Funding for this research was provided by:
Program for New Century Excellent Talents in University (NETC-13-0394)
the Sichuan Provincial Science Research Program of China (NO:2015GZ0051)
the National Natural Science Foundation of China (No.51104103)
Article History
Received: 18 January 2016
Revised: 28 March 2016
Accepted: 22 December 2016
First Online: 29 March 2017