astronomical > Los Angeles Photochemical smog incident
No. 1
洛杉矶光化学烟雾事件
洛杉矶光化学烟雾事件
洛杉矶光化学烟雾事件
洛杉矶光化学烟雾事件
Los Angeles in the United States of acute air pollution incidents. The city is surrounded by mountains, in a narrow basin. Vehicle emissions of hydrocarbons and nitrogen oxides formed by the photochemical reaction with the stimulating light blue or white photochemical smog. Since 1942, occurred several times since.
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No. 2
洛杉矶光化学烟雾事件
洛杉矶光化学烟雾事件
Los Angeles is located in the southwest coast of the United States, west sea, surrounded by mountains, is a sunny, warm climate, scenic places. Early gold, oil and the development of the canal, combined with geographical location, it soon became a business and tourism are well developed port city. Photochemical smog is due to automobile exhaust and industrial emissions caused by the generally occurs in low humidity, the temperature at 24-32 ℃ degree sunny day at noon or afternoon in summer. Automobile exhaust olefin hydrocarbons and nitrogen dioxide (no2) is emitted into the atmosphere, the ultraviolet radiation in the strong sunlight, will absorb the energy of sunlight possess. Molecules of these substances in the absorption of the energy of sunlight, it will become unstable together, the destruction of existing chemical chain to form new substances. This chemical reaction is known as photochemical reactions, and its product as containing highly toxic photochemical smog. Los Angeles in 40 years to 250 million vehicles a day, consumes about 1,100 tons of gasoline, emit more than 1,000 tons of hydrocarbon (ch) compounds, 3o0 tons of nitrogen oxide (nox) compounds, 700 tons of carbon monoxide (co). In addition, refineries, fuel stations and other petroleum combustion emissions, these compounds are released into the sunny skies above Los Angeles, nothing less than create a toxic smoke fog factory. Los Angeles photochemical smog event in the early 20th century, 40 in the United States at a Los Angeles smog. Los Angeles was the third largest city in the U.S., with aircraft manufacturing, military and other industries. Up to 400 million units of various vehicles, highways criss-crossing the city, accounting for 30% area of the city, each day through the car road 16.8 million vehicles. As the automotive oil, exhaust, gasoline evaporation, incomplete combustion, emissions over the city every day to a large number of petroleum hydrocarbon gases, carbon monoxide, nitrogen oxides and lead in smoke. These emissions, the role of solar energy through chemical reactions to produce peroxy acetyl nitrate and other components of a light blue photochemical smog, in addition to Los Angeles, surrounded by the mountain terrain, photochemical smog is not spread open, stuck in the city over the formation of pollution.
