Wang, Feng
Fan, Wenna
Liu, Juan
Wang, Ge
Chai, Wei
Funding for this research was provided by:
National Natural Science Foundation of China (71673270)
Think Tank of Energy Mining Economy (2018WHCC01)
Article History
Received: 21 December 2019
Accepted: 25 March 2020
First Online: 18 April 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.