专业英语第一篇文章翻译
Historical Development of Matertials and Technology
The common engineering materials include metals, cementing materials, concrete building stones, clay products, insulating materials, timber. Some of them are described here from the stand-point of occurrence, manufacture, properties, methods of testing, and use.
The development of materials with improved properties is a vital phase of engineering. Progress in engineering construction has been dependent on the availability of materials of suitable physical properties in large quantities; for example, the development of the modern automobile was critically dependent on availability of high quality alloy steels, and the all-metal airplane was made possible by the development of light weight high-strength alloys.
◆Phase: 相；阶段。
◆a distinct period or stage in a process of change or forming part of
something's development
Example：
phase two of the development is in progress.
◆第二阶段开发正在进行中。
◆Vital: 必要的，必不可少的。
◆it is vital that the system is regularly maintained.这个系统有必要
经常维修。
翻译：
常用工程材料包括金属、胶合材料、混凝土建筑石料、粘土产品、绝缘材料、木料。对其中的一些在这儿从出现、制造、性质、检验方法和用途等方面加以描述。具有改进性能材料的发展是工程上一个至关重要的发展过程。工程建筑上的进步一直以来依赖于具有合适物理特性材料的大量供应，例如，现代汽车工业严重依赖于高品质的合金钢的可用性，而轻质高强度合金的发展使全金属飞机的成为可能。
It can be said that "The history of materials is the history of man". Of course, the reverse can be stated:"The history of man is the history of materials". It is said that "New materials are a prerequisite for new technologies". Again the reverse is true. Furthermore, it is true that technology influences man and vice versa. From this viewpoint the question of pre-eminence among the three partners, man, materials and technology is an intellectual game: a controversy of the chicken and the egg type.
reverse 相反，相对。文中作名词用
“the reverse can be stated…..”
Example: This materi al didn’t resist to the heat, quite the reverse.
恰恰相反，这种材料根本就不耐热。
除做名词外，还可以做动词和形容词用。
做动词：the ship's engines reversed and cut out altogether.
船上的发动机出现反转，然后就全停了。
做形容词：the trend appears to be going in the reverse direction.
趋势似乎正在向反方向发展。
◆prerequisite 首要的，必备的，先决条件
◆prerequisite for (to) … 的前提或…的先决条件:
◆Training is a prerequisite for competence. 接受训练是掌握技能
的前提。
◆Recognition is a prerequisite to understanding.
◆认识是理解的前提。
◆pre-eminence 超群，优秀、卓越
◆文中，”question of pre-eminence”译为：优先性命题。
◆Furthermore, it is true that technology influences man and vice
versa.
另外，技术的确影响着人类，反之亦然。
vice versa:相反，反之亦然adv.
解释：with the main items in the preceding statement the other way round 反过来也一样，反之亦然
e.g. science must be at the service of man, and not vice versa.
科学必须为人类服务，反之并非这样。
◆From this view point the question of pre-eminence among the three
partners, man, materials, and technology, is an intellectual game: a controversy of the chicken and the egg type.
◆从这一观点可见，人类、材料和技术三者之间谁先谁后的问题
是一个智力游戏，是个象鸡和蛋之类的引起争论的问题。（即到
底是先有鸡然后有蛋，还是先有蛋然后有鸡这一类问题，人类、材料和技术三者谁为先，谁为后，就像鸡和蛋何者为先一样，
所以说这一问题是一个智力游戏。）
The earth's population has been continuously multiplying since early man first appeared about two million years B.C. The population grew by a factor of 100 about 500,000 years, from 100,000 to 10 million, and this was reached about 4000 B.C. Despite natural catastrophes, plagures, and decimating wars, by 1820 the population had grown again by a factor of 100 to 1 billion people, this time in less than 6000 years. Today there are about 5 billion people and the doubling rate is only about 33 years. Accordingly, it is possible that in not quite 200 years' time there will already be 100 billion (109) people on Earth.
◆翻译：
◆自从人类在大约公元前两百万年前出现在地球上以来，地球上
的人类一直在不停地成倍增长。在大约50万年内，人类人口的
数量增加了100倍，从10万到1千万，这一千万的人口大约是
在公元前4000年达到的。尽管受到了自然灾害、瘟疫和大规模
杀戮战争，到1820年，人口总数又增加了100倍，达到了10
亿，这次是在不到6000年的时间内完成的。现在地球上的人口
约有50亿，而翻倍的速度大约仅需要33年。因此，可能在不
到200年的时间内，地球上的人口会达到1千亿（109）。
◆catastrophe大灾害，灾祸。
◆an environmental catastrophe.环境大灾难。
◆Plague 瘟疫，祸患（文中做名词用）
◆做动词用：折磨，烦扰，打扰。
◆he has been plagued by ill..
◆他一直被病魔折磨着
◆decimating 杀死大部分的，毁灭大部分的。
The condition for the flourishing of the species Homo Sapiens have improved over time such that man has made the Earth his subject. Through his materials and their uses in technical devices and processes, man has made favorable living conditions which he modifies continually and to which he in turn continuously adapts.
