Li, Lei http://orcid.org/0000-0001-5304-8380
Liu, Jian-Guo http://orcid.org/0000-0002-9911-4045
Lu, Jianfeng http://orcid.org/0000-0001-6255-5165
Funding for this research was provided by:
National Science Foundation (RNMS11-07444, DMS-1514826)
National Science Foundation (DMS-1454939)
Article History
Received: 16 January 2017
Accepted: 23 August 2017
First Online: 2 September 2017