The molecular structure of cationic surfactants is closely related to their flotation performance. In this paper, three with different head group structures were selected as collectors kaolinite, and the substituent effects studied by DFT method. calculation results showed that increasing number substituents in dodecylamine can significantly increase its surface charge. Dodecylamine has lowest ...

new analogues of nifedipine, as a known calcium channel blocker, were synthesized by replacing the orthonitrophenyl group on position 4 with 1-(4-nitrobenzyl)-5-imidazolyl or 2-methylthio-1-(4-nitrobenzyl)-5-imidazolyl substituent. effects of the new synthesized compounds on blood pressure were studied at 15, 30 and 60 min after administration by indirect tail-cuff method and compared with nife...