查询词典 computer system

It includes four parts: 1 Part I, it introduces the basic knowledge of computer viruses such as computer virus definition, history and important viruses events, features, behavior phenomena, difference with computer software and hardware troubles, damage behavior and capability, classification, naming, future trend, etc; 2 Part II, it introduces the corresponding knowledge of computer systems related to computer viruses such as the composing of software and hardware of the computer system, storage media and its working mechanism, interrupt technologies,.com/.exe/.pe file formats and their working mechanism, etc; 3 Part III, it introduces computer virus mechanism and theory such as computer virus structure, work flow, working mechanism of key modules, typical technologies used to design computer viruses including the corresponding traditional technologies (interrupt filching, memory resident, etc.), the corresponding new routine technologies (self-encrypting, Mutation Engine, etc.), and the corresponding new technologies used by some prevalence computer viruses such as macro viruses, e-mail viruses, worm, hacker, Trojan, mobile phone viruses, the working mechanism analysis of some kinds of typical and prevalence computer viruses such as file-type viruses, macro viruses, e-mail viruses, worm viruses, hacker, Trojan, mobile phone viruses, the analysis of some typical and prevalence computer viruses examples including BALL viruses, WORD macro viruses, WantJob viruses, Code Red viruses, BO Trojan, etc; 4 Part IV, it introduces the defense and killing technologies of computer viruses such as the aim and criterion of computer viruses defense and killing, prevention methods and corresponding technologies, detection technologies (comparison method, character code scanning method, behavior inspecting method, analysis method, etc.), manual and automatic killing technologies, immunity technologies such as IBM digital immunity system, new anti-viruses technology trends (real-time anti-viruses technologies, 32 kernel technologies, active kernel technologies, etc.), some typical virus defense and killing softwares (Symantec AntiVirus product, PC-Cillin AntiVirus product, etc.), the defense and killing method analysis of some kinds of typical and prevalence computer viruses (file-type viruses, macro viruses, worm viruses, hacker, etc.), for example, firewall and intrusion detection technologies for anti-hacker, the defense and killing of some typical and prevalence computer viruses examples including WORD macro viruses, Code Red viruses, BO Trojan, etc.

课程内容具体包括四大部分：1）第一部分，介绍计算机病毒基本知识，包括：计算机病毒定义、病毒发展史及重大事件、病毒特点、病毒表现现象及与软硬件故障的区别、病毒破坏行为及危害性、病毒的传播途径及媒介、病毒分类、病毒的命名及计算机病毒技术发展趋势等内容；2）第二部分，介绍与计算机病毒有关的计算机系统相关知识，包括：计算机系统软硬件组成、存储介质结构及工作原理、计算机系统引导机理及流程、中断技术、。com/。exe/。pe等文件格式及工作机理等内容；3）第三部分，讲解计算机病毒机理，包括：计算机病毒的组成结构、病毒工作流程、病毒引导/触发/感染/破坏等模块的工作机理、计算机病毒所采取的编制技术（包括中断窃取/内存驻留等传统编制技术、自加密/隐形/变形机等新的常规编制技术、宏病毒/电子邮件病毒/网络蠕虫/特洛伊木马/黑客/手机病毒等一些新的流行病毒所采取的编制技术等）、一些类型的典型或流行计算机病毒的工作机理分析（包括：引导型病毒、文件型病毒、宏病毒、电子邮件病毒、蠕虫病毒、黑客、特洛伊木马、手机病毒等）、一些典型或流行的计算机病毒实例剖析（包括：小球病毒、WORD宏病毒、求职信病毒、红色代码病毒、冰河木马等）等内容；4）第四部分，讲解计算机病毒防治技术，包括：计算机病毒防治目的、病毒防治策略及规范、病毒在管理和技术上的预防措施、病毒检查技术（包括：比较法/病毒特征码扫描法/行为监测法/虚拟执行法/分析法等）、手工和自动病毒清杀技术、病毒免疫技术（包括：针对某种一次性感染病毒的基于病毒标签的免疫方法/基于自我完整性检查的计算机病毒免疫方法/IBM的数字免疫系统等）、反病毒技术的新发展（包括：实时反病毒技术/32位内核技术/主动内核技术/以毒攻毒技术等）、诺顿/趋势/金山等公司的病毒防治软件产品、一些类型的典型或流行的计算机病毒（包括：引导型病毒、文件型病毒、宏病毒、蠕虫病毒、电子邮件病毒、手机病毒、黑客、特洛伊木马）的防治措施（其中，也包括介绍面向防范黑客攻击的防火墙、入侵检测技术）、一些典型或流行的计算机病毒防治实例剖析（包括：WORD宏病毒、红色代码病毒、冰河木马v1.1/v2.2等）、多层次病毒防护体系等内容。

