材料科学专业英语翻译

1. Polyethylene is pliable and is used for applications such as “squeeze bottles.” In polystyrene, the comparatively large benzene side group restricts the motion of the long-chain molecules and makes the structure more rigid. If the benzene group in polystyrene is replaced with a Cl atom (intermediate in size between H and the benzene ring), polyvinylchloride is produced. The Cl atom will restrict the chain mobility more than an H atom but less than a benzene ring. A leathery material is produced with somewhat intermediate properties between polyethylene and polystyrene.

聚乙烯非常柔软，可以应用在“挤瓶”中，在聚苯乙烯中，较大的苯环侧基限制了长链分子的运动，使得结构变得刚性变大。如果苯乙烯中的苯环被氯原子代替（氯原子的尺寸在氢原子和苯环之间），就得到了聚氯乙烯。氯原子也会限制分子链的运动，但其限制能力比氢原子强但比苯环弱。从而生成性质介于聚乙烯和聚苯乙烯之间的皮革状材料。

2. The basic techniques used for processing materials may be divided into the following categories: (1) casting, (2) forming, (3) powder processing, and (4) machining. Not all processes are equally applicable to all material types.

加工材料的基本技术可以分为以下几类：(1)铸造，(2)成形，(3)粉体工艺和(4)机加工。不是所有的工艺都可以应用于所有类型材料的。

3. The major classes of engineering materials are considered to be ①metals, ②ceramics, ③polymers, ④composites, and ⑤semiconductors.

工程材料可以考虑分成以下几大类：金属、陶瓷、聚合物、复合材料和半导体。

4. The size scale of microelectronic devices continues to decrease. While a typical “chip” in a 486-computer contains about 1 million devices, it is anticipated that by the year 2000, chips will contain on the order of 100 million devices. This will result in smaller, faster, more powerful electronic devices of all kinds.

微电子器件的尺寸继续减小。486计算机中的典型芯片含有100万个器件，预计到2000年，芯片将会含有1亿个这样的器件。而这会使得所有类型的电子装置尺寸更小，速度更快，更加强大。

5. The electrical properties of polymers can be largely affected by impurities, either added impurities, naturally occurring impurities, or impurities on the surface. For example, the application of an antistatic coating or the addition of ions into the bulk of a polymer can change the conductivity of textile fibers by five orders of magnitude. Uncoated fibers can lead to serous static discharge problems, like the failure of a parachute to open.

杂质，不管是加入的，天然存在的还是表现上的，都会对聚合物的电性能产生很大的影响。比如，利用抗静电涂层或者在聚合物本体中加入离子，会使纺织纤维的电导率增加5倍。没有涂层的纤维会导致像降落伞打不开的严重的静电放电现象。

6. High-purity, acid-containing acrylic fiber yarn proceeds under tension into a circulating air oven at about 250℃, where the fiber oxidizes without melting. The black stabilized materials is then carbonized at about 1500℃in an inert atmosphere to remove all atoms except carbon. Finally, the fiber is heated to temperatures as high as 3000℃to develop high modulus.

高纯，含酸的丙烯酸纤维在拉伸状态下通过250℃的循环空气加热炉，纤维在不熔化的状态下氧化。接着，黑色的稳定化材料在1500℃的惰性气体中碳化，除去碳以外的所有原子。