基金Supported by the Natural Science Foundation of Hebei University,the NationalNatural Science Foundation of China(10471039),the Zhejiang Provincial Natural Science Foundationof China(M103087)
基金Research supported by National Natural Science Foundation of China ( No :10471149) , Mathematics Tian Yuan Youth Foundation ( A0324610) and the Doctoral Foundation of the Depart ment of Education of Hebei Province (B2004103) .