1. Key Lab of Aerosol Chemistry & Physics, State Key Lab of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences (CAS), Xi’an 710061, P. R. China
2. CAS Center for Excellence in Quaternary Science and Global Change, Xi’an 710061, P. R. China
3. School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an 710049, P. R. China
4. Department of Science and Environmental Studies, The Education University of Hong Kong, Hong Kong, P. R. China
5. Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, P. R. China