国家自然科学基金项目31170423,31270498、国家“十二五”科技支撑计划项目2011BAC09B05、四川省杰出青年学术与技术带头人培育项目2012JQ0008,2012JQ0059以及中国博士后科学基金项目2012T50782资助;Supported by the National Natural Science Foundation of China 31170423,31270498,the Key Sci-tech Project of the Twelfth Five-year Plan of China 2011BAC09B05,the Sichuan Youth Science and Technology Foundation 2012JQ0008,2012JQ0059,and the China Postdoctoral Science Foundation 2012T50782