Funding for this research was provided by:
National Natural Science Foundation of China (11774384, 11174324 and 11204122)
Youth Innovation Promotion Association of the Chinese Academy of Sciences (2011235)
Natural Science Research Project of the Education Department of Henan Province (12B430016)
Science and Technology Development Program of Henan Province (172102210402)
Henan Provincial Youth Backbone Teachers (2015GGJS-110)
Article History
Received: 31 January 2019
Accepted: 20 May 2019
First Online: 7 June 2019
Competing interests
: The authors declare no competing financial interests.