supported by the Natural Science Foundation of Shandong Province;China(No.Y2005D14);Science and Technology Program of Yantai Municipality;China(No.2008152);the Scientific Research Foundation for the Returned Overseas Chinese Scholars;Ministry of Education;China(No.20071108);the Discipline Construction Funds of Ludong University
supported by the Natural Science Foundation of Shandong Province,China(No.Y2005D14);Science and Technology Program of Yantai municipality(No.2008152);the Scientific Research Foundation of Education Ministry for the Returned Overseas Chinese Scholars;the Discipline Construction Funds of Ludong University