Materials are on of our oldest cultural assets. Historical eras are named after the materials that dominated at that time: the Stone Age, the Bronze Age and the Iron Age possibly the end of which we are living through at this time. New materials such as polymers, semiconductors and superconductors, advanced alloys and ceramics, the amorphous metals, and increasingly the composite materials, are appearing on the scene and providing an impetus for technological developments, often with far-reaching consequences. One can expect the discovery of more materials in the future. Every chemical compound and every alloy is a material that could potentially revolutionize our lives to the extent that
the first stone tools revolutionized the life the early man. Thus the name for the new era should be chosen carefully and perhaps is best left to the future; a position too close could distort the perspective.
翻译：
近代人类繁衍兴旺的条件随着时间的推移改善了很多，以至于人类使地球受其支配。通过他的材料和在技术装置和工艺上的应用，人类创造了有利的生活条件，并对它不断改善，反过来，人类也在不断地适应改善了的生活条件。
材料是我们最古老的文化财富之一。历史上的时代都以那个时代占重要地位的材料来命名，如石器时代，青铜时代，铁器时代，我们目前可能正在经历的是铁器时代晚期。新材料如聚合物、半导体和超导体，先进合金和陶瓷，非晶态金属，和越来越多的复合材料正在在不断涌现，并为常常具有深远影响的技术发展提供动力。
预计将来会有更多的新材料被发现。每一个化合物和每一种合金都对我们的生活有潜在的革命性的影响，在某种程度上就相当于第一件石器工具对早期人类的革命性影响一样。因此新时代的命名必须谨慎选择，可能最好是留到将在再命名，太靠近的位置会歪曲新材料的发展前景。
◆“made the Earth his subject”
◆使地球受其支配。
◆”providing an impetus for technological developments”
◆为技术发展提供了动力（刺激）
e.g. provide the new evidence for the proposed mechanism.
为所提出的机理提供了新的证据
to the extent that… that引导同位语从句。
to an extent 在…种程度上。
e.g.
To an extent, perhaps the fast remark was true.
To the extent that 还有“随着”之意
Its importance can’t but grow to the extent that knowledge improves.
随着知识增长，知识的重要性也随之增长。
Materials are turned into tools, devices, machines, houses and streets. Revolutionary technological developments have, as in the case of materials, followed in quick succession in modern times. Thus important developments, such as printing, radar, radio, telephone, satellites, rockets etc., greatly enhance man's favorable living conditions.
Obviously, it is not only materials and technology that have contributed to today's high standard of living, but also discoveries in medicine, agriculture, chemistry and pharmacy. All these areas have contributed to, as well as profited from, technological progress and thus play a significant role in the interactions of the disciplines.
◆In succession: 接二连三地
◆In the case of: 至于，就…来说
◆Play an important role:起到重要作用
◆contribute to: 贡献于，促进，推动…的进展
◆Materials are turned into tools, devices, machines, houses and
streets. Revolutionary technological developments have, as in the case of materials, followed in quick succession in morden times.
材料转化成工具、装置、机器、房屋和街道。在现代，就材料来说，革命性的技术发展接二连三地迅速出现。
In the case of
e.g.
1) In the case of light similar effects are present though we shall see some essential differences.
对于光也有类似的效应，虽然我们会看到一些本质的差别。
2）In the case of non-magnetic substances there is only one integral equation.
在非磁性物质的情况下，只有一个积分方程。
◆All these areas have contributed to, as well as profited from,
technological progress and thus play a significant role in the interactions of the disciplines
◆所有这些领域都有助于同时地得益于技术进步，因此在各学科
相互作用中起着重要作用。
翻译：
◆材料可转变成工具、装置、机器、房屋和街道。在现代，革命
性的技术发展就材料来说是接二连三地迅速出现。因此，像印刷、雷达、收音机、电话、卫星、火箭等重要的发展极大地促进了人们有利的生活水平的提高。
◆很明显，不仅材料和技术为今天高水平的生活作出了贡献，医
学、农学、化学和药学上的发现也为今天高水平的生活作出了贡献。所有这些领域都对技术进步作出贡献，同时也受益于技术进步，因此在学科间相互作用中起了重要的作用。
It has taken a long time for developments to reach their current rate. The question arises whether the steeply increasing population curve and the increasing pace of technological innovations, some of which have a great influence on society, really represent true progress. Indeed, does not a growing demand for materials imply the "looting" of our planet of nonrenewable resources? Will there come a day when we are no longer in control of our own technology and the human spirit no longer matches progress? These are questions of our times, the answers to which must come from the natural and engineering sciences, especially from their interdisciplinary branch materials science, as well as the social sciences. 翻译：发展达到目前的速度已经花费了很长时间。问题在于，这种人口的迅猛增长和技术革新速度的不断加快是否代表了真正的进步？它们中的一些已对社会产生了重大的影响。确实，难道对材料不断增
长的需求不就意味着在“掠夺”我们星球上不可再生资源吗？那一天会不会来临，即我们不再能控制我们自己的技术，人类精神不再能赶上这种进步的脚步？这是我们这个时代存在的问题，这些问题的答案必须来自自然科学和工程科学，特别是它们的交叉学科分支材料科学和社会科学。
The relation between man and technology holds a prominent, often emotionally charged position, within the inter-relationship of man, materials and technology. Ever since the Industrial Revolution, or even centuries before that, there have been intense controversies, unfortunately all too often linked with violence. In this context materials were entirely ignored, even though they have frequently triggered off technological progress in the past and present, and will continue to do so in the future. Materials are mostly a means to an end and were thus considered inferior. In fact materials are taken for granted: they are self-evident to most people.
