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| 1 | 实验室模拟研究大气二次有机气溶胶的形成显示文摘二次有机气溶胶(SOA)是大气中重要的气溶胶组分,主要由挥发性有机物(VOCs)经化学转化形成,对天气、气候、大气环境和人体健康有重要影响,但至今其确切的化学成分和形成机制还十分不清楚。研究SOA的方法主要采用实验室单个物种或多物种的化学过程的模拟研究,野外实际大气的SOA化学成分、源汇和多尺度分析的观测研究,以及大气中SOA形成的数值模拟的回报和预报研究。实验室研究是对SOA形成过程中获取基础数据和推究SOA生成机制的最主要手段。在过去的几十年中,特别是近五年,SOA的研究取得了较大的进展,其中包括SOA前体物、SOA形成机制及影响因子的进一步理解。本文就这些方面展开了概要性的综述,重点强调了我国研究人员所做的研究工作。在采用实验室烟雾箱系统模拟研究SOA方面,首先简述了烟雾系统的发展以及表征,讨论了跟烟雾箱箱体相关的壁效应问题,重点综述了萜烯类、芳香烃类、小分子类等化学物种转化形成SOA的研究进展。在采用流动管和其他反应器类模拟研究SOA方面,重点讨论了挥发性有机物在颗粒物表面或在液相中所形成的SOA的主要化学成分及其可能的作用。 | 徐永福 贾龙 | 2018 | 大气科学2018,42,4: | 7 |
| 2 | Differences of the oxidation process and secondary organic aerosol formation at low and high precursor concentrations显示文摘Current atmospheric quality models usually underestimate the level of ambient secondary organic aerosol(SOA), one of the possible reasons is that the precursors at different concentrations may undergo different oxidation processes and further affect SOA formation. Therefore, there is a need to perform more chamber studies to disclose the influence. In this work, SOA formation over a wide range of initial precursor concentrations(tens of ppb to hundreds of ppb levels) was investigated in a 30 m3 indoor smog chamber,and mainly through the analysis of multiple generations of VOCs detected from HR-To FPTRMS to expound the difference in the oxidation process between low and high precursor concentrations. Compared to high initial concentrations, gas-phase intermediates formed at low concentrations had a higher intensity by about one order of magnitude, and the lowvolatility compounds also had a higher formation potential due to the competition between semi-volatile intermediates and precursors with oxidants. In addition, the formed SOA was more oxidized with higher f44 value(0.14 ± 0.02) and more relevant to real atmosphere than that formed at high concentrations. This work should help to deeply understand SOA formation and improve the performance of air quality models for SOA simulation. | Tianzeng Chen Yongchun Liu Biwu Chu Changgeng Liu Jun Liu Yanli Ge Qingxin Ma Jinzhu Ma Hong He | 2019 | Journal of Environmental Sciences2019,31,5: | 4 |
| 3 | Secondary aerosol formation and oxidation capacity in photooxidation in the presence of Al_2O_3 seed particles and SO_2显示文摘To investigate the sensitivity of secondary aerosol formation and oxidation capacity to NOx in homogeneous and heterogeneous reactions, a series of irradiated toluene/NOx/air and ?