[1] Henan Shenhuo Coal & Power Co Ltd, Henan 476600, Yongcheng, Peoples R China
[2] China Univ Min & Technol, Sch Safety Engn, Xuzhou 221116, Peoples R China
[3] Henan Polytech Univ, Sch Safety Sci & Engn, Jiaozuo 454003, Peoples R China
[4] Guizhou Inst Technol, Guiyang 550003, Peoples R China