ACKNOWLEDGMENTS
This work was supported by grants from the National Natural Science Foundation of China (31960280), Science and Technology Base and Talent Special Project of Guangxi Province (AD20159042), Guangxi Natural Science Foundation of China (No. 2018GXNSFAA294024), Guangxi Universities Young and Middle-aged Teachers Scientific Research Basic Ability Improvement Project (2019KY0055), and Key Research Program of Guangxi Normal University (2017ZD009).