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Characterization of carbonaceous aerosols including CC (carbonate carbon), OC (organic carbon), and EC (elemental carbon) were investigated at Xi'an, China, near Asian dust source regions in spring 2002. OC varied between 8.2 and 63.7 μg m-3, while EC ranged between 2.4 and 17.2 μ m-3 during the observation period. OC variations followed a similar pattern to EC and the correlation coeflcient between OC and EC is 0.89 (n=31). The average percentage of total carbon (TC, sum of CC, OC, and EC) in PM2.5 during dust storm (DS) events was 13.6%, which is lower than that during non-dust storm (NDS) periods (22.7%). CC, OC, and EC accounted for 12.9%, 70.7%, and 16.4% of TC during DS events, respectively. The average ratio of OC/EC was 5.0 in DS events and 3.3 in NDS periods. The OC-EC correlation (R2=0.76, n=6) was good in DS events, while it was stronger (R2=0.90, n=25) in NDS periods. The percentage of water-soluble OC (WSOC) in TC accounted for 15.7%, and varied between 13.3% and 22.3% during DS events. The distribution of eight carbon fractions indicated that local emissions such as motor vehicle exhaust were the dominant contributors to carbonaceous particles. During DS events, soil dust dominated the chemical composition, contributing 69% to the PM2.5 mass, followed by organic matter (12.8%), sulfate (4%), EC (2.2%), and chloride (1.6%). Consequently, CC was mainly entrained by Asian dust. However, even in the atmosphere near Asian dust source regions, OC and EC in atmospheric dust were controlled by local emission rather than the transport of Asian dust. 相似文献
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随着工业、交通运输业迅猛发展及人口的剧增，广州、香港和澳门的大气环境质量越来越引起人们的关注。对该地区挥发性有机污染物（ＶＯＣｓ）和气溶胶中半挥发及不易挥发的有机污染物进行的初步研究表明，大气环境中有机污染物主要是苯系物的ＶＯＣｓ、多环芳烃（ＰＡＨｓ）和正构烷烃类。一些分子标志物，如β－胡萝卜烷、正构烷烃及荧蒽／芘、间四联苯／荧蒽、不同环数多环芳烃分布等参数，是比较有效的有机污染源判别指标 相似文献
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2007年4月利用黑碳仪（Aethalometer）、颗粒物在线观测仪（TEOM1400a）和现时天气现象传感器（PWD22）获得了大气细粒子中每5 min黑碳气溶胶（BC）浓度以及每30 min PM2.5浓度及大气能见度观测数据。结果发现：黑碳日均值浓度为7.4±2.9 μg·m－3，变化范围分别为2.1～11.6 μg·m－3。PM2.5日均值浓度为77.4±35.9 μg·m－3，浓度变化范围分别为29.6～183.3 μg·m－3。黑碳小时浓度变化具有2个明显的峰值，主要与机动车尾气排放密切相关。黑碳浓度与PM2.5浓度呈正相关，与大气能见度呈负相关，相关系数为分别为0.707和－0.529，表明黑碳是PM2.5中的重要组成部分，对大气能见度的影响较显著。 相似文献
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香港气溶胶烃类物质组成,分布及来源初探 总被引：13，自引：2，他引：13
总悬浮颗粒和１０μｍ以下人体可吸入颗粒物，即ＲＳＰ样品采自香港市区和郊区，样品采用超声抽提和硅胶层析柱分离，使用气相色谱，气相色谱－质谱（ＧＣ，ＧＣ－ＭＳＤ）分析饱和烃和芳烃馏分。研究表明，ＴＳＰ样品中含有化石燃料燃烧和生物来源的脂肪烃，包括正构烷烃，甾烷和藿烷类等有机物。芳香烃主要由２－７环的多环芳烃组成，其中１０种属美国优先控制污染物，ＲＳＰ样品中主要含生物来源的正构烷烃，含少量代表化石燃烧产 相似文献
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