supported by the National Natural Science Foundation of China(No.31300915);the Scientific Research Project Fund for Youth Teachers from Central China Normal University(No.CCNU15A05035)
This work was supposed by the National Natural Science Foundation of China(No.30470633,30270554)Doctorial Subject(No.20050698012)Key Item of Scientific and Technology for Ministry of Education(No.01161)the Doctorial Foundation of Xi’an Jiaotong University(No.2003-13).