1. School of Mines, China University of Mining & Technology, Xuzhou 221116, China
2. School of Geology and Mining Engineering, Xinjiang University, Urumqi 830046, China
3. Jiangsu Engineering Laboratory of Mine Earthquake Monitoring and Prevention, China University of Mining & Technology, Xuzhou 221116, China
4. Xinglongzhuang Coal Mine, Yanzhou Coal Industry Co., Ltd., Jining 272102, China