Funding for this research was provided by:
Key Research and Development Program of Shanxi Province (201603D211104)
Special Funds of the Natural Science Foundation of TaiYuan (11014908)
Shanxi Scholarship Council of China (No2017019, 2017019)
Article History
First Online: 2 May 2018
Compliance with Ethical Standards
:
: The authors declare that they have no conflict of interest.