State Key Laboratory of Coal Resources and Safe Mining, School of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing 100083, China.
Sci Total Environ. 2012 Jul 15;430:217-22. doi: 10.1016/j.scitotenv.2012.04.050. Epub 2012 May 29.
Atmospheric particles larger than 0.2 μm were collected at the top of Mt. Tai (36.25°N, 117.10°E, 1534 m a.s.l.) in eastern China in May 2008 during the passage of a strong cyclone. The particles were analyzed with electron microscopes and characterized by morphology, equivalent diameter and elemental composition. Soot particles with coating (coated soot particles) and those without apparent coating (naked soot particles) were predominant in the diameter range smaller than 0.6 μm in all samples. The number-size distribution of the relative abundance of naked soot particles in the prefrontal air was similar to that in the postfrontal air and their size modes were around 0.2-0.3 μm. However, the distribution of inclusions of coated soot particles showed a mode in the range of 0.1-0.3 μm. The coating degree of coated soot particles, which was defined by the ratio of the diameter of inclusion to the diameter of particle body, showed a mode around 0.5 with the range of 0.3-0.6. These results indicate that the status of soot particles in the prefrontal and postfrontal air was similar although air pollution levels were dramatically different. In addition, the relative abundance of accumulation mode particles increased with the decrease of soot particles after the front passage.
大气中直径大于 0.2μm 的粒子于 2008 年 5 月在中国东部泰山（36.25°N，117.10°E，1534m 海拔）山顶被采集，当时有一股强烈的气旋经过。这些粒子用电子显微镜进行了分析，并根据形态、等效直径和元素组成进行了特征描述。在所有样本中，直径小于 0.6μm 的范围内主要存在带涂层的（涂覆烟尘颗粒）和没有明显涂层的（无涂层烟尘颗粒）烟尘颗粒。在锋前空气中，无涂层烟尘颗粒的相对丰度的数-径分布与锋后空气中的相似，其粒径模式在 0.2-0.3μm 左右。然而，涂覆烟尘颗粒包裹体的分布呈现出 0.1-0.3μm 的模式。涂覆烟尘颗粒的涂层程度由包裹体直径与颗粒体直径的比值定义，其模式在 0.5 左右，范围在 0.3-0.6。这些结果表明，尽管空气污染水平有很大差异，但锋前和锋后空气中的烟尘颗粒状态相似。此外，在前锋过后，随着烟尘颗粒的减少，积聚模态粒子的相对丰度增加。
