Funding for this research was provided by:
National Natural Science Foundation of China (31460342)
Guangxi innovation-driven development special funding project (Guike-AA17204070)
High Level Innovation Team and Outstanding Scholar in Guangxi Colleges and Universities
Innovation Project of Guangxi Graduate Education (YCBZ2017012)
Innovation Project of Guangxi Graduate Education (YCSW2017047)
Text and Data Mining valid from 2018-08-10
Received: 8 June 2018
Accepted: 30 July 2018
First Online: 10 August 2018
Ethics approval and consent to participate
: The field work in this study was conducted in accordance with local legislation.
: No applicable.
: The authors declares that they have no competing interests.
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