He, Xingsheng
Lin, Yu-Ru
Funding for this research was provided by:
National Science Foundation (1423697, 1634944, 1634702)
China Scholarship Council (201506340067)
University of Pittsburgh (CRDF & CIS)
Article History
Received: 30 May 2017
Accepted: 12 November 2017
First Online: 22 November 2017
Competing interests
: The authors declare that they have no competing interests.