emotionally charged: 情绪激动的，紧张的
in this context: 在这种环境下，在这种背景下
trigger off：触发，引发take for granted：理所当然
self evident：不证自明的，不言而喻的
翻译：
在人类、材料和技术这种相互关系中，人类和技术之间的关系占据了
一个重要的，经常令人激动的地位。自从工业革命以来，或在那以前几个世纪，一直存在激烈的争论，不幸的是这些争论通常是和暴力联系在一起。在这种背景下，材料完全被忽视了，即使它们在过去和现在常常引发技术进步，并且在将来还会继续引发技术进步。材料大多是最后采用的一个方法，因此在过去被认为是不重要，实际上材料毫无疑问对于大多数人来说，其作用是不言而喻的。
It would be appropriate to discuss the train of thought Georgius Agricola (1556) expressed in one of his book. He wrote:" If mankind ceased to use metals, all the possibilities to guard and preserve health, as well as to lead a life corresponding to our cultural values would be taken away. For, if the metals would not exist, people would lead the most detestable and most miserable life among wild animals: people would return to eating acorns and berries, they would pull out roots or herbs and eat them, they would dig caves with their fingernails and lay there at night and would roam the woods and fields during the day just as it is custom with wild animals. Since such conduct is entirely unworthy to human reason, is there anyone so foolish and stubborn not to admit that metals are necessary for sustenance and clothing, and that they serve to protect the human life?"
the train of thought: 一系列思想
翻译：
在此讨论Georgius Agricola在他一本书中描述的一系列思想是比较合适的。他写道：“假如人类停止使用金属，所有保护和保持健康以及过上符合我们文化价值观生活的可能性都将不复存在。因为金属不存在，人们将过在野生动物中间最可怕和可悲的生活，人们将回到吃橡实和浆果的日子，他们将拔出根和草来吃，他们用手指挖洞，晚上在那里睡觉，白天则将在树林和陆地上游荡，就像野生动物具有的习惯一样。因为这样的行为完全不值得人们去思考，谁还会愚蠢和固执到不肯承认金属对人们的吃和穿是必不可少的，和用来保护人类的生活的呢？
Even after more than 400 years this statement is relevant. Everything said about metals can be generalized to all materials. Agricola addressed the social aspects of materials: problems of public health and culture as well as general questions of standards of living. Agricola made the connection between materials technology and society, in the context of his time. As the mayor of Chemnitz, earning a living as a town physician, he was the leading expert on the contemporary mining industry and metallurgy.
翻译：
即使过了400多年，这种说法也是可靠的。所说的关于金属的所有事情也可以推广到所有材料。Agricola论及材料的社会方面：公众健康和文化的问题以及生活标准的一般问题。Agricola在他当时的环境下建立起材料技术和社会的联系，作为Chemnitz(开姆尼茨)的市长，他
以城镇医生的职业谋生，但他同时还是当时采矿和冶金方面的首席专家。
◆stress
◆(1)压力精神紧张
e.g. The development of coronary atheros-elerosis reduces the capacity of vascular bed adapt to hypoxic sress.
动脉硬化的发展降低了血管床适应血氧压力的能力。
◆（2）应力
◆e.g The higher the stress the fewer will be the cycles before failure
can be expectd.
应力越高，在可以预料的破坏之前循环次数就越少。
◆（3）强度、内应力
e.g The diameters of the rotor and the stator are limited by mechanical stresses.
转子和定子的直径受到机械强度的限制。
◆衍生：
◆stress-component 分应力
◆stress intensity factor 应力强度因子
◆stress－ometer 应力计
◆stress-pulse 应力脉冲
◆stress-relaxation 应力松弛
◆stress-resultant 合应力
Strain
(1)应变，应变量
e.g. Strain is proportional to stress.
