Funding for this research was provided by:
the National Natural Science Foundation of China (No. 11671284)
Sichuan Provincial Natural Science Foundation of China (No. 2015JY0002, No. 2017JY0197)
the Research Foundation of the Education Department of Sichuan Province (No. 15ZA0032)
Article History
Received: 17 January 2018
Accepted: 7 August 2018
First Online: 23 August 2018