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...
Read these notes carefully and keep them for future reference.仔细阅读这些注释并将其保留下来以备将来之用。They exchange traveller's cheques at a different rate from notes.他们兑换旅行支票时依据的汇率跟兑换现钞时不同。Watson has a wonderful voice, with thrillin...
战争颠倒是非：杀戮与残忍成了美德。War turns morality inside out: killing and cruelty are virtues.甘地体现了克己、禁欲和自我约束的美德。Gandhi exemplified the virtues of renunciation, asceticism and restraint.谦虚被认为是一种美德。Humility is considered a virtue....
A blade guard is fitted to protect the operator.为保证操作人员的人身安全安装了桨叶保护罩。A sharp blade is likely to nick the skin and draw blood.锋利的刀刃可能会划伤皮肤，导致出血。The soil sticks to the blade and blocks the plough.土粘在犁铧上，卡住了犁。...
俄别以东和耶希亚也是约柜前守门的.Obed - Edom and Jehiah were also to be doorkeepers for the ark.于是将以色列神的约柜运到那里去.And they carried the ark of the God of Israel about thither.他们就把神的约柜送到以革伦.So they sent the ark of God to Ekron....