材料科學(xué)與工程_專業(yè)英語_Unit_2_Classification_of_Materials譯文

1、.Solid materials have been conveniently grouped into three basic classifications: metals, ceramics, and polymers. This scheme is based primarily on chemical makeup and atomic structure, and most materials fall into one distinct grouping or another, although there are some intermediates. In addition,

2、 there are three other groups of important engineering materialscomposites, semiconductors, and biomaterials.譯文：固體材料被便利的分為三個基本的類型：金屬，陶瓷和聚合物。這個分類是首先基于化學(xué)組成和原子結(jié)構(gòu)來分的，大多數(shù)材料落在明顯的一個類別里面，盡管有許多中間品。除此之外， 有三類其他重要的工程材料復(fù)合材料，半導(dǎo)體材料和生物材料。Composites consist of combinations of two or more different materials, whereas

3、 semiconductors are utilized because of their unusual electrical characteristics; biomaterials are implanted into the human body. A brief explanation of the material types and representative characteristics is offered next.譯文：復(fù)合材料由兩種或者兩種以上不同的材料組成，然而半導(dǎo)體由于它們非同尋常的電學(xué)性質(zhì)而得到使用；生物材料被移植進入人類的身體中。關(guān)于材料類型和他們特殊的特

4、征的一個簡單的解釋將在后面給出。METALSMetallic materials are normally combinations of metallic elements. They have large numbers of nonlocalized electrons; that is, these electrons are not bound to particularatoms. Many properties of metals are directly able to these electrons.be bound to 被約束于。be attribute to 歸屬于。歸

5、因于。譯文：金屬材料通常由金屬元素組成。它們有大量無規(guī)則運動的電子。也就是說，這些電子不是被約束于某個特定的原子。金屬的許多性質(zhì)直接歸屬這些不規(guī)則運動的電子。Metals are extremely good conductors of electricity and heat and are not transparent to visible light; a polished metal surface has a lustrous appearance. Furthermore, metals are quite strong, yet deformable, which accoun

6、ts for their extensive use in structural applications.科技英語在講述科學(xué)真理的時候通常用主動語態(tài)。如： Metals are extremely good conductors of electricity Deformable ？譯文：金屬是十分好的電和熱的導(dǎo)體，它們對可見光不透明；一個拋光的金屬表面有光輝的外表。除此之外，金屬是十分硬的，也是可變形的，這個性質(zhì)解釋了它們廣泛使用在結(jié)構(gòu)方面的應(yīng)用。CERAMICSCeramics are compounds between metallic and nonmetallic elements

7、; they are most frequently oxides, nitrides, and carbides. The wide range of materials that falls within this classification includes ceramics that are composed of clay minerals, cement, and glass.that引導(dǎo)的定語從句譯文：陶瓷是介于金屬和非金屬元素之間的化合物；它們通常是氧化物，氮化物和碳化物。落在這個分類種類中的寬的材料范圍包括陶瓷，它們由粘土礦物，水泥和玻璃組成。These materials

8、 are typically insulative to the passage of electricity and heat, and are more resistant to high temperatures and harsh environments than metals and polymers. With regard to mechanical behavior, ceramics are hard but very brittle.more. Than.with regard to.譯文：這些材料是典型的電和熱的絕緣體，并且它們比金屬和聚合物更加耐高溫和耐苛刻的環(huán)境。至

9、于機械性能，陶瓷是硬的但是卻很脆。POLYMERSPolymers include the familiar plastic and rubber materials. Many of them are organic compounds that are chemically based on carbon, hydrogen, and other nonmetallic elements; furthermore, they have very large molecular structures. These materials typically have low densities

10、and may be extremely flexible.譯文：聚合物包括常見的塑料和橡膠材料。它們中的大多數(shù)是有機化合物，這些化合物是以化學(xué)的方法把碳、氫和其他非金屬元素組合而成。因此，它們有非常大的分子結(jié)構(gòu)。這些材料通常有低的密度并且可能十分柔軟。COMPOSITESA number of composite materials have been engineered that consist of more than one material type. Fiberglass is a familiar example, in which glass fibers are embed

