查询词典 bond

It is shown that the C-NO2 bond of the alkyl is the weakest bond in the two class molecules.

进一步分析实验撞击感度与分子中最弱键离解能量的关系。

The valence electron structure of Fe_2B phase was studied on the basis of Yu's empirical electron theory of solids and molecules.The values of valence electrons on every bond in an atomic coordinate cluster were calculated by the method of bond length difference.

根据固体与分子经验电子理论对Fe_2B相的价电子结构进行了定量分析，通过键距差方法计算了Fe_2B晶体配位团各键上的共价电子数。

The theoretical system for describing the structures of organic and drug molecules using 3 types of molecular electronegativity-distance is created based on various atomic types and atomic attributes. These MEDVs include MEDV-4 based on 4 atomic types and relative electronegativity and relative bond length to carbon atom, and molecular holographic distance vector based on 13 atomic types and relative bond length to carbon atom, and MEDV-13 based on 13 atomic types and atomic attributes and the modified electrotopological state index.

通过不同原子类型与原子属性划分方案，创建了3种形式的分子电性距离矢量即以4种原子类型划分方案和以碳原子为标准的相对电负性与相对键长为基础的分子电性距离矢量MEDV-4、以13种原子类型划分方案和相对键长为基础的全息分子距离矢量MHDV、以13种原子类型与43种原子属性划分方案以及修饰的电拓扑状态指数和拓扑距离为基础的分子电性距离矢量MEDV-13等3种矢量描述子表征分子结构的理论体系。

Ti-Si composite materials are mixed at atomic scale, and Ti-O-Si bond appears in all of the samples with different TiO2 content; the mixed oxides are mainly existed in the form of amorphous pattern, anatase appears when the TiO2 content is more than 80%, but compared with the intension of pure TiO2, it has not integrate structure. The acetic content has great influence in the specific area and crystal structure of the mixed oxides. 20TiSi has good heat stability, still possesses 11m2/g after calcined at 1100℃; calcinations on the large scale of temperature does not cause the break of Ti-O-Si bond, TiO2 is well dispersed in 20TiSi calcined at 1100℃, and it still existed in the form of amorphous.

结果表明：制得的Ti-Si复合氧化物具有很高的比表面积，在TiO_2含量为10％时达到681.5m~2／g，Ti原子进入Si-O四面体结构中，形成Si-O-Ti键，复合氧化物的稳定性好，当TiO_2含量低于60 wt％时，以无定型形式存在；当含量为80％时，出现锐钛矿型TiO_2，但与纯TiO_2相比晶型不完整：醋酸对Ti-Si复合氧化物的比表面积、晶型都有很大的影响；TiO_2含量为20％的20TiSi经1100℃高温焙烧后，仍有较高的比表面积(11m~2／g)，稳定性好，在较宽的温度范围内焙烧，没有引起Ti-O-Si键的断裂，分散度高，没有出现晶型TiO_2。

Unfortunately, it has been shownthat these methods are not suitable to study about chemical bonds due to not involvingchemical bonds. In order to consider chemical bonds obviously, we have proposed an atom-bondelectronegativity equalization model on the basis of density-functionaltheory and electronegativity equalization principle. The main contents of our atom-bond electronegativity equalization model contain:(1)Considering the fact that there are varies of chemical bonds in molecules andpartitioning the molecular electron density as summations of atomic electron densitiesand chemical bond's electron densities, we obtained the basic equations of atom-bondelectronegativity equalization model: the expression of the total energy 〓, theexpression of the atom electronegativity 〓 and the expression of the bondelectronegativity 〓.

为了明确地考虑和处理分子中存在的化学键，以便能够更好地描述体系中的电荷分布进而准确地描述分子体系中的有关物理化学性质，尤其是与化学键有关的物理化学性质，我们在密度泛函理论和电负性均衡原理基础上提出了原子-键电负性均衡模型，原子-键电负性均衡模型的主要内容是：(1)考虑到分子体系中存在各种化学键这个事实，将分子空间看成是由原子区和化学键区组成的，将分子的单电子密度表达成为分子中各组成原子的单电子密度和各化学键的单电子密度的加和，从而得到了原子-键电负性均衡模型的基本方程：分子体系总能量〓和分子中原子电负性〓和化学键电负性〓表达式。

The generalized relationship which correlates the geminal coupling constants with the hybrid orbitals, net atomic charges, bond lengths and bond angles had been employed to obtain one concrete relationship for calculation of the geminal coupling constants 2JCaCbH in aromatic systems.

在前文工作的基础上，本文结合MNDO分子轨道方法和最大键级杂化轨道方法研究得到了计算苯及其取代物中孪位偶合常数2JCCH的多元级性关系式。

The ground state energies, atomic charges, bond lengths, bond angles, dipole moments, multipole moments, the molecular orbital compositions and orbital energies have been obtained.

采用RHF法对一卤代苯和卤甲基苯进行了计算，得到了它们的基态能量、原子电荷、键长、键角、偶极距、多极距、分子轨道组成和能级等。

The relation of the chromatographic retention indices of alkene to topological index,double bond atomic hybridization state index,polarizability effect index of branched chain to double bond atomic,immobile liquid polarity values and column temperatureat different temperatures on different stationary phases was studied.

通过对部分烯烃在不同固定相不同柱温下的1031个样本集的气相色谱保留指数值与其部分参数关系的研究，发现RI与拓扑指数、双键原子杂化状态指数、支链对双键的极化效应指数、固定液极性值及柱温的关系可表示为：^RI=-58.138+57.7460Q-8.2591Q+0.120T+0.807CP+36.460PBD+7.919DHSI(R=0.9989)继以留一法(Leave-one-out，LOO)进行交互检验，相关系数RCV=0.9977，说明所建模型具有良好的稳定性和预测能力，较好地揭示了烯烃类化合物气相色谱保留指数RI随固定相极性、柱温的改变而变化的规律

The formation situation of the bond for metallocarboranes and metalloboranes is analyses with the bond valence formula for atomic cluster compound.

运用原子簇化合物键价公式，对金属碳硼烷和金属硼烷进行了成键情况分析，提出了碳硼金属三中心键和硼硼金属三中心键的概念，并指出了簇合物型、夹心型和多层夹心型金属碳硼烷的稳定存在主要是形成金属三中心键的缘故

The pickup in bond prices, are quite prepared to take some of those gains off the table and put them back into the bond markets.

但我认为正如我们从今天上升美国债券价格中所知的，投资者可能准备把他们在股市上的所得拿去，重新放到债券市场上。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