Cui, Chunyan
Li, Xiaoru
Liu, Jixian
Hou, Yongchao
Zhao, Yuqing
Zhong, Guocheng
Funding for this research was provided by:
the Specialized Research Fund for the Doctoral Program of the Higher of Education (20123706120003)
Shandong Province Natural Science Fund of China (ZR2014EMQ002)