1. College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, China
2. Key Laboratory of Safety and High-efficiency Coal Mining, Ministry of Education (Anhui University of Science and Technology), Huainan, China
3. State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Xuzhou, China
4. Dongtan Coal Mine, YanzhouCoal Mining Company Ltd, Jining, China