1. Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of the Ministry of EducationChina University of Mining and Technology Xuzhou 221116 China
2. School of Resources and GeosciencesChina University of Mining and Technology Xuzhou 221116 China
3. State Key Laboratory for GeoMechanics and Deep Underground EngineeringSKLGDUEK1413, China University of Mining and Technology Xuzhou 221008 China
4. Geological Research Institute for Coal Green MiningXi'an University of Science and Technology Xi'an 710054 China
5. College of Geology and EnvironmentXi'an University of Science and Technology Xi'an 710054 China