查询词典 double bond

After hydrogenation of the double bond and the addition of alkyne to a carbonyl we introduced the N-hydroxy group by SN2 reaction.

不对称氢化和炔负离子对羰基的立体选择性加成构建了两个新的手性中心，之后用羟胺衍生物对羟基的SN2取代反应引入了羟胺片断。

THE FIRST TOTAL SYNTHESIS OF TAXAMAIRIN B Taxamairin B, representive of rare naturally-occuring rearrang-ed 9(10→20)-abeo-8, 11, 13-triene diterpenoids, has been firstsynthesized by a eleven-step route in an overall yield of 8.19%,starting from commercially available catechol and 1,3-cyclohexan-dione. The improved Friedel-Crafts annulation, thermodynamicallycontrolled-geminal pairing methylation, the selective oxidation ofallyl group and the selective reduction of the less-hindrancecarbon-carbon double bond are the key steps.

二。美丽红豆杉素B的全合成研究 1，美丽红豆杉素B的首次全合成以价廉，易得的邻苯二酚和1，3-环己二酮为原料，经过改良的Friedel-Crafts烷基化反应，热力学控制的α，β-不饱和酮结构的α一位双烷基化，烯丙位的选择性氧化，以及选择性还原位阻较小的碳碳双键等十一步反应，以8.19％的总收率首次完成了美丽红豆杉素B的全合成。

Starting from 3-benzoyl-5-formyl-indolizine, 3-benzoyl-5-(2'2'-diacetylethenyl)-indolizines and analogs were obtained by the 〓mediated aldol condensation or Wittig reaction. These compounds,promoted by low-valent titanium, gave highly functionlizedcycl[3,2,2]azine derivatives. The coupling reaction proceeded betweenthe carbonyl group and the carbon-carbon double bond, a rare example inMcMurry reaction.

我们以3-苯甲酰基-5-甲酰基中氮茚为原料，通过三碘化钐促进的aldol反应和Wittig反应制备了3-羰基-5-羰基乙烯基中氮茚，随后经低价钛还原偶联，没有生成正常的分子内羰基-羰基偶联产物，而是得到反常的羰基与α，β-不饱羰基的双键偶联产物，较高收率地得到了含多官能团的CycI[3，2，2]azine衍生物。

It was the interactional result of electronegative double bond and branched chain with positive induction effect and space steri.

研究发现，加入不同的添加剂使润滑脂的油膜强度、锥入度和滴点产生不同的变化，并对其产生的原因作了机理分析，认为是由于极压抗磨添加剂分子中带负电性的双键和带正诱导效应及空间位阻效应的支链共同作用的结果。

Using density functional theory, the rearrangement of butene double bond catalyzed by a 3T cluster model of zeolite was investigated.

基于含有两个Si和一个Al的分子筛3T簇模型，利用密度泛函方法研究了分子筛催化1-丁烯双键异构为cis-2-丁烯的反应机理。

Carbon bisulfide was the main poison in the hydrogenation reaction of conjugated double bond of styrene and the negative effect increased with the increase of carbon bisulfide content; the negative effect decreased with the increase of reaction temperature.

二硫化碳是苯乙烯中共轭烯烃加氢快速失活的主要硫化物。随着二硫化碳含量的增加，苯乙烯中共轭烯烃加氢活性下降程度增大；随温度升高，其加氢活性下降程度减小。

Fatty acids (chains of carbon atoms with hydrogens attached and an acid group at one end) with one double bond.

单不饱和脂肪酸：带有一个双键的脂肪酸（带有一个氢原子和羧基末端的碳原子链）。

The characteristic spectrum could be used to detect the double-bond DNA with one base mispairing.

