Funding for this research was provided by:
National Natural Science Foundation of China (51673004, 51703004)
Natural Science Foundation of Beijing Municipality (2162012)
Top Young Innovative Talents Program of Beijing Municipal University (CIT&TCD201704041)
Article History
Received: 4 August 2018
Accepted: 7 November 2018
First Online: 12 November 2018
Compliance with ethical standards
:
: The authors declare that they have no competing interests.