查询词典 carboxylic acid

There are 65 species of Chinese herbs with confirmed anti-HBV activityd, in which 16 probable active constituents are pointed out. They are arene, ketone derivatives, alicyclic carboxylic acid, aromatic carboxylic acid, ester, lactone, cyanide derivatives, heterocycle derivatives, carotenoids, anthraquinones, flavonoids, vegetable tannin, alkaloid, terpenoids, steroids and protein. Among them, the complexes of flavonoids, terpenoids, steroids and alkaloids are more abundant.

确定了具有抗乙肝病毒活性的中草药品种65种，其中含可能活性成分共16种，即芳烃、酮类衍生物、脂环族羧酸、芳香族羧酸、酯、内酯、氰类衍生物、杂环衍生物、类胡萝卜素、蒽醌类、黄酮类、植物鞣质、生物碱、萜类、甾类和蛋白质，而16种中以黄酮类、萜类、甾类和生物碱类成分为多。

Methoxycoumarin-3-carboxylic acid geranyl ester was synthesized from geraniol and 8-methoxycoumarin-3-carboxylic acid and its structure was characterized by IR, HRMS, 1H NMR and 13C NMR.

采用酰氯酯化法，以8-甲氧基－香豆素－3-甲酸与香叶醇为原料合成了8-甲氧基－香豆素－3-甲酸香叶酯，经IR，HRMS，1H NMR，13C NMR等鉴定，证实了其结构。

The results show that: 27 compounds were identified at 600℃, and most of them were alkenes, alkanes, acids, alcohols and phenolic substances; geraniol was identified, and its relative content was 3.6, which shows that geranyl 8-methoxycoumarin-3-carboxylic acid ester can release a certain amount of geraniol at smoke temperature; geranyl 8-methoxycoumarin-3-carboxylic acid ester can improve and modify the flavor, enhance the notes of sweet aroma and bean aroma, and reduce the biting taste of cigarette smoke.

结果表明，600℃时，8-甲氧基－香豆素－3-甲酸香叶酯的热解产物中共鉴定出27种成分，主要为烯类、烷类、酸类、醇类、酚类；鉴定出香叶醇，且相对峰面积3.6，说明8-甲氧基－香豆素－3-甲酸香叶酯能在卷烟燃吸温度下释放出一定量的香叶醇；8-甲氧基－香豆素－3-甲酸香叶酯具有改善和修饰卷烟香气，增加甜韵和豆香香韵，减轻刺激性的作用。

There are two synthetic methods for the two carboxylates starting from pyrrole,(1) the carbonylation of pyrrole using trichloroacetyl chloride and then the esterification reaction in methanol, or 2-MPC can be directly synthesized from pyrrole and methyl chloroformate,(2) the insertation of CO2 to pyrrole for the corresponding 1-pyrrole carboxylic acid or 2-pyrrole carboxylic acid and then the esterification reaction in methanol.

两种吡咯甲酸甲酯的合成从吡咯为起始原料有两种方法：（1）使用酰氯将吡咯酰化，然后与甲醇完成酯化反应，或者吡咯与氯甲酸甲酯直接合成吡咯甲酸甲酯；（2）先将吡咯通过CO2插入反应得到1-吡咯甲酸或2-吡咯甲酸，然后与甲醇反应完成酯化。

L-Azetidine-2-carboxylic acid, also named-Azetidine-2-carboxylic acid, commonly named L-Aze, was first isolated in 1955 by Fowden from Convallaria majalis and was the first known example of naturally occurring azetidine.

L-氮杂环丁烷-2-羧酸，又称-氮杂环丁烷-2-羧酸，简称为L-Aze.1955年，由Fowden从植物铃兰中分离得到，成为第一个被证实的植物中天然存在的氮杂环丁烷结构。

The main compositions of LP are shorter chain carboxylic acid and their ethyl esters, furan derivatives, cyclopentanone, phenol derivatives, benzene derivatives, aromatic ketone, aromatic acid derivatives, longer chain carboxylic ethyl esters and sterides. After upgrading, the main indexes reach the standard of fuel oil.

结果表明，LP的主要成分包括短链或环状脂肪酸及其酯、呋喃衍生物、环戊烯衍生物、苯酚衍生物、苯衍生物、芳酮、芳酸及其乙酯、长链脂肪酸乙酯和甾族化合物，经提质其主要指标达到了燃料油的标准。

The main compositions of LPs include shorter chain carboxylic acid derivatives, furan derivatives, cyclopentanone, phenol derivatives, benzene derivatives, cinnamic acid derivatives, longer chain carboxylic esters and sterides.

秸秆在亚/超临界醇中液化产生的LPs的主要组成成分包括短链脂肪酸衍生物、呋喃衍生物、环戊酮衍生物、含有取代基的肉桂酸衍生物、芳醛或酮衍生物、苯酚衍生物、苯衍生物，长链脂肪酸衍生物和甾族化合物。

A process as claimed in claim 5 wherein the acid groups are selected from the group consisting of carboxylic acid, phosphoric acid, polyphosphoric acid, phosphonic acid, sulphuric acid and sulphonic acid groups.

作为其中的酸群体从羧酸组成的小组选出的索赔5索赔的过程中，磷酸，聚磷酸，磷酸，硫酸和磺酸基团。

The first step in the degradation is most probably the classical ester scission reaction to give a carboxylic acid and olefinic end groups. Further ester scission on the adjacent ester groups of carboxylic acid and olefinic molecular chains can then lead to the formation of lower weight pyrolytic products, such as: CH〓=CHOCOPhCOOCH=CH〓、CH〓=CHOCOPhCOOH and HOOCPhCOOH, and they can pyrolyze continually to produce substrate pyrolytic compounds, such as: HOOCPhCOCH〓、PhCOOH、PhH、PhCOCH〓 and CO、CO〓. At the same time, a corsslinking cyclization reaction occurred of the formation of the gas products during the degradation of PET.

断裂大分子链端邻近羰基和乙烯基的酯键持续断裂，不断地形成小分子裂解产物，如：CH〓=CHOCOPhCOOCH=CH〓、CH〓=CHOCOPhCOOH以及HOOCPhCOOH，这些产物还会进一步裂解成分子量更低的小分子裂解产物，如：HOOCPhCOCH〓、PhCOOH、PhH、PhCOCH〓以及CO、CO〓等，与此同时，一部分乙烯基酯端基的大分子链碎片会发生支化而相互连接，再经&链脱离&和环化反应形成难燃的交联产物。

The experiment shows that this type of column has good column characteristics. It has good capability in separating C5~C8 alcohol, phenol, aromatic acid, C2~C8 carboxylic acid. The quantitative analysis of carboxylic acids was investigated.

结果表明，这种色谱固定相具有较强的极性和选择性，对於极性有机化合物如脂肪酸、芳香酸、醇、酚等有良好的分离能力，且出峰快，时间短、峰形尖锐对称，可不经衍生直接进样分析。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。