1. State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
2. State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China
3. School of Remote Sensing and Information Engineering, Wuhan University, Wuhan 430079, China
4. Microsoft Research Asia, Beijing 100080, China
5. Mechanical Engineering Department, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
6. College of Environment and Energy, Guangzhou Higher Education Mega Center, South China University of Technology, Guangzhou 510006, China