High blue power influence on the visible emissions of Er-doped germanosilicate optical fibres

The fluorescence decay of the ⁴F_3/2 transition in neodymium-doped silica optical fibers is analyzed with respect to neodymium concentration and temperature. New experimental data are compared with theoretical calculations based on (i) Grant's supposition [W.J.C. Grant, Phys. Rev. B 4 (1971) 648] and (ii) the Förster [T. Förster, Ann. Phys. (Paris) 2 (1948) 55] and Dexter [D.L. Dexter, J. Chem. Phys. 21 (1953) 836] model. Grant's predictions are in reasonable agreement with the data. The nonexponential decay predicted by Förster and Dexter is insufficient to explain the experimental data.     

Weighted Estimations from a Conjugate Operator

In this Letter we develop a general procedure leading from a Mourre-type estimation for a given self-adjoint operator H to a Hardy-type weighted inequality. We use this method in order to prove exponential decay for eigenvectors of a large class of perturbations of operators of convolution with bounded analytic functions.     

Vibration analysis of truncated conical shells subjected to flowing fluid

A method to predict the dynamic behaviour of anisotropic truncated conical shells conveying fluid is presented in this paper. It is a combination of finite element method and classical shell theory. The displacement functions are derived from exact solutions of Sanders’ shell equilibrium equations of conical shells. The velocity potential, Bernoulli’s equation and impermeability condition have been applied to the shell–fluid interface to obtain an explicit expression for fluid pressure which yields three forces (inertial, centrifugal, Coriolis) of the moving fluid. To the best of the authors’ knowledge, this paper reports the first comparison made between two works which deal with conical shells subjected to internal flowing fluid effects. The results obtained by this method for conical shells with various boundary condition and geometries, in vacuum, fully-filled and when subjected to flowing fluid were compared with those of other experimental and numerical investigations and good agreement was obtained.     

D→Klv～l衰变过程的研究

用光锥QCD求和规则研究D→Klv～_l衰变过程，首先计算D→K跃迁形状因子，通过构造新的关联函数，消除了twist-3波函数的不确定性给计算结果所带来的影响，从而使计算结果更加精确. 计算得到的分支比与最近的实验数据相一致. 关键词： QCD光锥求和规则 D介子半轻衰变 分支比 形状因子     

利用有效液滴模型对超重元素α衰变半衰期的研究

利用有效液滴模型计算了偶偶超重核的α衰变半衰期,计算过程中采用了保持碎片体积守恒的不对称形状描述以及有效惯性系数计算Gamow势垒穿透因子.首先在质子数Z为88—98的区域检验了有效液滴模型,发现计算结果与实验符合得比较好.随后将此模型推广到Z≥100的情况,虽然只用了两个模型参数,计算结果与实验数据符合,说明有效液滴模型是计算偶偶超重核素α衰变半衰期的一个成功模型.     

Theoretical study on decay of the 4d core-excited states of Cs III

In a recent XUV photoabsorption spectrum of Cs Ⅲ ions by Cummings and O＇Sullivan [2001 J. Phys. B 34 199], rather large linewidths were found for the 4d^95s^25p^6 - 4d^105s^25p^5 transition which are quite in disagreement with corresponding quasi-relativistic multiconfiguration Hartree Fock （MCHF） calculation. In the present work, a detailed multiconfiguration Dirac-Fock study has been carried out to explore this discrepancy. Owing to the detailed consideration of electron correlation effects, some ‘forbidden＇ Auger decay channels, such as 4d^105s^25p^35d and 4d^105s^05p^6, would become ‘open＇. As a result, remarkable improvement of the linewidths has been obtained in our calculation. Furthermore, the theoretical Auger spectrum of the 4d^ 95s^25p^6 core-excited states of Cs Ⅲ ions is Riven in the present work.     

175Hf核ε衰变的IXK/Iγ(343keV)比值计算和分析及其辐射数据计算

简要地介绍了¹⁷⁵Hf核ε衰变的I_XK/I_γ(343keV)比值的计算方法与实验测量的比较与分析,并在此基础上,计算得到了P_γ(343keV)=0.869±0.004,还给出了¹⁷⁵Hf核ε衰变的辐射数据的计算与推荐     

Formation mechanism of ethanol-water excimer

The fluorescent spectrum and the excitation spectrum were used to present the cluster molecular structure feature in ethanol-water solutions.Through analyzing the fluorescent characteristics of an excimer,it is proposed that the excimers are formed between the ethanol-water cluster molecules in the excited state and in the ground state.The fluorescent lifetime and the fluorescent intensity decay process give information about the photo-physical and photo-chemical processes of the formation and the dissociation of an excimer.The theoretical calculation and physical analysis coincide with the experimental results.The preliminary conclusion about the structure feature of ethanol-water cluster molecule is that it has a planar one like a sandwich.     

Gd激光等离子体的双电子复合过程研究

在自旋-轨道劈裂阵模型下,通过类铜的内壳层激发组态计算了类镍Gd的双电子复合速率系数,其中考虑了共振和非共振辐射平衡跃迁对自电离能级的影响,而忽略了因碰撞跃迁引起的电子俘获,非共振辐射平衡跃迁在低电子温度条件下主要影响双电子复合过程;本文讨论了双电子复合系数及双电子伴线强度比随电子温度的变化.     

Hypernuclear physics for neutron stars

The role of hypernuclear physics for the physics of neutron stars is delineated. Hypernuclear potentials in dense matter control the hyperon composition of dense neutron star matter. The three-body interactions of nucleons and hyperons determine the stiffness of the neutron star equation of state and thereby the maximum neutron star mass. Two-body hyperon–nucleon and hyperon–hyperon interactions give rise to hyperon pairing which exponentially suppresses cooling of neutron stars via the direct hyperon URCA processes. Nonmesonic weak reactions with hyperons in dense neutron star matter govern the gravitational wave emissions due to the r-mode instability of rotating neutron stars.