利用在线单颗粒气溶胶质谱仪(single particle aerosol mass spectrometer,简称SPAMS)对七种品牌香烟烟气气溶胶颗粒粒径及化学成分进行检测,研究七种不同口味的香烟烟气气溶胶化学成分与粒径的差异及老化过程中硫酸盐、硝酸盐、氯离子...
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利用在线单颗粒气溶胶质谱仪(single particle aerosol mass spectrometer,简称SPAMS)对七种品牌香烟烟气气溶胶颗粒粒径及化学成分进行检测,研究七种不同口味的香烟烟气气溶胶化学成分与粒径的差异及老化过程中硫酸盐、硝酸盐、氯离子、苯系物的变化情况。结果表明,香烟烟气气溶胶化学成分与不同粒径段上颗粒数比例的差异可能是导致不同种香烟口感差异的原因之一;烟气气溶胶老化硫酸盐和硝酸盐的数浓度百分含量增加,这是因为硫氧化物和氮氧化物转化成硫酸盐和硝酸盐,而氯离子含量的减少则可能是发生了非均相取代反应;新鲜烟气中苯系物数浓度百分含量最低,随着老化时间的增加,苯系物的数浓度百分含量逐渐上升,这可能是由于在老化过程中,烟气中的苯系物由气相到粒相之间的转化。
Using the visibility data during 2010 to 2012 obtained at Shenyang Atmosphere Observation Center, the relationships between visibility, PM mass concentration and meteorological elements were statistically analyzed. Th...
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Using the visibility data during 2010 to 2012 obtained at Shenyang Atmosphere Observation Center, the relationships between visibility, PM mass concentration and meteorological elements were statistically analyzed. The results show that: The monthly averaged visibility over Shenyang is higher in March and September with values about 19.0±4.3km and 17.1±4.3km, respectively. Low visibilities over Shenyang occur in January about 11.0±4.7km. Among the meteorological elements, wind speed was the main meteorological factor that influenced visibility and the PM mass concentrations. The number of days with visibility >19.0 km and visibility <10.0 km in Shenyang are 59, 123, 145 and 132, 119, 121 from 2010 to 2012. The relationship between visibility and PM indicated that human activities are already main sources of the pollutants, especially the fine particles which is the most important factor for the deterioration of visibility. The study shows an obvious diurnal variation and weekend effect of visibility and PM which are mainly due to human activities.
类腐殖质气溶胶(HULIS)是大气有机气溶胶的主要组成部分,对云凝结核的形成和气溶胶吸湿性增长至起着重要作用,但是HULIS的性质和来源在很大程度上仍是未知的。本文使用固相萃取法获得了2008年7月至2009年8月间西安PM2.5中的HULIS,并采用热光法获得HULIS的碳含量(HULIS-C)。HULIS-C年均质量浓度为3.1±3.0μg C m-3。HULIS含量冬季最高(6.2μg C m-3),秋季次之(3.3μg C m-3)、夏季(1.5μg C m-3)和春季较低(1.2μg C m-3)。冬季高浓度的主要原因是冬季能源消耗量大,比如燃煤和生物质燃烧;而春夏季低浓度主要是由于较少的能源消耗和较丰富的降水。HULIS是水溶性有机碳(WSOC)的重要组分,占WSOC的34.5%,表明其是影响WSOC吸湿性的重要组分;相关性分析表明,HULIS与左旋葡聚糖(r=0.84)和K+(r=0.81)呈显著相关,说明HULIS主要来源于生物质燃烧;此外,HULIS与二次有机碳(SOC)相关性良好(r=0.83),表明HULIS同时有二次来源。
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