国家自然科学基金31360369,21366007;广西自然科学基金2014GXNSFAA118097,2014GXNSFAA118078;广西主席基金[桂财教函2015284号];Supported by the National Natural Science Foundation of China 31360369,21366007,by the Natural Science Foundation of Guangxi Province 2014GXNSFAA118097,2014GXNSFAA118078 and by the Chairman Fund Project of Guangxi Province [2015284]