supported by the Project for the Plan of Science and Technology Exploitation of Fujian Province, China (No. 2005D073);the Natural Science Foundation of Fujian Province, China (No. C0410018);the Project of Science and Technology Bureau of Fujian Province, China (No. 2006F5046)
This work was supported by the Project of Science and Technology Exploitation of Fujian Province;China(No.2005D073);the Natural Science Foundation of Fujian Province;China(No.C0410018);the Project of Science and Technology Bureau of Fujian Province;China(No.2006F5046)