supported by grants from The National Natural Scientific Foundation of China(30901577);The Hengyang Technological Bureau of China(2009KJ14);Ministry of Education of Returned Overseas Students to Start Research and Fund Projects(20091590);Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province~~
supported by grants from The National Natural Science Foundation of China(30901577,30770868);National Basic Research Program of China(2006CB503808);Talent Program of USC(2008XQD01);Hengyang Municipal Bureau of Science and Technology(2009KJ14);Ministry of Education of Returned Overseas Students to Start Research and Fund Projects(20091590);Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province~~