中文摘要：

分析了2015年南京市二氧化硫（SO2）、二氧化氮（NO2）、一氧化碳（CO）和臭氧（O3）的污染特征。南京市SO2、NO2、CO和O3的年均浓度分别为19．3μg·m^-3、50．2μg·m^-3、0．972mg·m^-3和114μg·m^-3；SO2和CO污染相对较轻，NO2和O3污染相对严重。SO2、CO和O3的日变化呈“单峰型”，而NO2的呈“双峰型”；SO2、NO2和CO浓度在冬季最高，夏季最低，而O3相反。秸秆焚烧产物的区域输送在夏收（6月）和秋收（11月）时节对南京市c0的贡献显著。各监测点及全市的气态污染物普遍表现出“反周末效应”，指示外来污染源。

英文摘要：

This study focused on the pollution characteristics of sulfur dioxide （SO2） , nitrogen dioxide （NO2） , carbon monoxide （CO） , and ozone （O3） in Nanjing for the year 2015. The annual mean concentrations of SO2, NO2, CO, and 03 in Nanjing were 19.3 μg · m^-3, 50.2 μg · m^-3, 0. 972 mg · m-3 , and 114 μg · m^-3 , re- spectively. The pollution levels of both SO2 and CO were relatively low, whereas those of both NO2 and 03 were relatively high. Diurnal variations of SO2 , CO, and O3 showed bimodal distributions, whereas that of NO2 showed unimodal distribution. The concentrations of SO2 , NO2 , and CO were the highest in winter and the lowest in sum- mer, whereas that of 03 was the highest in summer and the lowest in winter. The regional transport of straw com- bustion products contributed greatly to CO concentrations during the summer and autumn harvest periods of 2015 in Nanjing. The gaseous pollutants exhibited an anti-weekend effect in all the monitoring sites of Nanjing, indica- ting external pollution sources.