中国城市空气质量的区域差异及归因分析
赵艳艳, 张晓平, 陈明星, 高珊珊, 李润奎

Regional variation of urban air quality in China and its dominant factors
ZHAO Yanyan, ZHANG Xiaoping, CHEN Mingxing, GAO Shanshan, LI Runkui
图3 城市6种空气污染物浓度的核密度函数曲线形态对比
Fig. 3 Comparison of kernel density curves of six urban ambient air pollutants