Free Radical Processes in the Atmosphere

大气中的自由基过程

基本信息

批准号：
05237106
负责人：
WASHIDA Nobuaki
金额：
$ 48.32万
依托单位：
National Institute for Environmental Studies
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1995
项目状态：
已结题

项目摘要

The following studies were carried out during the 1993-1995 fiscal years.1] Free radical kinetirs related to atmospheric chemistry1. Rate constants for reactions of RO_2 + NO,CH_2X + O_2, HS+O,NH_2+O,NHO+O,and CH_3 + N have been measured by a combination of pulsed laser photolysis and photoionization mass spectrometry.2. Rate constants for reactions of the vibrationally excited free radicals, such as CF_2^<**> (v2) + O,NH_2^<**> (v2) + NO,HCO^<**> (v_1, v_2, v_3) + O_2 were determined by using laser induced fluorescence technique.3. Photodissociation of O_3 at Huggins band (308-326nm) has been studied. The partial cross sections for the O (^1D) production in the photoobsorption of O_3 were determined.2] Model experiments related to atmospheric chemistry.1. The OH radical-initiated photooxidation of isoprene has been investigated experimentally by a 6-m^3 photochemical reaction chamber equipped with a long path length Fourier transform infrared spectrometer. The CO yield in the real atm … More osphere was evaluated as 30% on the carbon number basis, and global annual CO production from isoprene was estimated to be 105 TgCyr^<-1>.2. Ozone destruction by CFC's (CFCl_3 and CF_2Cl_2), BFC's (CF_3Br and C2H_4Br_2), HCFC's (CH_3CCl_2F,CF_3CHCl_2, and CF_3CHCl) and CH3Br was demonstrated using a 6-m^3 evacuable photochemical chamber equipped with UV-enhanced Xe arc lamps. The decay of ozone by a catalytic cycle involving CI of Br atoms released from the photolysis of halocarbons by UV light was evident, although the chain length was far less than in the real stratosphere : It was about 8 for CFCI_3 and 40 for CF_3Br.3] Development of a monitoring method of OH and HO_2Detection of OH radicals in low concentration was carried out using an infrared-ultraviolet double resonance (IR-DR) LIF method. The detection limit was determined to be 1.3 * 10^9 radical cm^<-3>.4] Heterogeneous reactions in the atmosphere.In order to analyze the transport processes of active species from the bulk atmosphere across the aqueous surfaces, a novel method, named as "impinging flow method" was developed. The uptake of SO^2 by the water was studied and the uptake coefficient was strongly dependent on the pH value of the water and showed a slightly negative temperature dependence. The uptake of OH radicals was also studied and the typical value was 0.006 in the neutral region. Less

以下研究是在1993年至1995财政年度进行的。1]与大气化学相关的自由基动物。1。 RO_2 + NO，CH_2X + O_2，HS + O，NH_2 + O，NHO + O和CH_3 + N的反应的速率常数已通过脉冲激光光解和光电离量质谱法的组合进行了测量。2。通过使用激光诱导的荧光技术确定了虚拟自由基反应的速率常数，例如CF_2^<**>（V2） + O，NH_2^<**>（V2） + NO，HCO^<**>（V_1，V_2，V_2，V_2，V_3） + O_2。 Huggins频段（308-326nm）的O_3的光解离已研究。确定了与大气化学相关的模型实验1。 OH自由基引发的异戊二烯的光氧化是通过6-m^3光化学反应室进行了实验研究的，其较长的路径长度傅立叶傅立叶转化感染光谱仪。实际ATM中的CO收益率…以碳数为30％评估了更多的Isphere，估计来自异戊二烯的全球年度CO产量为105 tgcyr^<-1> .2。 CFC（CFCL_3和CF_2CL_2），BFC（CF_3BR和C2H_4BR_2），HCFC（CH_3CCL_2F，CF_3CL_2F，CF_3CHCL_2，和CF_3CHCL）和CH3BR使用6-m-M^3 EVACUCHEM COMBER EQUIVER证明了CFC（CFCL_3和CF_2CL_2）的臭氧破坏。灯。 The decay of ozone by a catalytic cycle involving CI of Br atoms released from the photolysis of halocarbons by UV light was evidenced, although the chain length was far less than in the real strawsphere : It was about 8 for CFCI_3 and 40 for CF_3Br.3] Development of a monitoring method of OH and HO_2Detection of OH radicals in low concentration was carried out using an红外 - 硫酸酯双共振（IR-DR）LIF方法。确定检测极限为1.3 * 10^9自由基CM^<-3> .4]在大气中的异源反应。水的摄取量是研究的，并且摄取系数强烈依赖于水的pH值，并显示出略微负的温度依赖性。 OH自由基的吸收也被研究了，中性区域的典型值为0.006。较少的