Shanghai principle light software company Respective profession: Computer software Software test software engineer Mainly is engaged in the printer driver the test The Shanghai negotiable securities Times panoram network sponsor network starts off develops Respective profession: Computer software Does not have other The road develops the personnel Education experience Shanghai electrical machinery institute computer application technical college Programming language - familiar C, object-oriented language and so on programming C++, VB, java, assembly Computer network - computer network principle, website construction and maintenance Database - Access Computer application - computer assembly and service, construction of data The operating system - skilled grasps the Windows all operating system, has the certain foundation to Linux Charting - Auto CAD intermediate, PhotoShop, Flash, multimedia technical Authorware The science and technology manages the school computer application specialized middle school Computer network technology, computer composition principle, visible programming VB, Computer operation system, computer operation technology, homepage manufacture, network security, Computer system maintenance, microcomputer principle and assembly language, office automation and so on.

上海理光软件公司所属行业：计算机软件软件测试软件工程师主要从事打印机驱动程序的测试上海证券时报全景网络主办网上路演所属行业：计算机软件无其他路演人员教育经历上海电机学院计算机应用大专编程语言——熟悉C，面向对象程序设计C++、VB、java、汇编等语言计算机网络——计算机网络原理、网站建设与维护数据库——Access 计算机应用——计算机组装与维修、数据结构操作系统——熟练掌握Windows所有操作系统、对Linux有一定基础制图——Auto CAD中级、PhotoShop、Flash、多媒体技术Authorware科技管理学校计算机应用中专计算机网络技术，计算机组成原理，可视化程序设计VB，计算机操作系统，计算机操作技术，网页制作，网络安全，计算机系统维护，微机原理和汇编语言，办公自动化等等。

To be able to grasp more opportunities for sex crimes at the same time the relatively high use of three-station configuration, to operate a computer, here are divided into A Computer, B Computer and C computers, computer A computer-based operations, the main task is to buy and sell orders operations and holdings of individual stocks that have been tracked so that the best point and fled the country, late in the day or night, werewolves are the technical stock selection, with the potential to become a dark horse, or it is possible to start the second Stock elected, put into the C computer Optional Share Lane, B computer is a laptop, while wirelessly with a broadband connection, broadband and sometimes dropped to avoid or segment of electricity causes can not be traded, the general cases, the task of the computer B is always concerned about the A shares and Hong Kong stock market trend in broader market, in the opening period of time, C is Optional Share computer display, and interface options with the four shares of K-line column, and set to automatically turn the industry, so that If the C Optional Share computer technology, there are individual stocks will soon reach the selling points, werewolves can be found in the first time and simultaneously enter the code in the A computer, using keyboard shortcuts with the fastest speed for the next single!

