Funding for this research was provided by:
Strategic Priority Research Program of Chinese Academy of Sciences (XDA21010202, XDA03010402)
Young Scholar of CAS "Light of West China" Program (No. 2016-84)
Natural Sciences Foundation of Gansu Province (No. 17JR5RA298)
Article History
Received: 26 December 2018
First Online: 6 February 2019
Compliance with ethical standards
:
: All authors have no conflicts of interest to declare.