查询词典 electronegativity

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。

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 position of the hump shifts to a higher temperature with increasing atomic radius and decreasing electronegativity of addition elements.

结果表明：在高温处Al85Ni10M5液态合金的比热容曲线上均有驼峰出现，其位置随添加元素的原子半径的增大和电负性的减小而向高温处偏移。

Since most of the large molecules containing phosphorus element have double bonds, it is necessary to consider the special structures of double bonds in order to deal with these large systems more accurately. So, based on density functional theory and electronegativity equalization principle, applying a general atom-bond electronegativity equalization method , using separated program, through regression and least-squares optimization , the parameters of atoms and bonds in molecules are determined . By these parameters , the charge distributions and the energy of some molecules containing phosphorus element, especial the fragment of DNA, RNA, are calculated . The results are quite good.

由于这些含磷生物大分子体系都含有双键，为了明确的处理双键，进而更准确的解释带有双键和共轭双键的含磷生物大分子结构与性质的关系，我们以密度泛函理论~([1-4])和电负性均衡原理~([5-9])为基础，应用和开发原子-键电负性均衡方法中的σπ模型，利用最小二乘法，拟合确定了一些分子（含碳、氮、氧、氢以及磷等原子）的各种类型原子及化学键区域的参数，并利用上述参数计算了一些多聚核苷酸的电荷分布以及分子的总能量，进行了讨论，得到的结果可以和从头算相媲美。

We have proposed an atom-bond electronegativity equalization model on the basis of density functional theory and electronegativity equalization principle.

因此，发展准确的、计算上易于实行的方法用于探讨大分子的性质是现在理论化学的重要任务。

We have proposed modified electronegativity equalization method based on density functional theory and electronegativity equalization principle.

因而有必要发展一种准确的、计算上易于实现的方法来探讨体系的结构和性质间的内在关系。

We have built and developed an atom-bond electronegativity equalization model on the basis of density functional theory and electronegativity equalization principle.

我们以密度泛函理论和电负性均衡原理为基础，建立和发展了原子-键电负性均衡模型。

In the framework of density functional theory, the development of electronegativity, electronegativity equalization theory and their applications for exploring some molecular properties are overviewed.

文摘：以密度泛函理论为框架，综述电负性和电负性均衡理论的发展及其在探讨各种分子性质时的应用。

Optical electronegativity of binary oxide glasses based on the energy gap and refractive index Optical electronegativity is one of the most important parameters in understanding the nature of chemical bonding, and several important physical parameters can be predicted by using it.

光学电二元氧化物玻璃基于关于能源的差距和折射率光学电是其中最重要的参数在了解的性质，化学粘接，和几个重要的物理参数可以预测使用它。

Based on density functional theory and electronegativity equalization principle,applying an atom-bond electronegativity equalization σπ model,using a separated program,we calculated the charge distributions and dipole moments of guanine tautomers.

以密度泛函和电负性均衡原理为基础发展的原子-键电负性均衡方法的σπ模型。并结合自编程序，计算了鸟嘌呤五种异构体的电荷分布和偶极矩，计算结果表明，所计算出的电荷分布可以和从头算结果很好地关联。所计算的偶极矩与其它从头计算方法和力场方法相比总体趋势相同，进一步说明了ABEEMσπ模型的合理性

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。