1. Key Laboratory of Deep Coal Resource Mining, Ministry of Education of China, School of Mines, China University of Mining & Technology, Xuzhou, 221116, China (Corresponding author), e-mail: fxw_mining@foxmail.com, https://orcid.org/0000-0002-9348-9874 (X.F)
2. Key Laboratory of Deep Coal Resource Mining, Ministry of Education of China, School of Mines, China University of Mining & Technology, Xuzhou, 221116, China, (Corresponding author), e-mail: zhangnong@126.com (N.Z.)
3. Key Laboratory of Deep Coal Resource Mining, Ministry of Education of China, School of Mines, China University of Mining & Technology, Xuzhou, 221116, China