1. Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics & Fine Mechanics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
2. University of Science and Technology of China, Hefei, Anhui 230026, China
3. School of Environmental Science & Optoelectronic Technology, University of Science and Technology of China, Hefei, Anhui 230026, China
4. Center
for Excellence in Urban Atmospheric Environment, Institute of Urban
Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, China