1. School of Safety Science and Engineering, Anhui University of Science and Technology, Huainan 232001, China
2. School of Economics and Management, Huainan Normal University, Huainan 232038, China
3. Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining, Huainan 232001, China
4. School of Economics and Management, China University of Mining and Technology, Xuzhou 221116, China