基金supported by Young Teacher's Foundation of Anhui Normal University(2008xqn46)Ministry of Education of Science and Technology of Important Projects(207047)Natural Science Foundationof Anhui Province of China(050460103)
基金This research was supported by Ministry of Education of Science and Technology of I mportant Projects(No.207047)NaturalScience Foundation of Anhui of China(No.050460103)Key Natural Science Foundation bythe Bureau of Education of An-hui Province in China(No.2005kj031ZD).