英语听力文摘 English Digest 589、挡风玻璃为何如此牢实？

 　　What Makes Windshield Glass So Tough?

 

　　We tend to think of glass as fragile–but in fact, glass is pretty strong stuff.

 

　　A flawless fiber¹ of glass pulled lengthwise is five times stronger than steel! Although glass is quite strong, it’s also very brittle–and the brittleness² explains why glass breaks so easily.

 

　　But windshields in cars and airplanes are much more resistant³ to breaking than regular glass.

 

　　What Makes Windshield Glass So Tough?

 

　　Glass is commonly made more resistant to breaking in one of two ways: by tempering or by laminating it. Tempered glass is first heated just below melting, then exposed to bursts of cold air. The cold cools and shrinks the surface of the glass faster than the inside, compressing the surface inward.

 

　　This more dense⁴, inwardly compressed surface makes the glass stronger, so it takes a lot more force to break it. Tempered glass shatters into tiny bits, rather than large, jagged shards⁵ like regular glass. If you’ve seen little squares of a car windshield scattered⁶ on the street, you’ve seen how tempered glass shatters.

 

　　Car windshields are also commonly made from laminated glass, which has a tough, thin layer of plastic sandwiched between two layers of glass. If laminated glass shatters, it remains⁷ sticking to the plastic rather than scattering⁸ in splinters or shards.

 

　　Airplane windshields and bullet-resistant glass take this concept to a whole new level, with several layers of plastic layered with, and bonded⁹ to, layers of glass. That makes a composite material strong enough to withstand high pressures, varying temperatures, and even the impact of a bullet or an unlucky bird.

 

 

 

 

　　挡风玻璃为何如此牢实？

 

　　我们往往认为玻璃是易碎的—但事实上，玻璃很坚固。

 

　　无裂缝的玻璃纤维纵向拉长后其坚固程度是钢的五倍！玻璃虽然足够坚固，但同时它也非常脆—这也解释了为何玻璃如此易碎。

 

　　但汽车和飞机上的挡风玻璃却比普通玻璃牢固多了。

 

　　挡风玻璃何以如此牢实？

 

　　有两种办法可以造出更牢固的玻璃：钢化或是层压。制造钢化玻璃首先要将玻璃加热升温接近其熔点，然后直接暴露于冷空气中。低温促使玻璃表面比内部冷却和收缩得更快。

 

　　由于密度增加，表面收缩内陷，玻璃的强度也增加了，因此打碎玻璃需要的力量也就更大了。钢化玻璃破裂时不会像普通玻璃那样形成大块，锋利的碎片，而是会碎成细块。如果你见过街上散落的汽车挡风玻璃的小碎块，你就会知道钢化玻璃破碎后是怎样的了。

 

　　汽车挡风玻璃也经常采用层压玻璃，这种玻璃表面坚硬，两层玻璃之间有一层薄塑料，层压玻璃损坏时，玻璃碎片会沾在塑料上，而不会散落得到处都是。

 

　　通过将多层塑料夹层和多层玻璃叠压在一起，飞机挡风玻璃和防弹玻璃将层压玻璃的概念提升到了一个全新高度。这种复合材料牢固到能经受高压、温度变化，甚至是子弹的影响，更不用说撞到飞机上的倒霉的鸟儿了。

1 fiber   

n.纤维，纤维质

参考例句：

• The basic structural unit of yarn is the fiber.纤维是纱的基本结构单元。
• The material must be free of fiber clumps.这种材料必须无纤维块。

2 brittleness   

n.脆性，脆度，脆弱性

参考例句：

• Brittleness is often a result of alloying. 脆性往往是合金化的一种结果。 来自辞典例句
• The mechanism of brittleness of the alloy has been discussed. 对硬质含金脆性机理进行了探讨。 来自互联网

3 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

4 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

5 shards   

n.（玻璃、金属或其他硬物的）尖利的碎片( shard的名词复数 )

参考例句：

• Eyewitnesses spoke of rocks and shards of glass flying in the air. 目击者称空中石块和玻璃碎片四溅。 来自辞典例句
• Ward, Josh Billings, and a host of others have survived only in scattered shards of humour. 沃德、比林斯和许多别的作家能够留传下来的只是些幽默的残章断简。 来自辞典例句

6 scattered   

adj.分散的，稀疏的；散步的；疏疏落落的

参考例句：

• Gathering up his scattered papers,he pushed them into his case.他把散乱的文件收拾起来，塞进文件夹里。

7 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

8 scattering   

n.[物]散射；散乱，分散；在媒介质中的散播adj.散乱的；分散在不同范围的；广泛扩散的；（选票）数量分散的v.散射(scatter的ing形式)；散布；驱散

参考例句：

• The child felle into a rage and began scattering its toys about. 这孩子突发狂怒，把玩具扔得满地都是。 来自《简明英汉词典》
• The farmers are scattering seed. 农夫们在播种。 来自《简明英汉词典》

9 bonded   

n.有担保的，保税的，粘合的

参考例句：

• The whisky was taken to bonded warehouses at Port Dundee.威士忌酒已送到邓迪港的保稅仓库。
• This adhesive must be applied to both surfaces which are to be bonded together.要粘接的两个面都必须涂上这种黏合剂。