乙醛

Glyoxylic acid was prepared by reaction of sodium hydroxide surplus with methyl dichloroacetate in methanol solution via neutralization of filtrate with 50 percentage sulfuric acid to pH 2～3 and hydrolyzation after separation of salts.

二氯乙酸甲酯和过量的氢氧化钠在甲醇溶液中反应，滤出氯化钠后，直接加入适量的 5 0 %的硫酸调 pH值为 2～ 3，滤出硫酸钠，蒸馏回收甲醇，水解、浓缩，得到不含乙二醛的 4 0 %乙醛酸溶液。

Allantoin was synthesized from glyoxylic and urea as raw materials using organic acid such as formic acid,oxalic acid and organic sulfonic,and one or two of organic acids such as hydrchloric acid,sulfuric acid and acetic acid catalyst.

以乙醛酸和尿素为原料，有机酸(如甲酸、乙二酸、有机磺酸等)、无机酸(如盐酸、硫酸、磷酸、醋酸等中的一种或两种)作催化剂合成了尿囊素产品。

Using glyoxylic acid to replace the harmful chemical substance such as formaldehyde as a reducing agent, an electroless copper plating on difficulty deposited substrates was fulfilled, which including Al,Ti and wafers having TiN and TiSiN as the barrier layers.The surface morphologies and grain structures of copper deposits prepared were analyzed.

摘 要：采用乙醛酸代替有害的化学药品作为还原剂的化学镀技术，在工业纯铝片、工业纯钛片、以TiN作为扩散防护层的硅片和以TiSiN作为扩散防护层的硅片等难镀材料实现了化学镀铜。

Acetaldehyde(0\^1 mol) was treated with n propylthiol(0\^1 mol) at 35 ℃ for 20 min to yiled 72% acetaldehyde propyl mercaptal .

以 0 。1 mol乙缩醛和 0 。1 mol 正丙硫醇为原料，35℃下在四氯化碳中反应，经红外光谱，色谱，质谱，元素分析以及核磁共振谱检测，确证了产物为乙醛正丙硫醇缩醛。

The major causes of off-flavour of the cooked rice was due the intractions among rice proteins, lipids and carbohydrates, which result in the production of carbonyl compounds,the increase of caproaldehyde,and the decrease of acetaldehyde and mercapto group as well as the changes in the cell wall structures.

本文结合近几年研究工作及国内外对大米陈化研究的新进展，综合阐述了随大米存放时间的延长，其化学组织特别是大米蛋白质、类脂与淀粉的共同作用，促使羰基化合物的生成、乙醛减少、己醛增加、SH基减少，以及胞壁改变，是造成大米陈化、米饭&陈米臭&的主因。

Don't use snail bait that contains metaldehyde, fly bait that contains methomyl, and mole or gopher bait where your dog or cat can get to it.

不要使用蜗牛的饵料，包含聚乙醛，飞饵包含灭，和摩尔或鼠饵所在狗或猫可以得到它。

Secondly, the silver based catalysts modified by phosphorus, zirconium, zinc, potassium and so on using molecular sieve as carrier, which were produced by ion-exchange method, had also good catalytic performance for 1,2-propane glycol oxidation to methylglyoxal. The conversion of 1,2-propane glycol and the selectivity of methylglyoxal were both high, and the impurity such as formaldehyde and acetaldehyde in the product is little. At the condition of the temperature 300 ℃, the molar ratio of oxygen to 1,2-propane glycol 1.7:1, the space velocity 6000h~(-1), and the concentration of 1,2-propane glycol 70wt%, the conversion of 1,2-propane glycol is 90% and the selectivity of methylglyoxal is 45% on the Ag-P catalyst.

其次对采用离子交换法制备的负载在分子筛上的银系催化剂进行了研究，发现此催化剂在助催化剂磷、锆、锌、钾等的作用下对丙二醇的低温氧化脱氢具有很高的活性，可以得到较好的丙酮醛的收率，并且产物中的甲醛、乙醛副产物的量比较低；经过对Ag-P催化剂上反应条件的考察，发现当温度为300℃、氧醇比1.7：1、空速6000h~(-1)、丙二醇浓度为70wt%时，丙二醇的转化率为90%，丙酮醛的选择性为45%。

Methanol hydrochlorinate has two steps: one is to produce monochloro methane by methanol hydrochlorinate reaction and the other is to make monochloro methane produce polychlorinated methane.

二硫化碳法、氯油法和乙醛法因不经济和环保问题在国外已被淘汰；C1一C3废氯烃全氯化法是利用氯乙烯等装置的副产废料生产四氯化碳并联产四氯乙烯，该法是一种非常经济的工艺，在国外曾被十分广泛地采用，但随着发达国家四氯化碳的停止使用，目前大部分基于该工艺的装置被迫停产。

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 regularities of the influence of various factors includingreaction temperature,reaction time,the ratio of formaldehyde to acetaldehyde,the quantity of alkali and the concentration of formaldehyde on the yieldsof pentaerythritol and dipentaerythritol were studied.

通过单因素实验，考察了反应温度、反应时间、甲醛与乙醛的配比等因素对单、双季戊四醇收率的影响。

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。