Funding for this research was provided by:
the National Key R&D Program of China (2017YFC0404801)
the National Science Foundation of China (51779194)
Article History
Received: 27 November 2018
Accepted: 12 November 2019
First Online: 30 November 2019
Compliance with Ethical Standards
:
: No conflict of interest exits in the submission of this manuscript, and manuscript is approved by all authors for publication. We would like to declare that the work described was original research that has not been published previously, and not under consideration for publication elsewhere, in whole or in part. All the authors listed have approved the manuscript that is enclosed.