Funding for this research was provided by:
National Natural Science Foundation of China (11671235, 11801324)
Natural Science Foundation of Shandong Province (ZR2018BA007)
Nanyang Technological University Research Grant (M4080456)
Article History
Received: 2 September 2018
Revised: 19 January 2019
Accepted: 11 March 2019
First Online: 21 March 2019