中石油英语60篇课文翻译.doc

一、Carbon-based Alternative 碳基替代燃料 1.Although recent years have seen substantial reductions in noxious pollutants from individual motor vehicles, the number of such vehicles has been steadily increasing. Consequently, more than 100 cities in the United States still have levels of carbon monoxide, particulate matter, and ozone (generated by photochemical reactions with hydrocarbons from vehicle exhaust) that exceed legally established limits. There is a growing realization that the only effective way to achieve further reductions in vehicle emissions-short of a massive shift away from the private automobile- is to replace conventional diesel fuel and gasoline with cleaner-burning fuels such as compressed natural gas. liquefied petroleum gas, ethanol, or methanol. 1、尽管近几年来私人机动车辆排放的有害污染物已有相当程度的减少，但这类车辆的数量却仍在稳 定地增长。因此，美国100多个城市仍然存在着超过法律限定的一氧化碳、悬浮颗粒物和臭氧（由于 车辆排出气体中碳氢化合物经过光化反应产生）。人们逐渐认识到实现车辆尾气排放更进一步减少的 唯一有效方法--大规模消减私人小汽车除外--是用燃烧更为清洁的燃料，如压缩天然气、液化石油气、 乙醇或甲醇代替传统的柴油和汽油。 2.All of these alternatives are carbon-based fuels whose molecules are smaller and simpler than those of gasoline. These molecules burn more cleanly than gasoline, in part because they have fewer, if any, carbon-carbon bonds and the hydrocarbons they do emit are less likely to generate ozone. The combustion of larger molecules, which have multiple carbon-carbon bonds involves a more complex series of reactions. These reactions increase the probability of incomplete combustion and are more likely to release uncombusted and photochemically active hydrocarbon compounds into the atmosphere. On the other hand, alternative fuels do have drawbacks. Compressed natural gas would require that vehicles have set of heavy fuel tanks- a serious liability in terms of performance and fuel efficiency-and liquefied petroleum gas faces fundamental limits on supply. 2、所有这些替代物都是碳基燃料，它的分子要比汽油的小而简单。这些分子要比汽油燃烧得更为清 洁，部分是因为他们碳-碳键较少，而且即使会释放出碳氢化合物，也不太可能会成为臭氧。较大分子 的燃烧，由于它们具有多重碳-碳，伴随着更为复杂的一系列反应。这些反应增加了不完全燃烧得可能性并且易于放出未燃烧的、易起光化反应的碳氢化合物释放到大气中。从