机械工程英语第2版叶邦彦unit1
Unit 1 Computer Technologies IntroductionAs we know,the central and essential ingredient[组成部分]of CAD/CAM is the digital computer.[1]Therefore,to understand CAD/CAM,it is important to be familiar with the concepts and technology of the digital computer.There are three basic hardware components of a general-purpose digital computer:1.Central processing unit (CPU)2.Memory3.Input/output(I/O)sectionFig.1.1 Basic hardware strucure of a digital computerControl UnitCPUArithmetic-logic [算术逻辑]UnitComputer Programming Languages1.Machine language2.Assembly language[汇编语言]3.Procedure-oriented(high-level) languages[程序导向(高级)语言]Computer Process InterfacingSome of the important components of a computer process control system.(1)Manufacturing process data.These data can be classified into three categories:1) Continuous analog signals [连续模拟信号]2) Discrete binary data [离散二进制数据]3) Pulse [脉冲] data(2)System interpretation of process data.There are six categories of computer-process interface representing the inputs and outputs for the three types of process data.They are:6) Pulse generators1)Analog to digital2)Contact input3) Pulse counters4) Digital to analog5)Contact outputCategoriesComputer Network StructuresThe various network arrangements divide themselves into several basic categories,and we mainly introduce five of the most common used categories.Network Protocols and OSI System Structure(1) Physical layer(2) Data link layer(3) Network layerSeven Layers(4) Transport layer(5) Session layer [会话层](6) Presentation layer(7) Application layer [应用层]Fig.1.3 Structure of ISO/OSI System ModelInternet Application and DevelopmentNowadays,more and more computers and devices are connected with internet system,more and more service and information can be offered by the utilization of internet.It is developing by an incredibly speed and it has become an indispendable component of human's civilization.Control UnitThe control unit coordinates the operations of all the other components.It controls the input and output of information between the computer and the outside world through the I/O section,synchronizes the transference of signals between the various sections of the computer,and commands the other sections in the performance of their functionsArithmetic-logic UnitThe arithmetic-logic unit carries out the arithmetic and logic manipulations[操作]of data. It adds,subtracts,multiplies,divides,and compares numbers according to programmed instructions.Machine LanguageThe language used by the computer is called machine language.It is written in binary,with each instruction containing an operation code and an operand.On the whole,programming in machine language is tedious,complicated,and time-consuming.Assembly LanguageA language consisting of mnemonic instructions is called an assembly language.It is considered to be one kind of low-level language.Assembly language programs must be converted into machine language before the computer can execute them.High-level LanguagesHigh-level languages are procedure oriented.The program written on one computer can be run on a different computer without any significant modifications to the program.It is not necessary for the programmer to be familiar with the machine language through using the high-level languages.Fig.1.2Types of computer network structuresa)Point-to-point.b)Multidrop.c)Star.d)Loop.e)TreeNotes1. The central and essential ingredient of CAD/CAM is the digitalcomputer.分析：CAD/CAM——计算机辅助设计与计算机辅助制造集成系统。
句意：CAD/CAM的核心部分是计算机。
2．Signal conditioners, which filter random electrical noise and smooth the analog signal emanating from transducing device.句意：信号调整器，它可滤掉杂乱的电噪声，并可修整由传感装置送出的模拟信号。
3．A pulse counter is used to convert the pulse trains into a digital representation, which is then applied to the computer’s input channel.分析：be applied to ——适用于。
句意：脉冲记数器可将脉冲串转换为一种数字代码，以适合于计算机输入通道。
4．This results from the shared nature of the communication lines.分析：the shared nature of the communication lines——通信线的共享特性。
句意：这来自通信线的共享特性。
5．Messages to a specific computer are usually transmitted to all computers in the network, with the addressee decoding itsaddress and accepting the information.分析：With——同时。
句意：送往某特定计算机的信息，一般都传送到网络中的所有计算机，同时由信息接收计算机译出地址码并接收信息。
6．In a network, all computers are connected and communicated with each other according to some kinds of enacted regulations or agreement, which is called “network protocols”分析：Network Protocols—网络协议句意：在网络中，所有的计算机都根据一些规则和协议进行连接和通信，规则和协议称为网络协议。
机械工程英语第二版叶邦彦_汉语翻译(机械工业出版社)--全本书翻译
•Types of Materials 材料的类型Materials may be grouped in several ways. Scientists often classify materials by their state: solid, liquid, or gas. They also separate them into organic (once living) and inorganic (never living) materials.材料可以按多种方法分类。
科学家常根据状态将材料分为：固体、液体或气体。
他们也把材料分为有机材料(曾经有生命的)和无机材料(从未有生命的)。
