1. Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining, Anhui University of Science and Technology, Huainan, Anhui 232001, P.R. China
2. College of Public Safety and Emergency Management, Anhui University of Science and Technology, Hefei, Anhui 231131, P.R. China
3. Institute of Energy, Hefei Comprehensive National Science Center, Hefei, Anhui 230051, P.R. China