查询词典 electron cloud

Photoinduced Electron Transfer [2+2] Cycloaddition Reactions ofBenzannelated Isoquinolin-1-ones with Electron Deficient Alkenes Photoinduced [2+2] cycloaddition reactions of 11H-benzoxazolo[3,2-b]isoquinolin-11-one 8 and 11H-benzothiazolo[3,2-b]isoquinolin-11-one 13 with electron deficient alkenessuch as acrylonitrile, methyl acrylate, dimethyl fumarate and dimethyl maleate afforded a group of polycyclic isoquinoline derivatives bearing cyclobutane moieties ingood to excellent yields and resulted in the Schenck isomerization of the alkenes.

3苯并增环异喹啉-1-酮与缺电子烯烃的光诱导电子转移[2+2]环加成反应 11H-苯并恶唑[3，2-b]异喹啉-11-酮8和11H-苯并噻唑[3，2-b]异喹啉-11-酮13与缺电子烯烃如丙烯腈，丙烯酸甲酯，富马酸二甲酯及马来酸二甲酯的光诱导[2+2]环加成反应以高产率给出一系列含有环丁烷结构单元的多环异喹啉衍生物并导致烯烃的Schenck异构化作用。

In order to know irradiant dynamic process we must have excitation crosssection of electron collision with molecule. Incident electron energy is inintermediate range. At low energy, there are several good methods thatcalculate electron collision with molecule for example Variation, R-matrix.

此时入射电子的能量已经达到中能，在低能范围内的电子与分子散射有许多好的方法如变分法、R-矩阵方法，在高能范围内利用Born近似等方法也能得到满意的结果，在中等能量范围的电子与分子碰撞则没有相应的成熟的方法，使用比较多的是密耦(Closing-Couple)方法，这种方法将相互作用势分为静态势、交换势、极化势，在耦合态的选取上比较自由，可以根据实际的问题及分子的特性选取耦合作用比较强的通道，这样既能保证精度又能减少计算量。

There are many merit for NBCD used in electron transfer reactions:(1) Photoactive compounds such as electron donor and acceptor could be dissolved in water, so it is possible to mimic the electron transfer in biological systems.

NBCD在电子转移反应中具有诸多优点：1。光活性有机物即电子给体、受体能够溶于水，使得模拟生物体系电子转移反应成为可能；2。

The resultsshowed that one electron was photochemically transfered from rich electron part inside the C〓 derivatives to C〓 football. On the other hand,two step PET took place between C〓 and additional electron donor Et〓N, and so C〓anion as well as C〓 dianion could be detected in C〓/ Et〓N system.

结果表明：C〓衍生物分子内的富电子部分与C〓区域间发生分子内光诱导的一步单电子转移过程，对比而言，C〓分子与外加给体Et〓N间可相继发生两步光诱导电子转移反应，依次生成C〓和C〓阴离子自由基。

A group of pyrylium salts with different substituents has been synthesized in this work. Their fluorescence life time, quantum yield and quenching constant by BVE have also been measured. It was found that a strong interaction was observed between BVE and pyrylium salt which contains an electron-withdrawing group, and contrary, the introduction of electron-repulsive groups to the pyrylium salt will decrease this effect. It indicated that these reactions possess the characteristic of electron transfer.

本工作合成了一组带不同取代基的氧鎓盐化合物，并对它们的荧光寿命、荧光量子产率以及用丁基乙烯基醚进行猝灭的荧光猝灭常数进行了测定，发现带拉电子基的氧鎓盐化合物和BVE间存在着较强的相互作用，相反，推电子基的引入则减弱了这种影响，表明反应具有电子转移性质。

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。

The process of DC discharge in O2/N2 mixtures with the different N2 concentration has been simulated. The dependences of number of collisions with the E/N and the energy of electron are given. It is analyzed stressfully that the process of electron-molecule collision with the E/N and the energy of electron in air at atmospheric pressure.

对于O_2／N_2混合气体，模拟了不同配比条件下直流放电过程，得出了发生碰撞的粒子数随E／N、电子能量的变化；着重分析了空气中激发、电离、分解及分解电离碰撞的粒子数随E／N的变化，给出了电子漂移速度和平均电子能量随E／N的变化。

Materials and methods: The method of the electron grid therapy is to place a cerrobend grid on the end of an electron cone. Film dosimetry was used to measure the relative surface optical density and depth profile of grided electron beam with energies of 6 to 14 MeV.

材料与方法：使用底片测量术的方法，观察当15×15cm^2铅合金网眼板上的网眼孔径大小(d=0.45， 1.0， 1.5 cm)、网眼之间的间隔宽度(s=0.4， 0.2cm)不同时，以不同能量的电子射束(6、8、10、12、14 MeV)照射剂量50 M.U。，对底片的相对表面平均光密度及深度等光密度曲线分布情形所引起的变化。

In this paper several technologies, such as Fourier transform infrared spectroscopy, elemental analyzer, wide angle X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and high resolution transmission electron microscopy were used to systemically investigate the evolution of crystal structure, chemical structure, microstructure and properties of wet-spinning and dry-jet wet-spinning PAN precursor fibers during proxidation and carbonization process, analysis the structural change of carbon fibers during graphitization, and discuss the correlation between the structure and properties.

本文采用傅里叶变换红外光谱、元素分析仪、X射线衍射仪、场发射扫描电镜、透射电镜以及高分辨透射电镜等测试技术，分别系统研究了湿纺原丝和干喷湿纺原丝在预氧化和碳化过程中纤维晶体结构、化学结构、微观结构和力学性能的演变规律，分析了碳纤维在石墨化过程中的结构转变，并对碳纤维结构与性能的相关性问题作了探讨。

By analyzing the electron emission waveforms, the natural parameters of the ferroelectric electron emission and the theory of the electron emission have been generalized.

其中，对BT、BNBT两种环保无铅铁电材料电子发射性能的详细研究，并公开报道了其最大发射电流密度分别为30A/cm~2、20A/cm~2，这在国际上尚属首次。

The Master of Science degree program in Economics features a curriculum that is flexibl...

在经济学理学硕士学位的课程计划的特点是灵活而全面的方法，在理论和应用课程培训工作。

This module is used for constructing and visualizing 3D models.

该模块是用于建设和可视化的三维模型。