DOAS大气环境质量监测系统与传统点式采样监测法可比性研究

系统比较了DOAS大气监测系统与传统点式采样设备在测定环境空气中二氧化硫的性能。     

DOAS环境空气质量自动化监测系统运行维护

介绍了DOAS环境空气质量自动化监测系统的性能和特征,指出该系统在日常运行时,需要进行预防性定期例行维护和现场故障排除,总结分析了该系统运行维护的方法,并对常见故障作了剖析.     

Observation of atmospheric nitrous acid with DOAS in Beijing, China

Measurements of nitrous acid （HONO） and nitrogen dioxide （NO2） in Beijing City have been performed by means of a developed differential optical absorption spectroscopy （DOAS） system based on photodiode array （PDA）, during the autumn of 2004. HONO and NO2 were simultaneously identified by their characteristic absorption bands in the spectral region between 337 nm and 372 nm with high sensibility and time resolution. The concentrations of HONO exhibit obviously diurnal variation with a nocturnal maximum and a daytime minimum. The highest HONO value up to 11.8 μg/m^3 was observed during the night of 2/3 September. Possible sources of the observed HONO were discussed. Good correlation to NO2 indicates that NO2 is a main source component. The measurement also shows direct emission of HONO is an imnortant source in strongly polluted urban area.     

Volatile Organic Compounds: Sampling Methods and Their Worldwide Profile in Ambient Air

The atmosphere is a particularly difficult analytical system because of the very low levels of substances to be analysed, sharp variations in pollutant levels with time and location, differences in wind, temperature and humidity. This makes the selection of an efficient sampling technique for air analysis a key step to reliable results. Generally, methods for volatile organic compounds sampling include collection of the whole air or preconcentration of samples on adsorbents. All the methods vary from each other according to the sampling technique, type of sorbent, method of extraction and identification technique. In this review paper we discuss various important aspects for sampling of volatile organic compounds by the widely used and advanced sampling methods. Characteristics of various adsorbents used for VOCs sampling are also described. Furthermore, this paper makes an effort to comprehensively review the concentration levels of volatile organic compounds along with the methodology used for analysis, in major cities of the world.     

紫外大气甲醛卫星遥感反演方法和研究现状

在我国长期稳定的甲醛观测站点十分缺失,卫星平台高时频、大面积覆盖等优势使得通过卫星遥感探测大气甲醛成为了一种重要的研究手段.本文讨论了现有载荷的反演理论和方法,分析了我国大气甲醛的研究现状及不足.简述了从20世纪至今可用于甲醛探测的主要载荷：GOME/ERS-2,SCIAMACHY/ENVISAT,OMI/Aura,GOME-2/MetOp-A（B）,OMPS/Suomi-NPP,总结归纳了各个卫星载荷仪器的轨道信息、时间空间分辨率等相关参数,以及各个传感器在大气甲醛遥感反演中的可行性.由于卫星自上而下的观测方式与地基平台不同,其反演方法也有不同之处,因此本文针对卫星平台综合论述了两种甲醛反演算法：传统的差分吸收光谱法（DOAS）和针对于甲醛反演的一系列改进算法以及近几年提出的主成分分析法（PCA）;另外,本文针对现有反演算法和时空分布在我国中东部地区的研究现状和不足进行了综合讨论,并给出了一定的改进策略.     

差分吸收光谱法(DOAS)与紫外荧光法自动测量空气中SO2的对比

DOAS自动监测系统越来越广泛用于环境空气质量监测中SO2、NO2的监测,将差分吸收光谱法与紫外荧光法自动测量空气中SO2进行对比实验,并对监测结果进行讨论和统计检验,得出两种方法测定空气中的SO2,其监测结果具有较好的相关性、一致性、两者无显著性差异,在今后的监测工作中可用DOAS自动监测系统代替传统的干法点式自动监测系统监测SO2,以降低运行成本,减少仪器维护量,节约经费。     

差分光学吸收光谱法测量大气污染气体的研究

介绍了差分光学吸收光谱(DOAS)法测量大气污染气体的基本原理,描述了收发一体的DOAS系统的设计以及在同一波段对多种被测气体浓度同时进行反演的数据处理方法,并且对周围环境中的SO₂,O₃和NO₂进行了长期监测,得到的结果与实际情况相符合.      

紫外差分光学吸收法测量污染气体的实验研究

采用差分光学吸收光谱法，对紫外波段的SO2、NO、NO2污染气体吸收光谱进行了测量．得到了紫外波段的差分吸收截面．提出的分波段计算方法对混合气体测量的误差达到15％以内，测量精度与所选测量波段有关．     

Observations of nitrous acid and its relative humidity dependence in Shanghai

Nitrous acid, HNO2, is an important precursor of OH radicals in the troposphere. Measurements of HNO2 and NO2, using differential optical absorption spectroscopy （DOAS）, were performed in Shanghai, China for a period from October 22, 2004 to January 4, 2005. The mean （and median） hourly concentrations of HNO2 and NO2 during this period were 1.1 （0.7） ppb and 24 （21.4） ppb respectively. A correlation between HNO2/NO2 and PM10 mass concentrations was obtained. This correlation suggests that significant heterogeneous chemical production of HNO2 may occur through NO2 reactions on aerosol surfaces. This hypothesis was further supported by detailed analysis of selected pollution episodes in this study. At the same time, the water dependence of HNO2 formation was studied by analysis of relative humidity （RH）. It showed that the maximum HNO2/NO2 ratio was increased along with RH below 70% and inhibited at RH〉70%.     

差分光谱法连续监测空气中SO2、NO2、苯、甲苯方法探讨

差分光谱法(简称DOAS)已广泛用于空气中SO2、NO2、苯、甲苯监测.通过对差分光谱法监测结果与其他传统仪器进行时比,发现用DOAS监测SO2、NO2与点式仪器有较好的一致性,但用DOAS系统监测苯、甲苯与气相色谱法有机物连续监测结果差异较大,相关性较差,运行有一定的局限性.另外,本文对DOAS的最佳运行条件进行了探讨,发现影响光强的氙灯老化和气候条件对DOAS系统运行有较大影响.