时基

We found that when acetone was used as solvent, in the presence of TFA, cis-4-pyrrodin-1-yl-L-proline could catalyze the direct asymmetric aldol reaction between acetone and 4-nitrobenzaldehyde with 84% ee.

研究发现，该催化剂以丙酮为溶剂时，加入催化剂等当量的三氟乙酸可以较好的催化丙酮与对硝基苯甲醛之间的直接不对称Aldol反应，得到84%的ee值。

Addition , the alkyl of the position is always more to replace the carbon in the ...

加成时，烃基化的位置总是在取代较多的碳。。。

A process for preparing alkylene glycols including reacting an alkylene oxide with water in the presence of a combination of additives and an anion exchange resin, wherein the combination of additives comprises carbon dioxide and an organic or inorganic base provided in an amount sufficient to maintain a pH of the reaction mixture between about 5.0 and 9.0, with the proviso that, when the base is bicarbonate or carbonate, then the anion exchange resin is a trimethyl benzyl ammonium anion exchange resin.

制备亚烷基二醇的方法，包括让烯化氧与水在添加剂组合和阴离子交换树脂存在下进行反应，其中添加剂组合包括二氧化碳和以足以保持反应混合物的pH值在约5.0和9.0之间的量提供的有机或无机碱，前提条件是当碱是碳酸氢盐或碳酸盐时，阴离子交换树脂是三甲基苄基铵阴离子交换树脂。

No obvious difference was observed when 6′-OH of isonucleoside was free or was protected by allyl group.

异核苷6′-OH处于游离和烯丙基保护状态时的结果没有显著差异。

And when they were at the great stone which is in Gabaon, Amasa coming met them.

当他们来到基贝红的大石旁时，阿玛撒也迎面而来。

While in the case of system Ⅱ, hydrogen bonding is introduced into SAMs by the amide group.

当末端为氨基和磺酸基时，LB膜与基底间则以离子键的形式存在。

When the role ratio was high, and the osmosis preferable, the removal rate of total phosphor, ammoniac nitrogen, and chemical oxygen demand were high, and reduced with the prolonged time.

当基质渗透性较好、孔隙率较高时，污水总磷、氨氮、以及化学需氧量去除率较高；随时间延长，各指标去除率降低，其中总磷去除率与时间有较好的线性相关。

The kinetics of tertamyl methyl ether synthesis using C5 fraction of FCC gasoline was studied. The molar ratio of tertiary amylene to methanol was 1.0 and the kinetic experimental data was obtained at the temperature range from 55℃ to 90℃.

研究了FCC汽油中C5馏分合成甲基叔戊基醚的宏观动力学。C5原料与甲醇摩尔比为1/1，在温度分别为55℃~90℃时反应得到了动力学实验数据。

By making up of time-frequency local property and multi-scale analytical capability of wavelet transformation and self-learning and prediction function of artificial neural network,chapter three develops a prediction model loose combining wavelet analysis and Radial Basis Functionsneural network,abbreviated as Wavelet-RBFNN.

第三章利用小波变换的时频局域化特性和多尺度分析能力及神经网络的自学习、预测功能，通过小波分析与神经网络的松散型结合方式，建立小波分析和径向基函数神经网络(Wavelet-RBFNN)预测模型。

When Kiefer played Igor Andreev in the Kremlin Cup final, that's exactly the way the German was reacting.

当基佛在克里姆林杯与安得烈夫打决赛时﹐他就是都这样子的

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