查询词典 aromatic compounds

Reaction Chemistry of Aromatic Compounds - Electrophilic Aromatic Substitution: Halogenation, Nitration, Sulfonylation and Friedel-Crafts Alkylation and Acylation.

芳香化合物的化学反应--亲电芳香取代反应：卤化，硝基化，磺基化和Friedel-Crafts 烷基化和醯基化。

It was found that the geometries of the studied materials were significantly affected by the ring size and intramolecular charge transfer. The HOMO level, LUMO level, and band gap of the studied model compounds were well controlled by the acceptor strength. However, the electronic properties of the studied polymer showed a significant different trend with the acceptor strength due to the geometrical transformation. The model compound of EDOT-TP and T-TP has the aromatic geometry but is transformed to the quinoid geometry for large intramolecular charge transfer. The small bond length alternation and large acceptor strength in the EDOT-BDP polymer also results in the smallest Eg of 0.7 eV among the studied polymers.

我们发现环的大小以及分子内电荷转移对结构有很大的影响，而小分子的HOMO、LUMO和能隙受到电子受体强度所控制，然而，高分子的电子特性与其构成分子却有明显不同的趋势，这主要是由於分子结构的转变，如小分子EDOT-TP以及T-TP因分子内电荷转移，使其高分子结构由aromatic转变成quinoid；而EDOT-BPP因其键长改变量小和良好的电子受体强度，使其能隙仅0.7个电子伏特。

In this paper,the behavioral,physiological, ecological adaption mechanism of H.armigera and H.assulta to their common host plant tobacco were studied comparatively,and the main results were summarized as follows:Electroantennogram response of adult to tobacco volatiles:(1) H.armigera and H.assulta elicited similar EAG responses to the tested 20 tobacco volatiles;both of them elicited significantly more sensitive to green leaf volatiles,aliphatic and aromatic compounds, than to monoterpene,sesquiterpene,heterocyclic compounds under lower concentration; while the similar EAG responses under higher concentration were detected,but most of them were not significantly different with each other.

本文从行为、生理和生态适应三个方面，对棉铃虫和烟夜蛾与烟草间的互作进行了比较研究，主要结果如下：成虫对烟草挥发物的EAG反应：(1)两种夜蛾对测试的20种烟草挥发物均可产生EAG反应；低浓度下对绿叶气味、脂肪族、芳香族化合物的EAG反应显著高于单萜类、倍半萜类和杂环化合物；高浓度下的EAG反应也表现出相似的总体反应趋势，但多数反应值间的差异未达显著水平。

Azo aromatic compounds exist widely in the world and millions of tons of azo compounds are produced each year.

偶氮芳香族化合物在自然界广泛存在，而且每年以数百万吨的数量被制造出来。

As a result of aromatization of organic matter during the thermal cracking of original bitumen into gas,the aromatic hydrocarbons in the bitumen are characterized by abnormally abundant tetra-and penta-cyclic compounds,and predominated by parent aromatic compounds without alkyl chain,such as fluoranthene,pyrene,chrysene, benzofluoranthene etc.

沥青的芳烃组成独特，富含四、五环芳烃化合物，且以萤蒽、芘、和苯并萤蒽等无烷基取代的母体芳烃化合物为主，反映出沥青裂解成气过程中的有机质芳构化作用。

Recent developments of clean oxidation systems catalyzed by polyoxometalates are summarized in detail. The emphasis is on the epoxidation reaction of olefinic compounds, oxidation of alkanes and aromatic compounds with the comparatively ideal oxidants, hydrogen peroxide and molecular oxygen respectively.

文本总结了多金属氧酸盐在液相清洁催化氧化方面的进展，主要针对以过氧化氢和分子氧为氧化剂的烯烃类化合物的环氧化反应、烷烃和芳香族化合物的氧化反应，并详细探讨了此类氧化反应的反应机理。

Halogenated aromatic compounds with great q〓(the most negative net atomic charges on an atom of the molecule), ENC (electron-nuclear attraction energy of the one-center term for the carbon atoms of the weakest carbon-halogen bond), qc (thenet atomic charges on the carbon atom of the weakest carbon-halogen bond) and E〓 tend to be reductively dehalogenated slow, while halogenated aromatic compounds with high values of △E (the difference of front-line orbital energy), EEC (electron-electron repulsion energy of the one-center term for the carbon atoms of the weakest carbon-halogen bond), Mw, q〓 and α tend to be reductively dehalogenated fast.

卤代芳烃化合物的整个分子的最负的原子净电荷，键序最小的碳卤键中碳原子的单中心项电子-核吸引能，该碳-卤键上碳原子的净电荷和E〓与该卤代芳烃化合物还原脱卤的速率常数负相关；而前线轨道间隙能，键序最小的碳卤键中碳原子的单中心项电子-电子推斥能，Mw，q〓和α与该卤代芳烃化合物还原脱卤的速率常数正相关。

Accordingly, aromatic compounds can be divided into three groups and a delocalized π system itself is always destabilized, the dependence of aromatic ring current upon the CT was reveled, and ring rigidity has been defined as a new aromatic index.

据此，我们提出了芳环化合物新的分类准则，揭示了芳香环流起因的必要条件，定义环的刚度为芳香性一个新判据。发现，分子内基团间的局部作用同它们对分子整体性能的影响是完全相反的。

The application, proposed hydrotalcite-like compounds as a new type of environmentally friendly solid catalysts in the aldol condensation, nitrile hydrolysis, epoxide ring-opening reaction of the oxidation of aromatic compounds, alcohols oxidation, reduction of nitro compounds, and many other important reactions in organic synthesis has an important application potential, and with little pollution compared to conventional catalysts, easy separation of advantages of high reactivity.

叙述了水滑石类化合物作为固体酸碱催化剂、氧化还原反应催化剂、催化剂载体等方面的应用情况，提出了水滑石类化合物作为一类新型的环境友好的固体催化剂，在醇醛缩合、腈类水解、环氧化物的开环反应、芳烃类化合物的氧化、醇类氧化、硝基化合物的还原等许多重要的有机合成反应具有重要的应用前景，并且与传统催化剂相比具有污染小、易分离、反应活性高等优点。

The selective chlorination reaction of the aromatic ring among the aromatic compounds is very important in the economy and environmental protection aspects.

芳香族化合物的芳环选择性氯代，在经济和环保上都是一个重要的课题。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。