应变与应力成正比。
(2)张力、拉力
（3）紧张，紧张气氛
翻译：
（1）对一个物体的受力进行完整分析有必要知道在它每一点的分应力。
（2）正如我们前面提到的，应力会产生形变。
数学专业英语论文(含中文版)
Differential Calculus Newton and Leibniz,quite independently of one another,were largely responsible for developing the ideas of integral calculus to the point where hitherto insurmountable problems could be solved by more or less routine methods.The successful accomplishments of these men were primarily due to the fact that they were able to fuse together the integral calculus with the second main branch of calculus,differential calculus. In this article, we give su ?cient conditions for controllability of some partial neutral functional di ?erential equations with in?nite delay. We suppose that the linear part is not necessarily densely de?ned but satis?es the resolvent estimates of the Hille -Yosida theorem. The results are obtained using the integrated semigroups theory. An application is given to illustrate our abstract result. Key words Controllability; integrated semigroup; integral solution; in?nity delay 1 Introduction In this article, we establish a result about controllability to the following class of partial neutral functional di ?erential equations with in?nite delay: 0,) ,()(0≥?? ???∈=++=?? t x xt t F t Cu ADxt Dxt t βφ (1) where the state variable (.)x takes values in a Banach space ).,(E and the control (.)u is given in []0),,,0(2>T U T L ,the Banach space of admissible control functions with U a Banach space. C is a bounded linear operator from U into E, A : D(A) ? E → E is a linear operator on E, B is the phase space of functions mapping (?∞, 0] into E, which will be speci?ed later, D is a bounded linear operator from B into E de?ned by B D D ∈-=????,)0(0 0D is a bounded linear operator from B into E and for each x : (?∞, T ] → E, T > 0, and t ∈ [0, T ], xt represents, as usual, the mapping from (?∞, 0] into E de?ned by ]0,(),()(-∞∈+=θθθt x xt F is an E-valued nonlinear continuous mapping on B ??+. The problem of controllability of linear and nonlinear systems repr esented by ODE in ?nit dimensional space was extensively studied. Many authors extended the controllability concept to in?nite dimensional systems in Banach space with unbounded operators. Up to now, there are a lot of works on this topic, see, for example, [4, 7, 10, 21]. There are many systems that can be written as abstract neutral evolution equations with in?nite delay to study [23]. In recent years, the theory of neutral functional di ?erential equations with in?nite delay in in?nite dimension was deve loped and it is still a ?eld of research (see, for instance, [2, 9, 14, 15] and the references therein). Meanwhile, the controllability problem of such systems was also discussed by many mathematicians, see, for example, [5, 8]. The objective of this article is to discuss the controllability for Eq. (1), where the linear part is supposed to be non-densely de?ned but satis?es the resolvent estimates of the Hille-Yosida theorem. We shall assume conditions that assure global existence and give the su ?cient conditions for controllability of some partial neutral functional di ?erential equations with in?nite delay. The results are obtained using the integrated semigroups theory and Banach ?xed point theorem. Besides, we make use of the notion of integral solution and we do not use the analytic semigroups theory. Treating equations with in?nite delay such as Eq. (1), we need to introduce the phase space B. To avoid repetitions and understand the interesting properties of the phase space, suppose that ).,(B B is a (semi)normed abstract linear space of functions mapping (?∞, 0] into E, and satis?es the following fundamental axioms that were ?rst introduced in [13] and widely discussed
汽车专业英语翻译综合
