supported by the National Natural Science Foundation of China(61006065,61076039,10804071);Research Fund for the Doctoral Program of Higher Education of China(20102216110001,20112216120005);Developing Project of Science and Technology of Jilin Province, China(20091039,20090555,20101546,20121816,201201116);Foundation of Department of Education of Jilin Province,China(JYT2011-05, JYT2011-10,JYT2011-11)~~