For industrial purposes, materials are divided into engineering materials or nonengineering materials. Engineering materials are those used in manufacture and become parts of products.就工业效用而言，材料被分为工程材料和非工程材料。
那些用于加工制造并成为产品组成部分的就是工程材料。
Nonengineering materials are the chemicals, fuels, lubricants, and other materials used in the manufacturing process, which do not become part of the product.非工程材料则是化学品、燃料、润滑剂以及其它用于加工制造过程但不成为产品组成部分的材料。
Engineering materials may be further subdivided into: ①Metal ②Ceramics ③Composite ④Polymers, etc.工程材料还能进一步细分为：①金属材料②陶瓷材料③复合材料④聚合材料，等等。
机械英语2
机械工程英语第二版叶邦彦陈统坚主编Casting is a manufacturing process in which molten metal is poured or injected and allowed to solidify in a suitably shaped mold cavity. During or after cooling, the cast part is removed from the mold and then processed for delivery.铸造是一种将熔化的金属倒入或注入合适的铸模腔并且在其中固化的制造工艺。
在冷却期间或冷却后，把铸件从铸模中取出，然后进行交付。
Casting processes and cast-material technologies vary from simple to highly complex. Material and process selection depends on the part’s complexity and function, the product’s quality specifications, and the projected cost level.铸造工艺和铸造材料技术从简单到高度复杂变化很大。
材料和工艺的选择取决于零件的复杂性和功能、产品的质量要求以及成本预算水平。
Castings are parts that are made close to their final dimensions by a casting process. With a history dating back 6,000 years, the various casting processes are in a state of continuous refinement and evolution as technological advances are being made.通过铸造加工，铸件可以做成很接近它们的最终尺寸。
机械工程专业英语教程(第2版)[施平主编][翻译]_lesson1
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Basic Concept in MechanicsThe branch of scientific analysis which deals with motions , time , and forces is called mechanics and is made up of two parts , statics and dynamics , Statics deals with the analysis of stationary systems , i.e. , those in which time is not a factor , and dynamics deals with systems which change with time .对运动、时间和作用力做出科学分析的分支称为力学。
它由静力学和动力学两部分组成。
静力学对静止系统进行分析，即在其中不考虑时间这个因素，动力学对随时间而变化的系统进行分析。
When a number of bodies are connected together to form a group or system , the forces of action and reaction between any two of the connecting bodies are called constraint forces . These forces constrain the bodies to behave in a specific manner . Forces external to this system of bodies are called applied forces .当一些物体连接在一起形成一个组合体或者系统时，任何两个相连接的物体之间的作用力和反作用力被称为约束力。
这些力约束着各个物体，使其处于特定的状态。
从外部施加到这个物体的系统的力被称为外力。
机械工程英语第2版叶邦彦Unit1
机械⼯程英语第2版叶邦彦Unit1Unit1 Advanced Engineering MaterialsTypes of materialsBy state：solid, liquid, or gasBy living：organic, inorganicBy industrial purposes：engineering materials.nonengineering materials.Engineering materialsused in manufacture and become parts of products.Nonengineering materialschemicals, fuels, lubricants, and other materials used inthe manufacturing process, which do not become part of the product.Engineering materials may be further subdivided into:MetalsCeramics(陶瓷)Composite(复合材料)Polymers(聚合体)othersMetals and Metal AlloysMetalsare elements that generally have good electrical and thermal conductivity.Many metals have high strength,high stiffness,and have good ductility.Some metals,such as iron,cobalt and nickel are magnetic（adj.有磁性的）.At extremely low temperatures,some metals and intermetallic compounds(⾦属间化合物)become superconductors.Differences between a metal alloy and a pure metalPure metals are elements which come from aparticular area of the periodic table.Examples：1. copper in electrical wires2. aluminum in cooking foil and beverage cans.Metal Alloys contain more than one metallic element.Their properties can be changed by changing the elements present in the alloy.Examples ：1. stainless steel which is an alloy of iron, nickel, andchromium;2. gold jewelry which usually contains an alloy of goldand nickel.Some important properties of metalsDensity is defined as a material's mass divided by its volume. Most metals have relatively high densities,especially compared to polymers.Materials with high densities often contain atoms with high atomic numbers,such as gold or lead.However,some metals such as aluminum or magnesium have low densities,and are used in applications that require other metallic properties but also require low weight.Fracture Toughness can be described as a material‘s ability to avoid fracture,especially when a flaw is introduced.Plastic deformation is the ability of a material to bend or deform before breaking.As engineers,we usually design materials so that they don't deform under normal conditions.You don't want your car to lean to the east after a strong west wind.However, sometimes we can take advantage of(利⽤)plastic deformation.Alloys are compounds consisting of more than one metal. Adding other metals can affect the density, strength, fracture toughness, plastic deformation, electrical conductivity and environmental degradation.For example, adding a small amount of iron to aluminum will make it stronger. Also, adding some chromium to steel will slow the rusting process, but will make it more brittle.The atomic bonding of metalsIn metals, the outer valence electrons are shared among all atoms, and are free to travel everywhere. Since electrons conduct heatand electricity, metals make good cooking pans and electricalwires. It is impossible to see through metals, since these valence electrons absorb any photons of light which reach the metal .