Funding for this research was provided by:
National Natural Science Foundation of China (11602042)
Chongqing Research Program of Basic Research and Frontier Technology (NO. cstc2016jcyjA0259, cstc2015jcyjA50010)
Scientific and Technological Research Program of Chongqing Municipal Education Commission (KJ1601304)
Received: 18 June 2018
Accepted: 15 August 2018
First Online: 29 August 2018
: Both authors declare that they have no competing interests.
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