A New Relation Connecting Vibrationai Constant and Electronegativity in the Case of Diatomic Molecules

The electronegativity was defined by Pauling¹ as a measure of the power of an atom in the molecule to attract electrons to itself. This concept of electronegativity has undergone radical changes. Recent calculations of electronegativity show^2,3 that it is a complex quantity including an important atomic term depending on the charge and hybridization of the atom, and a molecular term depending on the length and the nature of the bonds in the molecule. In a molecular group of the type A-B, B is a halogen atom, say chlorine and A stands for different atoms of a subgroup of the periodic table. Since the nature of the bonds in the molecule AB and the electronegativity of halogen atom, B, is constant for a molecular group, the electronegativity, X, of atom A may be related to the dissociation energy and bond length which in its turn is related to the vibrational constant,ω_e, and the reduced mass, μ, of the molecule AB.     

双原子分子电子光谱的振动结构分析

从电子振转能级的光谱项出发,分析了双原子分子电子振动谱带序和电子振动谱带列的规律,并归纳出德兰德斯表(Deslandres table)及其主要性质。以C₂分子电子振动光谱的斯簧谱带系作为实例,说明了如何对电子振动光谱的测量值进行标识,并将它们按振动结构规律整理成德兰德斯表,从而获得有关分子光谱不同态的非谐性常数、振动频率等重要参数以及任意谱带的波数公式。     

q变形转动振子模型(Ⅰ)——q振子与双原子分子振动谱

我们提出具有量子群对称性的q变形转动振子模型,并采用这一模型对一类微观系统的转动振动谱给出相当精确的描述。本文集中讨论q振子模型,指出,q振子代数的表示及相应的能级结构可以准确地描述双原子分子的红外振动谱、振动喇曼谱、电子跃迁振动谱及相应的选择定则。 关键词：     

A New Type of High Frequency Vibrational Modes for Diatomic Chain with Quartic Substrate Nonlinearity

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强激光场中对称三原子分子多光子振动激发的动力学李代数计算

用分子的内坐标给出的动能加上用动力学代数方法给出的用内坐标表示的分子势能得出对称三原子分子的总的能量表达式,给出了时间演化算子并计算了对称三原子分子在强激光场中振动激发.作为例子,计算了H2O分子在频率wF=3652 cm-1的激光场中的激发,通过讨论可以发现H2O在激光场中的跃迁几率随时间的变化是周期性的,水分子从激光场中吸收的能量由吸收的平均光子数确定,被吸收的平均光子数随时间的变化也是周期性的.     

强激光场中对称三原子分子多光子振动激发的动力学李代数计算

用分子的内坐标给出的动能加上用动力学代数方法给出的用内坐标表示的分子势能得出对称三原子分子的总的能量表达式,给出了时间演化算子并计算了对称三原子分子在强激光场中振动激发。作为例子,计算了H2O分子在频率 的激光场中的激发,通过讨论可以发现H2O在激光场中的跃迁几率随时间的变化是周期性的,水分子从激光场中吸收的能量由吸收的平均光子数确定,被吸收的平均光子数随时间的变化也是周期性的。     

Circularly Polarized Luminescence of Free Complex Molecules in a Constant Magnetic Field

It is shown that the magnetic fieldinduced optical activity in the luminescence of complex molecules in vapors in the presence of rotational anisotropy in the ensemble of luminescent molecules provides information also on the intramolecular orientation of the initiating dipole moments of transitions, including borrowed ones. The relationships between the rotational force of the optical activity and this orientation in the case of anisotropy induced by a linearly polarized exciting light are obtained.     

一种由酸效应系数计算pH值的简便方法

利用数学不等式关系推导出一种新的由酸效应系数计算pH时非线性部分的修正方法。本法无需进行指数和对数运算,方法简便,计算结果令人满意。     

A Vibrational Force Field For 1-Alkynes and Nitriles

Abstract

Normal coordinate calculations were made for 1-butyne, propionitrile, and the two conformers each of 1-pentyne and butyronitrile, using a thirty-one parameter modified valence force field. Only the triple bond stretching force constant was assumed to be different in the two families of compounds. Twenty force constants were refined to fit 117 frequencies of the six molecules, with the average error being 5.1 cm^?1, or 0.65%.     

Multiple-Photon Dynamics in Molecules: A New Approach to High Resolution Spectroscopy of Highly Excited Vibrational States

Multi-photon transitions with two simultaneously interacting IR laser fields lead to final excited states with frequenciesnν = n₁ν₁+ n₂ν₂, withnthe total number of photons absorbed and (n,n₁,n₂) = (2, 1, 1), (3, 2, 1), (4, 1, 3), etc. The nature of the actual transition is determined by shift measurements, where the lasers are frequency-tuned by δν_iin opposite directions keeping the sum frequency,nν, resonant with the molecular transition. This technique opens a new spectral range for multi-photon transitions and a unique identification of the observed features. Forn₁andn₂both positive the excitation will lead to a “normal” up–up multi-photon transition. Many three- and four-photon transitions in the ν₃vibrational ladder of SF₆could be resolved with a resolution of 1 MHz, as well as four new two-photon transitions. As long asn₁+ n₂≥ 0, one of the twon_imay be negative resulting in an, e.g., up–down excitation pathway with its particular selection rules. The up–down excitations are demonstrated both for one- and two-photon transitions using the frequency shift technique. The different possible excitation schemes which meet the resonance condition for these transitions lead to interference effects and local couplings to highly excited states. Changes in resonance frequency for a one-photon transition (n= 1), due to these effects, are demonstrated. Evidently, the radiative coupling of participating levels to high-lying or quasi-continuum states may drastically change for different δν_ileading both to ac Stark shift and transition probability variations.     

