烯醇

The reaction process in methanol solvent can be deduced from the computational results with CPCM solvent model and the supermolecular handling, namely the reaction involves four steps in the methanol solvent. The nucleophilic addition of trimethylamine to acraldehyde generates an enolate. Nucleophilic attack of the enolate on the aldehyde forms the carbon-carbon bond, followed by the proton-transfer process and the further elimination generating the product and liberating the trimethylamine catalyst.

对于CH3OH对反应体系的影响，可以综合考虑CPCM溶剂模型及超分子模型下的研究结果，即CH3OH溶剂中反应按四步进行，催化剂三甲胺首先与丙烯醛发生亲核加成，生成的两性离子中间体与甲醛发生类似于Aldol的醛醇缩合，形成碳-碳键，之后发生分子内质子转移，最后经E1cb消除得到产物，并释放催化剂三甲胺。

A range of waterborne alkyd resins has been prepared by fatty acid process, based on soybean fatty acid, trimellitic anhydride, and various polyols and polybasic carboxylic acids, which are modified with benzoic acid, maleic anhydride and oleic acid.

通过脂肪酸法，选用豆油脂肪酸、偏苯三甲酸酐和不同的多元醇、多元酸制备了一系列水性醇酸树脂，用苯甲酸、顺丁烯二酸酐和油酸对其改性进行了研究。

The process includes the steps of reacting a plurality of ethylenically unsaturated monomers and a reaction moderator with a macromer having induced unsaturation in the presence of a carrier polyol, a free radical polymerization initiator, and a first graft polyol.

本发明方法包括使多种烯键不饱和单体和反应调节剂与具有诱导不饱和度的大分子单体在载体多元醇、自由基聚合引发剂和初级接枝多元醇存在下反应的步骤。

Oil and polyol firstly hydrolyze, and then react with maleic anhydride to give semi ester, the residual maleic anhydride hydrolyzing to give maleic acid, finally are adducted with DCPD. The result of experiment shows that the synthesized resin is of perfect air drying performance and improved flexibility and anti-greening because of the use of oil, meetin...

试验结果表明，油与多元醇在210～220℃下先醇解，然后与顺酐反应形成半酯，剩余顺酐水解成顺丁烯二酸，然后与DCPD加成，合成的树脂具有优良的空干性；同时油的使用极大地提高了涂膜的柔韧性和抗绿化性，得到的树脂性能上可满足涂料用不饱和聚酯树脂的要求。

Pregnana-3, 16, 20-triol was efficiently transformed into pregn-16-ene-3S, 20S-diol diacetate. And then the Pd-catalyzed reaction was reinvestigated.

提供了一种将剑麻皂甙元降解产物孕甾三醇转化为孕甾－16-烯－3S，20S-二醇二乙酸酯的高效合成方法，并重新考察了其钯催化反应。

The polymer particles were prepared by copolymerization of phthalic aldehyde, allyl mercaptan and ethylene glycol dimethacrylate after heating. The fluorescence intensity of the polymer particles was very weak.

利用邻苯二甲醛与烯丙基硫醇、乙二醇二甲基丙烯酸酯在偶氮二异丁腈引发下热聚合制得了一种新型聚合物颗粒。

Contains: Deionised Water, Mineral Oil, Glycerine, Stearic Acid, Cetearyl Alcohol, Triethanolamine, Carbomer, Lanolin, Tocopherol Acetate, Fragrance, Propylene Glycol, Methyl Paraben, Ethyl Paraben, Butyl Paraben, Isobutyl Paraben, Propyl Paraben, Disodium EDTA.

成分：离子水，矿物油，甘油，硬脂酸油脂剂，棕榈醇乳化剂，三乙醇胺酸碱值调节剂，稳定乳化剂，绵羊油，维生素E，香料，丙烯甘醇保湿剂，甲基木精胶，乙酯，丁酯，尼泊金异丁酯，丙酯，稳定剂缓冲剂。

The trace amount of impurities,namely C5,tert-butyl alcohol,di-secondary butyl ether,methyl ethyl ketone and secondary butyl alcohol,in C4 hydrocarbon from butylene hydration tail gas were analysed by means of gas chromatograph with a column packed with sebaconitrile and polyethylene glycol-20M,and liquid-phase admission valve.

2m×4mm为填充柱，采用液相进样阀液态直接进样的填充柱气相色谱法分析了丁烯水合尾气C4烃中的C5、叔丁醇、二仲丁醚、甲乙酮及仲丁醇等微量杂质的含量。

Some technologies,including olefines from methanol,oxalates and ethylene glycol from carbon monoxide,carbon dioxide-based polymers,chemicals from the syngas prepared by biomass gasification,acetone and butanol by fermentation,and chemicals from acetylene,ethanol,glycerol,furfural,hydroxymethyl furfural and starch,were reviewed.

包括甲醇制烯烃，一氧化碳制草酸酯和乙二醇，乙炔化学品，二氧化碳聚合物，生物质气化合成化工产品，发酵法生产丙酮、丁醇，乙醇衍生化工产品，甘油合成化工产品，糠醛和羟甲基糠醛合成化工产品，淀粉合成化工产品等重要的石油替代化学品生产技术被介绍。

It is important to use the best available water blended with not more than 60 percent ethylene glycol base antifreeze or 50 percent propylene glycol base antifreeze.

最重要的是要利用现有的水混合不超过60%或50%乙烯丙烯乙二醇防冻剂乙二醇基制药基地。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。