多参考组态相互作用方法计算研究XOn(X=S,Cl; n=0,±1)的解析势能函数和光谱常数

采用从头计算的多参考组态相互作用方法和含扩散基的3个基组aug-cc-PVXZ(X=D,T,Q)计算了SO和ClO分子及其分子离子的势能曲线,确定了平衡几何结构、离解能,并采用Feller拟合递推方法得到了基函数为无穷大计算水平值.确定了SO-,ClO ,ClO-分子离子的基态.通过Murrell-Sorbie势能函数和最小二乘法拟合得到了解析势能函数.基于所得的势能函数,通过解核运动的薛定谔方程得到振动能级,精确计算了相应的光谱常数,并与现有的理论值和实验值进行了比较.     

Lattice dynamical study of alkali metals: An unified approach based on CGW model

The phonon dispersion relations for lithium, sodium, potassium, rubidium and cesium along the principal symmetry directions as well as their lattice specific heats have been deduced using Clark, Gazis and Wallis angular force model. This model which conforms to the translational symmetry of the lattice, reproduces the observed crossover in lithium along [ζ00] direction at ζ = 0·49, without producing any crossovers in other alkali metals. Besides, the theoretical dispersion curves of all alkali metals are in excellent agreement with the corresponding experimental or homologous dispersion relations and theirϑ _D values compare well with the experimental values over a wide temperature range. It is shown that the strength of electron-ion interactions plays a significant role in the success of any unified lattice dynamical study of alkali metals while the three-body interactions of thecgw model do not. The importance of umklapp processes, failure of the earlier models to produce a crossover and the experimentalϑ _D-T curve in lithium as well as the apparent variation in the nature and range of atomic interactions of alkali metals are discussed.     

Spectroscopic investigations on cometary molecules CO, CH and CH

The experimental potential energy curves for the electronic ground states of molecules like CO⁺, CH and CH⁺ observed in comets are constructed by using the Rydberg-Klein-Rees method as modified by Vanderslice et al. The ground state dissociation energies are determined by curve fitting technique using the five parameter Hulburt-Hirschfelder (H-H) function. The estimated dissociation energies are 8.33±0.19, 3.48±0.903 and for CO⁺, CH and CH⁺, respectively. These values are in good agreement with the literature values. Estimated dissociation energies of CO⁺, CH and CH⁺ are used in the relation given by Gaydon and ionization potentials are evaluated for CO and CH molecules. The estimated ionization potentials are 14.03 and , respectively for CO and CH. The Franck-Condon factors and r-centroids for the band system of - of CO⁺ molecule have been calculated employing an approximate analytical methods of Jarmain and Fraser. The absence of the bands in this system is explained.     

Revêtements des courbes en caractéristique p>0 et ordinarité

Let X be a proper, smooth, connected curve, defined over an algebraically closed field of characteristic p>0 and of genus g 2. We show that there exists a finite solvable group G, of order prime to p, and a Galois étale cover Y X, with Galois group G, which is not ordinary.     

Canonical Heights on Elliptic Curves in Characteristic p

Let be the rational function field with finite constant field and characteristic , and let K/k be a finite separable extension. For a fixed place v of k and an elliptic curve E/K which has ordinary reduction at all places of K extending v, we consider a canonical height pairing which is symmetric, bilinear and Galois equivariant. The pairing for the infinite place of k is a natural extension of the classical Néron–Tate height. For v finite, the pairing plays the role of global analytic p-adic heights. We further determine some hypotheses for the nondegeneracy of these pairings.     

Maximum curves and isolated points of entire functions

Given , curves belonging to the set of points were defined by Hardy to be maximum curves. Clunie asked the question as to whether the set could also contain isolated points. This paper shows that maximum curves consist of analytic arcs and determines a necessary condition for such curves to intersect. Given two entire functions and , if the maximum curve of is the real axis, conditions are found so that the real axis is also a maximum curve for the product function . By means of these results an entire function of infinite order is constructed for which the set has an infinite number of isolated points. A polynomial is also constructed with an isolated point.

     

Tailoring of strong orange-red-emitting materials for luminescence lifetime thermometry,anti-counterfeiting,and solid-state lighting applications

Strong orange-red-emitting Ba₂LaTaO₆:Eu³⁺ phosphors were designed and applied in various optical applications of luminescence lifetime thermometer, anti-counterfeiting film, and solid-state lighting applications. The crystal structure, elemental composition, asymmetry ratio, and other luminescent behaviors were investigated in detail. Especially, the optimal Ba₂LaTaO₆:0.1Eu³⁺ phosphor presented remarkable quantum yield (45.29%) and thermal stability (71.52% at 423 K). Based on the temperature-dependent luminescence decay curves, the maximum relative sensing sensitivity was 0.185 × 10^?2 K^?1 at 513 K. In addition, a novel anti-counterfeiting technique was introduced. The fabricated polydimethylsiloxane films exhibited three different colors under the irradiations of room light, 254 nm light, and 365 nm light, respectively. Eventually, the packaged light-emitting diode displayed the pure orange-red emission. Briefly, a series of the Eu³⁺-activated Ba₂LaTaO₆ phosphors with excellent luminescent properties were characterized and further applied in several optical fields for the first time.     

主导曲线法测定J阻力曲线的研究

本文利用主导曲线法测定了国产核容器用钢材料Ａ５０８－３的Ｊ阻力曲线，并将实验结果与卸载柔度法作了对比，进而说明这种新方法有其广阔的应用前景；同时，本实验引入了计算机数据实时采集及自动处理系统．这些系统的引入大大提高了实验精度和效率．     

A generalized Paris’ law for fatigue crack growth

An extension of the celebrated Paris law for crack propagation is given to take into account some of the deviations from the power-law regime in a simple manner using the Wöhler SN curve of the material, suggesting a more general “unified law”. In particular, using recent proposals by the first author, the stress intensity factor K(a) is replaced with a suitable mean over a material/structural parameter length scale Δa, the “fracture quantum”. In practice, for a Griffith crack, this is seen to correspond to increasing the effective crack length of Δa, similarly to the Dugdale strip-yield models. However, instead of including explicitly information on cyclic plastic yield, short-crack behavior, crack closure, and all other detailed information needed to eventually explain the SN curve of the material, we include directly the SN curve constants as material property. The idea comes as a natural extension of the recent successful proposals by the first author to the static failure and to the infinite life envelopes. Here, we suggest a dependence of this fracture “quantum” on the applied stress range level such that the correct convergence towards the Wöhler-like regime is obtained. Hence, the final law includes both Wöhler's and Paris’ material constants, and can be seen as either a generalized Wöhler's SN curve law in the presence of a crack or a generalized Paris’ law for cracks of any size.