Funding for this research was provided by:
National Key Research and Development Program of China (2016YFA0600401)
National Natural Science Foundation of China (41420104002, 41671197, 41631175)
Natural Science Foundation of Jiangsu Higher Education Institutions (14KJA170002)
Open Funds of State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS (SKLLQG1820)
Priority Academic Program Development of Jiangsu Higher Education Institutions (164320H116)
Financial support from the program of China Scholarships Council (201806860029)
Article History
Received: 30 March 2019
Accepted: 20 August 2019
First Online: 3 September 2019