...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Atmospheric research >Characteristics of aerosol size distributions and chemical compositions during wintertime pollution episodes in Beijing
【24h】

Characteristics of aerosol size distributions and chemical compositions during wintertime pollution episodes in Beijing

机译：北京冬季污染发生期间气溶胶粒径分布和化学成分特征

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

To characterize the features of particle pollution, continuous measurements of partide number size distributions and chemical compositions were performed at an urban site in Beijing in January 2013. The particle number and volume concentration from 14 nm to 1000 nm were (37.4 +/- 153) x 10(3) cm(-3) and (85.2 +/- 65.6) mu m(3) cm(-3), respectively. N-Alt (Aitken mode) particles dominated the number concentration, whereas N-Acc (accumulation mode) particles dominated the volume concentration. Submicron particles were generally characterized by a high content of organics and SO42-, and a low level of NO3- and Cl-. Two types of pollution episodes were observed, characterized by the "explosive growth" (EXP) and "sustained growth" (SUS) of PM25. Fine particles greater than 100 nm dominated the volume concentration during the ends of these pollution episodes, shifting the maximum of the number size distribution from 60 nm to greater than 100 nm in a few hours (EXP) or a few days (SUS). Secondary transformation is the main reason for the pollution episodes; SO42-, NO3- and NH4+ (SNA) accounted for approximately 42% (EXP) and greater than 60% (SUS) of the N-Acc particle mass increase. The size distributions of particulate organics and SNA varied on timescales of hours to days, the characteristics of which changed from bimodal to unimodal during the evolution of haze episodes. The accumulation mode (peaking at approximately 500-700.nm) was dominated by organics that appeared to be internally mixed with nitrate or sulfate. The sulfate was most likely formed via heterogeneous reactions, because the SOR was constant under dry conditions (RH < 50%) and began to increase when RH > 50%, suggesting an important contribution from heterogeneous reactions with abundant aerosol water under wet conditions. Finally, the correlations between [NO3-]/[SO42-] and [NH4+][SO42-] suggest that the homogenous reaction between HNO3 and NH3 dominated the formation of nitrate under conditions of lower aerosol acidity. Therefore, controlling the precursors of SNA will effectively help to reduce the fine particulate pollution during winter in Beijing. (C) 2015 Elsevier B.V. All rights reserved.
机译：为了表征颗粒物污染的特征，2013年1月在北京的城市现场对颗粒物的粒径分布和化学成分进行了连续测量。颗粒数和体积浓度从14 nm到1000 nm为（37.4 +/- 153） x 10（3）cm（-3）和（85.2 +/- 65.6）微米（3）cm（-3）。 N-Alt（Aitken模式）粒子主导了数字浓度，而N-Acc（累积模式）粒子主导了体积浓度。亚微米颗粒的特征通常是有机物和SO42-含量高，NO3-和Cl-含量低。观察到两种类型的污染事件，其特征在于PM25的“爆炸性增长”（EXP）和“持续性增长”（SUS）。在这些污染事件的末期，大于100 nm的细颗粒占主导地位，在数小时（EXP）或几天（SUS）内，数大小分布的最大值从60 nm变为大于100 nm。二次转化是造成污染事件的主要原因。 SO42-，NO3-和NH4 +（SNA）约占N-Acc颗粒质量增加量的42％（EXP），大于60％（SUS）。颗粒有机物和SNA的大小分布在数小时至数天的时间尺度上变化，在霾事件演变过程中，其特征从双峰变为单峰。累积模式（大约在500-700.nm的峰值）主要由似乎与硝酸盐或硫酸盐内部混合的有机物所主导。硫酸盐很可能是通过异质反应形成的，因为SOR在干燥条件下（RH <50％）是恒定的，并且在RH> 50％时开始增加，这表明湿润条件下与大量气溶胶水的异质反应起了重要作用。最后，[NO3-] / [SO42-]与[NH4 +] [SO42-]之间的相关性表明，在较低的气溶胶酸度条件下，HNO3与NH3之间的均相反应主导了硝酸盐的形成。因此，控制SNA的前体将有效减少北京冬季的细颗粒物污染。 （C）2015 Elsevier B.V.保留所有权利。

著录项

  • 来源
    《Atmospheric research》 |2016年第2期|1-12|共12页
  • 作者

    Liu Zirui; Hu Bo; Zhang Junke; Yu Yangchun; Wang Yuesi;

  • 作者单位

    Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & Atm, Beijing 100029, Peoples R China;

    Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & Atm, Beijing 100029, Peoples R China;

    Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & Atm, Beijing 100029, Peoples R China;

    Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & Atm, Beijing 100029, Peoples R China;

    Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & Atm, Beijing 100029, Peoples R China;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Particle number size distribution; Chemical composition; Secondary transformation; Evolution of pollution episode;

    机译：粒度分布;化学成分;二次转化;污染发作的演变;

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号