环烷

The relationship between molecular modification of erythromycin and NMR chemical shifts was summarized. It's noticeable that downfield of shifts of H-3 (△δ 0.2) after silylation and upfield of shifts (△δ-0.4) after methylation. No changes were observed after methylation.

分析总结了红霉素分子修饰与核磁共振化学位移变化之间的关系，并且发现大环上H-3硅烷化后由高场移至低场（△δ为0.2），甲基化后又由低场移至高场（△δ为-0.4），变化均较大；而且一旦甲基化后H-3化学位移在高场几乎不再变化。

Uranium solution is obtained electrolytically by reducing uranyl ion on mercury cathode. The effect of the addition of various aminopolycarboxylic acids (such as EDTA, DTPA, CyDTA and TTHA) and organic water-miscible solvents (such as CH3OH, C2H5OH and CH3COCH3) on the stability of ura-nium in air has been investigated. The absorption spectra of uraniumand uraniumin 1 mol/l and 9mol/l hydrochloric acid solutions are examined.

本文采用汞阴极电解还原法制备了铀溶液，研究了在盐酸介质中各种氨羧络合剂乙二胺四乙酸二钠、二乙三胺五乙酸、1，2-环已烷二胺四乙酸、三乙基四胺六乙酸和水溶性有机溶剂甲醇、乙醇和丙酮的存在对铀稳定性影响，测定了在不同盐酸浓度中铀和铀的吸收光谱。

A large number of bond-type complexes, as long as the hydrogen of the molecules covalently coupled to the molecular approach in an electronegative atom up, that constitutes a hydrogen bond, there are intramolecular hydrogen bonds and intermolecular hydrogen bonds of the points, will affect the formation of complex reaction carried out, such as in solution adding dioxa cyclohexane, or tetrahydrofuran, will reduce the alkylation reaction rate.

氢键型络合物为数众多，只要含氢的分子以共价键方式耦合到分子中一个电负性原子上去，即构成氢键，有分子内氢键和分子间氢键之分，络合物的形成将会影响反应的进行，如在溶液中加入二氧杂环己烷或四氢呋喃，都会降低烷基化反应速率。

Advances in the catalysts for synthesis of ethylene glycol ethers via etherification were reviewed, and some suggestion were made for development of new catalysts.

介绍了醚化反应法合成乙二醇醚催化剂的研究进展，并对催化剂的开发提出了建议。在进行环氧乙烷与醇的醚化反应时，使用传统的碱性催化剂，反应容易形成多醚；使用传统的酸性催化剂，反应容易形成有毒物质二烷。

First, one of the termini of 1,3-diethynylbicyclo[1.1.1]pentane was coupled with a brominated aza heterocycle, and second, 3 equiv of the resulting extended arm were coupled with 1,3,5-triiodobenzene or 4 with 1,2,4,5-tetraiodobenzene.

第一，一个总站的1，3 - diethynylbicyclo [ 1.1.1 ]戊烷是加上溴化杂环字，并第二， 3相当于由此产生的延长臂被加上1，3，5 triiodobenzene或4 1，2，4，5 - tetraiodobenzene 。

The mechanisms of the formation of 1, 3, 5-trinitro-1, 3, 5-triazacyclohexane in the nitrolysis of hexamethylenetetramine with nitric acid and with the mixture of nitric acid and ammonium nitrate were first studied by NMR tracing.

本文首次采用核磁共振跟踪化学反应的方法研究了在直接法和K-法中黑索金（1，3，5-三硝基-1，3，5-三氮杂环已烷，RDX）的生成反应机理。

A new kind of oil in water emulsified SBS paper-plastic laminating adhesive was prepared with SBS thermoplastic elastomer as the main material, rosin as the viscosity increaser, cyclohexane as the solvent and OP-10 as the emulsifier.

采用SBS热塑性弹性体为胶粘剂主要原料，松香为增粘剂，环己烷为溶剂，OP-10为乳化剂，制备出一种新型以O/W型乳状液形态存在的环境友好型纸塑复合胶粘剂。

It is found that the coexisting curves of the temperatures versus the volume fractions of water, cyclohexane and diethylene glycol monobutyl ether are respectively inverse "S" type curve, positive "S" type curve and "knot-shape" curve.

用改进的相体积法测定了水－环己烷－二乙二醇丁醚三元体系的相平衡，给出了不同温度下平衡共存三液相的体积分数及平衡共存三液相的相密度的共存曲线。

Simultaneously, when the volume fractions of coexisting three-liquid-phases are converted into mass densities, it is also found that the coexisting curve of temperatures versus mass densities of phases is also standard inverse "S" type curve.

实验结果表明，在平衡共存三液相中，水、环己烷和二乙二醇丁醚的体积分数随温度改变的变化曲线分别是倒"S"型，正"S"型，"结"型；将共存三液相的体积分数转化为对应的相密度后，相密度随温度改变的变化曲线也是规整的倒"S"型；而且，3条"S"曲线形状均表现出不对称的特性。

N-formyl morpholine was synthesized using morpholine and formic acid as starting materials,phosphorous acid as catalyst and cyclohexane as water carrying agent.

以吗啉和甲酸为原料，磷酸为催化剂，环己烷为带水剂合成了N-甲酰吗啉。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失