Lanzhou University, Lanzhou University, Lanzhou University - Key Laboratory for Environmental Pollution Prediction and Control, affiliation not provided to SSRN, Lanzhou University, Lanzhou University - Key Laboratory for Environmental Pollution Prediction and Control, Lanzhou University, Lanzhou University, Lanzhou University, Lanzhou University, Lanzhou University, Lanzhou University - Key Laboratory for Environmental Pollution Prediction and Control and Peking University