East China University of Science and Technology (ECUST), East China University of Science and Technology, East China University of Science and Technology, affiliation not provided to SSRN, Ningxia University, Ningxia University, Taiyuan University of Technology - State Key Laboratory of Clean and Efficient Coal Utilization, East China University of Science and Technology (ECUST), Ningxia University and East China University of Science and Technology (ECUST)