| 北京夏季高温高湿和降水过程对大气颗粒物谱分布的影响 |
| 摘要点击 8903 全文点击 2571 |
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| 中文关键词 颗粒物 质量浓度谱分布 数浓度谱分布 高温高湿 降雨 |
| 英文关键词 particle mass size distribution number size distribution high temperature, high relative humidity rainfall |
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| 中文摘要 |
| 2004-07-13～2004-08-23使用TDMPS-APS系统在线测量颗粒物的数浓度谱分布，并于07-16～07-18选取了高温闷热夜晚、日间高温高湿和雨后晴朗干洁3种天气条件，使用多级串联撞击式采样器（MOUDI）测量颗粒物的质量浓度谱分布，结果表明：高温高湿天气条件下颗粒物的污染、尤其细粒子污染严重，导致很低的能见度（2.5km）；PM1.8和PM10的质量浓度分别为170.68μg/m3和249.35μg/m3，细粒子质量浓度占PM10的68%；粒径为50～100nm颗粒物的数浓度最高，为2×104～3×104个/cm3；降雨过程对粗粒子和细粒子均有去除作用，对细粒子的去除作用尤为明显；降雨后PM10和PM1.8浓度分别比降雨前降低3倍和6倍；降雨过后的晴朗干洁天气有利于新粒子（3～20nm）的生成，生成的新粒子快速长大到50～100nm；随着污染物的累积，以后几天内又变为污染天气。 |
| 英文摘要 |
| On-line measurements of particle number size distribution were conducted during 2004-07-13～2004-08-23 by using TDMPS-APS system in Beijing; in between the size distributions of particle mass and chemical compositions were measured by using MOUDI cascade impactor under three kinds of weather conditions: ① high temperature and high relative humidity night, ② high temperature and high relative humidity day, and ③ clear days. The results indicate that particulate matter, especially fine particle pollution becomes severe under high temperature and high relative humidity conditions, which results in low visibility (2.5km); the average concentrations of PM1.8 and PM10 are 170.68μg/m3 and 249.35μg/m3, respectively, PM1.8 accounts for 68% of PM10; number concentration mainly concentrates in the range of 50～100nm, about 2×104～3×104cm-3; rain process has a great effect on scavenging particles, especially fine particles. After the rain process PM10 is 3 times lower and PM1.8 is 6 times lower than the values before the rain; in the following clear day, new particle formation is observed, the newly formed particles (3～20nm) grow to 50～100nm rapidly. After that, the pollutants start to accumulate and it becomes heavy polluted in few days. |
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