为了能够把握更多的机会，狼人同时运用3台配置相对较高的电脑进行操作，这里分为A电脑、B电脑和C电脑，其中A电脑为主操作电脑，主要任务就是进行买卖下单操作和对已经持有的个股进行跟踪，以便在最佳点位出逃，在每天的盘后或者是晚上，狼人都会进行技术选股，把有可能成为黑马或者是有可能二次启动的股票选出，放入到C电脑的自选股里，B电脑是笔记本，同时以无线方式与宽带连接，避免了有时宽带掉线或者是段电的原因造成无法进行交易，一般情况下B电脑的任务是随时关注A股大盘和港股大盘走势，在开盘的时间内， C电脑显示为自选股，同时界面上选择4股K线同列，并设置为自动翻业，这样，如果在C电脑的自选股中有个股即将到达技术买点，狼人可以在第一时间发现并同时在A电脑中输入代码，使用键盘快捷方式以最快速度进行下单！

Spyware is a kind of software that installed in computer user's computer, it installed by spyware user without computer user's consentment or although spyware user get computer user's consentment but the function of spyware is beyond the function which spyware user tell during the installment ,or use a fraud tell manner to tell the computer user, or force the spyware run , or dosen't offer computer user a method that can easily and fully uninstall all the module of the software ,and its function s are as follow: control、destroy computer software and hardware; force computer's behavior; scout computer user's behavior, steal or cheat computer user's private information.

间谍软件是指安装在用户计算机上的程序，此程序的安装未经用户的同意，或虽经用户的同意但超出了告知的功能范围，或采用欺诈的方式征得用户的同意，或者强行运行，或者不能简便地一次性彻底卸载所有功能模块；并且其具有如下功能：控制、破坏用户计算机软硬件；强制用户行为；监视用户行为、盗窃或以欺诈的形式骗取用户信息。

Concept; In 1989 GRiD Corporation promoted first section to havetouches the type screen then to take along the computer; In 1992,Microsoft has promoted "Windows for Pen", after but two years sufferthe elimination; In 1996 Palm developed the first section successapplication to touch the pen type computer; In 1997 Oracle joinedMicrosoft the ranks to start to study the dull technology; 2000 is oneof plate computer important turning points, Bill Gates starts by 2000,continuously at in two session of Comdex congress speech vigorouslyinitiates the plate computer; In 2002, in plate computer history amost important year, also is a year which most bustles about,This year in May, Gates brings 150 plates computers to attend theMicrosoft year CEO summit, meets in August, plate computer software isbeing open to the computer manufacturer, follows closely in November,the plate computer officially is going on the market, seven bigcomputers manufacturers develop this new product, in December theplate computer Chinese edition goes on the market.

概念；1989年GRiD公司推出第一款带有触摸式屏幕的便携电脑；1992年，微软推出了"Windows for Pen"，但两年后遭淘汰；1996年Palm研制出第一款成功应用的触笔式电脑；1997年Oracle加入微软的行列开始研究平板技术；2000年是平板电脑的重要转折点之一，比尔盖茨由2000年开始，连续两届Comdex大会上的讲话中大力倡导平板电脑；2002年，平板电脑发展史上最重要的一年，也是最忙碌的一年，该年5月，盖茨带着150台平板电脑参加微软年度CEO峰会，接着8月份，平板电脑软件向电脑制造商开放，紧接着在11月份，平板电脑正式上市，七大电脑制造商开发这一新产品，12月平板电脑中文版上市。

Network project construction, network monitor system, computer hardware maintenance, computer software, commercial POS several machine maintenance and repair, the LED screen machine maintenance, networking, ADSL VLAN and VPN connections, network cabling system design, network integrated wiring, residential network cabinet design and construction, computer peripheral equipment maintenance, computer data backup and restore, computer hardware upgrades, various kinds of commercial bill printer, intelligent arrangement system, a computer virus clearing installation, EXCEL, WINDOWS server system, WINDOWS server installation and sales system, data server SQL server data to create WEB server FPT data, E-mail, E - the server, AutoCAD drawings.

