Funding for this research was provided by:
National Natural Science Foundation of China (No.61806138)
Natural Science Foundation of Shanxi Province (No.201801D121127)
Taiyuan University of Science and Technology Scientific Research Initial Funding (No.20182002)
Article History
Received: 22 April 2019
Accepted: 13 August 2019
First Online: 26 August 2019