Funding for this research was provided by:
National Natural Science Foundation of China (61873186, 61773282)
Application Base and Frontier Technology Research Project of Tianjin of China (13JCQNJC03600)
South African National Research Foundation (112142, 112108)
South African National Research Foundation Incentive Grant (114911)
Article History
Received: 26 June 2018
Accepted: 19 September 2018
First Online: 26 September 2018
Compliance with ethical standards
:
: The authors declare that they have no conflicts of interest.