该特征可被用于检测1个错配碱基的双链DNA。

The UV and IR spectroscopic studies of the monomer films showed that the photoreaction ratio of monomer (about 50%) was higher than the corresponding photosensitive polymer (about 10%, PVCi). The polarized IR spectra proved that obvious anisotropic absorption was displayed in the irradiated photosensitive film. With polarizing microscopy method, we found that these kinds of photoalignment films exhibited good alignment ability, and the stability of the photoalignment film could reach about 100℃. 2 A photosensitive self-assembled monolayer was fabricated that contained photo-cycloadditable groups, such as, coumarin and cinnamate. The reaction process were detected by contact angle method because the IR absorption of monolayer was very weak. The photosensitive self-assembled monolayer promote uniform alignment of nematic liquid crystals by LPUV, and it thermal stability could reach about 130℃. 3 A cationic bolaform amphiphiles was synthesized that had two photosensitive double bonds, and can be polymerized by ultraviolet. A layer-by-layer self-assembled deposition film was prepared in aqueous solution by using this material and poly (sodium 4-styrenesulfonate). The UV-Vis. spectra proved that the multilayers film was uniform and layer-by-layer. When LPUV irradiated the film, the photopolymerizable double bond underwent [2+2] cycloaddition, and the production of the reaction distributed along the polarized direction of incident LPUV. Polarized UV-Vis. spectra indicated that the irradiated self-assembled multiplayer film was anisotropic, and the dichromic ration is about 0.09, it is higher than the spin-coating method of photosensitive polymer or monomer. We used this anisotropic film as alignment layer of nematic liquid crystals, and obtained a uniform and stability alignment result, the static contrast ratio is about 100, which is very close to application of liquid crystal device. This thesis is an instance that the photochemical material was used in the physics region of liquid crystals, the route that was from photosensitive monomer, self-assembled monolayer film to self-assembled multiplayer film was undergone, by this logical research method photoailgnment of liquid crystal was extended and consummated.

围绕上述思路开展了如下工作：1合成了三种可进行光二聚反应的光敏小分子单体，LPUV 辐照制作了光控取向膜；用紫外-可见光谱法和红外光谱法分析了薄膜中的光化学反应，发现小分子的光反应程度可达到50%以上，至少比光敏高分子高出5倍；薄膜的偏振红外光谱证实，经过LPUV 辐照后薄膜出现了明显的各向异性；将小分子光控取向膜制成液晶器件，在偏光显微镜下观察看到均匀一致的液晶取向；并且热稳定性达到100℃左右，接近实用化要求。2制备了含肉桂酸、香豆素基团的自组装单层膜；采用接触角的方法监测自组装反应的动力学过程；紫外-可见光谱证实了自组装单层膜在石英基板表面形成；自组装单层膜经LPUV 辐照后能诱导液晶均匀取向，而且热稳定性可达130℃，热稳定性进一步提高。3合成了含有光敏双键的双季铵盐，在水溶液状态下将它和聚乙烯基苯磺酸钠沉积生成layer-by-layer 自组装多层膜，紫外-可见光谱证实这是一个逐层均匀的沉积；在LPUV 照射下，自组装膜中的光敏双键按照偏振方向发生[2+2]环加成反应，形成取向膜，用二向色性值评价的分子取向度高于高分子及小分子光控取向膜的水平；实验证明用自组装多层膜制成的液晶器件亮暗态均匀，静态对比度约为100，达到实用化器件的水平。

Three part of research works had been carried out in the dissertation. The first part: a kind of multidentate amine modified silica gel was synthesized through the following steps:(1) introduce the amino groups onto the surface of silica-gel by the treatment of surface silanol groups withγ-aminopropyl trimethoxy silane;(2) michael addition of excess trihydroxymethyl propyl triacrylate to amino groups on the silica gel surface;(3) amidation of the unreacted double bonds of TMPTA on the surface of TMPTA modified silica gel with diethylenetriamine;(4) the multidentate amine modified silica gel was finally obtained by the reaction of amino groups on the surface of DETA modified silica gel with double bond of butyl acrylate.

本论文进行了三部分研究工作，第一部分：通过多步反应对硅胶进行改性合成了一种多齿胺改性硅胶配体，合成过程如下：1通过γ-氨丙基三甲氧基硅烷与硅胶表面的硅羟基反应，使硅胶表面带有氨基；2利用硅胶表面氨基与过量的三羟甲基丙烷三丙烯酸酯发生Michael加成反应；3利用二乙烯三胺与TMPTA改性硅胶表面未反应的双键发生反应使硅胶表面氨基化；4最后用丙烯酸正丁酯与DETA改性硅胶表面氨基充分反应成功合多齿胺改性硅胶配体。

What are your goals and strategies for growth?

你的成长目标和策略是什么？

And unto the angel of the church in Sardis write; These things saith he that hath the seven irits of God, and the seven star I know thy works, that thou hast a name that thou livest, and art dead.

3：1 你要写信给撒狄教会的使者，说，那有神的七灵和七星的，说，我知道你的行为，按名你是活的，其实是死的。