气候变化领域集成服务门户(CCPortal): Technical Note: Effect of varying the λ = 185 and 254nm photon flux ratio on radical generation in oxidation flow reactors

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DOI	10.5194/acp-20-13417-2020
	Technical Note: Effect of varying the λ = 185 and 254nm photon flux ratio on radical generation in oxidation flow reactors
	Rowe J.P.; Lambe A.T.; Brune W.H.
发表日期	2020
ISSN	16807316
起始页码	13417
结束页码	13424
卷号	20 期号:21
英文摘要	Oxidation flow reactors (OFRs) complement environmental smog chambers as a portable, low-cost technique for exposing atmospheric compounds to oxidants such as ozone (O3), nitrate (NO3) radicals, and hydroxyl (OH) radicals. OH is most commonly generated in OFRs via photolysis of externally added O3 at λ = 254 nm (OFR254) or combined photolysis of O2 and H2O at λ = 185 nm plus photolysis of O3 at λ = 254 nm (OFR185) using low-pressure mercury (Hg) lamps. Whereas OFR254 radical generation is influenced by [O3], [H2O], and photon flux at λ = 254 nm (I254), OFR185 radical generation is influenced by [O2], [H2O], I185, and I254. Because the ratio of photon fluxes, I185 V I254, is OFR-specific, OFR185 performance varies between different systems even when constant [H2O] and I254 are maintained. Thus, calibrations and models developed for one OFR185 system may not be applicable to another. To investigate these issues, we conducted a series of experiments in which I185 V I254 emitted by Hg lamps installed in an OFR was systematically varied by fusing multiple segments of lamp quartz together that either transmitted or blocked λ = 185 nm radiation. Integrated OH exposure (OHexp) values achieved for each lamp type were obtained using the tracer decay method as a function of UV intensity, humidity, residence time, and external OH reactivity (OHRext). Following previous related studies, a photochemical box model was used to develop a generalized OHexp estimation equation as a function of [H2O], [O3], and OHRext that is applicable for I185 V I254 ≈ 0:001 to 0.1. © Author(s) 2020.
语种	英语
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/143818
作者单位	Department of Meteorology and Atmospheric Science, Pennsylvania State University, University Park, PA, United States; Center for Aerosol and Cloud Chemistry, Aerodyne Research Inc., Billerica, MA, United States; Department of Chemistry, University of Colorado, Boulder, CO, United States
推荐引用方式 GB/T 7714	Rowe J.P.,Lambe A.T.,Brune W.H.. Technical Note: Effect of varying the λ = 185 and 254nm photon flux ratio on radical generation in oxidation flow reactors[J],2020,20(21).
APA	Rowe J.P.,Lambe A.T.,&Brune W.H..(2020).Technical Note: Effect of varying the λ = 185 and 254nm photon flux ratio on radical generation in oxidation flow reactors.Atmospheric Chemistry and Physics,20(21).
MLA	Rowe J.P.,et al."Technical Note: Effect of varying the λ = 185 and 254nm photon flux ratio on radical generation in oxidation flow reactors".Atmospheric Chemistry and Physics 20.21(2020).