基金supported by the National Natural Science Foundation of China(No.30870800)the Ph.D Program Foundation of Ministry of Education,China(No.200810650002)the Bureau of Science and Technology of Qingdao Municipal,China(No.08-2-1-2-nsh)
基金This project is supported by National Natural Science Foundation of China (No. 30271441) Key Project of Shandong Educational Committee(J01K03)Qingdao Municipal Science & Technology Commission (02-1-KJ-YJ-49).