Funding for this research was provided by:
National Natural Science Foundation of China (61472298)
National Natural Science Foundation of China (61672408)
National Natural Science Foundation of China (61702403)
National Natural Science Foundation of China (U1135002)
China 111 Project (B16037)
China Postdoctoral Science Foundation (2018M633473)
Natural Science Basic Research Plan in Shaanxi Province of China (2015JQ6227)
the Fundamental Research Funds for the Central Universities (JB170308)
the Fundamental Research Funds for the Central Universities
the Innovation Fund of Xidian University
Article History
Received: 25 June 2018
Revised: 29 October 2018
Accepted: 28 November 2018
First Online: 7 January 2019