羟基乙醛

Glyceraldehyde, glycoladehyde, glycolic acid, and formaldehyde were identified as the intermediate products.

甘油光催化降解最终产物是H_2O和CO_2，检测到了甘油醛、羟基乙醛、羟基乙酸、甲醛等中间产物。

In order to obtain 3-methoxy-4-hydroxymandelic acid with high quality and high yield, guaiacol was condensed with glyoxylic acid in an alkaline aqueous solution using solid acid as catalyst. The reaction temperature and reaction time was 15℃ and 18 hours respectively.

为了得到高质量和高收率的3-甲氧基－4-羟基苯乙醇酸，使愈创木酚和乙醛酸在碱性水溶液中在固体酸催化剂存在下进行缩合反应，反应温度15℃，反应时间18h。

Hydroxybutyraldehyde, which is main material of synthesizing 3-hydroxybutyric acid was prepared through the aldol condensation of acetaldehyde in this paper. The properly reaction conditions of acetaldehyde condensation and paraldehyde depolymerization was studied and obtained.

本文自行制备了氧化反应的主要原料3-羟基丁醛，并对乙醛羟醛缩合反应及三聚乙醛的解聚反应进行了初步研究，确定了反应的最佳条件。

It shown that PDC does not only catalyze the production of acetaldehyde (PDC's main activity), but also catalyzes an aldoltype condensation reaction in which the hydroxyethyl-ThDP intermediate of enzyme is condensed with a second acetaldehyde to form acetoin.

在研究中发现PDC不仅能催化产生乙醛，还具有醛连接酶的活性。即将二个乙醛分子缩合成3-羟基丁酮，尽管这个活性比产生乙醛的活性低得多。

The bio-oil was composed of acetic acid, hydroxyacetaldehy, acetol, levoglucosan, furaldehyde, and a small quantity of phenols.

结果表明，热解温度为460~520℃时热解油产率最大，主要有醋酸、羟基乙醛、羟基丙酮、左旋葡聚糖、糠醛，油热值为17.0MJ.kg-1；热解气主要为CO2和CO，还含有少量H2、CH4和C2~C4的烯烃。

D, L-p-HPH was produced by employing amidoalkylation reaction of phenol with glyoxylic acid and urea under acidic conditions.

用尿素、乙醛酸和苯酚合成底物D，L-对羟基苯海因，收率为62％，与文献报道相近。

Ethoxy-4-hydroxy mandelic acid was synthesized from glyoxylic acid and o-ethoxyphenol in alkaline solution.

在碱性条件下由乙醛酸和邻乙氧基苯酚合成了3-乙氧基-4-羟基苯乙醇酸。

As an intermediate for preparing vanillin derived from glyoxylic acid, 3, 4-dihydroxymandelic acid is synthesized based on condensation of catechol and glyoxylic acid in alkaline aqueous solution.

以邻苯二酚和乙醛酸为原料，在碱性条件下发生缩合反应，合成了3， 4-二羟基扁桃酸，此物质是多种香料和药物合成的重要中间体。

By using gas chromatography technique nine kinds of fragrance components(acetic aldehyde,ethyl acetate,ethanol,propyl acetate,3-hydroxy-2-butanone,acetic acid,furfural,metacetonic acid,2,3-butylene glycol)were measured quantitatively in different kinds of Shanxi overmature vinegar and the other kinds of vinegar.

应用气相色谱方法对山西老陈醋和其他种类醋的9种香气成分(乙醛、乙酸乙酯、乙醇、乙酸丙酯、3-羟基-2-丁酮、乙酸、糖醛、丙酸、2，3-丁二醇)进行了定性、定量测定，并用聚类分析、模糊综合评判、方差分析、回归分析的方法对实验结果进行了数理分析。

The following main results are obtained: The TiO_2 photocatalyst with small crystallite size, high surface area, narrow and uniform pore size distribution, and microporous frameworks could be prepared out by applying MW radiation in the preparation process. The microwave-induced fluorescence technique verified for the first time that microwave enhanced the formation rate of hydroxyl radical, leading to the increase in the photocatalytic efficiency. Compared with the conventional catalyst, TiO_2 prepared by MW dielectric heating owns a higher UV absorption ability, and its optical absorption edge and photovoltaic response are shifted toward the short wavelength region, resulting in increase of photooxidation efficiency. The photocatalytic conversion and the mineralization ratio of acetaldehyde are increased respectively by 30% and 40% over the TiO2 prepared by MW radiation when compared to the TiO2 prepared by the conventional heating. For the MW-assisted photocatalytic reaction over the MW-prepared TiO2, production of hydroxyl radicals is enhanced by 22.5%, and the photocatalytic conversion is accordingly increased by 20%. Similarlly, applying MW also increased the photocatalytic conversion and the mineralization ratio of acetaldehyde over TiO2/Al2O3 sample.

论文得到如下主要结果和结论：(1)微波介电加热TiO_2 溶胶可得到晶粒度小、光催化活性高、比表面积大和孔径分布窄而均一，且微孔发达的TiO_2光催化剂；在溶胶干燥处理过程中微波可使催化剂表面缺陷增加，进而导致光催化反应过程有更多的活性羟基自由基产生；(2)微波制备能显著增强TiO_2 样品的紫外光吸收率，并使其光吸收和光伏响应阈值发生蓝移，从而提高TiO_2的氧化还原能力；(3)与常规加热法所制TiO_2比较，微波法制备的TiO_2对乙醛的光催化降解转化率提高30%，CO_2生成率提高40%以上；(4)与未加微波辐射时相比，发现在光催化反应过程中施加微波，TiO_2 的羟基自由基生成速率提高了22.5%，相应CH_3CHO 光催化降解转化率提高了20%；对Al_2O_3/TiO_2催化剂，CH_3CHO 光催化降解转化率甚至提高了33%，同时CO_2 的生成率也都大幅度提高；(5)微波辐射可改变光催化降解乙醛的产物分布，推断施加微波时乙醛光催化降解按照羟基自由基引发的链式反应机理进行，微波&非热效应&起主要作用。

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。