Funding for this research was provided by:
National Natural Science Foundation of China (U1501252, 61572146, U1711263)
Natural Science Foundation of Guangxi Province (2016GXNSFDA380006)
Guangxi Innovation-Driven Development Grand Project (AA17202024)
Guangxi University Young and Middle-aged Teacher Basic Ability Enhancement Project (51200B)
Article History
Received: 27 September 2018
Revised: 12 June 2019
Accepted: 13 August 2019
First Online: 20 August 2019