酯化了的

In recent progress in chemical modification of hemicelluloses has been reviewed in this article,including esterification and etherification.

对近十年半纤维素的化学改性如：醚化改性、酯化改性进行了综述，主要从多相反应和均相反应两个方面进行了归纳说明，最后提出了半纤维素改性的前景。

The effects of reaction temperature, reaction time, catalyst dosage, addition of esterification agent and the ratio of monoglyceride to glycerol were examined.

分别考察了反应温度、反应时间、催化剂添加量、酯化剂添加量和单甘酯与甘油的比例对酸值的影响。

This invention carrying through alcoholysis of common gloss polyester chip, getting low-molecular polymer of polytetramethylene terephthalate, using this low-molecular polymer as pregnant liquor, doing esterification reaction and polycondensation reaction of PTA and hybrid diatomic alcohol in normal pressure, getting the modified copolyester product which has inherent viscosity of 0. 65-0. 85dl/g, fine pellucidity and is suitable in the application of engineering plastics.

本发明是通过对普通大有光聚酯切片进行醇解，得到对苯二甲酸乙二酯低聚物，以此低聚物为母液，在常压下使PTA与混合二元醇进行酯化反应和缩聚反应，制备得到了特性粘数在0.65-0.85dl/g且具有良好透明性的适用于工程塑料领域应用的改性共聚酯产品。

With the yield of methyl monochloroacetate as evaluating standard,the synthesized condition of methyl chloroacetate was optimized through orthogonal experiment.

以氯乙酸母液和甲醇为基本原料，固载磷钨酸为催化剂，通过连续酯化的方法制备了氯乙酸甲酯；以氯乙酸甲酯的质量收率为基准，采用三因素三水平正交实验的方法对酯合成的条件进行了优化。

In the forth part, in the presence of chiral phosphoric acid, highly enantio-enriched (up to 98% ee)α-aryl glycine derivatives could be synthesized via asymmetric transfer hydrogenation of the α-aryl imino esters using Hantzsch ester as the hydrogen source.

第四部分工作中，利用Hantzsch酯作为氢源，高对映选择性地实现了手性磷酸催化芳基酮酸酯亚胺的不对称仿生氢化反应，以最高98％的对映选择性得到苯甘氨酸衍生物。

The progresses in the synthesis study of isoamyl isovalerate at home and abroad were reviewed.

考察了催化剂的活化温度和活化时间以及酯化反应条件对酯收率的影响。

Based on our intensive studies on the lactonization of oligo/polysialic acids, we proposed for the first time that the lactone-ring formation of oligo/polysialic acids has three stages. We also provided a novel model to explain the conformational changes of oligo/polysialic acids caused by the repulsing forces among the carboxyl groups of sialic acid residues. Our results should provide novel approaches for further investigation of the structural-functional relationships of oligo/polysialic acids.

在对多/寡聚唾液酸内酯化过程进行深入研究的基础上，于国际上率先提出多/寡聚唾液酸内酯的形成具有三个阶段的观点，并首创性地提出了羧基排斥所致多/寡聚唾液酸分子空间构象改变的模型，为深入研究多/寡聚唾液酸结构与功能的关系提供了新生长点。

The high stable colorless rosin esters were prepared from rosin and polyhydric alcohol.

针对现有松香酯化产品颜色较深和稳定性较差的缺点，本文首次对催化剂、抗氧剂和光稳定剂等各种化学助剂在松香酯中的应用进行了系统地研究。

Dibutyl succinate was synthesized catalyzed by a strong acid cation exchange resin from succinic acid and n-butyl alcohol.

用强酸性阳离子交换树脂催化丁二酸和正丁醇的酯化反应，合成了丁二酸二丁酯。

In this research, liposoluble chlorogenic laurate was synthesized by the acylation with lauroy chloride in the existence of alkali catalyst in non-water phase, and yellowish CGL powders with a yield of 81.24% were obtained under the optimal synthesis conditions determined via single-factor tests and orthogonal experiments, that is, carrying out the acylation at 35℃ for 8h with a n:n: n ratio of 1:1:1.5 and with dimethylformamide as the solvating agent and the thinner.

文中对绿原酸进行了改性，即在碱性催化剂催化的条件下使其与月桂酰氯进行非水相的酯化反应，得到了脂溶性的绿原酸月桂酸酯。经过单因素及正交试验，确定了最佳合成条件为：以N，N-二甲基甲酰胺作为溶解、稀释剂，绿原酸／月桂酰氯／三乙胺的摩尔比为1：1：1.5，温度控制在35℃，反应时间8h。

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。