Funding for this research was provided by:
the Natural Science Foundation of Guangxi Province (No. 2017GXNSFAA198274)
Text and Data Mining valid from 2019-11-01
Received: 7 July 2019
Revised: 9 September 2019
Accepted: 7 October 2019
First Online: 6 November 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This research was approved by the Hezhou University Ethic Committee and all experiments were performed in accordance with the Guideline for Experimentation of Hezhou University.