第一章汽车总论 1)Today’s average car contains more than 15,000 separate, individual parts that must work together. These parts can be grouped into four major categories: body, engine, chassis and electrical equipment 。P1 现在的车辆一般都由15000多个分散、独立且相互配合的零部件组成。这些零部件主要分为四类：车身、发动机、底盘和电气设备。 2)The engine acts as the power unit. The internal combustion engine is most common: this obtains its power by burning a liquid fuel inside the engine cylinder. There are two types of engine: gasoline (also called a spark-ignition engine) and diesel (also called a compression-ignition engine). Both engines are called heat engines; the burning fuel generates heat which causes the gas inside the cylinder to increase its pressure and supply power to rotate a shaft connected to the power train. P3 发动机作为动力设备，常见的类型是内燃机，其原理是通过发动机缸内的液体燃料燃烧而产生能量。发动机可分为两类：汽油机（点燃式）和柴油机（压燃式），都属于热力发动机。燃料燃烧产生热量使缸内气压上升，产生的能量驱动轴旋转，并传递给动力传动系。 第二章内燃机 1)Power train system: conveys the drive to the wheels 2)Steering system: controls the direction of movement 3)Suspension system: absorbs the road shocks 4)Braking system: slows down the vehicle P4 传动系把发动机输出的扭矩传递给驱动轮。传动系包括离合器（对应机械变速器）或液力变矩器（对应液力自动变速器）、变速器、驱动轴、主减速器、差速器和驱动桥。 5)Drum brakes have a drum attached to the wheel hub, and braking occurs by means of brake shoes expanding against the inside of the drum. With disc brakes, a disc attached to the wheel hub is clenched between two brake pads. P6 鼓式制动器的制动鼓和轮毂连接，制动蹄张开压紧制动鼓内侧从而产生制动。在盘式制动器上，连着轮毂的制动盘被紧紧夹在两个制动块之间。 1)Linking the piston by a connecting rod to a crankshaft causes the gas to rotate the shaft through half a turn.The power stroke"uses up"the gas,so means must be provided to expel the burnt gas and recharge the cylinder with a fresh petrol-air mixture:this control of gas movement is the duty of the valves;An inlet valve allows the mixture to enter at the right time and an exhaust valve lets out the burnt gas after the gas has done its job . P10 活塞通过连杆和曲轴连接，使得气体带动曲轴旋转半圈。作功冲程耗尽了所有的气体，这样就必须采取相应的措施排出废气并且向气缸内充入新的可燃混合气：气体的运动由气门来控制。进气门使可燃混合气在恰当的时刻进入气缸，排气门使燃烧后的废气排出气缸。 2)The spark-ignition engine is an internal-combustion engine with externally supplied in ignition,which converts the energy cntained in the fuel to kinetic energy.The cycle of operations is spread over four piston strokes. To complete the full cycle it takes two revolutions of the crankshaft. P11 火花点火式发动机是由外部提供点火的内燃机，从而将含在燃料内的能量转化成动能。发动机的一个工作循环分布在活塞的四个行程中，一个完整的工作循环曲轴需要转动两圈。 3)The oil pump in the lubricating system draws oil from the oil pan and sends it to all working parts in the engine. The oil drains off and runs down into the pan. Thus,there is constant circulation of oil between the pan and the working parts of the engine. P15
专业英语第一篇文章翻译
Historical Development of Matertials and Technology The common engineering materials include metals, cementing materials, concrete building stones, clay products, insulating materials, timber. Some of them are described here from the stand-point of occurrence, manufacture, properties, methods of testing, and use. The development of materials with improved properties is a vital phase of engineering. Progress in engineering construction has been dependent on the availability of materials of suitable physical properties in large quantities; for example, the development of the modern automobile was critically dependent on availability of high quality alloy steels, and the all-metal airplane was made possible by the development of light weight high-strength alloys. ◆Phase: 相；阶段。 ◆a distinct period or stage in a process of change or forming part of something's development Example： phase two of the development is in progress. ◆第二阶段开发正在进行中。 ◆Vital: 必要的，必不可少的。 ◆it is vital that the system is regularly maintained.这个系统有必要 经常维修。
数学专业英语2-10翻译
