中文摘要：

2009年8月至2010年7月，对北京城区、城乡结合部和远郊区3种典型区域大气中的SO。CO、NO。0，浓度和气象因素进行了监测，并分析了其污染特征．结果表明，城区、城乡结合部的SO：、CO、NO。浓度在全年四季都呈双峰型日变化，与人类活动和交通尾气排放特征基本一致，而远郊区没有明显的日变化．SO，、CO、NO。浓度存在季节变化，冬季明显高于夏季，表明北京冬季取暖以及低边界层等对大气中此类一次污染物的积累具有重要贡献．0，浓度在四季均呈单峰型日变化，表明局地光化学0，生成起主导作用．城区和城乡结合部的O，浓度夜间降至接近零，远郊区的0，夜间浓度在春、夏季可维持在100P,g·m。以上，在秋、冬季可维持在40斗g·m13以上，主要因为城区和城乡结合部夜间存在大量NO排放源，NO对O，的滴定作用导致O，浓度的极大降低，而远郊区缺乏NO排放源．春、夏季O，的浓度为冬季3．0—4．8倍，体现出不同季节光化学反应活性对0，的影响．从整体趋势上看，城区和城乡结合部的SO：、CO、NO。浓度高于远郊区，而0，浓度的分布正好相反．

英文摘要：

The concentrations of air pollutants SO2, CO, NOx, O3 and meteorological parameters in three representative regions of Beijing i. e. central urban, urban-fringe and exurban, were analyzed based on the data from August 2009 to July 2010. From the results, the diurnal change of SO2, CO and NOx concentration in central urban and urban-fringe regions showed a dual-peak pattern in the four seasons, which was consistent with the characteristics of anthropogenic activities and motor vehicle exhaust. However, no obvious diurnal variation of SO2, CO and NO~ concentrations was found in the exurban region. The concentrations of SO2, CO, NO~ were significantly higher in the winter than those in the summer, indicating that the accumulation of primary pollutants was mainly due to winter heating in Beijing and low atmospheric boundary layer. On the other hand, the diurnal change of 03 concentration showed single peak pattern during the four seasons, suggesting a leading role of local photochemical formation. The 03 concentration in central urban and urban- fringe regions dropped to nearly zero at night, whereas in exurban region it stayed above 100 p.g.m-3 at night in the spring and summer, and more than 40 txg＂ m-3 in the autumn and winter. In the central urban and urban-fringe regions, a large number of NO emission sources at night might play an important role in the titration of 03. Furthermore, the 03 level in spring and summer was 3.0---4.8 times higher than that in the winter, suggesting that the effect of photochemical reaction on 03 formation was different among the four seasons. Overall, the concentrations of SO2, CO, NO, in central urban and urban-fringe regions were higher than that in exurban region, whereas the 03 concentration showed the opposite distribution.