查询词典 esters

In order to study on the QSRR of fatty esters, 100 fatty esters were optimized by semiempirical calculations AM1, then calculated them by quantum chemistry algorithnl and the technique of molecule graphics and AM1 to acquire the Kier index and Kappa shape index.

为了研究脂肪酯的构效关系，应用半经验量子化学AM1法得到了100种脂肪酯分子的优势构象，利用量子化学算法和分子图形学技术获得Kier指数和Kappa形状指数，再在分子拓扑理论的基础上，提出了一个修正的拓扑染色指数mL，用多元回归技术建立了脂肪酯化合物的结构与色谱保留值的相关性模型。

In general, the phosphoamino acid esters were unable to transfer their phosphoryl group to other hydroxyl nucleophiles even with the presence of imidazole, but the N-phosphoserine and threonine esters were two exceptions.

二、测定了部分磷酰化D—氨基酸的磷酰基转移反应速率常数，并对外消旋化合物的酯交换反应进行了旋光度跟踪，发现磷酰化丝、苏氨酸的对映体有明显的区别。

By the comparison of juice tlavour components with those of wild grape wine,wefound that wild grapes consisted of acetals,esters,alcohols, aldehydes, ketones etc,theyexisted in glycosidically-bound forms.Some wine flavour components had been poten-tially in grape,fermentation helped them showup,many alcohols and esters formedmade wine aroma and flavour richer and more complicated.

对葡萄汁与酒中的香味成分对比发现，野生葡萄中的香味成分由烷、酯、醇、醛、酮等组成，它们可能以结合态存在于汁中；葡萄酒中的许多香味成分已潜在于葡萄原料中，发酵能使它们充分表现，发酵中形成了较多的醇、酯类物质，使酒的风味更浓郁、复杂。

The result shows that the viscosity was improved with the increase of the molecular mass of the product, the viscosity at 100℃ was between 17.827.6 mm^2/s, the viscosity index was more than 125, solidifying point was below -27℃, the oxidative stability was also improved with the increase of the molecular mass of the product. The biodegradabilities of complex esters were more than 70%. The value of PB was 784 N, the value of wear diameter was 0.41 mm, the temperature of thermal decomposition was above 250℃. The complex esters can be used as excellent green lubricants.

结果表明，复合酯的粘度随着分子量的增大而增大，粘度指数大于125，凝点低于－27℃，氧化稳定性随分子量的增大而提高，生物降解率＞70%，最大无卡咬负荷为784N，磨斑直径0.41mm，热分解温度＞250℃，因此目标产物是性能良好的绿色润滑剂。

The reduce of esters,the increase of acids,and the imbalance of the ratio of esters and acids are the main reasons for washy liquor taste and unpleasant liquor flavor after a period of storage.

酯类物质减少，酸类物质增加，酸酯比例失衡，是低度白酒贮存后口味淡薄、出现不愉快气味的主要原因。

Analytical results showed that the upper clear liquid of pyrolysis oils was mainly consisted of water-soluble substances,such as phenol,cresol,xylenol,sugars,hydantoins,morpholines,pyranones and pyridine derivatives compounds,etc.,while the lower sediment was mainly insoluble or hardly water-soluble substances,such as the big substituent phenolics(the number of substituent carbon atoms of which is greater than or equal to 2),aryl phosphate esters,fatty acid esters and nitrile compounds,and so on.

研究表明，热解油上层清液主要是一些较易溶于水的物质，如苯酚、甲酚、二甲酚、糖类、乙内酰脲类、吗啉类、吡喃酮类和吡啶类化合物等；而下层沉淀则主要为不溶或难溶于水的物质，如大取代基酚类（取代基碳原子数≥2）、磷酸三芳基酯类、脂肪酸酯类和腈类化合物等。

In addition, a benzene, toluene (0.32%), was also detected in 80% ripening fruit. In 90% ripening fruit were detected 27 kinds of aroma components belonging to 2 categories. Among the components, 17 were esters, and 10 alkenes. Of the 17 esters, methyl octanoate is the highest (21.00%), followed by ethyl hexanoate (17.64%), methyl hexanoate (14.34%). Of the 10 alkenes cis-β-ocimene is the highest (1.00%), followed by à-copaene (0.81%) and trans-ocimene (0.48%).

在9成熟果实中检测到2类共27种香气成分，分别是酯类17种和烯类10种；在酯类中，相对含量最高的是辛酸甲酯(25.27%)，其次是辛酸乙酯(21.00%)、己酸乙酯(17.64%)、己酸甲酯(14.34%)；在烯类中相对含量较高的有β-顺式－罗勒烯(1.00%)、à-蒎烯(0.81%)和反式－罗勒烯(0.48%)。

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。

A catalyst composition for the polymerization of propylene comprising one or more Ziegler-Natta procatalyst compositions comprising one or more transition metal compounds and one or more esters of aromatic dicarboxylic acid internal electron donors; one or more aluminum containing cocatalysts; and a mixture of two or more different selectivity control agents, said SCA mixture comprising from 1 to 99 percent of one or more esters of one or more aromatic monocarboxylic acids or substituted derivatives thereof, and from 99 to 1 percent of one or more alkoxysilane compounds.

一种用于丙烯聚合的催化剂组合物，包括：一种或多种齐格勒-纳塔主催化剂组合物，该齐格勒-纳塔主催化剂组合物包括一种或多种过渡金属化合物和一种或多种芳族二羧酸酯内部电子给体；一种或多种包含铝的辅催化剂；和两种或更多种不同的选择性控制剂的混合物，所述SCA混合物包括1到99％的一种或多种芳族单羧酸的一种或多种酯或其取代衍生物、和99到1％的一种或多种烷氧基硅烷化合物。

Conditions to prepare the NHS-esters of all olefine acids" and polymer-NHS esters were studied. And these products" basic physical and chemical properties were also tested.

研究了合成烯酸NHS酯及聚合物的NHS酯的合成条件，测试了烯酸NHS酯及聚合物NHS酯的特性。

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。