Funding for this research was provided by:
Nanyang Technological University (SUG-M4081842.110)
CHINESE SCHOLARSHIP COUNCIL (No. 201506775038)
MOE AcRF (Tier 1 M401110000)
Office of Science (ERKJE45)
Oak Ridge National Laboratory
Article History
Received: 15 November 2016
Accepted: 19 October 2017
First Online: 2 November 2017