concentration on注意力集中于concentrationn.集中；专心；浓度concentration of spermine.浓度的精胺。concentration-time profile浓度-时间轮廓图concentration of coal powder煤粉浓度concentration-contact time浓缩-接触时间concentration index of space空间集聚指数concentration of enterprises企业集中concentration of blastospore孢子浓度concentration of agarose gel琼脂糖凝胶浓度concentration depolarization浓度消偏振concentration of chlorine gas氯气浓度