时间:2019-02-17 作者:英语课 分类:双语有声阅读


英语课
Hydrogen and Industries
 
Hydrogen,the lightest and simplest of the elements, has several properties that make it valuable for many industries. It releases more heat per unit of weight than any other fuel.In rocket engines, tons of hydrogen and oxygen are burned, and hydrogen is used with oxygen for welding torches that produce temperatures as high as 4, 000 degrees F and can be used in cutting steel. Fuel cells to generate electricity operate on hydrogen and oxygen.
 
Hydrogen also serves to prevent metals from tarnishing 1 during heat treatments by removing the oxygen from them. Although it would be difficult to remove the oxygen by itself, hydrogen readily combines with oxygen to form water, which can be heated to steam and easily removed.
 
Hydrogen is also useful in the food industry for a process know as hydrogenation. Products such as margarine and cooking oils are changed from liquids to semisolids by adding hydrogen to their molecules 2. Soap manufacturers also use hydrogen for this purpose.
 
Hydrogen is also one of the coolest refrigerants. It does not become a liquid until it reaches temperatures of -425 degrees F. Pure hydrogen gas is used in large electric generators 3 to cool the coils. In addition, in the chemical industry, hydrogen is used to produce ammonia, gasoline, methyl alcohol, and many other important products.
 

氢与工业
 
氢作为最轻和最简单的无素,有几种特性对工业非常有用。 作为燃料,它每单位重量释放热量最多,在火箭的引擎中,成吨的氢和氧被燃烧掉。 氢和氧合在一起用于焊接,能够产生高达华氏四千度的高温而可以切割钢铁。发电的燃料房就是使用氢和氧。氢也可以用来在金属热处理中通过从中除去氧的方法来防锈。虽然单独除去氧本身是困难的,氢和氧很容易结合成水,而水是可以加热蒸发除去的。 氢在食品工业中对于所谓的氢化过程也很有用。 人造黄油和食用油的分子中加上氢,就由液态变成半固态。 肥皂制造商也为此使用氢。 氢是温度最低的冷冻剂。 它要到华氏-425 度才会液化。 纯氢被用于大型发电机线圈的冷却。 除此之外,在化学工业中,氢被用来制造氨、汽油、甲醇以及其它许多重要产品。


(印花)白地沾色
  • The causes of tarnishing gold and silver-plated connectors were studied respectively. 分别探讨了接插件镀金和镀银层变色的原因。
  • Bright tin electrodeposits on copper wire are susceptible to tarnishing. 铜线材经光亮镀锡后易产生腐蚀变色。
分子( molecule的名词复数 )
  • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
  • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里,大分子裂变为小分子。
n.发电机,发生器( generator的名词复数 );电力公司
  • The factory's emergency generators were used during the power cut. 工厂应急发电机在停电期间用上了。
  • Power can be fed from wind generators into the electricity grid system. 电力可以从风力发电机流入输电网。 来自《简明英汉词典》