单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,专业英语,主讲：石翠萍,专业英语主讲：石翠萍,1,Unit1 科技英语基础知识 Unit8 Data Communications,Unit2 Electrical Technique Unit9 3rd Generation Mobile,Unit3 Microelectronics Communications,Unit4 Electronic Communications Unit10 Images and Televisions,Unit5 Digital modulation Unit11 Optical Fiber,Unit6 Digital Signal Processing Communication,Unit 12 Modern Switching,Technique,Unit,7 ISDN,Unit1 科技英语基础知识,2,Unit 1 科技英语基础知识,1.1 科技英语的特点,复杂长句多,将其分解为适当数目的简单分句，使之简化。,例1.The 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.,可将其分解为：,beam sweeps each line.,then flies back to scan another line.,it is desired to break picture into lines in desired sequence.,Unit 1 科技英语基础知识1.1 科技英语的特点复杂长,3,例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 world.,该句的骨架是：The possibilities of network could exist.,例2.The technical possibilities,4,被动语态多,科技英语为了避免主观性和个人色彩，常用被动语态。译时可译为“被”、“经过”、“受了”、“由于“等。,例3 A database may,be designed,for batch processing,real-time processing,or in-line processing.,例4 If we consider binary transmission,the complete information about a particular message,will always be obtained,by simply detecting the presence or absence of pulse.,被动语态多科技英语为了避免主观性和个人色彩，常用被动语态。译,5,例5 Noise,can be introduced,into transmission path in many different ways,perhaps via a nearby lighting strike,the sparking of a car ignition system,or the thermal low-level noise within the communication equipment itself.,Lighting strike 照明,Ignition system 点火系统,thermal noise 热噪声,例5 Noise can be introduced in,6,非谓语动词多,英语语法要求，每个简单句只能有一个动词。如果有几个动作，则选出一个主要动作当谓语，其余动作用非谓语动词表示。,非谓语动词,动名词,分词（包括现在分词和过去分词）,不定式,非谓语动词多英语语法要求，每个简单句只能有一个动词。如果有几,7,例6 To be a true professional,requires,lifelong learning.,例7 Heating water does not,change,its chemical composition.,例6 To be a true professional,8,词性转换多,英语单词中有不少是多性词：既是名词，又可作动词、形容词、介词等。,如：current,adj 当前的,n 电流,determinant,adj 确定的,n 行列式,potential,adj 潜在的,n 电位,词性转换多英语单词中有不少是多性词：既是名词，又可作动词、形,9,多是论述性问题，感情色彩淡,句子力求简单严谨，因此常用省略手法和图表表示法,词语力求短小精悍，常用复合词,文章力求层次分明，多用连接词,用词较正规，多为技术性用词,多是论述性问题，感情色彩淡句子力求简单严谨，因此常用省略手法,10,1.2 词汇,词汇,普通词汇,专业词汇,缩写词汇,转义词汇,虚义词,1.2 词汇词汇普通词汇专业词汇缩写词汇转义词汇虚义词,11,常用专业词汇,electron,diode,transistor,field-effect transistor(FET),oscillator,radio,anode,cathode,电子,二极管,晶体管,场效应晶体管,振荡器,无线电通信（接收装置）,阳极,阴极,triode,三极管,常用专业词汇electrondiodetransistorf,12,Ohms law,amplifier,microprocessor,impedance,electromagnetic wave,resonant frequency,phase-shift keying(PSK),modem,codec,欧姆定律,放大器,微处理器,阻抗,电磁波,共振频率,调制解调器,相移键控,编解码器,Ohms lawamplifiermicroprocess,13,Nyquist rate,Rayleigh fading,transceiver,serial data,transmission,electromagnetic carrier,multi-access,root mean square,asynchronous transmission,奈奎斯特率,瑞利衰落,收发器,串行数据,传输,电磁载波,均方根,异步传输,多路存取的,Nyquist rateRayleigh fadingtra,14,radio frequencies(RF),electrical-optical conversion,optical carrier,analog modulation,frequency spectrum,radio-relay transmission,packet switching,fixed telephone service,spectrum allocation,射频,电光转换,光载波,模拟调制,频谱,无线电中继传输,分组交换,固定电话服务,频谱分配,radio frequencies(RF)electrica,15,handover,frequency hopped,multi-path fading,ring network,bus network,gateway,移交,跳频,多径衰落,环网,总线网络,网关,handoverfrequency hoppedmulti-,16,常用转义词汇,转义词 普通含义 专业含义,resistance 阻力，抵抗 电阻（值）,charge 起诉，负责 电荷；充电,relay 接转，接力 中继器,field 田野，范围 （电、磁）场,filter 过滤器，漏斗 滤波器,rectifier 修正者 整流器,regulator 调整者 稳压器,filp-flop 后手翻 触发器,常用转义词汇 转义词,17,常用缩写词汇,如AC,A/D，ADC,D/A 等。,常用缩写词汇如AC,A/D，ADC,D/A 等。,18,虚义词,例：The electrons,as,shown in Fig.5,are very light.,如图5所示，电子非常轻。（as引导主语定语）,例：The current increases,as,the voltage does.,电流随电压的增大而增大（as 表示伴随）,或：电流就像电压那样增大（as 表示比较）,例：The circuit，,while,it contains some nonlinear devices，can be considered linear.,尽管这个电路包含一些非线性器件，但它仍可看做是线性的。（while引导让步从句）,虚义词例：The electrons,as shown i,19,例：,For,all its great size,the machine moves noiselessly.,尽管体积大，但该机器的运转噪声很小。（for引导让步短语）,例：For all its great size,the,20,1.3 虚拟语气,科技文写作中常用的虚拟语气形式有以下几种：,（1）条件式,1）涉及现在或将来的情况。,从句用一般过去时，主句用过去将来时,。,例：If there,were,no gravitation,everything,would fly,off the earth into space.,2)涉及过去的情况。,从句用过去完成时，主句用过去将来完成时,。,例：If，this method,had been adopted,(at that time),much time,would have been saved,.,1.3 虚拟语气科技文写作中常用的虚拟语气形式有以下几种：,21,（2）出现在某些主语从句、宾语从句、表语从句和同位语从句中的情况。,1）在主语从句中,例：It is desired that the switch,(should)produce,only one clock pulse each time it is closed.,例：It is not necessary that the primary,be suddenly connected or disconnected,.,2）在宾语从句中,例：This requires that the transistor,(should)be properly biased,.,（2）出现在某些主语从句、宾语从句、表语从句和同位语从句中的,22,1.4 翻译的技巧,多义词的含义选择常是正确翻译的难点，需根据上下文判断。,多注意翻译中语言顺序的变换。,例：Transit time is the primary factor which limits the ability of a transistor to,operate,at high frequency.,例：In a transistor th