丙酮基

CAR has high stereoselectivity for aromtic ketones such as acetophenone,2'-chloroacetophenone, 3'-chloroacetophenone, 4'-chloroacetophenone, 3-chloropropiophenone and2-chloro-2',4'-difluoroacetophenone.

羰基还原酶对芳香酮类化合物具有很高的立体选择性，对苯乙酮、2'-氯-苯乙酮、3'-氯-苯乙酮、4'-氯-苯乙酮、3-氯-1-苯丙酮和2-氯-2'，4'-二氟苯乙酮还原产物的e.e。

As well as activity was exhibited. Theaddition of cinchonidine led to a remarkable increase in the reaction rate, as confirmed bythe IR study that the modifier activates the carbonyl groups of the reactant through itsquinuclidine nitrogen. On the contrary,〓 exerted a strong inhibition effect on theenantioselective hydrogenation. Chapter 3 Finely dispersed polyvinylpyrrolidone-stabilized iridium andbimetallic clusters were prepared by the alcohol-water reduction method.

第三章 采用醇水还原的方法制备了聚乙烯基吡咯烷酮稳定的铱纳米簇及双金属纳米簇，对丙酮酸甲酯的催化氢化表明，在铱金属簇催化体系中，辛可尼定不仅诱导了一定的对映选择性，同时对反应活性有明显的促进作用，平均反应速率可提高2-6倍。

Molecular conformation calculations were made for two possible conformers(eclipsed and staggered with respect to the methyl group)of the compound Calculated results show that:the stable conformer of pyruvic acid is the eclipsed one;The BLYP/6-31G* and scaled HF/6-31G* frequencies correspond well with each other and with available experimental assignment of the normal vibrational modes.

结果表明：在丙酮酸分子的两种构象中，重叠式比较稳定*B3LYP计算得到的构型参数与实验结果比较一致；在振动频率的计算中，BLYP未标度力场所计算的非CH3伸缩振动基频预测值和实验值的平均绝对偏差为10.4cm-1；而HF标度力场的平均绝对偏差为17.9cm-1。

Their structures were characterized as dihydroconiferyl dihydro-p-coumarate, vanillin, apocynin, p-hydroxybenzaldehyde, syringaldehyde, syringic acid, syringylethanone,α-hydroxypropiosyringone, coniferyl aldehyde, dihydroconiferyl alcohol, 2-hydroxyphenylpropanol, and 3-hydroxy-4-methoxy-phenylethanol, respectively.

结果 从该植物中分离得到12个酚性化合物，其结构分别为二氢松柏醇二氢对羟基桂皮酸酯，香草醛，罗布麻宁，对羟基苯甲醛，丁香醛，丁香酸，丁香乙酮，α-羟基丁香丙酮，松柏醛，二氢松柏醇，2-羟基苯丙醇和3-羟基－4-甲氧基苯乙醇。

Cefminox sodium reacted with 2,4 dinitrophenol to form a charge transfer complex in methanol acetone and can be quantitatively determined by spectrophotometric method at 403 nm.

利用头孢米诺钠与2，4 二硝基苯酚在甲醇丙酮介质中反应，形成电荷转移络合物，采用分光光度法测定。

At the same concentration, extracts show the highest scavenging rate on the four different free radicals extracted by ethyl ether, acetone, ethyl ether and ethyl acetate, respectively.

在相同的浓度下，对自由基的清除作用最大的分别为乙醚、丙酮、乙醚和乙酸乙酯提取物。

Secondly,a mixture of acetone and methyl formate was added into the methanol solution of sodium methoxide to prepare sodium formyl acetone by Claisen reaction.

以金属钠为原料，甲醇为溶剂，先制成甲醇钠的饱和甲醇溶液，再滴加丙酮和甲酸甲酯进行Claisen酯缩合制得丁酮烯醇钠，最后在强酸作用下与甲醇进行缩醛化反应合成了4，4-二甲氧基-2-丁酮，过程总收率达到73.1%，纯度98.7%。

Objective: To establish a method for detection of mesityl oxide in the air of workplace by GC chromatography.

目的：建立工作场所空气中异亚丙基丙酮的采样和测定方法。

Phosphoenolpyruvate is one of the two phosphoryl group donor s in the synthesis of ATP during glycolysis.

磷酸烯醇式丙酮酸是糖酵解中合成ATP的两种磷酸基的供体之一。

Phosphoenolpyruvate is one of the two phosphoryl group donors in the synthesis of ATP during glycolysis.

磷酸烯醇式丙酮酸是糖酵解中合成ATP的两种磷酸基的供体之一。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。