Funding for this research was provided by:
National Natural Science Foundation of China (51704278)
International Postdoctoral Exchange Fellowship Program (20160001)
Independent Research Project of State Key Laboratory of Coal Resources and Safe Mining, CUMT (SKLCRSM19X0016)
Article History
Received: 3 September 2018
Accepted: 19 April 2019
First Online: 2 May 2019