The hydroxyl groups can be changed into esters , ethers , acetals and ketals, etc.最常用的羟基保护基可归纳为三类:酯类 、 醚类和缩醛或缩酮类.Eight acetals ( Ketals ) were synthesized under the optimal conditions.在最佳条件下,合成了八个缩醛 ( 酮 ) 化合物.The yields ...
The yields of other cyclic acetals were between 62.并在此条件下合成了多种环缩醛,收率62.Eight acetals ( Ketals ) were synthesized under the optimal conditions.在最佳条件下,合成了八个缩醛 ( 酮 ) 化合物.The hydroxyl groups can be changed into esters , ethe...
She trudges , schlepps, trains, drags, trascines her load.她吃力地跋涉, schlepps 、 trains 、 drags、trascines重荷.Matvey , who has not tasted food or drink all day , trudges up the hill again.玛特威从一大早起就什么也没吃过,什么也没喝过, 这时候却又爬上坡去.Andy...
她帮他翻了个身，免得他生褥疮。She turned him in the bed so that the sheets wouldn't chafe his skin into sores.目的寻找一种治疗褥疮的有效方法.To search an effective therapeutic method in treatment of bedsore.结论复方车前草软膏对褥疮有一定的治疗作用.Conclusion Compou...
They can neither read nor write, nor can they comprehend such concepts.他们不会读，不会写，也理解不了这样的概念。Whenever she failed to comprehend she invariably laughed.每当她听不懂的时候，她总是会笑。The infinite distances of space are too great for the h...
Fears for the President's safety could overshadow his peace-making mission.对总统安全的担忧可能会给他的调解使命蒙上阴影。Her new book will overshadow all her earlier ones.她的新书将会使她以前写的书都黯然失色.Large oak trees overshadow the garden.高大的栎树把花园遮得...