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本文利用先进的高分辨飞行时间气溶胶质谱仪(HR-ToF-AMS)于2011年深圳世界大学生运动会前后(2011年8月3日~9月22日)对深圳市区大气亚微米细粒子(PM1)化学成分和粒径分布进行了在线测量.结果表明,整个观测期间PM1质量浓度平均为51.1±32.6gm3,其中有机物占颗粒物总质量的37.9%,硫酸盐为37.1%,铵盐11.9%,黑碳6.6%(由一台单颗粒黑碳光度计(SP2)单独测量),硝酸盐5.8%,氯化物0.6%.观测期间各成分(除黑碳外)的粒径分布峰值位于真空动力学粒径550nm附近,而有机物在较小粒径范围(100~200nm)仍有较多质量分布,显示出本地一次源的明显贡献.基于高分辨有机质谱计算得到的有机气溶胶的平均元素组成为:碳34.0%、氢53.2%、氧12.0%和氮0.8%(原子个数百分比),对应的OM/OC(有机物与有机碳质量比)平均值为1.66±0.16.采用正矩阵因子解析(PMF)模型对有机气溶胶高分辨质谱进行因子解析,得到三类有机气溶胶:HOA(还原态有机气溶胶),SV-OOA(半挥发氧化态有机气溶胶)和LV-OOA(低挥发氧化态有机气溶胶),分别占有机物总量的31.3%,39.8%和28.9%,说明二次有机气溶胶(以SV-OOA和LV-OOA之和代表)是有机气溶胶的主体部分.结合气团来源分析不同时段PM1化学组成和粒径分布特征表明,大运会召开期间PM1质量浓度水平比整个观测期间的平均值低60.7%,是气团来自洋面等有利气象条件和黄标车限行等污染源控制措施的综合作用结果.
In this paper, we used the advanced HR-ToF-AMS to analyze the atmospheric sub-micron fine particles in Shenzhen city before and after the 2011 Shenzhen Universiade (August 3 to September 22, 2011) PM1) were measured online.The results showed that the average concentration of PM1 was 51.1 ± 32.6gm3 during the whole observation period, of which organic accounted for 37.9% of the total mass of the particles, sulfate was 37.1% and ammonium was 11.9% Black carbon 6.6% (measured separately by a single particle black carbon photometer (SP2)), nitrate 5.8%, chloride 0.6% The peak of the particle size distribution of each component (excluding black carbon) Particle size of 550nm near the organic matter in the smaller size range (100 ~ 200nm) is still more mass distribution, showing a significant contribution to the local primary source calculated based on high-resolution organic mass spectra of organic aerosols average elemental composition of (34.0% of carbon, 53.2% of hydrogen, 12.0% of oxygen and 0.8% of nitrogen (atomic percentages)), and the corresponding OM / OC average mass ratio of organic matter to organic carbon was 1.66 ± 0.16. Positive matrix factor analysis ) Model of organic aerosol high-resolution mass spectrometry factor analysis, three types of organic Aerosols: HOA (reduced organic aerosol), SV-OOA (organic volatile aerosol) and LV-OOA (low volatile organic oxide aerosol) accounted for 31.3% and 39.8% of the total organic compounds, respectively 28.9%, indicating that the secondary organic aerosol (represented by the sum of SV-OOA and LV-OOA) is the main part of the organic aerosol.The analysis of chemical composition and particle size distribution of PM1 in different periods by combining the source of air mass indicates that during the Universiade PM1 The mass concentration level is 60.7% lower than the average during the whole observation period, which is the combined effect of control measures such as favorable meteorological conditions such as the ocean surface and the limit line of yellow markings.