据1992年报道,目前在西方国家,汽车排放的废气已成为城市空气最严重污染之一,汽油和柴油燃烧时排出的未燃尽的碳氢化合物、一氧化碳和二氧化碳,不仅污染环境,而且会加剧温室效应。在造成空气污染的汽车中,重型柴油车,尤其是大型公共汽车,最为严重。针对这种情况,日本日野汽车公司开发了一种柴油—电动混合发动机,使废气排放量减少20—30％,这种新发动机的自重只有500公斤,但效率要比一般柴油发动机高。西方纷纷制订严格的汽车排污标准,但 According to a report in 1992, in western countries, the emissions of motor vehicles have become one of the most serious urban air pollutants. Unburned hydrocarbons, carbon monoxide and carbon dioxide that are emitted during the combustion of gasoline and diesel fuel not only pollute the environment but also exacerbate the situation Greenhouse effect. Among the air pollution-causing vehicles, heavy-duty diesel vehicles, especially large buses, are the most serious ones. In response to this situation, Hino Motors Japan has developed a diesel-electric hybrid engine to reduce emissions by 20-30%, the new engine weighs only 500 kg, but more efficient than the average diesel engine. The West has set strict standards for car emissions, but