乙醛

Production technology of synthesis of allantoin are reviewed, including glyoxal oxidation, electrochemical synthesis, calcium glyoxylate synthesis, dichloroacetic acid synthesis, acetochloral method, and oxidative decarboxylation.

评述了乙二醛氧化法、电化学法、乙醛酸钙法、尿素三氯乙醛合成法、尿酸二氯乙酸法和尿酸氧化脱羧法等合成尿囊素的各种工艺。

The results showed that ascorbic acid oxidase activity in the flesh of 'brumal Jujube' became significantly higher than in pericarp with the development of maturity; but these activities of peroxidase , Polyphenoloxidase and phenylalanine ammonia-lyase in flesh were lower than in pericarp . During the development from green to half-red then to red, the lignin and fibre contents in pericarp gradually increased higher than in flesh; ethanol content also increased , acetaldehyde content reached to a peak during the red maturity stage and then declined.

随着贮期的延长，冬枣果肉中乙醇和乙醛含量增加，乙醇发酵关键酶的活性逐渐升高；气调贮藏延缓了果实中乙醇和乙醛的积累，抑制了PDC和ADH的活性，显著提高了果实的贮藏品质；说明气调贮藏延缓了果实的乙醇积累；但CA_1比CA_2促进果实乙醇积累的作用较明显，表明冬枣对高浓度CO_2较敏感，这可能是枣果实不耐高CO_2的原因之一。

The glyoxalic acid and oxalic acid in electrosynthesis of glyoxalic acid from oxalic acid was determined by reversed-phase high performance liquid chromatography,this method is simple,low cost and high performance.

采用高效液相色谱法测定了草酸电合成乙醛酸中乙醛酸和草酸的含量，方法简便，成本低廉，效果良好。

A spectrophotometric simultaneous determination of glutaraldehyde and ethanal based on the reaction between gluaradehyde or ethanal and thiobarbituric acid in acetic acid solution is described.

在醋酸介质中，硫代巴比妥酸与戊二醛及乙醛分别可生成2∶1及1∶1的缩合产物，这两种缩合产物在可见光区具有不同波长的最大吸收，籍此可同时测定戊二醛及乙醛。

To improve the selectivity, the Co/Mn/Br catalyst system with ethanal as an additive was studied and the reaction conditions were also optimized, which were as follows:the amount of ethanal 10%(mole ration base on the substrate), reaction temperature 100℃,reaction time 30min,the oxygen pressure 0.2MPa, the amount of the composite catalyst Co/Mn/Br 7%,the mass ration of different ingredients 2:2:1. Under these conditions, the yield comes to 24.10% and the selectivity reaches 75.03%.

为了提高反应的选择性，论文初步研究了以乙醛作为添加剂条件下各工艺参数的影响，并进行正交优化，得出最佳条件为：乙醛加入量1：10，反应温度100℃，反应时间30min，氧气压力0.2MPa， Co/Mn/Br混合催化剂加入量7%，质量比2：2：1，在此条件下，反应产率为24.10%，选择性可达75.03%。

The results showed that the degrdation rate of fluorobenzene by TiO2/SnO2 coating rosed from 71.9% to 90.1% compared with pure TiO2 coating. The apparent rate constant k of the photocatalytic degradation is related to the initial concentration of fluorobenzene and the reaction order is zero. The corresponding degradation rate of aldehyde with the concentration of 100ppm rosed from 69.2% to 91.4% and the reaction order is one.

结果表明：与未改性涂料相比，SnO2改性涂料的活性对氟苯的降解率由71.9％提高到90.1％，反应表观速率常数与降解液初始浓度有关，光催化降解氟苯属于零级反应；对100ppm乙醛的降解率由69.2％提高到91.4％，光催化降解乙醛属于一级反应。

The determination of glyoxal and glyoxalic acid in aldehyde solution was performed by high performance liquid chromatography.

利用醛基与2，4-二硝基苯肼反应得到的腙产物对紫外-可见光有吸收的特性，采用高效液相色谱法测定乙醛溶液中乙二醛和乙醛酸的含量。

The derivative ratio of UV spectrum is used to analyze a mixture of glyoxal and glyoxalic acid.

用紫外光谱的比值导数法对乙二醛与乙醛酸的二元混合物进行分析，该方法能将乙二醛和乙醛酸重叠光谱分开并消除互相干扰，从而方便的完成两组分混合体系中各组分的测定。

The guaiacol methods of synthesizing vanillin mainly includes: nitroso group method, Glyoxalic acid method, formaldehyde method, Reimer-Tiemann method, Trichloroacetaldehyde acetochloralb method, electrolytic oxidation method.

愈创木酚法合成香兰素的方法主要有亚硝基法、乙醛酸法、甲醛法、Reimer-Tiemann法、三氯乙醛法、电解氧化法，本文综述了愈创木酚法合成香兰素的研究进展，并对愈创木酚法合成香兰素提出了展望。

The distribution coefficient of oxalic acid was larger than that of glyoxylic acid,and both of them decreased with the pH. The selectivity of oxalic acid to glyoxylic acid also decreased with pH.

在本实验的条件范围内，草酸的分配系数较乙醛酸大，且随溶液pH值的增大而下降，草酸对乙醛酸的分离系数随pH值的增大而减小。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。