1. College of Mining and Safety Engineering, Shandong University of Science and Technology, Qingdao 266590, China
2. State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao 266590, China
3. Energy Flagship, Commonwealth Scientific and Industrial Research Organisation, P.O. Box 883,
Kenmore, Brisbane, QLD 4069, Australia