查询词典 addition reaction

The effects of the amount of catalyst, the amount of acetic anhydride, reaction time, and addition of solvents etc. on the acylation reaction were investigated.

考察了催化剂用量、乙酐用量、反应时间和溶剂的加入等因素对该酰化反应的影响。

The reaction process in methanol solvent can be deduced from the computational results with CPCM solvent model and the supermolecular handling, namely the reaction involves four steps in the methanol solvent. The nucleophilic addition of trimethylamine to acraldehyde generates an enolate. Nucleophilic attack of the enolate on the aldehyde forms the carbon-carbon bond, followed by the proton-transfer process and the further elimination generating the product and liberating the trimethylamine catalyst.

对于CH3OH对反应体系的影响，可以综合考虑CPCM溶剂模型及超分子模型下的研究结果，即CH3OH溶剂中反应按四步进行，催化剂三甲胺首先与丙烯醛发生亲核加成，生成的两性离子中间体与甲醛发生类似于Aldol的醛醇缩合，形成碳-碳键，之后发生分子内质子转移，最后经E1cb消除得到产物，并释放催化剂三甲胺。

It was demonstrated that addition of CO2 in the reaction system could increase the reaction rate significantly.

结果表明，反应速率随着CO2压力的增加大幅度提高。

In addition, some aryl-substituted propenoic acids were prepared via Perkin reaction. The cyclization and decarboxylation reaction were studied.

此外，通过Perkin反应合成了4种芳基取代丙烯酸，研究了其关环和脱羧反应。

In addition, ioding was found to be an efficient catalyst for the imino Diels-Alder reaction of N-arylimine and enol ethers and the reaction provided tertrahydroqinolines in good yields. One pot synthesis of tetrahydroqinolines from aldehyde, aniline and enol ethers was also achieved using iodine as the catalyst. The chemical yield of the"one pot"reaction was comparable with that obtained using preformed N-arylimine.

此外我们也发现碘能够有效地催化N-芳基亚胺与烯醇醚的Diels-Alder反应，以很高的化学收率得到了四氢喹啉衍生物，并且发现碘也能够直接催化芳香醛、苯胺、烯醇醚的三组分"一锅"反应，获得的化学产率与使用预制的N-芳基亚胺相当。

The catalytic action of mercury on the colour reaction between potassium ferrocyanide and 4, 7-diphenyl-1, 10-phenanthrolihe has been studied, The addition of thiourea will further increase the sensitivity of the reaction.

本文研究了汞催化亚铁氰化钾与4，7-二苯基-1，10-菲啰啉显色反应体系，硫脲的加入显著提高了体系的灵敏度，摩尔吸光系数ε＝4。

A new kind of magnesium alloys has been synthesized by high energy ball-milling of Mg and Fe mixed powders.Due to the high corrosion speed and reacting efficiency,the alloys are generally called super-corroding alloys.A SCA bulk is fabricated through cold-pressing and sintering the mechanically alloyed Mg-Fe powders.The chemical reaction of SCA with seawater rapidly releases heat and hydrogen gas,which may play very important roles in many ocean applications.For example,the reaction heat can be used to keep diver clothes warm;SCA corrosive links with the function of self-destruction can be utilized to control the sinking and floating of sonobuoy, and to salvage the training torpedo or other instruments.In addition,the reaction heat of SCA can be applied to heat food,machinery and ice or snow,which is thus very helpful for mountaineers.

超腐蚀合金采用Mg和Fe混合粉末，经高能球磨机械合金化、冷压、烧结，形成Mg-Fe合金块体，具有很高的海水腐蚀速率和反应效率，该合金化学反应放出的热量和氢气可在海洋工程中发挥重要作用，例如：可为深海作业潜水衣的保暖提供热量；由其制造的腐蚀链通过自毁机制，可用来控制声纳浮标的沉浮时间，打捞和回收水中的贵重仪器、装置以及训练用的靶雷；在偏远地区和寒冷地带，利用该合金的反应放热特性，不仅可加热机械、仪表或食品，而且能为登山运动员提供取暖所需的热量。

In addition, ioding was found to be an efficient catalyst for the imino Diels-Alder reaction of N-arylimine and enol ethers and the reaction provided tertrahydroqinolines in good yields. One pot synthesis of tetrahydroqinolines from aldehyde, aniline and enol ethers was also achieved using iodine as the catalyst. The chemical yield of the"one pot"reaction was comparable with that obtained using preformed N-arylimine.

此外我们也发现碘能够有效地催化N-芳基亚胺与烯醇醚的Diels-Alder反应，以很高的化学收率得到了四氢喹啉衍生物，并且发现碘也能够直接催化芳香醛、苯胺、烯醇醚的三组分&一锅&反应，获得的化学产率与使用预制的N-芳基亚胺相当。

The experimental results showed that the molecular weight and its distribution is restrained by the reaction mass's ratio, reaction temperature, and the different addition of reaction promoter, molecular weight regulator and additive, the correspinding product's scale inhibitive perfomance of Water Stabiliser is different.

结果表明：单体配比、反应温度、引发剂、分子量调节剂和添加剂的不同用量对分子量及其分布都有制约作用，相应的水质稳定剂产品的阻垢性能也不同

8Ps for native and NaBH〓 chemically modified reaction centers, and the transfer process from H〓 to the final electron acceptor Q〓 occurs in about hundreds of picoseconds. On the other hand, the energy transfer from excited B was obviously slowed down in the pheophytin-exchanged RC. By considering the change of free energy of ion pair P〓Phe〓, it could be expected there might exist alternative pathway of charge separation and electron transfer in pigment-exchanged reaction center. In addition, the influence of acid environment on the ultrafast dynamics of reaction center was also experimentally observed, which shows an evident difference from that of in native RC, and further investigation should be carried out to elucidate the origination.

在色素置换后的反应中心中，以B为起点的能量传递较天然RC的情况明显减慢，约在450fs左右，考虑到置换后的反应中心中P的自由能有所提高以及其仍然保持的光化学活性，这一较慢的能量传递也可能预示着还存在着其它的能量传递通道；另外，还对酸性处理的反应中心中的超快光动力学过程进行了尝试性的研究，发现由于色素分子的聚集以及蛋白环境的改变，BChl分子的激发态动力学过程有着明显不同于天然反应中心的情况。

Objective To investigate the effects of interleukin-1 β converting enzyme gene on the biologic characteristics of ovarian cancer cells.

目的 探讨白细胞介素-1 β转换酶的表达，对卵巢癌细胞生物学特性的影响。

Campylobacter: This illness is the most commonly identified cause of diarrheal illness in the world.

弯曲：这种病是最常见的原因查明腹泻病，在世界上。