网络工程策划，网络工程施工，网络监控系统，电脑硬件维护，电脑软件恢复，商用POS几机修复，LED大屏维修，触摸屏机维护，VLAN网络互连，ADSL与VPN系统连接，网络综合布线设计，网络综合机柜配线，住宅网络设计与施工，电脑周边设备维护，电脑数据备份与恢复，电脑各类硬件升级，商用各类票据打印机，智能排列系统安装，电脑病毒清除方案，EXCEL服务器开发，WINDOWS系统恢复，WINDOWS服务器安装，图书销售系统，SQL数据服务器创建，WEB数据服务器开发，FPT数据服务器开发，E—mail服务器开发，AutoCAD图纸设计。

Equipment: 2 meters in diameter has a film blowing machine Units 1, 1 m film blowing machine 2 Units, 800-type film blowing machine 2 Units, 600 Units 5 film blowing machine, film blowing machine 400 Units 8, self-styled pocket machine 2 Units , bubble machine BAG 3 Units, 1000-type computer high-speed 8-color printing press 1, 800 computer-based 6-color press 2 Units, 600 computer-based 6-color press 2 Units, 600 2-color presses 5 Units, 600 single - Units 6 color printing press, 800-type compound machine 2 Units, 600-type compound machine 2 Units, 600 Units 2 computer triangular closure .600 PC .600 scalding machine 10 Units self-sealing machine hot computer 2 Units, 600-type computer hot bubble bag machine 3 Units, 1000 Units 1 computer perm machine perm machine .800 PC .600 Units 1 type bag machine automatic hot computer 3 Units, 3 Units polypropylene film blowing machine, poly bag machine hot 20 Units, contraction Film Blown Machine 2 Units, hot shrink film machine 12 Units, demolition machine, in closing down the machines, machine, granulating machine, grinder of the Units 1, as well as other equipment and so on

拥有2米直径吹膜机1台，1米吹膜机2台，800型吹膜机2台，600型吹膜机5台，400型吹膜机8台，自封口袋机2台，气泡袋机3台，1000型电脑8色高速印刷机1台，800型电脑6色印刷机2台，600型电脑6色印刷机2台，600型2色印刷机5台，600型单色印刷机6台，800型复合机2台，600型复合机2台，600型电脑三边封2台。600型电脑烫机10台。600型自封口电脑烫机2台，600型电脑气泡袋烫机3台，1000型电脑烫机1台。800型电脑烫机1台。600型手提袋全自动电脑烫机3台，聚丙吹膜机3台，聚丙袋烫机20台，收缩膜吹膜机2台，收缩膜烫机12台，拆边机，中封机，分切机，造粒机，粉碎机各一台，还有其它设备等等

