作者机构:[1]Department of Mathematics, Shanghai Key Laboratory of Pure Mathematics and Mathematical Practice, East China Normal University, Shanghai 200241, P. R. China, [2]Department of Mathematics and Computer Sciences, Emory University, Atlanta, GA 30322, USA, [3]School of Mathematics and Statistics, Hu 'nan University of Commerce, Changsha 410205, P. R. China
相关基金:The first author is partially supported by National Natural Science Foundation of China (Grant Nos. 11371268 and 11471117) and Science and Technology Commission of Shanghai Municipality (Grant No. 13dz2260400); the third author is partially supported by National Natural Science Foundation of China (Grant No. 11471117) and by PERS of Emory