1. State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, P. R. China
2. School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
3. Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas, Patras GR-26504, Greece
4. Department of Civil, Environmental and Construction Engineering, University of Central Florida, Orlando, Florida 32816, United States
5. School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
6. Tianjin Eco-Environmental Monitoring Center, Tianjin 300191, P. R. China
7. School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, United States