作者机构:[1]Department of Systems Science, School of Management, Beijing Normal University, Beijing 100875, China, [2]Wuhan Institute of Physics and Mathematics, The Chinese Academy of Sciences, P.O. Box 71010, Wuhan 430071, China, [3]Beijing Higher Education Press, Chaoyang District, Beijing 100029, China
相关基金:Project supported by the National Natural Science Foundation of China (Grant Nos 60534080, 60774085, and 70771012).Acknowledgements The authors are grateful to Wang You-Gui for useful comments.