基金supported in part by the Special Funds for Major State Basic Research Project (2007CB814906)the National Natural Science Foundation of China (10471019,10471103, and10771158)+2 种基金Social Science Foundation of the Ministry of Education of China (numerical methods for convertiblebonds,06JA630047)Tianjin Natural Science Foundation (07JCYBJC14300)the State Key Laboratory ofScientific and Engineering Computing,and Tianjin University of Finance and Economics