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The synthesis of acrolein by means of the catalytic vapor phase condensation of formaldehyde and acetaldehyde was studied.

利用冷凝甲醛和乙醛的气相催化法，来研究丙烯醛的合成。

Acetaldehyde generated from the 2 - butene aldehyde carbonyl and the reaction is the condensation of methylene ...

由乙醛生成2－丁烯醛的反应是羰基与亚甲基发生缩合的。。。

An oily colorless liquid obtained by the condensation of two molecules of acetaldehyde.

一种无色的油质液体，浓缩两个乙醛分子而获得。

3-Nitrodiphenylamine is generally synthesized by the Ullmann condensation of N-（3-nitrophenyl） acetamide with bromobenzene.

摘 要：间-乙酰氨基硝基苯与溴苯发生Ullmann缩合反应是制备3-硝基二苯胺最常用的方法。

A new way of synthesis 2-methoxy-4'-trifluoromethyl acetophenone by the method of crossed ester condensation was investigated in the overall yield of higher than 85%.

本文提出了一种新的方法——交叉酯缩合法合成2-甲氧基-4'-三氟甲基苯乙酮。

We have used GC to follow up the formation of epoxy acid and established the acidify condition; we have done series of parallel experiments to better the pivotal condensation reaction between acid and amine; In the cyclization step, we use cheap and available reagent-Lithium amide , rather than expensive LiHMDS, to proceed the reaction; and at last, we introduced green reagent-ozone to clear the phenyl group of nitrogen to avoid using heavy metal reagent-CAN. The total yield for this method is 29.8%.

通过GC监测，确定环氧酸的最佳酸化条件；对关键的酸和胺的缩合步骤，平行试验了多种条件；在环合一步，用价廉易得的氨基锂及催化量的HMDS代替昂贵的LiHMDS进行反应；氮上苯基的脱除采用臭氧，避免了重金属试剂-硝酸铈铵的使用，总收率为29.8％。

Recently, the interest for obtaining acrolein by aldol condensation has

后来，使用丙烯氧化，就对这些进程失去了兴趣。

For the advantages of mild reaction conditions,DDC condensation method and acyl chloride esterification method are much more popular.

由于具有反应条件温和的优点，二环己基碳二亚胺脱水缩合法和酰氯酯化法是目前国内外最常用的两种方法。

The homogeneous nucleation rate, saturation rate, and droplet growth equation at state 250K、100Kpa for pentone affected by single expansion wave has been obtained in the joined international cooperation research. Results exposed that temperature decrease in the homogenous nucleation and condensation is the preponderant factor in unsteady adiabatic expansion process.

参与同质核化率实验的国际合作研究，获得250K、100KPa状态附近戊醇在单脉冲膨胀波作用下的同质核化率、饱和度及同质核化微滴在低压状态中长大状态方程；研究表明非定常绝热膨胀过程中，降温因素在同质核化和凝结过程中占主导作用。

The air content in condenser should be reduced as far as possible due to the great influence of air content in condenser on steam condensation heat transfer.

由于凝汽器中空气含量对蒸汽凝结放热的影响很大，因此要尽可能减少凝汽器中的空气含量。

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％。