Funding for this research was provided by:
the National High Technology Research and Development Program of China (2014AA020707)
the National Natural Science Foundation of China (31271013, 51173076, 81102489)
the National Natural Science Foundation of China (51503232, 91129712)
the Program for New Century Excellent Talents in University (NCET-13-0272)
Article History
Received: 5 October 2017
Accepted: 2 January 2019
First Online: 14 February 2019
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