Li, Husheng
Song, Ju Bin
Funding for this research was provided by:
National Science Foundation (1407679)
National Science Foundation (1525226)
National Science Foundation (1525418)
National Science Foundation (1543830)
National Science Foundation (1617394)
Article History
Received: 15 August 2017
Accepted: 8 January 2018
First Online: 19 January 2018
Competing interests
: The authors declare that they have no competing interests.
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