PART 1 UNIT 1 B Electrical and Electronic Engineering Basics A Electrical Networks ———————————— 3 Three-phase Circuits A The Operational Amplifier ——————————— 5 UNIT 2 B Transistors A Logical Variables and Flip-flop —————————— 8 UNIT 3 B Binary Number System A Power Semiconductor Devices —————————— 11 UNIT 4 B Power Electronic Converters A Types of DC Motors —————————————15 UNIT 5 B Closed-loop Control of DC Drivers A AC Machines ———————————————19 UNIT 6 B Induction Motor Drive A Electric Power System ————————————22 UNIT 7 B PART 2 UNIT 1 B Power System Automation Control Theory A The World of Control ————————————27 —————29 The Transfer Function and the Laplace Transformation UNIT 2 B A Stability and the Time Response ————————— 30 Steady State————————————————— 31 A The Root Locus ————————————— 32 ————— 33 UNIT 3 B The Frequency Response Methods: Nyquist Diagrams UNIT 4 A The Frequency Response Methods: Bode Piots ————— 34 B Nonlinear Control System 37 UNIT 5 A Introduction to Modern Control Theory B State Equations 40 38 UNIT 6 A Controllability, Observability, and Stability B Optimum Control Systems UNIT 7 A Conventional and Intelligent Control B Artificial Neural Network Computer Control Technology A Computer Structure and Function 42 B Fundamentals of Computer and Networks 43 44 PART 3 UNIT 1 UNIT 2 A Interfaces to External Signals and Devices B The Applications of Computers 46 UNIT 3 A PLC Overview B PACs for Industrial Control, the Future of Control UNIT 4 A Fundamentals of Single-chip Microcomputer 49 B Understanding DSP and Its Uses 1 UNIT 5 A A First Look at Embedded Systems B Embedded Systems Design Process Control A A Process Control System B 50 PART 4 UNIT 1 Fundamentals of Process Control 52 53 UNIT 2 A Sensors and Transmitters B Final Control Elements and Controllers UNIT 3 A P Controllers and PI Controllers B PID Controllers and Other Controllers UNIT 4 A Indicating Instruments B Control Panels Control Based on Network and Information A Automation Networking Application Areas B Evolution of Control System Architecture PART 5 UNIT 1 UNIT 2 A Fundamental Issues in Networked Control Systems B Stability of NCSs with Network-induced Delay UNIT 3 A Fundamentals of the Database System B Virtual Manufacturing—A Growing Trend in Automation UNIT 4 A Concepts of Computer Integrated Manufacturing B Enterprise Resources Planning and Beyond Synthetic Applications of Automatic Technology A Recent Advances and Future Trends in Electrical Machine Drivers B System Evolution in Intelligent Buildings PART 6 UNIT 1 UNIT 2 A Industrial Robot B A General Introduction to Pattern Recognition UNIT 3 A Renewable Energy B Electric Vehicles UNIT 1 A

电路 2 电路或电网络由以某种方式连接的电阻器，电感器和电容器等元件组成。如果网络不包含能源，如电池或发电机，那么就被称作无源网络。换句话说，如果存在一个或多个能源，那么组合的结果为有源网络。在研究电网络的特性时，我们感兴趣的是确定电路中的电压和电流。因为网络由无源电路元件组成，所以必须首先定义这些元件的电特性。就电阻来说，电压-电流的关系由欧姆定律给出，欧姆定律指出：电阻两端的电压等于电阻上流过的电流乘以电阻值。在数学上表达为： u=iR (1-1A-1)式中 u=电压，伏特；i =电流，安培；R =电阻，欧姆。纯电感电压由法拉第定律定义，法拉第定律指出：电感两端的电压正比于流过电感的电流随时间的变化率。因此可得到：U=Ldi/dt 式中 di/dt =电流变化率，安培/秒； L =感应系数，享利。电容两端建立的电压正比于电容两极板上积累的电荷 q 。因为电荷的积累可表示为电荷增量 dq 的和或积分，因此得到的等式为 u=，式中电容量 C 是与电压和电荷相关的比例常数。由定义可知，电流等于电荷随时间的变化率，可表示为 i = dq/dt。因此电荷增量 dq 等于电流乘以相应的时间增量，或 dq = i dt，那么等式(1-1A-3)可写为式中 C =电容量，法拉。

