国家自然科学基金61363074;广西自然科学基金2013GXNSFAA019346;广西教育厅科研项目2013YB148 Foundation Items:The National Natural Science Foundation of China61363074;The Natural Science Foundation of Guangxi Province of China2013GXNSFAA019346;The Scientific Research Fund of Guangxi Education Department of China2013YB148