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2篇 您的检索式:作者名="Lewei Zeng"
    题名 作者 年代 出处 被引量
1Ambient volatile organic compounds at a receptor site in the Pearl River Delta region:Variations,source apportionment and effects on ozone formation显示文摘We present the continuously measurements of volatile organic compounds(VOCs)at a receptor site(Wan Qing Sha,WQS)in the Pearl River Delta(PRD)region from September to November of 2017.The average mixing ratios of total VOCs(TVOCs)was 36.3±27.9 ppbv with the dominant contribution from alkanes(55.5%),followed by aromatics(33.3%).The diurnal variation of TVOCs showed a strong photochemical consumption during daytime,resulting in the formation of ozone(O_(3)).Five VOC sources were resolved by the positive matrix factorization(PMF)model,including solvent usage(28.6%),liquid petroleum gas(LPG)usage(24.4%),vehicle exhaust(21.0%),industrial emissions(13.2%)and gasoline evaporation(12.9%).The regional transport air masses from the upwind cities of south China can result in the elevated concentrations of TVOCs.Low ratios of TVOCs/NO_(x)(1.53±0.88)suggested that the O_(3) formation regime at WQS site was VOC-limited,which also confirmed by a photochemical box model with the master chemical mechanism(PBM-MCM).Furthermore,the observation on high-O_(3) episode days revealed that frequent O_(3) outbreaks at WQS were mainly caused by the regional transport of anthropogenic VOCs especially for aromatics and the subsequent photochemical reactions.This study provides valuable information for policymakers to propose the effective control strategies on photochemical pollution in a regional perspective.Yao Meng Junwei Song Lewei Zeng Yingyi Zhang Yan Zhao Xufei Liu Hai Guo Liuju Zhong Yubo Ou Yan Zhou Tao Zhang Dingli Yue Senchao Lai 2022Journal of Environmental Sciences2022,34,1:5
2Characterization and prediction of tailpipe ammonia emissions from in-use China 5/6 light-duty gasoline vehicles显示文摘On-road tailpipe ammonia (NH3) emissions contribute to urban secondary organic aerosol formation and have direct or indirect adverse impacts on the environment and human health. To understand the tailpipe NH3 emission characteristics, we performed comprehensive chassis dynamometer measurements of NH3 emission from two China 5 and two China 6 light-duty gasoline vehicles (LDGVs) equipped with three-way catalytic converters (TWCs). The results showed that the distance-based emission factors (EFs) were 12.72 ± 2.68 and 3.18 ± 1.37 mg/km for China 5 and China 6 LDGVs, respectively. Upgrades in emission standards were associated with a reduction in tailpipe NH3 emission. In addition, high NH3 EFs were observed during the engine warm-up period in cold-start cases owing to the intensive emissions of incomplete combustion products and suitable catalytic temperature in the TWCs. Notably, based on the instantaneous NH3 emission rate, distinct NH3–emitting events were detected under high/extra high velocity or rapid acceleration. Furthermore, NH3 emission rates correlated well with engine speed, vehicle specific power, and modified combustion efficiency, which were more easily accessible. These strong correlations were applied to reproduce NH3 emissions from China 5/6 LDGVs. The predicted NH3 EFs under different dynamometer and real-world cycles agreed well with existing measurement and prediction results, revealing that the NH3 EFs of LDGVs in urban routes were within 8.55–11.62 mg/km. The results presented here substantially contribute to improving the NH3 emission inventory for LDGVs and predicting on-road NH3 emissions in China.Lewei Zeng Fengbin Wang Shupei Xiao Xuan Zheng Xintong Li Qiyuan Xie Xiaoyang Yu Cheng Huang Qingyao Hu Yan You Ye Wu 2024Frontiers of Environmental Science & Engineering2024,18,1:0
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