乙醛

OBJECTIVE Acetaldoxime was prepared by using acetaldehyde and hydroxylamine sulfate as main materials then methylthio acetaldoxime was synthesized by using the former products as main material.

目的本文研究了以乙醛和硫酸羟胺为主要原料合成乙醛肟，并以乙醛肟为原料合成甲硫基乙醛肟的工艺。

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 emphasis was on chemical properties,application,main production methods,market,and prospects of main deriva- tives of acetaldehyde such as ethyl acetate,pentaerythritol,glyoxal,peracetic acid, crotonaldehyde and pyridine.

介绍了国内外乙醛及其主要衍生物的生产技术发展及其市场供需状况，尤其对乙醛主要衍生物乙酸乙酯、季戊四醇、乙二醛、乙醛酸、丁烯醛、吡啶的化学性质与用途、主要生产方法、市场供需状况及开发前景作详细介绍和分析。

The standard curves for glyoxal and glyoxalic acid both had good linear relations in the ranges of 2~20 mg/L and 10~100 mg/L, respectively.

乙二醛质量浓度在2～20 mg/L范围内，乙二醛二腙的峰面积与乙二醛的质量浓度之间呈良好的线性关系；乙醛酸质量浓度在10～100 mg/L范围内，乙醛酸腙的峰面积与乙醛酸的质量浓度之间呈良好的线性关系。

This catalyst was applied for the liquid phase oxidation of glyoxal to glyoxylic acid.

研究结果表明，V_2O_5/C催化剂对乙二醛的氧化具有良好的催化活性和乙醛酸选择性，反应过程中无需控制溶液pH值即可得到乙醛酸，乙醛酸在V_2O_5/C催化剂作用下不存在过度氧化，乙二醛的氧化产物主要是甲酸和乙醛酸，它们是一平行反应。

The glyoxal and glyoxalic acid contents in the solution of oxidation of acetaldehyde to glyoxal by nitric acid were determined by this method, the repeatabilities of analysis results were excellent and the relative error compared to chemical analysis of glyoxal was 1.77%.

用HPLC测定乙醛硝酸氧化法制乙二醛反应液中乙二醛和乙醛酸的含量，结果的重复性好；对乙二醛的测定结果与应用化学分析法测定结果的平均相对误差为1.77%；对反应液中乙二醛、乙醛酸含量的测定有着较高的加标回收率，分别为99.6%～103.3%和98.1%～102.4%。

In this process, the electrolylic bath with cationic exchange membrance and leas electrode is used. The cathode liquor is oxalic acid, the anode liquor is diluted sulfuric acid. The process above has following advantages with high yield, top quality, lower cost, no "three wastes" pollution, and no oxalic aldehyde in the product. It is a cleaner and environment-friend technology, and is a development trend for production of glyoxalic acid. Complete analytical process for raw materials, intermediate and final products were established.

本论文通过对乙醛酸合成路线的研究，确定了草酸电解法制乙醛酸的工艺路线，此法采用装有阳离子交换隔膜和铅电极的电解槽，阴极电解液为草酸溶液，阳极电解液为稀硫酸，该工艺具有产品收率高、质量好、成本低、无三废污染、产品中无乙二醛等特点，是一条清洁、绿色工艺，是生产乙醛酸的主要发展方向。

This paper introduced the typical application of glyoxylic acid in the synthesis of fine chemical products and the basic manufacture method.

本文介绍了乙醛酸在精细化学品合成中的典型应用和乙醛酸的基本生产方法，并比较了不同生产方法的各自特点，同时分析了乙醛酸的市场情况，指出了高质量乙醛酸将具有良好的市场前景。

By using catalysts based on sodium nitrite, hydrochloric acid and sodium nitrite, cerium dioxide and sodium nitrite, and cupric nitrate and sodium nitrite correspondingly.

结果表明，用亚硝酸钠作催化剂乙醛酸产率为73.9%，盐酸和亚硝酸钠作催化剂时乙醛酸产率为84.6%，二氧化铈和亚硝酸钠作催化剂时乙醛酸产率为80.2%，硝酸铜和亚硝酸钠作催化剂时乙醛酸产率为78.2%。

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。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。