具有很低的错误拒绝率。在这点上，任何一项简单的技术都很难实现。我们可以从不同的匹配技术中汇总多个证据从而提高系统的总体精确度。在实际应用中，传感器、采集系统、性能随时间的变化是关键因素。为了评价系统性能，我们有必要对少数使用者在一段时间内进行现场试验。 每天我们可以从法医鉴定、出入口控制、驾驶证登记等多个方面的应用中采集并保存大量的指纹。基于指纹的自动识别系统需要把输入的指纹与数据库中大量的指纹进行匹配验证。为了缩短搜索时间、降低计算复杂度，要以准确而一致的方式将这些指纹分类，从而使输入的指纹只需与数据库某一子集中的指纹进行比对。 指纹分类是将指纹划分入多个预定义指纹类型中的一类中的一项技术。这些预定义的指纹类型是由提供索引机制的文献建立的。图12.2表示了不同类型的指纹。它们有螺纹状的、右旋状的、左旋状的、弓形的、帐篷形的。输入指纹首先粗略地被匹配为预定义的类型中的一类，随后，输入指纹仅与这一大类指纹库中的子集作更精细的比较。 图12.2 不同类型的指纹 指纹自动匹配中关键的一步是自动并且可靠地从输入指纹图像中提取出细节。然而，细节提取算法的好坏很大程度上依赖于输入图像质量的好坏。为确保自动指纹识别或确认系统的性能对于不同指纹图像质量具有稳健性，必须在细节提取模块中加入指纹增强算法。快速指纹增强算法能根据对局部指纹脊方向和频率（密度）的估计自适应地改善输入指纹图像中脊和沟结构的清晰度，如图12.3所示。实验证明加入增强算法可以显著增强指纹认证的精度。 图12.3 指纹增强 Unit 12-2 第二部分：说话人辨认介绍 介绍 现代安全系统范围很广, 通常要通过多层系统才能完全被突破。除了标准的锁和警报系统以外，还有很复杂的方法来保护重要资料。其中多数的方法为可以允许或者不允许一个特定人员获取资料——计算机系统必须能够检测出指纹、读取个人眼孔图样、或者确定说话者的真实身份。最后一点是本文讨论的重点——说话人辨认。说话人辨认经常会与其他类似的术语混淆。以下对这些术语的精确定义做出解释。 说话人识别：确定是谁在说话。 说话人辨认：初始情况下不知道说话人是谁，必须在与模板比较后确定说话人的身份。通常会有很多相关的模板。 说话人确认：确定说话者是否就是他（她）自称的那个人。仅将说话者的话音与一个样板进行比对，即他（她）自称的那一个。 语音识别：识别出人们说话时的语句。换句话说，识别出一个人在说什么而不是谁在说话。这个术语经常与声音识别相混淆。声音识别是识别出说话人。
一．电子元器件Electronic Components 1．保险元器件safety device （1）保险丝座 fuse block （2）电流保险丝 current fuse （3）其他保险元器件 other （4）温度保险丝 temperature fuse （5）温度开关 temperature switches （6）自恢复熔断器since the resumption of fuse 2. 变频器transducer （1）PLC 变频器 PLC transducer （2）高性能通用变频器High-performance Universal transducer （3）恒功率变频器Constant Power Inverter （4）恒转矩变频器Constant Torque converter （5）专用变频器Exclusive Inverter 3.变压器transformer （1）电源变压器Power Transformer （2）隔离变压器the isolation transformer （3）恒压变压器constant voltage transformer （4）脉冲变压器pulse transformer （5）其他变压器other transformers （6）音频变压器Audio transformers （7）自耦变压器autotransformer （8）耦合变压器coupling transformer 4.场效应管voltage controller 5. 