国家自然科学基金资助项目51104016;稀贵金属综合利用新技术国家重点实验室开放课题资助SKL-SPM-201204 Project 51104016 supported by Natural Science Foundation of China;Project SKL-SPM-201204 supported by State Key Laboratory of New Technology for Comprehensive Utilization of Rare and Precious Metals, China