A General Variational Algorithm to Calculate Vibrational Energy Levels of Tetraatomic Molecules

A general variational method for calculating vibrational energy levels of tetraatomic molecules is presented. The quantum mechanical Hamiltonian of the system is expressed in a set of coordinates defined by three orthogonalized vectors in the body-fixed frame without any dynamical approximation. The eigenvalue problem is solved by a Lanczos iterative diagonalization algorithm, which requires the evaluation of the action of the Hamiltonian operator on a vector. The Lanczos recursion is carried out in a mixed grid/basis set, i.e., a direct product discrete variable representation (DVR) for the radial coordinates and a nondirect product finite basis representation (FBR) for the angular coordinates. The action of the potential energy operator on a vector is accomplished via a pseudo-spectral transform method. Six types of orthogonal coordinates are implemented in this algorithm, which is capable of describing most four-atom systems with small and/or large amplitude vibrational motions. Its application to the molecules H₂CO, NH₃, and HOOH and the van der Waals cluster He₂Cl₂ is discussed.     

A New Invariant For G-Invariant Star Products

The purpose of this Letter is to propose an invariant for a G-invariant star product on a G-transitive symplectic manifold which remains invariant under the G-equivalence maps. This invariant is defined by using a quantum moment map which is a quantum analogue of the moment map on a Hamiltonian G-space. On S ² regarded as an SO(3) coadjoint orbit in , we give an example of this invariant for the canonical G-invariant star product. In this example, there arises a nonclassical term which depends only on a class of G-invariant star products.     

A New Model For the Double Well Potential

A new model for the double well potential is presented. In the new potential, the exchanging rate could be easily calculated by the perturbation method in supersymmetric quantum mechanics. It gives good results whether the barrier is high or sallow. The new model has many merits and may be used in the double well problem.     

Cooper对质心定向运动速度的研究

研究了稳恒超导电流密度 j=ensνs中 ,νS在产生磁场方面的作用 ;指出超导抗磁性起源的物理本质是 ,νSC(T)很大 (约为 1 0 3 - 1 0 4 ms- 1) ,νSC(0 )的上限是 0 K时电子 Fermi速度 (数量级为1 0 5ms- 1) ;并说明了 London穿透深度的物理意义。指出 L ondon穿透深度是产生拆对磁场 Hc(T)所要求的 Jc(T)分布的最小线度。     

A New Proof of the Analyticity of the Electronic Density of Molecules

We give a new proof of the regularity away from the nuclei of the electronic density of a molecule obtained by Fournais et al. (Commun. Math. Phys. 228(3):401–415, 2002; Ark. Math. 42(1):87–106, 2004). The new argument is based on the regularity properties of the Coulomb interactions underlined by Hunziker (Ann. Inst. Henri Poincaré, section A, tome 45, no. 4, pp 339–358, 1986) and by Klein et al. (Commun. Math. Phys. 143(3):607–639, 1992). Well-known pseudodifferential techniques for elliptic operators are used and the method works in a larger framework.     

一种新的反向投影条纹生成方法研究

反向条纹投影技术是一种应用于在线或批量检测的快速而稳定的光学三维面形检测技术.提出了一种新的产生反向条纹的算法,新的算法建立投影器坐标系与摄像机坐标系的正向映射变换关系,通过投影器坐标系上一个像素点的两套相位值,找到其在摄像机坐标系中对应的位置,即产生投影器坐标系像素点在摄像机坐标系中的注册.由于期望在摄像机中观察到的条纹图像只是简单的正弦条纹图像,直接读取注册点的期望条纹相位,很容易产生反向条纹.计箅机模拟和反向条纹投影实验中的相位标准差分别达到7.044×10-6 rad和3.34×10-2rad,比以前的方法在精度上有了较大的提高,并简要分析了精度提高的原因.计算机模拟和实物测试实验都验证了该方法的可行性.     

提高多孔硅传感特性的一种新方法(英文)

研究了多孔硅(PS)吸附有机溶剂分子后对多孔硅荧光谱的淬灭效应。结果表明:淬灭多孔硅发光的有机溶剂分子是极性分子,有机溶剂分子的极性不同对多孔硅发光的淬灭程度也不同,且有些有机溶剂分子吸附氧化多孔硅比吸附多孔硅引起的发光淬灭具有更好的可逆性和选择性;用含有胺基的正丁胺(CH3CH2CH2CH2-NH2)作碳源,用射频辉光放电等离子系统在多孔硅表面沉积c n膜对多孔硅进行钝化处理后发现:其电致发光强度明显增强,发光峰位兰移,且在大气中存放60天后,其电致发光谱强度基本不衰减,峰位不再移动。经钝化处理的器件较未经处理的器件具有小的串联电阻Rs和低的驱动电压。这为提高多孔硅的传感特性提供了一种新方法。