[2]No photons pass through.Ceramics and GlassesA ceramic is often broadly defined as any inorganic nonmetallic material. By this definition, ceramic materials would also include glasses; however, many materials scientists add the stipulation (n.约定, 约束, 契约) that "ceramics" must also be crystalline.A glass is an inorganic nonmetallic material that does not have a crystalline (晶体) structure. Such materialsare said to be amorphous (⾮晶体).Properties of Ceramics and Glassesusual properties :high melting temperature, low density, high strength, stiffness, hardness, wear resistance, and corrosion resistance.special properties:electrical and thermal insulators;magnetic materials;piezoelectric materials;superconductors at very low temperatures.Ceramics and glasses have one major drawback : they are brittle.Ceramics FormingCeramics are not typically formed from the melt. This is because most ceramics will crack extensively (i.e. form a powder)upon cooling from the liquid state. Hence, all the simple and efficient manufacturing techniques used for glass production such as casting and blowing, which involve the molten state, cannot be used for the production of crystalline ceramics.Sintering——ceramic powders are processed into compacted shapes and then heated to temperatures just below the melting point. At such temperatures, the powders react internally to remove porosity and fully dense articles can be obtained.Application ——An optical fiberAn optical fiber contains three layers:a core made of highly pure glass with a high refractive index for the light to travel,a middle layer of glass with a lower refractive index known as the cladding which protects the core glass from scratches and other surface imperfections,and an outer polymer jacket to protect the fiber from damage.[4]In order for the core glass to have a higher refractive index than the cladding,the core glass is doped with a small,controlled amount of an impurity,or dopant,which causes light to travel s l o w e r,b u t d o e s n o t a b s o r b t h e l i g h t.Because the refractive index of the core glass is greater than that of the cladding,light traveling in the core glass will remain in the core glass due to total internal reflection as long as the light strikes the core/cladding interface at an angle greater than the critical angle.The total internal reflection phenomenon,as well as the high purity of the core glass,enables light to travel long distances with little loss of intensity.Two types of CompositesFiber Reinforced Composites Particle Reinforced CompositesFiber Reinforced CompositesReinforcing fibers makeup：can be made of metals, ceramics, glasses, or polymers that havebeen turned into graphite and known as carbon fibers.Fibers advantages：increase the modulus of the matrix material. The strong covalent bonds along the fiber's length gives them a very high modulus inthis direction because to break or extend the fiber the bonds must also be broken or moved.Fibers disadvantage：As it is difficult to process into composites，making fiber-reinforced composites relatively expensive.Fiber-reinforced composites are used in some of the most advanced, and therefore most expensive, sports equipment, such as a time-trial racing bicycle frame which consists of carbon fibers in a thermoset polymer matrix. Body parts of race cars and some automobiles are composites made of glass fibers in a thermoset matrix.。
关于机械工程专业英语课件.ppt
Specialized English for ……. “机械工程专业英语”
Specialized English for Mechanical Engineering
机械工程专专业英业语 英语和普通英语的区别
一、词汇： 专业词汇是基础
二、句子： 长句多 被动语态多 后置定语多 大量的名词化结构 等等
copper 生铜
(2) dog: 狗
(机械专业) 挡块
机械工程专业英语
2. 按照习惯搭配确定词义 e.g: (1) I have a short memory. 我的记忆力不好 (2) This biscuit eats short. 这种饼干吃起来松脆 (3) Indeed he has a short temper. 他确实是个急 性子
disadvantage 高速磨削不存在（知道）这个缺点。
机械工程专业英语 二、句子特点
1. 句子长（学会分解句子结构）
If a hard-grade wheel were to be used for grinding a hard material, the dull grains would not be pulled off from the bond quickly enough, thus impeding(阻 碍) the self-dressing process of the surface of the wheel and finally resulting in clogging(堵塞) of the wheel and burns on the ground surface.
机械工程专业英语教程第2版
In the field of mechanical engineering
• Mechanical engineers work in various industries, including automotive, aerospace, energy, manufacturing, and more.