-pinene/NOx/air experiments were conducted in smog chambers in the absence or presence of Al2O3 seed particles. Various concentrations of NOx and volatile organic compounds(VOCs) were designed to simulate secondary aerosol formation under different scenarios for NOx. Under 'VOC-limited' conditions, the increasing NOx concentration suppressed secondary aerosol formation, while the increasing toluene concentration not only contributed to the increase in secondary aerosol formation, but also led to the elevated oxidation degree for the organic aerosol. Sulfate formation was suppressed with the increasing NOx due to a decreased oxidation capacity of the photooxidation system. Secondary organic aerosol(SOA) formation also decreased with the presence of high concentration of NOx, because organo-peroxy radicals(RO2) react with NOx instead of with peroxy radicals(RO2 or HO2), resulting in the formation of volatile organic products. The increasing concentration of NOx enhanced the formation of sulfate, nitrate and SOA under 'NOx-limited' conditions, in which the heterogeneous reactions played an important role. In the presence of Al2O3 seed particles, a synergetic promoting effect of mineral dust and NOx on secondary aerosol formation in heterogeneous reactions was observed in the photooxidation. This synergetic effect strengthened the positive relationship between NOx and secondary aerosol formation under 'NOx-limited' conditions but weakened or even overturned the negative relationship between NOx and secondary aerosol formation under 'VOC-limited' conditions. Sensitivity of secondary aerosol formation to NOx seemed different in homogeneous and heterogeneous reactions, and should be both taken into account in the sensitivity study. The sensitivity of secondary aerosol formation to NOx was further investigated under 'winter-like' and NH3-rich conditions. No obvious difference for the sensitivity of secondary aerosol formation except nitrate to NOx was observed. | Biwu Chu Tengyu Liu Xiao Zhang Yongchun Liu Qingxin Ma Jinzhu Ma Hong He Xinming Wang Junhua Li Jiming Hao | 2015 | Science China Chemistry2015,58,9: | 3 |
| 4 | 汽车尾气与大气光化反应中气固态污染物演变规律显示文摘利用烟雾箱系统,在不同温湿环境下进行了汽车尾气与大气的光化反应试验,通过检测反应中不同时刻气态固态物浓度,揭示尾气与大气光化反应中不同气固态物的演变规律.结果表明:在尾气与大气的光化反应中,气态物NO及HC主要来自于尾气,NO_2及O_3主要为新生成的产物,而固态物PM2.5主要是二次颗粒物;随着反应时间增加,NO及HC体积分数下降,其下降速率与温湿度分别呈负相关及正相关,而NO_2,O_3体积分数及PM2.5质量浓度先迅速增加,后趋于平稳,且增长速率与湿度正相关;与温度相比,湿度对污染物浓度变化的影响更大;尾气与大气作用生成二次颗粒物的主要时段是最初的1.5 h,且尾气体积分数越高越有利于二次颗粒物的生成,柴油车在大气中形成的二次颗粒物多于汽油车. | 戴兵 石鑫 袁银男 钱鹏 杨宗苓 | 2017 | 江苏大学学报(自然科学版)2017,38,6: | 2 |
| 5 | 用于汽车尾气光氧化的烟雾箱研究及其表征实验显示文摘大气中光氧化反应是造成大气中复合污染,加剧中国大气环境污染的重要因素。为了研究汽车尾气在大气中的光氧化反应,设计制作了一套用于汽车尾气光氧化反应的较大容积的室内烟雾箱实验系统,该系统主要包括反应系统、进样系统和检测分析系统。反应系统采取了移动式对箱设置,尾气进样系统考虑了汽车尾气的排放特点,检测系统采取了负压采气装置。通过对该烟雾箱的光强分布、光解实验、NO_2及O_3衰减等系列的表征实验表明,该烟雾箱系统的一些性能较国内已有的烟雾箱有一定程度的提高,而且更适合于模拟汽车尾气的光氧化反应,同时,该系统具有采样方便、两箱对比和可模拟多种环境等特点。 | 杨宗苓 石鑫 乔星 韩月 钱鹏 戴兵 | 2016 | 环境科学与技术2016,39,12: | 2 |
| 6 | 气溶胶吸湿性的影响因素及其对光学特性的影响显示文摘吸湿性是气溶胶重要的理化性质之一,气溶胶吸湿增长不仅会通过大气辐射效应影响气候,还对大气能见度有重要影响。介绍了气溶胶粒径吸湿增长与散射吸湿增长的概念,总结了测量气溶胶吸湿增长的方法,分析了粒径、化学组分、污染条件和混合状态对吸湿性的影响。结果表明:气溶胶的吸湿增长会使颗粒物含水量增多,改变气溶胶消光能力,从而对大气能见度以及气溶胶辐射强迫造成影响。未来,建议着重关注高相对湿度(相对湿度大于95%)下的气溶胶吸湿增长,加强气溶胶吸湿增长的垂直观测研究,并广泛开展吸湿和脱水2种环境下的气溶胶散射吸湿增长的测量和研究。 | 陈建华 沈毅成 迟翔予 竹双 | 2023 | 环境工程技术学报2023,13,6: | 0 |