Funding for this research was provided by:
Open Project of State Key Laboratory of Transient Optics and Photonic Technology (SKLST201505)
National Natural Science Foundation of China (61077072)
Article History
Received: 8 October 2017
Accepted: 28 December 2017
First Online: 12 January 2018
Compliance with ethical standards
:
: There is no conflict of interest.