国家自然科学基金项目51575442;陕西省自然科学基金2016JZ011;陕西省教育厅基金2014SZS10-Z01资助.The project supported by the National Natural Science Foundation of China51575442;the Natural Science Foundation of Shaanxi Province2016JZ011;the Fund of Shaanxi Province Department of Education2014SZS10-Z01