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The highest ee value of 71% was achieved by using chiral molybdenum 2'-pyridingyl alcoholate complex at 0 ℃. After addition of phase transfer catalyst Bu4NBr, the yield and ee value were remarkably increased.

其中手性吡啶醇二氧合钼在0℃下的对映选择性ee值达到71%；加入相转移催化剂四正丁基溴化铵，催化剂的活性和对映选择性有显著提高，其中手性吡啶醇二氧合钨在50℃下ee值由54％提高到78%。

In the function of sodium methoxide, several factors effecting on alcoholysis of urea by zinc oxide catalyst were obtained.

探讨了在甲醇钠作用下，氧化锌催化尿素醇解的影响因素。

The effect of temperature, catalyst, and alcoholysis agent, etc, on PET alcoholysis was studied, and reacting conditions and formulation of PET alcoholysis were determined.

深入研究了温度、催化剂和醇解剂等对PET醇解反应的影响，确定了醇解工艺条件及配方。

With methanol as solvent and NaOH as catalyst,the influence of the concentration of NaOH ,reaction temperature and reaction time to the alcoholysis of polyvinyl acetate is studied by the homogeneous design procedure.

使用均匀设计法研究了甲醇作为溶剂，氢氧化钠作为催化剂时，聚醋酸乙烯酯醇解反应中碱的物质的量比、反应温度和反应时间对聚乙烯醇醇解度的影响。

The catalysts used in the preparation of di acetone alcohol by the Aldol condensation were studied in detail, and a new kind of catalyst Ca 2/Al 2O 3 is developed.

对丙酮经Aldol缩合制二丙酮醇的催化剂进行了研究，研制出新型催化剂Ca 2 /Al2 O3，这种催化剂对丙酮的缩合反应具有较理想的活性及选择性。

We first examined the ability of the catalyst to promote the direct aldol reaction between acetone and 4-nitrobenzaldehyde under various conditions.

通过偶联反应将催化剂1固载到硅胶上，并将其用于催化环己酮和硝基苯甲醛的aldol反应，dr值最高达到90：10，ee最高76%。

In part Ⅰ, the aquous direct aldol reactions catalyzed by small organo-catalyst—imidazolc were studied in detailed.

本文第一部分详细研究了咪唑为有机小分了催化剂催化水相直接羟醛缩合反应。

When 5 mol% of 1a was used to catalyze the reaction at 0℃to room temperature, the aldol products were obtained with up to 96% ee, which were comparable to the effect with 30 mol% of L-proline as catalyst.

在0℃～室温下，以5mol％的1a催化即可获得相当或优于30mol％脯氨酸本身所具有的催化效果，ee值最高可达96％。

Through experiment, we have found that the combination of naphthol/sodium naphtholate is a high efficient bifunctional catalyst for direct aldol reaction.

通过实验，我们发现并筛选出了一组活性较高的β-萘酚和其钠盐双功能催化剂，该方法不需要预先活化Aldol反应的底物就能直接反应，且反应可在室温进行，条件温和，速度快，收率高达98%。

The catalyst Ti-MCM-41 is used in epoxidation of propylene, in which cumenen hydroperoxide is used as oxidant, alkalescence of solution, reaction temperature and solvent are tested.

将所合成的Ti-MCM-41催化剂用于CHP氧化丙烯的环氧化反应中，对反应液的酸碱性、反应温度及溶剂进行了考察。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。