1. Key Laboratory of Coalbed Methane Resources & Reservoir Formation Process, Ministry of Education, China University of Mining and Technology, Xuzhou221008, Jiangsu, China
2. School of Resources and Geosciences, China University of Mining and Technology, Xuzhou221116, Jiangsu, China
3. State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan232001, Anhui, China