查询词典 acid reaction

Two synthetic routes starting from 1,3-dihydroxyacetone and formamidine acetate as well as imidazole-4,5-dicarboxylic acid as starting material were investigated, and the reductive reaction of ethyl imidazole-4-carboxylate was also investigated.

本文对以1，3-二羟基丙酮和醋酸甲脒为原料和以4，5-二羧酸咪唑为原料合成4(5)-羟甲基咪唑的两条工艺进行了研究并优化，同时对4(5)-羧酸咪唑乙酯的还原反应进行了探索性实验。

Dihydroxyacetone; formamidine acetate; imidazole-4,5-dicarboxylic acid; optimizing process; ethyl imidazole-4-carboxylate; reductive reaction; 4(5)-hydroxymethylimidazole

关键字或关键词组： 1，3-二羟基丙酮；醋酸甲脒；4，5-二羧酸咪唑；工艺优化；4(5)-羧酸咪唑乙酯；还原反应；4(5)-羟甲基咪唑

Under the optimal reaction conditions of 0.5MPa pressure, at 150℃, H2 gas flow rate of 5000 mLh^(-1) and liquid flow rate of 5.0mLh^(-1), the conversion of furoic acid, selectivity to methyl tetra-hydro-furan formiate and yield of methyl tetra-hydro-furan formiate can reach 99.0%, 98.2% and 97.2%, respectively.

结果表明：在0.5MPa，150℃，氢气流速5000mLh^(-1)，液体流速5.0mLh^(-1)（氢油比为50）时，呋喃甲酸转化率为99.0%，四氢糠酸甲酯的选择性98.2%，产率97.2%。

As expected from the reaction mechanism, the carboxyl groups of aspartic and glutamic acid residues were not modified, while the amino group s that could react with the activated peptides were concomitantly protected by formylation.

如反应机理所预测的那样，天门冬氨酸和谷氨酸残基未被修饰，而能与活性肽反应的氨基则同时被甲酰化保护起来。

As expected from the reaction mechanism, the carboxyl groups of aspartic and glutamic acid residues were not modified, while the amino groups that could react with the activated peptides were concomitantly protected by formylation.

如反应机理所预测的那样，天门冬氨酸和谷氨酸残基未被修饰，而能与活性肽反应的氨基则同时被甲酰化保护起来。

Keywords 5-nitrosaicy|aldehyde polyphosphoric acid formylation Duff reaction

5-硝基水杨醛；多聚磷酸；甲酰化； Duff反应

Effects of the reaction temperature, pressure, gas flow rate of H2, liquid flow rate of furoic acid and methol were studied.

研究了反应的温度、压力、气、液体流速等工艺条件对糠酸杂环选择性催化加氢甲酯化过程的影响。

Furoic acid was synthesied by catalytic oxidation in the mimic enzyme microreactor, which was constructed by strong stirring a non homogeneous phase system of organic reagent and water using β cyclodextrin derivative as an imitating enzyme. This method is easy to handle and more effective than the corresponding reaction in homogeneous phase.

在水与有机试剂组成的非均相体系中，用β环糊精(β cyclodextrin ，缩写：β CD)衍生物模拟生物酶，以强力搅拌下分散在有机溶剂中的小水珠作为微型反应器进行糠醛催化氧化为糠酸的反应，停止搅拌后体系立即分层，产物在有机相，残留的原料和模拟酶在水相。

Low density silicon nitride with about 55% porosity and globed macropores was prepared by reaction-bonded raw silicon powder and adding 30% in mass pore-forming agent of benzoic acid ball-like particles.

以硅粉为原料，添加质量分数为30%的成孔剂球形颗粒，反应烧结制备了气孔率为55%，具有球形宏观孔的低密度多孔氮化硅陶瓷。

When hydrochloric acid was added into saccharin sodium solution,chemical reaction happened,whose product was glucide,which cannot be dissolved in water,however,it can be dissolved by ethyl acetate,therefore glucide can be extracted from other components,then can be determined by titration with sodium hydroxide.

利用糖精钠与盐酸反应生成不溶于水而溶于乙酸乙酯的物质，将其萃取出来，然后再利用氢氧化钠对其进行滴定分析，采用二分试差法准确测定了某镀光亮镍添加剂中糖精钠及某镀光亮镍液中糖精钠的含量，分别为88。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。