Mechanical Engineering Professional English Tutorial 2nd Edition
目 录
• introduce • Fundamentals of Mechanical
Engineering • Professional vocabulary and
expressions • Professional literature reading and
03
流畅自然的表达
在保证准确性的前提下，使译文 流畅自然，符合中文的表达习惯， 易于读者理解。
05 Practical application and case analysis
Mechanical Design Cases
机械工程英语叶邦彦第二单元到第四单元课文 翻译综述
Unit 2 Numerical Control of Production EquipmentUnit 2 生产设备的数字控制Numerical Control (NC) is a form of programmable automation in which the processing equipment is controlled by means of numbers, letters, and other symbols. The numbers, letters, and symbols are coded in an appropriate format to define a program of instructions for a particular work-part or job. 数控是程序控制的自动化，在数字控制系统中，设备通过数字，字母和符号来编码，以一种合适的格式为每一个特定的零件或工件定义一个程序指令集。
When the job changes, the program of instructions is changed. The capability to change the program is what makes NC suitable for low-and medium-volume production. It is much easier to write new programs than to make major alterations of the processing equipment.当工件变化时，程序也变化，改变程序的能力亦适合中小批量生产。
写一个新程序比改变大量生产设备要容易的多。
Basic Components of NC数控基本结构A numerical control system consists of the following three basic components:数控系统由下面三部分组成：• Program of instructions控制程序• Machine control unit机器控制单元• Processing equipment加工设备The general relationship among the three components is illustrated in Fig. 2.1. The program is fed into the control unit, which directs the processing equipment accordingly.三部分的基本关系，由图 2.1 所示。
机械工程专业英语精品PPT课件
专利检索资源荟萃（二）
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机械工程专业信息检索
ASME-American Society of Mechanical Engineers美国机械工程师协 会 SAE-Society of Automobile Engineers美国汽车工程师协会 EI-Engineering Index工程索引 IEEE-Institute of Electrical and Electronics Engineers (美国)电机及 电子工程师学会 IET-The Institution of Engineering and Technology英国工程技术学 会（IET）系英国电气工程师学会（IEE）和英国企业工程师学会 （IIE）于2006年初合并组建而成 NTIS-National Technical Information Service美国国家技术情报服务 局 UMI-美国UMI公司，学位论文的信息服务（ProQuest ）。 ISO-International Organization for Standardization国际标准化组织。
机械工程英语第二版第二部分完整翻译(叶邦彦、陈统坚主编)教学提纲
机械工程英语第二版第二部分翻译Unit 1Introduction前言The central and essential ingredient of GAD/CAMis the digital computer.〔1〕Its inherent speed and storage capacity have made it possible to achieve the advances in image processing, real-time process control, and a multitude of other important functions that are simply too complex and time-consuming to perform manually. To understand CAD/CAM it is important to be familiar with the concepts and technology of the digital computerCAD/CAM的重要组成部分是数字计算机，它固有的速度以及存储能力似的它能够在图像处理，实时过程控制以及很多因太复杂太费时而人工无法完成的其他重要功能方面获得进步，要想懂得CAD/CAM，熟悉数字电脑的概念和技术是很重要的.The modern digital computer is an electronic machine that can perform mathematical and logical calculations and data processing functions in accordance with a predetermined program of instructions. The computer itself is referred to as hardware, whereas the various programs are referred to as software.现在数字计算机是一部能够根据预定的程序来完成数字和逻辑运算以及数据处理功能的电子设备，计算机本身称为硬件，而各种各样的程序称为软件There are three basic hardware components of a general-purpose digital computer; 一般用途的数字计算机由三种基本硬件组成.Central processing unit (CPU) 微处理器.Memory存储器.Input/output ( I/0 )section输入/输出设备The relationship of these three components is illustrated in Fig. 1.1. The central processing unit is often considered to consist of two subsections; a control unit and an arithmetic-logic unit (ALU). 这三个组成部分的关系如图1.1所示，中央处理器通常被认为包含两部分:一个控制器和一个运算器.The control unit coordinates the operations of all the other components. 控制器控制所有其他组成部分的运输。
机械工程专业英语教程第2版
例如，在产品设计期间，交互式的计算机辅助设计系统使得 完成绘图和分析工作所需要的时间比原来减少了几倍，而且 精确程度得到了很大的提高。此外，用于样机的试验与评价
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《机械工程专业英语教程》
The instantaneous updating of production-control data permits better planning and more effective scheduling. Expensive equipment, therefore, is used more productively, and parts move more efficiently through production,
计算机正在将制造业带入信息时代。计算机长期以来在商 业和管理方面得到了广泛的应用，它正在作为一种新的工 具进入到工厂中，而且它如同蒸汽机在200多年前使制造
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《机械工程专业英语教程》
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The computer is the key to meet these requirements. It is the only tool that can provide the quick reflexes, the flexibility and speed, to meet a diversified market. And it is the only tool that enables the detailed analysis and the accessibility of accurate data necessary for the integration of the manufacturing system.