基金supported by theNational Natural Science Foundation of China (No. 30670688,30771140)the Natural Science Foundation of Education De-partment of Henan Province (No. 2007180008)+1 种基金the Natural Science Key Program of Henan University (No. 2008YBGG048)the International Cooperation Program of Science andTechnique Department of Henan Province, China (No.094300510044)