分析下这个句子呢……? it is a object of this invention to modify the countercurrent extraction of mixtures comprising alkenylpyridines and alkylpyridines with aqueous acidic solutions so as to enhance the selectivity to alkenylpyridines. additional objects and advantages of this invention will be apparent from the disclosure and the appended claims. 这项发明的一个目的就是改进含有烯基嘧啶和烷基嘧啶的混合物在酸水溶液中的逆流萃取来加强烯基嘧啶的选择性。其余关于此发明的目的和优势,将在公开和附加声明中披露。 查看更多