Although dependence and independence are properties of sets of elements, we also apply these terms to the elements themselves. For example, the elements in an independent set are called independent elements. 虽然相关和无关是元素集的属性，我们也适用于这些元素本身。 例如，在一个独立设定的元素被称为独立元素。 If s is finite set, the foregoing definition agrees with that given in Chapter 8 for the space n V . However, the present definition is not restricted to finite sets. 如果S 是有限集，同意上述定义与第8章中给出的空间n V ，然而，目前的定义不局限于有限集。 If a subset T of a set S is dependent, then S itself is dependent. This is logically equivalent to the statement that every subset of an independent set is independent. 如果集合S 的子集T 是相关的，然后S 本身是相关的，这在逻辑上相当于每一个独立设置的子集是独立的语句。 If one element in S is a scalar multiple of another, then S is dependent. 如果S 中的一个元素是另一个集中的多个标量的，则S 是相关的。 If S ∈0,then S is dependent. 若S ∈0，则 S 是相关的。 The empty set is independent. 空集是无关的。 Many examples of dependent and independent sets of vectors in V were discussed in Chapter 8. The following examples illustrate these concepts in function spaces. In each case the underlying linear space V is the set of all real-valued function defined on the real line. V 中的向量的相关和无关设置的许多例子是在第8章讨论。下面的例子说明这些概念在函数空间。在每个 基本情况下，线性空间V 是实线定义的所有实值函数集。 Let 1)(),(sin )(,cos )(32221===t u t t u t t u for all real t. The Pythagorean identity show that 0321=-+u u u , so the three functions 321,,u u u are dependent. 321,,u u u 是相关的。 Let k k t t u =)(for k=0,1,2,…, and t real. The set ,...},,{210u u u S = is independent. To prove this, it suffices to show that for each n the n+1 polynomials n u u u ,...,,10 are independent. A relation of the form ∑=0k k u c means that
专业英语课文翻译
United 1 材料科学与工程 材料在我们的文化中比我们认识到的还要根深蒂固。如交通、房子、衣物，通讯、娱乐和食物的生产，实际上，我们日常生活中的每一部分都或多或少地受到材料的影响。历史上社会的发展、先进与那些能满足社会需要的材料的生产及操作能力密切相关。实际上，早期的文明就以材料的发展程度来命名，如石器时代，铜器时代。早期人们能得到的只有一些很有限的天然材料，如石头、木材、粘土等。渐渐地，他们通过技术来生产优于自然材料的新材料，这些新材料包括陶器和金属。进一步地，人们发现材料的性质可以通过加热或加入其他物质来改变。在这点上，材料的应用完全是一个选择的过程。也就是说，在一系列非常有限的材料中，根据材料的优点选择一种最适合某种应用的材料。直到最近，科学家才终于了解材料的结构要素与其特性之间的关系。这个大约是过去的 60 年中获得的认识使得材料的性质研究成为时髦。因此，成千上万的材料通过其特殊的性质得以发展来满足我们现代及复杂的社会需要。很多使我们生活舒适的技术的发展与适宜材料的获得密切相关。一种材料的先进程度通常是一种技术进步的先兆。比如，没有便宜的钢制品或其他替代品就没有汽车。在现代，复杂的电子器件取决于所谓的半导体零件. 材料科学与工程有时把材料科学与工程细分成材料科学和材料工程学科是有用的。严格地说，材料科学涉及材料到研究材料的结构和性质的关系。相反，材料工程是根据材料的结构和性质的关系来设计或操纵材料的结构以求制造出一系列可预定的性质。从功能方面来说，材料科学家的作用是发展或合成新的材料，而材料工程师是利用已有的材料创造新的产品或体系，和/或发展材料加工新技术。多数材料专业的本科毕业生被同时训练成材料科学家和材料工程师。“structure”一词是个模糊的术语值得解释。简单地说，材料的结构通常与其内在成分的排列有关。原子内的结构包括介于单个原子间的电子和原子核的相互作用。在原子水平上，结构包括原子或分子与其他相关的原子或分子的组织。在更大的结构领域上，其包括大的原子团，这些原子团通常聚集在一起，称为“微观”结构，意思是可以使用某种显微镜直接观察得到的结构。最后，结构单元可以通过肉眼看到的称为宏观结构。 “Property”一词的概念值得详细阐述。在使用中，所有材料对外部的刺激都表现出某种反应。比如，材料受到力作用会引起形变，或者抛光金属表面会反射光。材料的特征取决于其对外部刺激的反应程度。通常，材料的性质与其形状及大小无关。实际上，所有固体材料的重要性质可以概括分为六类：机械、电学、热学、磁学、光学和腐蚀性。对于每一种性质，其都有一种对特定刺激引起反应的能 力。如机械性能与施加压力引起的形变有关，包括弹性和强度。对于电性能，如电导性和介电系数，特定的刺激物是电场。固体的热学行为则可用热容和热导率来表示。磁学性质
汽车专业英语翻译
About car engine Of all automobile components,an automobile engie is the most complicated assembly with dominant effects on the function of an autombile.So, the engine is generally called the"heat"of an automobile. 在汽车的所有部件中，汽车发动机是最复杂的组件，其对整车性能有着决定性的作用。因而发动机往往被称作发动机的“心脏”。 There are actually various types of engines such as electric motors,stream engines,andinternal combustion engines.The internal combustion engines seem to have almost complete dominance of the automotive field.The internal combustion engine,as its name indicates,burns fuel within the cylinders and converts the expanding force of the combustion into rotary force used to propel the vehicle. 事实上，按动力来源分发动机有很多种，如电动机、蒸汽机、外燃机等。然而内燃机似乎在发动机领域有着绝对的统治地位。就像其字面意思一样，内燃机的染料在气缸内燃烧，通过将燃烧产生气体的膨胀力转换成转动力来驱动发动机前进。 