丁酮二酸的

Catalytic activity of phosphotungstic acid on synthesizing butanone 1,2-propanediol ketal was discussed,the factors influencing the synthesis were discussed and the best conditions were found out.

探讨了磷钨酸对丁酮1，2 丙二醇缩酮合成反应的催化活性，研究了酮醇摩尔比、催化剂用量、反应时间等因素对产品收率的影响。

Methods The propylbridged biferrocenyl substituted pyridazinone was synthesized by the reaction of propylbridged biferrocene with ethyl succinyl chloride, and then condensed with hydrazine hydrate.

双二茂铁丙烷先与丁二酸单乙酯酰氯发生酰化反应，生成的1，4酮酸酯再与水合肼缩合得到含有双二茂铁丙烷的哒嗪酮衍生物。

Metabolic pathway analysis for this strain showed that pentose and hexose could be transferred to succinic acid and other byproducts including acetic acid and α-ketoglutaric acid.

对菌株的代谢途径分析表明细胞具有五、六碳糖代谢酶系，以及在大量合成丁二酸的同时也产生少量乙酸、α-酮戊二酸等副产物。

The results showed that there were 8 kinds of aliphatic, 5 kinds of esters, 2 kinds of aldehydes, 2 kinds of nitrogen sulfur heterocyclic rings and one kind of hydrocarbon, alcoholics, ketone, lactones respectively in the analyzed 21 kinds of aroma components, and the content of furfural,β-methyl valeric acid, palmitic acid, nicotine, neohytadiene were higher, next were acetyl ethyl propionate, caleric acid, phenyl ethyl acetate, hydroxylic diethyl succinate.

结果表明，在分析出的21种香气成分中，分别有脂肪酸类8种，酯类5种，醛类2种，氮硫杂环类2种，烃类、醇类、酮类、内酯类各l种，其中相对含量较高的物质成分是糠醛、β-甲基戊酸、十六碳酸、烟碱、新植二烯，其次是乙酰丙酸乙酯、异戊酸、苯乙酸乙酯、羟基丁二酸二乙酯等。

Firstly, 3-ethylthiobutanal was prepared from crotonaldehyde reacting with ethanehiol in triethylamine with high yield. Secondly, methyl acetoacetate was converted to 6-ethylthiohept-3-en-2-one by three steps via hydrolysis, condensation with 3-ethyltio-butanal and dehydration, then 6-ethylthiohept-3-en-2-one was cycloco ndensed with dimethyl malonate by Michael addition and Claisen condensation, followed by saponification and decarboxylation to give the intermediate of 5-(2-ethylthiopropyl)-cyclohexane-1,3-dione.

首先，以巴豆醛与乙硫醇为原料，在三乙胺的催化作用下高收率制得3-乙硫基丁醛；然后从乙酰乙酸甲酯出发，通过碱水解、与3-乙硫基丁醛缩合、脱水三步反应合成6-乙硫基-3-烯-2-庚酮，接着6-乙硫基-3-烯-2-庚酮与丙二酸二甲酯通过Michael加成和Claisen缩合成环，再通过皂化和脱羧反应生成中间体5-[2-丙基]-1，3-环己二酮；再与丙酸酐反应丙酰化，最后与0-3-氯-2-丙烯基羟胺肟化，得到目标化合物烯草酮。

A series of polyether based polyurethaneurea aqueous dispersions with well-defined hard segments were prepared by fractional steps with polyether polyol, 4,4'-diphenylmethane diisocyanate, dimethylolpropionic acid, 1,4-butanediol, isophorone diisocyanate and ethylenediamine.

以二苯基甲烷二异氰酸酯、二羟甲基丙酸、1，4-丁二醇、异佛尔酮二异氰酸酯和乙二胺为硬段，聚醚多元醇为软段，通过分子设计采用分步合成法，制备了具有规整硬段和良好分散性能的聚醚型聚氨酯脲水分散液。

A series of polyether based polyurethaneurea aqueous dispersions with well-defined hard segment s were prepared by fractional steps with polyether polyol, 4,4′-diphenylmethane diisocyanate,dimethylolpropionic acid,1,4-butanediol,isophorone diisocyanate and ethylenediamine.

以二苯基甲烷二异氰酸酯、二羟甲基丙酸、1，4-丁二醇、异佛尔酮二异氰酸酯和乙二胺为硬段，聚醚多元醇为软段，通过分子设计采用分步合成法，制备了具有规整硬段和良好分散性能的聚醚型聚氨酯脲水分散液。

The chemical constituents of extracts of Tamarindus indica L were determined by GC-MS. The relative contents of constitutes were determined by area normalizing method. 48 compounds were identified, amounting to total mass fraction 98.5%. The main compounds were 5-methyl-2(3H)-furanone, diethyl succinate, furfural, hexadecanoic acid, linolenic acid, 5-methylfurfural, oleic acid, linoleic acid, etc.

并利用气相色谱仪-质谱仪对罗望子萃取物的化学组成进行了分析鉴定，并用面积归一化法测定了各种成分的质量分数，共鉴定了48种成分，占总质量分数为98.35%，其中主要成分为：5-甲基-2(3H)-呋喃酮、丁二酸二乙酯、糠醛、十六酸、亚麻酸、5-甲基糠醛、油酸、亚油酸等。

Results The mixing, loading and storing processes of the construction, might generate lots of occupational hazards, including toluene, dimethylbenzene, trimethylbenzene, isopropanol, butyl alcohol, propanol, methyl methacrylate, butyl acetate, methyl isobutyl ketone, methyl ethyl ketone, acetic ether, nitro-cotton, n-hexane, n-heptane, carbinol, ethanol, ethyl propionate, diisobutyl ketone, glycol ether, isoamyl acetate, 2,4-toluene diisocyanate, isophorone, noise, power frequency electric fields.

结果 该项目在混兑生产和装卸、仓储过程中，可能产生的职业病危害因素主要有甲苯、二甲苯、三甲苯、异丙醇、丁醇、丙醇、甲基丙烯酸甲酯、乙酸丁酯、甲基异丁基甲酮、丁酮、乙酸乙酯、硝化棉、正己烷、正庚烷、甲醇、乙醇、乙酸丙酯、二异丁基甲酮、乙二醇乙醚、乙酸异戊酯、2，4甲苯二异氰酸酯、异佛尔酮、噪声、工频电场。

Polyurethane-acrylics hybrid latexes were prepared using isophorone diisocyanate, dimethylol propanoic acid and polypropylene oxides of different molecular weights as main materials for PU component, and butyl acrylate, methyl methacrylate and a crosslinker, trihydroxymethyl propanetriacrylate as main acrylic monomers. Hydroxyethyl acrylate was used as the coupling agent between PU and AC.

以异佛尔酮二异氰酸酯、二羟甲基丙酸和聚丙醚二醇等为聚氨酯原料，丙烯酸丁酯、甲基丙烯酸甲酯、三羟甲基丙烷三丙烯酸酯为丙烯酸酯类单体，丙烯酸羟乙酯为聚氨酯和聚丙烯酸酯间的偶联剂合成了丙烯酸酯改性水性聚氨酯乳液。

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。