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春季气温回升较快,低层空气极不稳定,低层空气的流动将地面沙尘卷向空中形成沙尘(浮沉、扬沙、沙尘暴)天气,是干旱地区特有的一种灾害性天气。近年来,我国北方沙尘天气发生频繁,影响区域广泛,对人体健康的危害日益受到人们的关注。1沙尘和沙尘暴天气的特征1.1沙尘的理化性质1.1.1沙尘中含有大量呼吸性粉尘沙尘由粗沙粒和大量细颗粒物(粉尘)组成,沙粒大小多集中在0.1~0.5 mm,粉尘则在0.003 9~0.250 0 mm,其中
In spring, the temperature rises rapidly and the low-level air is extremely unstable. The flow of low-level air turns the dust on the surface into the air to form dust (dust, sand, sand and dust). It is a severe weather unique to arid areas. In recent years, frequent occurrence of dust weather in northern China has affected a wide range of areas and harms people’s health. 1 Dust and sandstorm weather characteristics 1.1 Physical and chemical properties of dust 1.1.1 Dust contains a large number of respiratory dust Dust from the coarse sand and a large number of fine particles (dust) composition, sand size mostly concentrated in the 0.1 ~ 0.5 mm , While the dust is 0.003 9 ~ 0.250 0 mm, of which