Funding for this research was provided by:
National Natural Science Foundation of China (61271233, 61401004, 61601005)
the Ph.D Programs Foundation of Anhui Normal university (2016XJJ129)
Plan of introduction and cultivation of university leading talents in Anhui (gxfxZD2016013)
the HIRP program of Huawei technology
Article History
Received: 2 May 2018
Revised: 22 October 2018
Accepted: 27 November 2018
First Online: 10 December 2018