Funding for this research was provided by:
National Natural Science Foundation of China (51606045)
Guangzhou Science Technology and Innovation Commision (2016201604030063)
Department of Education of Guangdong Province (2015KQNCX031)
Department of Science and Technology of Foshan Municipality (2015IT100162)
Article History
Received: 6 December 2017
Accepted: 29 April 2018
First Online: 10 May 2018
Competing Interests
: The authors declare that they have no competing interests.
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