Funding for this research was provided by:
National Natural Science Foundation of China (41701121, 41871202)
the Fundamental Research Funds for the Central Universities (2-9-2017-041)
the Graduate teaching reform program of China University of Geosciences, Beijing (YJG2019002)
Article History
Received: 5 September 2018
Accepted: 17 August 2019
First Online: 24 August 2019