PART 1 Electrical and Electronic Engineering Basics UNIT 1 A Electrical Networks B Three-phase Circuits UNIT 2 A The Operational Amplifier ——————————— 5 B Transistors UNIT 3 A Logical Variables and Flip-flop —————————— 8 ———————————— 3 B Binary Number System UNIT 4 A Power Semiconductor Devices —————————— 11 B Power Electronic Converters UNIT 5 A Types of DC Motors —————————————15 B Closed-loop Control of DC Drivers UNIT 6 A AC Machines ———————————————19 B Induction Motor Drive UNIT 7 A Electric Power System ————————————22 B Power System Automation PART 2 Control Theory UNIT 1 A The World of Control ————————————27 B The Transfer Function and the Laplace Transformation UNIT 2 A B —————29 Stability and the Time Response ————————— 30 ————————————— 32 Steady State————————————————— 31 UNIT 3 A The Root Locus B The Frequency Response Methods: Nyquist Diagrams ————— 33 UNIT 4 A The Frequency Response Methods: Bode Piots ————— 34 B Nonlinear Control System 37 UNIT 5 A Introduction to Modern Control Theory B UNIT 6 State Equations 40 38 A Controllability, Observability, and Stability B Optimum Control Systems UNIT 7 A Conventional and Intelligent Control B Artificial Neural Network PART 3 UNIT 1 Computer Control Technology A Computer Structure and Function B 42 43 44 Fundamentals of Computer and Networks UNIT 2 A Interfaces to External Signals and Devices B The Applications of Computers 46 UNIT 3 A PLC Overview B PACs for Industrial Control, the Future of Control 1 UNIT 4 A Fundamentals of Single-chip Microcomputer B Understanding DSP and Its Uses 49 UNIT 5 A A First Look at Embedded Systems B Embedded Systems Design PART 4 UNIT 1 Process Control A A Process Control System 50 B Fundamentals of Process Control 53 52 UNIT 2 A Sensors and Transmitters B Final Control Elements and Controllers UNIT 3 A P Controllers and PI Controllers B PID Controllers and Other Controllers UNIT 4 A Indicating Instruments B Control Panels PART 5 UNIT 1 Control Based on Network and Information A Automation Networking Application Areas B Evolution of Control System Architecture UNIT 2 A Fundamental Issues in Networked Control Systems B Stability of NCSs with Network-induced Delay UNIT 3 A Fundamentals of the Database System B Virtual Manufacturing—A Growing Trend in Automation UNIT 4 A Concepts of Computer Integrated Manufacturing B Enterprise Resources Planning and Beyond PART 6 UNIT 1 Synthetic Applications of Automatic Technology A Recent Advances and Future Trends in Electrical Machine Drivers B System Evolution in Intelligent Buildings UNIT 2 A Industrial Robot B A General Introduction to Pattern Recognition UNIT 3 A Renewable Energy B Electric Vehicles 2 UNIT 1 A

电路 电路或电网络由以某种方式连接的电阻器，电感器和电容器等元件组成。如果网络不包含能源，如电池或发电机，那么就被称作无源网络。换句话说，如果存在一个或多个能源，那么组合的结果为有源网络。在研究电网络的特性时，我们感兴趣的是确定电路中的电压和电流。因为网络由无源电路元件组成，所以必须首先定义这些元件的电特性。就电阻来说，电压-电流的关系由欧姆定律给出，欧姆定律指出：电阻两端的电压等于电阻上流过的电流乘以电阻值。在数学上表达为： u=iR (1-1A-1)式中 u=电压，伏特；i =电流，安培；R =电阻，欧姆。纯电感电压由法拉第定律定义，法拉第定律指出：电感两端的电压正比于流过电感的电流随时间的变化率。因此可得到：U=Ldi/dt 式中 di/dt =电流变化率，安培/秒； L =感应系数，享利。电容两端建立的电压正比于电容两极板上积累的电荷 q 。因为电荷的积累可表示为电荷增量 dq 的和或积分，因此得到的等式为 u=，式中电容量 C 是与电压和电荷相关的比例常数。由定义可知，电流等于电荷随时间的变化率，可表示为 i = dq/dt。因此电荷增量 dq 等于电流乘以相应的时间增量，或 dq = i dt，那么等式(1-1A-3)可写为式中 C =电容量，法拉。

