1. Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong 999077, China
2. Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00014, Finland
3. Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
4. Environment Research Institute, Shandong University, Qingdao 266237, China
5. State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China