The selectivity of extractant is high and only Au, Pd , Hg ete. are extracted.该萃取剂选择性高,它仅萃取Au 、 Pd和Hg等几种元素.An extractant - screening method with a vapor - liquid equilibrium apparatus in the extractive distillation was i...
阐明了止汗剂的种类及其作用机理.The type and mechanism of antiperspirant action were given.止汗剂有不同的强度, 分为处方的和 非 处方的两种.Antiperspirants come in a range of strengths, both over - the counter and prescription....