Funding for this research was provided by:
National Natural Science Foundation of China (61771078, 61271161)
Chongqing Research Program of Basic Research and Frontier Technology (cstc2017jcyjB0182)
Fundamental Research Funds for the Central Universities (106112016CDJXZ238826)
Article History
Received: 19 April 2018
Accepted: 19 July 2018
First Online: 21 July 2018