Funding for this research was provided by:
National Natural Science Foundation of China (61673220)
State Administration for Science, Technology and Industry for National Defense (JCKY2017209B010, JCKY2018209B001)
Science and Technology Major Project of Sichuan (2018TZDZX0002)
Basic Research Programs of Sichuan Province (ZYF-2018-106)
Article History
Received: 18 March 2019
Accepted: 7 August 2019
First Online: 20 August 2019
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.