Funding for this research was provided by:
Chinese Scholarship Council (201506290085)
Shaanxi Provincial International Science and Technology Collaboration Project (2017KW-ZD-14)
VUB Interdisciplinary Research Program through the EMO-App project, and the Agency for Innovation by Science and Technology in Flanders (131814)
the Natural Science Foundation of China (61273265)
Article History
Received: 30 December 2017
Revised: 30 September 2018
Accepted: 23 November 2018
First Online: 15 December 2018