supported by the National Natural Science Foundation of China(No.60433020,No.60673099,No.60773095);the"Computing and Software Science and Technology Innovation Flat"of project 985;the Key Laboratory for Symbol Computation and Knowl-edge Engineering of the National Education Ministry of China(No.02090);the Science and Technology Development Planning Project of Jilin Province(No.20080168);the Jilin University Graduate Innovation Foundation of"Project 985"(No.20080236)