国家自然科学基金No.21107039;辽宁省教育厅科学技术研究项目No.L2011002;辽宁省科学技术计划项目No.2011230009 Supported by the National Natural Science Foundation of China No.21107039,the Science and Technology Research Project of Liaoning Provincial Education Department No.L2011002,and the Science and Technology Plan Project of Liaoning Province No.2011230009