Funding for this research was provided by:
National Natural Science Foundation of China (61633011, 61703346, 61374078)
Chongqing Research Program of Basic Research and Frontier Technology (cstc2015jcyjBX0052)
Graduate Student Research Innovation Project of Chongqing (CYB17076)
Article History
Received: 16 September 2017
Accepted: 20 April 2018
First Online: 28 April 2018
Compliance with ethical standards
:
: The authors declare that there is no conflict of interest.