国家自然科学基金批准号:51276147、中央高校基本科研业务费批准号:3102014KYJD005和西北工业大学基础研究基金批准号:NPU-FFR-JC20120201资助的课题.Project supported by the National Natural Science Foundation of China Grant No.51276147,the Fundamental Research Fund for the Central Universities,China Grant No.3102014KYJD005,and the Fundamental Research Foundation Northwestern Polytechnical University,China Grant No.NPU-FFR-JC20120201.