PART 1 Electrical and Electronic Engineering Basics UNIT 1 A UNIT 2 A UNIT 3 A UNIT 4 A UNIT 5 A UNIT 6 A UNIT 7 A Electrical Networks ———————————— 3 B Three-phase Circuits The Operational Amplifier ——————————— 5 Logical Variables and Flip-flop —————————— 8 Power Semiconductor Devices —————————— 11 Types of DC Motors —————————————15 AC Machines ———————————————19 Electric Power System ————————————22 B Transistors B Binary Number System B Power Electronic Converters B Closed-loop Control of DC Drivers B Induction Motor Drive B Power System Automation PART 2 Control Theory UNIT 1 A B UNIT 2 A UNIT 3 A UNIT 4 A The World of Control ————————————27 Stability and the Time Response ————————— 30 The Root Locus ————————————— 32 The Transfer Function and the Laplace Transformation —————29 B Steady State————————————————— 31 B The Frequency Response Methods: Nyquist Diagrams ————— 33 The Frequency Response Methods: Bode Piots ————— 34 B Nonlinear Control System 37 UNIT 5 A Introduction to Modern Control Theory B B B PART 3 B B B State Equations Optimum Control Systems Artificial Neural Network Computer Control Technology 42 43 44 Fundamentals of Computer and Networks The Applications of Computers 46 40 38 UNIT 6 A Controllability, Observability, and Stability UNIT 7 A Conventional and Intelligent Control UNIT 1 A Computer Structure and Function UNIT 2 A Interfaces to External Signals and Devices UNIT 3 A PLC Overview PACs for Industrial Control, the Future of Control 1 UNIT 4 A Fundamentals of Single-chip Microcomputer 49 B B PART 4 B B B B PART 5 B B B B PART 6 Understanding DSP and Its Uses Embedded Systems Design Process Control 50 52 53 Fundamentals of Process Control UNIT 5 A A First Look at Embedded Systems UNIT 1 A A Process Control System UNIT 2 A Sensors and Transmitters Final Control Elements and Controllers PID Controllers and Other Controllers Control Panels Control Based on Network and Information Evolution of Control System Architecture Stability of NCSs with Network-induced Delay Virtual Manufacturing—A Growing Trend in Automation Enterprise Resources Planning and Beyond Synthetic Applications of Automatic Technology UNIT 3 A P Controllers and PI Controllers UNIT 4 A Indicating Instruments UNIT 1 A Automation Networking Application Areas UNIT 2 A Fundamental Issues in Networked Control Systems UNIT 3 A Fundamentals of the Database System UNIT 4 A Concepts of Computer Integrated Manufacturing UNIT 1 A Recent Advances and Future Trends in Electrical Machine Drivers B B B System Evolution in Intelligent Buildings A General Introduction to Pattern Recognition Electric Vehicles UNIT 2 A Industrial Robot UNIT 3 A Renewable Energy 2 UNIT 1 A

电路 电路或电网络由以某种方式连接的电阻器，电感器和电容器等元件组成。如果网络不包含能源，如电池或发电机，那么就被称作无源网络。换句话说，如果存在一个或多个能源，那么组合的结果为有源网络。在研究电网络的特性时，我们感兴趣的是确定电路中的电压和电流。因为网络由无源电路元件组成，所以必须首先定义这些元件的电特性。就电阻来说，电压-电流的关系由欧姆定律给出，欧姆定律指出：电阻两端的电压等于电阻上流过的电流乘以电阻值。在数学上表达为： u=iR (1-1A-1)式中 u=电压，伏特；i =电流，安培；R =电阻，欧姆。纯电感电压由法拉第定律定义，法拉第定律指出：电感两端的电压正比于流过电感的电流随时间的变化率。因此可得到：U=Ldi/dt 式中 di/dt =电流变化率，安培/秒； L =感应系数，享利。电容两端建立的电压正比于电容两极板上积累的电荷 q 。因为电荷的积累可表示为电荷增量 dq 的和或积分，因此得到的等式为 u=，式中电容量 C 是与电压和电荷相关的比例常数。由定义可知，电流等于电荷随时间的变化率，可表示为 i = dq/dt。因此电荷增量 dq 等于电流乘以相应的时间增量，或 dq = i dt，那么等式(1-1A-3)可写为式中 C =电容量，法拉。

Hanna: That's over now, isn't it?

都结束了，对吗

You must be ill. You look so pale.

你一定是病了，你的脸色苍白。