查询词典 propylene glycol

In pilot test of 150 t/a of synthesizing ethylene glycol tbutyl ether from isobutene and ethylene glycol, reaction temperature, catalyst life, reaction heat draw and affection of LHSV on etherization are investigated.

通过异丁烯与乙二醇合成乙二醇特丁醚 1 50 t/a中间试验，考察了反应温度、液体空速对醚化反应的影响及反应器的撤热情况，考察了催化剂的寿命，提出精制各塔操作参数和产品质量指

Ethylene glycol glycosides,useful as humectant in cosmetics,were prepared by phosphoric acid-catalyzed acetalization of glucose with ethylene glycol.

在磷酸催化下，由葡萄糖和乙二醇经缩醛化反应制备了乙二醇葡糖苷，可用作化妆品保湿剂。

The experimental result showed that three byproducts was formed and the optimal condition was as follows: the molar ratio of ethylene glycol, hydrogen bromide, and acetic acid was 1:1:1.3, when ethylene glycol was 1 mol, refluxed 5 h under the action of 100 mL toluene.

结果表明：较适宜的合成条件为乙二醇1 mol， n：n：n=1：1：1.3，在带水剂甲苯(100 mL)的作用下，回流反应5 h，约4 h后分两次追加0.12×2 mol醋酸酐，合成效果最好，产率可达到95%，反应副产2-溴乙醇及少量的1， 2-二溴乙烷、乙二醇二乙酸酯和二乙二醇二乙酸酯。

Under the catalyst, the polymerization retarder, the including water medicinal preparation existence condition, the methylacrylic acid and the polyethylene glycol single methyl ether (400) direct esterification synthesis methylacrylic acid polyethylene glycol single methyl ether (400) ester, and the influence factors of the catalyst, polymerization retarder, including water medicinal preparation has mellowly carried on the comparison.

摘要在催化剂、阻聚剂、带水剂存在的条件下，由甲基丙烯酸与聚乙二醇单甲醚(400)直接酯化合成甲基丙烯酸聚乙二醇单甲醚(400)酯，并对酸醇比、催化剂、阻聚剂、带水剂等影响因素进行了比较。

PES/NMP were used as the model membrane-forming system, H〓, 1butanol, and diethylene glycol (as well as isopropanol and ethylene glycol) was selected as nonsolvent additives.

本文选取PES/NMP为制膜体系，研究NSA——水、正丁醇、一缩二乙二醇在浸入凝胶成膜过程中的作用。

Organic substances (diethylene glycol, glycol methyl ether and methyl ethyl ketone) were used as nonsolvent additives and N-methyl-2-pyrrolidone used as a solvent in membrane preparation. The effects of PPESK concentration, the type of additives and the NSA concentration in casting solution on the morphology and performance of the PPESK hollow fiber ultrafiltration membrane were systematically investigated.

以PPESK为膜材料，NMP为溶剂，水为凝胶剂，选用乙二醇甲醚、一缩二乙二醇和丁酮为非溶剂添加剂，系统研究了聚合物浓度、添加剂种类和含量对PPESK中空纤维超滤膜结构和性能的影响，制备了一系列具有不同孔径和通量的中空纤维超滤膜。

The phase separation behavior of different nonsolvent additives (methyl ethyl ketone, glycol methyl ether and diethylene glycol) on PPESK casting solution was studied at 20℃according the linerized cloud point correlation.

结合线性浊点关系，根据浊点滴定试验，通过三元相图研究了20℃下非溶剂添加剂(丁酮，乙二醇甲醚，一缩二乙二醇)对PPESK铸膜液体系的相分离行为。

A study of Chemically Induced Dynamic Poiarization spectra is made, using a highly time resolved ESR, of photolized anthracenequinone radicals to determine the influence of surfactant micelles on the spin polarization of anthracenequinone anion. It is found that the CIDEP mechanism of photolization is mainly the radical pair mechanism of anthracenesemiquinone radical and of ethylene glycol ketyl R〓〓 or R〓 radical whose center is carbon in anthracenequinone/ethylene glycol system, but there is a certain amount of triplet state mechanism polarization.

分别研究了胶束和微乳液的"笼效应"对蒽醌和苯醌的光解CIDEP的影响，其结果如下：(1)对于蒽醌的CIDEP，在乙二醇溶剂中，极化的蒽醌自由基AQ〓和R〓自由基通过光解经过夺氢反应产生，其CIDEP机理主要是自由基对机理，但也包含了一部分三重态机理。

The result showed that Ti02 nanowires with a diameter of 20 nm and a length up to several micron only can be synthesized in NH4F/glycol solution with a small amount of water (glycol: H20=39:1), 60V anodic voltage and 2h anodic time. The nanowires originated from the vertical splitting of anodically grown nanotubes.

结果表明，当醇水体积比为39：1时，60V电压下氧化2h，TiO2纳米管顶部的氧化层在缺陷处发生二次击穿溶解，产生自组装的孔核，场助溶解驱动力使纳米管顶部在孔核处沿管轴向垂直劈裂，形成直径20nm、长度可达几微米的TiO2纳米线。

A series of novel polyethylene glycol derivatives was synthesized by esterification of chloroacetic acid with polyethylene glycol.

介绍了一氯乙酸在农药、医药、日用化工及有机工业中的应用，评述了一氯乙酸的工业生产现状。

Finally it offers the analysis of the fault-tolerance system as well as its test verification.

这样，运行于空间环境中的系统的设计目标就是在保证系统实时性

However, it is still difficult to find out the real reason of the increase of the keratinized gingiva during the orthodontic extrusion whether it is due to the proliferation of the gingival tissue or to its elastic nature, that is because the proliferation of the fibroblasts as well as the connective tissue changes in volume and the intra-fibers spaces were all immeasurable in most of the studies.

然而，仍然难以找到真正的原因增加的角化牙龈在正畸挤压它是否是由于扩散的牙龈组织或其弹性性质，这是因为增殖的成纤维细胞以及作为结缔组织的变化量和内部纤维空格都是不可估量的，大多数的研究。