11、ded within a polymeric material.more than譯文：許多復(fù)合材料被作用工程使用，它們由至少一種類型的材料組成。玻璃絲是一個熟悉的例子，玻璃纖維被埋入聚合物材料中。A composite is designed to display a combination of the best characteristics of each of the component materials. Fiberglass acquires strength from the glass and flexibility from the polymer. Many of th

12、e recent material developments have involved composite materials.譯文：為了聯(lián)合顯示每一種組分材料最好的特性，一種復(fù)合材料被設(shè)計出來。玻璃絲從玻璃中獲得強度并且從聚合物中獲得柔軟性。最近發(fā)展中的絕大多數(shù)材料包含了復(fù)合材料。SEMICONDUCTORSSemiconductors have electrical properties that are intermediate between the electrical conductors and insulators. Furthermore, the electrical c

13、haracteristics of these materials are extremely sensitive to the presence of minute concentrations of impurity atoms, which concentrations may be controlled over very small spatial regions. be sensitive to 對敏感的譯文：半導(dǎo)體有電的性質(zhì)，它們是介于電導(dǎo)體和絕緣體之間的中間物。除此之外，這些材料的電學(xué)性質(zhì)對微量雜質(zhì)原子的存在十分敏感，雜質(zhì)原子濃度可能只是在一個十分小的區(qū)域內(nèi)可以控制。The s

14、emiconductors have made possible the advent of integrated circuitry that has totally revolutionized the electronics and computer industries (not to mention ourlives) over the past two decades.譯文：這些半導(dǎo)體使得集成電路的出現(xiàn)變得可能，在過去20多年間，這些集成電路革新了電子裝置和計算機工業(yè)（更不用說我們的生活）。BIOMATERIALSBiomaterials are employed in compo

15、nents implanted into the human body for replacement of diseased or damaged body parts. These materials must not produce toxic substances and must be compatible with body tissues (i.e., must not cause adverse biological reactions).譯文：生物材料被應(yīng)用于移植進入人類身體以取代病變的或者損壞的身體部件。這些材料不能產(chǎn)生有毒物質(zhì)而且必須同人身體器官要相容（比如，不能導(dǎo)致相反

16、的生物反應(yīng)）。All of the above materialsmetals, ceramics, polymers,composites, and semiconductorsmay be used as biomaterials. For example, some of the biomaterials such as CF/C (carbon fibers/carbon) and CF/PS (polysulfone) are utilized in artificial hip replacements.譯文：所有以上材料金屬，陶瓷，聚合物，復(fù)合材料和半導(dǎo)體材料可能用作生物材料。比

17、如，如CF/C和CF/PS（聚砜）這些生物材料被用作人工腎的取代物。ADVANCED MATERIALSMaterials that are utilized in high-technology (or high-tech) applications are sometimes termed advanced materials. By high technology we mean a device or product that operates or functions using relatively intricate and sophisticated principles; e

18、xamples include electronic equipment (VCRs, CD players, etc.), computers, fiberoptic systems, spacecraft, aircraft, and military rocketry.譯文：用在高科技中的材料有時被稱作先進材料。借助于高科技，我們預(yù)定一個裝置或者產(chǎn)品，這些產(chǎn)品用相對復(fù)雜和熟練的原理運轉(zhuǎn)或者起作用；這些例子包括電子設(shè)備（ VCRs, CD 播放器），計算機，光纖系統(tǒng)，宇宙飛船，航天飛機和軍事火箭。These advanced materials are typically either t

19、raditional materials whose properties have been enhanced or newly developed, high-performance materials. Furthermore, they may be of all material types (e.g., metals, ceramics, polymers), and are normally relatively expensive.譯文：這些高級材料或是典型的傳統(tǒng)材料，它們的性質(zhì)被提高，最近開發(fā)出來的，高性能材料。除此之外，它們可能是所有材料類型（比如，金屬、陶瓷和聚合物），通

