Funding for this research was provided by:
National Natural Science Foundation of China (61562013)
Natural Science Foundation of Guangxi Province (2017GXNSFDA198025)
the Study Abroad Program for Graduate Student of Guilin University of Electronic Technology (GDYX2018006)
China Scholarship Council
Article History
Received: 6 November 2019
Accepted: 17 June 2020
First Online: 7 July 2020