Liu, Aiqin
Zhang, Jia
Zhao, Jingmin
Zhao, Wei
Wang, Rongjun
Zhang, Longxian
Funding for this research was provided by:
Heilongjiang Province Education Bureau (No.12531266.)
Article History
Received: 28 April 2015
Accepted: 18 September 2015
First Online: 22 September 2015