Funding for this research was provided by:
National Natural Science Foundation of China (11503018)
National Natural Science Foundation of China the Joint Research Fund in Astronomy (U1631133)
Scientic and Technological Innovation Programs of Higher Education Institutions in Shanxi (2016033)
China Scholarship Council (201606935031)
Article History
Received: 13 February 2019
Accepted: 8 September 2019
First Online: 27 September 2019
Disclosure of Potential Conflicts of Interest
: The authors declare no conflicts of interest.