Wang, Hao
Peng, Ran
Wang, Junjie
Qin, Zelian
Xue, Lixiang
Funding for this research was provided by:
National Natural Science Foundation of China (91749107, 81672091)
Beijing Natural Science Foundation (7172232)
Article History
Received: 23 January 2018
Accepted: 10 April 2018
First Online: 23 April 2018
Ethics approval and consent to participate
: Not applicable.
: The authors declare that they have no competing interests.
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