Feng, Xinlei http://orcid.org/0000-0002-4086-5805
Yang, Xiaoli
Funding for this research was provided by:
China Scholarship Council (2014085151114)
Scientific Research Fund of Sichuan Provincial Education Department (16ZA0304)
Research Project of Leshan Normal University (Z1514)
Article History
Received: 18 June 2018
Accepted: 21 November 2018
First Online: 28 November 2018
Competing interests
: The authors declare that they have no competing interests.