乙二醇

Isopentanol, nitrochlorobenzene, nitrotoluene and diethylbenzene were well separated in the range of optimal carrier gas velocity of 13~17cm/s.

SE-30系列毛细管色谱柱的最佳载气线这范因为13~17cm/s，且在最佳线速度下很好地分离了异戊醇、硝基氯苯、硝基甲苯及二乙苯同分异构体体系。

The cis-decalin 79 was obtained from 2-methoxy-4-methylphenol (77) via a sequence of reactions involving intermolecular Diels-Alder reaction of masked o-benzoquinone derived from 77 and ethyl vinyl ketone, silyl enol ether formation and Cope rearrangement.

第一部份：以2-甲氧基-4-甲基酚(77)为起始物，经由二乙醯基亚碘苯氧化、分子间Diels-Alder反应、烯醇矽醚的形成及Cope重排反应得到具有十氢萘骨架化合物79。

D-Pantothenyl alcohol, also called ortho-vitamin 85, is an important nutrition suppled substance. It has been widely applied in the field such as medicine, cosmetic, foodstuff, feed additive, and so on. The preparation of D-pantothenyl alcohol and the optimization of key factor are discussed mainly in this paper. It mainly includes three section.In the first section, with formaldehyde, isobutyl aldehyde and diethyl oxalate as the starting materials, D-pantolactone is prepared via three steps including condensation, catalytic hydrogenation and physical resolution. The specific rotatory power of the product is consistent with imported product.

D-泛醇，俗称原维生素B_5，属维生素B旋类营养增补剂，广泛应用于医药、化妆品、食品、饲料等领域，本文着重探讨了其制备及关键因素的优化，主要内容可分三部分：第一是D-泛内酯的制备，先以甲醛、异丁醛和草酸二乙酯为起始原料合成酮基泛内酯，再经催化氢化得到DL-泛内酯，然后通过物理拆分获得D-泛内酯，得到产物的比旋光度与进口产品基本一致。

The process parameters, such as the ratio of starting materials and the reaction time, were optimized. Thus, the optically pure ethambutol was obtained in 81.25% yield under the optimum reaction conditions.

对以-2-氨基丁醇和1，2-二氯乙烷为反应原料，合成产物乙胺丁醇的工艺路线进行了探讨，对不同的投料比，反应时间等工艺参数进行了优化，收率为81.25%。

In this thermodynamic study, the minimum requirements in molar fraction of the solvents (x3) on the azeotropic feed plate are: 0.20 for N,N-dimethylformamide, 0.36 for 2-ethoxyethanol, 0.40 for 1-pentanol and 0.66 for butyl propionate,.

在这个热力学研究中，共沸混合物喂料盘上各溶剂摩尔分数最小值(x3)分别是：N，N-二甲基甲酰胺：0.20；2-乙氧基乙醇：0.36；1-戊醇：0.40；丙酸丁酯：0.66。

Acetic acid equipments using material in PTA, PVA, aldehyde oxidation and methyl alcohol carbonyl synthetic four plants in chemical industry and chemical fibre production are analyzed.

对化工化纤生产中的精对笨二甲酸、聚乙烯醇、乙醛氧化生产醋酸与甲醇羰基合成醋酸4个装置醋酸设备用材进行分析，并对含Cl-、含Br-、含I-的醋酸及含Cl-的甲乙混酸对不锈钢、铜、钛与镍基合金等金属材料腐蚀原因作了讨论。

ABSTRACT: In the presence of sodium t-butoxide and DMSO,ethyl 2-oxocyclopentanecarboxylate was subjected to C-alkylation with 2-(4-bromomethylphenyl)propanoic acid with high regioselectivity to give 2-［4-(1-ethoxycarbonyl-2-oxo-1-cyclopentanylmethyl)phenyl］propanoic acid (4) which was followed by hydrolysis,decarboxylation and salt formation to afford loxoprofen sodium in about 72% overall yield.

在叔丁醇钠和二甲基亚砜的存在下，2-丙酸对2-乙氧羰基环戊酮进行C-烷基化，再经水解脱羧，成盐即得洛索洛芬钠，以2-丙酸计算，总收率为72%。

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。