苄基氯化镁的制备? 为什么不用甲基四氢呋喃试试呢?如果需要methf样品,给我发邮件. 以下是原文献资料: methf can be used to produce high yields of benzyl and allyl grignard reagents at low magnesium ratios. thf can only be used to make benzyl and allyl grignard reagents at reasonable yields by using high molar ratios of magnesium to benzyl or allyl halide. for instance, a yield of greater than 90% of benzylmagnesium bromide is made with methf, but mostly bibenzyl is made with thf at a magnesium:benzylbromide ratio of 1.2:1. 查看更多
离心泵出口法兰DN40与其相连的法兰迅速变为DN 100的管径 ...? 一般情况下,大1到2个尺寸。dn40 的应该用dn50或dn60的管子。个人认为泵的管口口径有问题。 generally, discharge piping is one or two sizes larger than the pump discharge nozzle size. 查看更多