查询词典 rearrangement

Based on the addition of vinyl magnesium bromide to the chiral non-racemic synthon 2 derived from-1, an enantioselective total synthesis of-3, the antipode of marine alkaloid halitulin 10 steps, overall yield: 5.3% from (R-1 was achieved using aza-Claisen rearrangement as a key step.

取得的主要结果如下：一、从-苯基甘氨醇1出发，通过已知的哌啶手性合成砌块2的加成反应，建立了经aza-Claisen重排反应进行海洋生物碱halitulin手性分子片断的对映体--isohaliclorensin 3不对称合成的路线。

According to this,the reconstruction algorithms such as Linear Back Projection,Filter Back Projection and projection rearrangement method cannot be applied directly and must be improved.

根据这一情况，在医学CT中常用的一些图像重建算法如反投影法、滤波反投影法和投影重排方法都必须加以改进才能引用。

First, when operating the DABCO-catalyzed Ireland-Claisen rearrangement of propargylic acrylates 18b-d, we added dienophiles 40a-f in the reaction system to capture the rearranged allenes products respectively. The Diels-Alder adducts 41a-i were obtained with complete regioselectivity. Thus a novel tandem Ireland-Claisen rearrangement /Diels-Alder reaction process with propargylic acrylates has been developed.

首先在进行DABCO-催化的丙烯酸炔丙酯类化合物18b-d的Ireland-Claisen重排反应的同时，于反应体系中分别加入亲二烯体40a-f捕获重排得到的连二烯中间体，一步反应获得了单一区域选择性的Diels-Alder环加成产物41a-i，从而创建了一条新颖的丙烯酸炔丙酯类化合物的Ireland-Claisen重排与Diels-Alder环加成的串联反应路线。

The results show that both norbornenic and cyclopentenic double bonds are involved in the polymerization. The propagation on the NB double bond generates structural unit I by direct addition and unit II by carbocation rearrangement, respectively. Similarly, the propagation on the CP double bond produces structural unit III by direct addition and unit IV by transannular rearrangement, respectively.

结果表明， DCPD分子的降冰片烯双键和环戊烯双键均参与了聚合反应并根据不同链增长机理产生四种链结构单元：通过NB双键的链增长反应可生成直接加成结构单元I和重排结构单元II，通过CP双键的链增长反应生成直接加成结构单元III和跨环重排单元IV。

However, the excessive propagation of rearrangement in the secondary market and ignorance of the study on its risks make the rearrangement performance unconspicuous.

然而， 许多上市公司一味地将重组当作&题材&在二级市场炒作，忽视了对其风险的研究，使得我国上市公司的重组绩效并不明显。

The presence of isopropanol in the crystallization process is beneficial for the formation of small Silicalite-1 nanocrystals. The rearrangement reaction results on the different Silicalite-1 indicate that the rearrangement reaction takes place at the external surface of the crystallites as well as in the mouths of zeolitic pores, but not inside the zeolitic pores.

制备条件对Silicalite-1的催化行为影响较大，在由硅酸乙酯水解老化后的溶胶中添加异丙醇可以促进小晶粒Silicalite-1的生成，改变模板剂的用量、晶化温度和时间等可以合成不同晶粒尺寸和形貌的Silicalite-1纳米晶。

The rearrangement reaction of Oxim is a typical Beckmann rearrangement reaction.

环己酮肟重排反应是一典型的贝克曼重排反应。

In addition, the application of the RTILs (BF4, PF6) in the Beckmann rearrangement have been firstly studied. On the conditions of the reducing the oil of vitriol, the effects of the two RTILs in the Beckmann rearrangement have been reviewed and contrast experiment.

另外，首次将咪唑类离子液体应用于Beckmann重排反应体系，考察了在减少发烟硫酸用量的情况下，两种离子液体对Beckmann重排反应的影响并做了空白实验。

This article starts with the current situation of our national land rearrangement to analyse the requirement for the agricultural land quality information of land settlement required and the application of agricultural land grading results on land rearrangement.

本文从我国土地整理的现状入手，来分析土地开发整理对农用地质量信息的需求分析以及农用地分等成果在土地整理中的应用。

Moreover, the determination of the content of dissociate cyclohexanone-omine in the mixture of rearrangement process in caprolactam production was also studied. The rearrangement mixture is a complicated and difficult system to directly analyze, containing great volume of sulfuric acid and some amount of sulphur trioxide, with higher viscosity and strong corrosivity.

此外本论文还对己内酰胺生产过程中的重排混合物中游离环己酮肟含量测定进行了研究，重排混合物是一个很特殊、难以直接分析的体系，含大量硫酸和少量三氧化硫，粘度大，腐蚀性强，且杂质种类较多。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。