传感器sensor （1）电磁传感器Power Transformer （2）光电传感器Photoelectric Sensors （3）光纤传感器Fiber Optic Sensors （4）加速度传感器Accelerometer （5）接近传感器Proximity sensor （6）料位、液位传感器Level, liquid level sensor （7）压力传感器Pressure Sensor （8）振动传感器Vibration Sensor （9）气体传感器Gas Sensor （10）声波传感器Acoustic sensor （11）视觉、图像传感器Visual, image sensor （12）水分、湿度传感器Moisture and humidity sensor （13）位移传感器Displacement sensor （14）敏感元件传感器Sensor sensor 6.传声器microphone 7.电容器capacitor （1）玻璃电容器Glass capacitors （2）玻璃釉电容器Glazed glass capacitors （3）复合介质电容器Composite Dielectric Capacitors
第一单元元件与定律 A．课文译文 电阻器、电容器和电感器 在电子电路中，电阻器、电容器和电感器是非常重要的元件。 电阻器和电阻 电阻器是二端口元件。电阻是阻止电流流动，更确切地说，是阻止电荷流动的能力。在国际单位制中，电阻用欧姆来度量。希腊字母Ω是欧姆的标准符号。较大的电阻一般用千欧和兆欧来表示。 模拟这种特性常用的电路元件是电阻器。图1.1表示电阻器的电路符号，R表示电阻器的电阻值。 图1.1 电阻器的电路符号 为了进行电路分析，我们必须在电阻器中指明电流和电压的参考方向。如果我们选择关联参考方向，那么电压和电流之间的关系是： v=iR(1.1) 这里v是电压，其单位是伏特，i是电流，其单位是安培，R是电阻，其单位是欧姆。 如果选择非关联参考方向，我们必须写成： v=－iR(1.2) 用在公式（1.1）和（1.2）中的代数式就是著名的欧姆定律。欧姆定律表示了电压作为电流的函数。然而，要表示电流是电压的函数也是非常方便的。欧姆定律是电阻两端的电压和电流间的代数关系。 电容器和电容 电能可以存储在电场中，存储电能的装置叫电容器。电容器存储电能的能力叫做电容。图1.2表示电容器的电路符号。电容的电路参数用字母C表示，用法拉来度量。因为法拉是相当大的电容量，实际上电容值通常位于皮法和微法之间。 图1.2 电容器的电路符号
当电压随时间变化时，电荷的位移也随时间变化，引起了众所周知的位移电流。在终端，位移电流和传导电流没有区别。当电流参考方向和电压参考方向是关联参考方向时，电流正比于电容两端电压随时间的变化率的数学表达式为： dt dv C i = (1.3) 这里 i 的单位是安培，C 的单位是法拉，v 的单位是伏特， t 的单位是秒。 电感器和电感 众所周知，电感是电子电路中的模块之一。所有的线圈都有电感。电感是抵抗流过线圈电流的任何变化的性质。电感用字母L 表示，其单位是亨利。 图1.3表示一个电感器。 图1.3 电感器的电路符号 当电流和电压的参考方向关联时，有 dt di L v = (1.4) 这里v 的单位是伏特，L 的单位是亨利，i 的单位是安培，t 的单位是秒。 由公式（1.4）显示电感器两端电压与电感器中电流随时间的变化率成正比。在此，我们可以得到两条重要的结论：第一，如果电流是常数，理想电感器的端电压为0，这样电感器在恒量或直流中可以当作短路；第二，在电感器中电流不能瞬时变化，也就是说，在0时间内电流不能以有限量改变。电感器和电容器一样，存储供给它的能量，但是它是以磁场的形式而不是以电场的形式存储能量。 习题答案 I ． 1. two-terminal element 二端口元件 2. associated reference direction 关联参考方向 3. Ohm ’s Law 欧姆定律 4. electric field 电场 5. displacement current 转移电流 6. short circuit 短路 7. magnetic field 磁场 8. conduction current 传导电流 II. 1. capacitance 2. capacitor 3. resistance 4. resistor 5. Inductance 6. Inductor III.