20、常相對較貴。In subsequent chapters are discussed the properties and applications of a number of advanced materialsfor example, materials that are used for lasers, integrated circuits, magnetic information storage, liquid crystal displays (LCDs),fiber optics, and the thermal protection system for the Space

21、 Shuttle Orbiter.譯文： 在下面的章節(jié)將討論眾多先進材料的性質(zhì)和應(yīng)用比如被用作激光，集成電路，磁信息存儲，液晶顯示器，光纖和空間艙軌道的熱保護系統(tǒng)的材料。MODERN MATERIALS NEEDSIn spite of the tremendous progress that has been made in the discipline of materials science and engineering within the past few years, there still remain technological challenges, including t

22、he development of even more sophisticated and specialized materials, as well as consideration of the environmental impact of materials production. Some comment is appropriate relative to these issues so as to round outthis perspective.譯文：在過去幾年內(nèi)，不論材料科學(xué)與工程的規(guī)律取得了巨大的進步，仍然有一些技術(shù)挑戰(zhàn)，包括開發(fā)更加熟練的專業(yè)化的材料，并且考慮材料生產(chǎn)

23、對環(huán)境導(dǎo)致的影響。針對這個問題，一些評論是十分相關(guān)的。Nuclear energy holds some promise, but the solutions to the many problems that remain will necessarily involve materials, from fuels to containment structures to facilities for the disposal of radioactive waste.譯文：核能還保持著一些承諾，但是解決許多仍然存在的問題，將有必要把材料包括在里，從燃料到保護結(jié)構(gòu)以便方便處置這些放射性廢料。

24、Significant quantities of energy are involved in transportation. Reducing the weight of transportation vehicles (automobiles, aircraft, trains, etc.), as well as increasing engine operating temperatures, will enhance fuel efficiency. New high strength,low-density structural materials remain to be de

25、veloped, as well as materials that have higher-temperature capabilities, for use in engine components.譯文：相當(dāng)數(shù)量的能源用在交通上。減少交通工具（汽車，飛機，火車等）的重量，和提高引擎操作溫度，將提高燃料的使用效率。新的高強，低密度結(jié)構(gòu)材料仍在發(fā)展，用作引擎部位能耐高溫材料也在發(fā)展中。Furthermore, there is a recognized need to find new, economical sources of energy, and to use the present

26、 resources more efficiently. Materials will undoubtedly play a significant role in these developments.譯文：除此之外，尋找新的、經(jīng)濟的能源資源，并且更加有效的使用目前現(xiàn)存的資源是公認(rèn)為必須的。材料將毫無疑問的在這些發(fā)展過程中扮演重要的角色。For example, the direct conversion of solar into electrical energy has been demonstrated. Solar cells employ some rather complex

27、and expensive materials. To ensure a viable technology, materials that are highly efficient in this conversion process yet less costly must be developed.譯文：比如，太陽能直接轉(zhuǎn)化為電能已經(jīng)被證實了。太陽能電池使用相當(dāng)復(fù)雜并且昂貴的材料。為了保證技術(shù)的可行，在這個轉(zhuǎn)化過程中的高效但不貴的材料必須被發(fā)展。Furthermore, environmental quality depends on our ability to control air

28、 and water pollution. Pollution control techniques employ various materials. In addition, materials processing and refinement methods need to be improved so that theyproduce less environmental degradation, that is, less pollution and less despoilage of the landscape from the mining of raw materials.譯文：除此之外，環(huán)境質(zhì)量取決于我們控制大氣和水污染的能力。污染控制技術(shù)使用了各種材料。再者，材料加工和精制的方法需要改善以便它們產(chǎn)生很少的環(huán)境退化，也就是說，在生材料加工過程中，帶來更少的污染和更少的對自然環(huán)境的破壞。Also, in some materials manufacturing processes, toxic substances are produced, and the ecological impact of theirdisposal must be considered.Many materials that we use are derived fr