Funding for this research was provided by:
Fundamental Research Funds for the Central Universities (2019kfyXKJC056)
Program for HUST Academic Frontier Youth Team (2018QYTD12)
Text and Data Mining valid from 2020-02-07
Received: 12 October 2019
Accepted: 29 January 2020
First Online: 7 February 2020
: The authors declare that they have no competing interests.