Engine is the power source of the automobile.Power is produced by the linear motion of a piston in a cylinder.However,this linear motion must be changed into rotary motion to turn the wheels of cars or trucks.The puston attached to the top of a connecting rod by a pin,called a piston pin or wrist pin.The bottom of the connecting rod is attached to the crankshaft.The connecting rod transmits the up-and-down motion of the piston to the crankshaft,which changes it into rotary motion.The connecting rod is mounted on the crankshaft with large bearings called rod bearing.Similar bearings, called main bearings,are used to mount the crankshaft in the block. 发动机是整部车的动力来源。能量来自于活塞在气缸内的（往复）直线运动。然而这种（往复）直线运动必须要转换成旋转运动才能驱动车轮。活塞与连杆通过一个销来连接，这个销称为活塞销。连杆的下部连接于曲拐。连杆把活塞的上下往复运动传递给曲拐，从而将往复直线运动转变成旋转运动。连杆和曲拐的连接使用大的轴承，称之为连杆轴承，类似的轴承也用于将曲轴连接到机体，称之为主轴承。 They are generally two different types of cooling system:water-cooling system and air-cooling system.Water-cooling system is more common.The cooling medium, or coolant, in them is either water or some low-freezing liquid, called antifreeze.A water-cooling system consists of the engine water jacket, thermostat, water pump, radiator, radiator cap, fan, fan drive belt and neccessary hoses. 主要有两种类型的冷却系统：水冷和风冷。水冷系统更为普遍。系统所用冷却介质或是冷却液常委水或其他低凝固点液体，称为抗凝剂。一个完整的水冷系统包括机体水套，节温器，水泵，散热器，散热器罩，风扇，风扇驱动皮带和必需的水管。 A water-cooling system means that water is used as a cooling agent to circulate through the engine to absorb the heat and carry it to the radiator for disposal.The ebgine is cooled mainly through heat transfer and heat dissipation.The heat generated by the mixture burned in the engine must be transferred from the iron or aluminum cylinder to the waterin the water jacket.The outside of the water jacket dissipates some of the heat to the air surrounding it, but most of the heat is carried by the cooling water to the radiator for dissipation.When the coolant temperature in the system reaches 90°,the termostat valve open fully, its slanted edge shutting off
数学专业英语第二版-课文翻译-converted
2.4 整数、有理数与实数 4－A Integers and rational numbers There exist certain subsets of R which are distinguished because they have special properties not shared by all real numbers. In this section we shall discuss such subsets, the integers and the rational numbers. 有一些R 的子集很著名，因为他们具有实数所不具备的特殊性质。在本节我们将讨论这样的子集，整数集和有理数集。 To introduce the positive integers we begin with the number 1, whose existence is guaranteed by Axiom 4. The number 1+1 is denoted by 2, the number 2+1 by 3, and so on. The numbers 1,2,3,…, obtained in this way by repeated addition of 1 are all positive, and they are called the positive integers. 我们从数字 1 开始介绍正整数，公理 4 保证了 1 的存在性。1+1 用2 表示，2+1 用3 表示，以此类推，由 1 重复累加的方式得到的数字 1,2,3，…都是正的，它们被叫做正整数。 Strictly speaking, this description of the positive integers is not entirely complete because we have not explained in detail what we mean by the expressions “and so on”, or “repeated addition of 1”. 严格地说，这种关于正整数的描述是不完整的，因为我们没有详细解释“等等”或者“1的重复累加”的含义。 Although the intuitive meaning of expressions may seem clear, in careful treatment of the real-number system it is necessary to give a more precise definition of the positive integers. There are many ways to do this. One convenient method is to introduce first the notion of an inductive set. 虽然这些说法的直观意思似乎是清楚的，但是在认真处理实数系统时必须给出一个更准确的关于正整数的定义。有很多种方式来给出这个定义，一个简便的方法是先引进归纳集的概念。 DEFINITION OF AN INDUCTIVE SET. A set of real number s is cal led an i n ductiv e set if it has the following two properties: (a) The number 1 is in the set. (b) For every x in the set, the number x+1 is also in the set. For example, R is an inductive set. So is the set . Now we shall define the positive integers to be those real numbers which belong to every inductive set. 现在我们来定义正整数，就是属于每一个归纳集的实数。 Let P d enote t he s et o f a ll p ositive i ntegers. T hen P i s i tself a n i nductive set b ecause (a) i t contains 1, a nd (b) i t c ontains x+1 w henever i t c ontains x. Since the m embers o f P b elong t o e very inductive s et, w e r efer t o P a s t he s mallest i nductive set. 用 P 表示所有正整数的集合。那么 P 本身是一个归纳集，因为其中含 1，满足(a)；只要包含x 就包含x+1, 满足(b)。由于 P 中的元素属于每一个归纳集，因此 P 是最小的归纳集。 This property of P forms the logical basis for a type of reasoning that mathematicians call proof by induction, a detailed discussion of which is given in Part 4 of this introduction.
