Lu, Chengbo
Ke, Haifeng
Zhang, Gaoyan
Mei, Ying
Xu, Huihui
Funding for this research was provided by:
First-class Disciplines of Zhejiang Province - Mathematics
Scientific Research Foundation of Zhejiang Provincial Education Department (Y201432787)
National Natural Science Foundation of China (61373057)
Article History
Received: 2 January 2017
Accepted: 20 June 2017
First Online: 29 June 2017