Funding for this research was provided by:
National Natural Science Foundation of China (61771078)
National Natural Science Foundation of China (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