计算机专业英语课文翻译部分(第四版)
1.2 总线互连 总线是连接两个或多个设备的通信通路。总线的关键特征是，它是一条共享传输介质。多个设备连接到总线上，任一个设备发出的信号可以为其他所有连接到总线上的设备所接收。如果两个设备同时传送，它们的信号将会重叠，引起混淆。因此，一次只能有一个设备成功地（利用总线）发送数据。 典型的情况是，总线由多条通信通路或线路组成，每条线(路)能够传送代表二进制1和0的信号。一段时间里，一条线能传送一串二进制数字。总线的几条线放在一起能同时并行传送二进制数字。例如, 一个8位的数据能在8条总线线上传送。 计算机系统包含有多种不同的总线，它们在计算机系统层次结构的各个层次提供部件之间的通路。连接主要计算机部件(处理机, 存储器, I/O)的总线称为系统总线。系统总线通常由50~100条分立的(导)线组成。每条线被赋予一个特定的含义或功能。虽然有许多不同的总线设计，但任何总线上的线都可以分成三个功能组：数据线、地址线和控制线。此外可能还有为连接的模块提供电源的电源线。 数据线提供系统模块间传送数据的路径，这些线组合在一起称为数据总线。典型的数据总线包含8、16或32根线，线的数量称为数据总线的宽度。因为每条线每次传送1位，所以线的数目决定了每次能同时传送多少位。数据总线的宽度是决定系统总体性能的关键因素。 地址线用于指定数据总线上数据的来源和去向。例如，如果处理机希望从存储器中读一个字的数据，它将所需要字的地址放在地址线上。显然，地址总线的宽度决定了系统最大可能的存储器容量。 控制线用来控制对数据线和地址线的访问和使用。由于数据线和地址线被所有部件共享，因此必须用一种方法来控制它们的使用。控制信号在系统模块之间传送命令和定时信息。定时信息指定了数据和地址信息的有效性，命令信号指定了要执行的操作。 大多数计算机系统使用多总线，这些总线通常设计成层次结构。图1.3显示了一个典型的高性能体系结构。一条局部总线把处理机连接到高速缓存控制器，而高速缓存控制器又连接到支持主存储器的系统总线上。高速缓存控制器集成到连接高速总线的桥中。这一总线支持连接到：高速LAN、视频和图形工作站控制器，以及包括SCSI 和FireWire的局部外设总线的接口控制器。低速设备仍然由分开的扩充总线支持，用一个接口来缓冲该扩充总线和高速总线之间的通信流量。 PCI 外部设备互连是流行的高带宽的、独立于处理机的总线，它能够作为中间层或外围设备总线。当前的标准允许在66MHz频率下使用多达64根数据线，其原始传输速率为528MB/s, 或4.224Gbps。PCI被设计成支持各种各样基于微处理机的配置，包括单处理机和多处理机的系统。因此，它提供了一组通用的功能。PCI使用同步时序以及集中式仲裁方案。 在多处理机系统中，一个或多个PCI配置可通过桥接器连接到处理机的系统总线上。系统总线只支持处理机/高速缓存单元、主存储器以及PCI桥接器。使用桥接器使得PCI独立于处理机速度，又提供快速接收和传送数据的能力。 2.1 光存储介质：高密度存储器 2.1.1 光盘 光盘技术最终可能使磁盘和磁带存储淘汰。用这种技术，磁存储器所用的读/写头被两束激光代替。一束激光通过在光盘上刻制微小的凹点，对记录表面进行写；而另一束激光用来从光敏感的记录表面读取数据。由于光束容易被偏转到光盘上所需要的位置，所以不需要存取臂。 对用户而言，光盘正成为最有吸引力的选择。它们(光盘)对环境变化不太敏感，并且它们以每兆字节比磁盘低得多的存储器价格提供更多的直接存取存储器。光盘技术仍在出现，并且还需要稳定；然而，目前有三种主要类型的光盘。它们是CD-ROM、WORM盘和磁光盘。 CD-ROM 1980年引入的，非常成功的CD，或紧密盘是设计来提高音乐的录音重放质量的光盘。为了制作一张CD，把音乐的模拟声音转换成等价的数字声音，并且存储在一张4.72英寸的光盘上。在每张光盘上可以用数字格式（用20亿数字位）记录74分钟的音乐。因为它的巨大存储容量，计算机工业的企业家们立刻认
汽车专业英语_单词表
unit1 body 车身chassis 底盘enclosure外壳、套hood车棚、车顶sway 摇摆frame车架steering转向、操作brake 制动weld焊接rivet铆钉bolt螺钉washer垫圈vibration 振动stabilizer稳定器ride乘坐舒适性handling操作稳定性linkages转向传动机构plier钳子distributor分电器alternator交流发电机regulator调节器carburetor化油器radiator散热器、水箱defroster除冰装置sludge金属碎屑transmission变速器differential 差速器power train 传动系unitized body 承载式车身suspension system 悬架系统steering system 转向系braking system 制动系shock absorbers减震器control arms控制臂steering wheel 转向盘steering column转向管柱steering gears 转向器tie rod 横拉杆idler arm随动臂brake shoe制动蹄disc brake 盘式制动器drum brakes 鼓式制动器ignition system 点火系统exhaust system 排气系统lubrication system 润滑系oil filters 机油滤清器drive（or propeller）shaft传动轴universal joints 万向节dynamo发电机horn喇叭swived 旋转steering box转向器timing gear 正时齿轮bevel gear 锥齿轮mesh with与啮合leaf spring 钢板弹簧stub axle 转向节 unit2 longitudinal纵向的transverse横向的reciprocate往复spin旋转piston活塞ignite点火rub摩擦quart夸脱reservoir油箱mechanical机械的enclosed被附上的gallon加仑stroke冲程camshaft凸轮轴combustion燃烧disengaged脱离啮合的flywheel飞轮internal-combustion engine内燃机diesel-fuel柴油LPG=Liquefied Petroleum Gas液化石油气体CNG=Compressed natural gas压缩天然气spark ignition火花点火compression ignition压缩点火spark plug火花塞gas-turbine engine蒸汽机Stirling engine斯特灵发动机lubricating system润滑系统oil pan油底壳oil pump机油泵exhaust system排气系统emission-control system排放控制系统energy conversion能量转换air/fuel ratio空燃比connecting rod连杆TDC=Top Dead Center上止点BDC=Bottom Dead Center 下止点intake stroke进气冲程compression stroke压缩冲程power stroke作功冲程exhaust stroke排气冲程compression ratio压缩比lifter挺柱rocker摇臂retainer弹簧座seal密封件tappet 推杆lobe凸起gasket垫圈valve train配气机构cam follower气门挺柱rocker arm摇臂combustion chamber燃烧室intake valve进气阀exhaust valve排气阀valve stem气门杆valve cover气门室盖valve port阀口valve guide气门导管 unit3