Funding for this research was provided by:
the National High Technology Research and Development Program (863 Program) of China (2015AA017203)
the Key Program of NSFC (U1405255)
the Natural Science Basis Research Plan in Shaanxi Province of China (2016JM6034)
China 111 Project (B16037)
the Special Research Foundation of MIIT (MJ-2014-S-37)
the National Natural Science Foundation of China (61303033)
Article History
First Online: 20 November 2017