Subdifferential representation of homogeneous functions and extension of smoothness in Banach spaces

In this paper, we mainly consider proximal subdifferentials of lower semicontinuous functions defined on real Hilbert space and Clarke＇s subdifferentials of locally Lipschitzian functions defined on Banach space respectively, and obtain the generalized Euler identity of homogenous functions. Then, by introducing a multifunction F, we extend the smoothness of sphere and differentiability of norm function in Banach space.     

ZnSe晶体中Mn2+离子的能级

研究了ZnSe:Mn的光导激发谱.室温下观察列两个峰:4600Å和5380Å.还研究了4400Å及5200Å激发下光导与温度的关系.根据这些实验认为:Mn2+离子的第一激发态4T1,非常接近导带.理论上导出了5200Å激发下光导对温度的依赖.调节参数将理论与实验进行拟合.从选定参数中得出:Mn2+的4T1态位于导带下0.054eV.4400Å激发下光导与况度的关系用陷阱的作用解释.陷阱深度估计为0.4eV.     

非晶半导体光致发光的温度依赖关系

研究了a-Si:H,a-Si:H,F,a-Si:H,Cl以及a-Si:H,Cl,O等非晶硅薄膜光致发光的温度依赖关系。测量了各种样品的无辐射跃迁激活能ε,并试图寻求激活能ε与样品的制备条件和结构之间的关系;同时从发光强度的温度相关性确定了带尾态密度分布参数T0,以及T0与发光光谱形状之间的关系。并将实验结果与瞬态光电导的数据进行了比较。     

Modeling longevity risks using a principal component approach: A comparison with existing stochastic mortality models

This research proposes a mortality model with an age shift to project future mortality using principal component analysis (PCA). Comparisons of the proposed PCA model with the well-known models—the Lee-Carter model, the age-period-cohort model (Renshaw and Haberman, 2006), and the Cairns, Blake, and Dowd model—employ empirical studies of mortality data from six countries, two each from Asia, Europe, and North America. The mortality data come from the human mortality database and span the period 1970-2005. The proposed PCA model produces smaller prediction errors for almost all illustrated countries in its mean absolute percentage error. To demonstrate longevity risk in annuity pricing, we use the proposed PCA model to project future mortality rates and analyze the underestimated ratio of annuity price for whole life annuity and deferred whole life annuity product respectively. The effect of model risk on annuity pricing is also investigated by comparing the results from the proposed PCA model with those from the LC model. The findings can benefit actuaries in their efforts to deal with longevity risk in pricing and valuation.     

Instanton effects on the interaction potential between light quarks and the isomultiplet mass splitting of baryons

On the basis of current assumptions of instanton theory we derive strictly the explicit dependence on the masses and spins of the instanton induced potential between a pair of light quarks in baryons, namelyV ₁₂=γ+β(m _* ^1+α )(m _* ^2+α )η(1-σ ₁ησ ₁), wherem _i ^* andσ _i (i=1.2) are respectively the mass and Pauli spin of theith quark. On the additional basis of the MIT bag model, we obtain γ=c/R ³ and β=b/R ³>0, and α>0 is independent of the radiusR of the baryon. The magnitudes of the parametersb and α are also estimated. The MIT bag model is improved by taking into account this potential. Isomultiplet mass splitting formulas are derived in good agreement with experiment.     

Convergence of compressible Euler-Poisson system to incompressible Euler equations

In this paper, we study the quasi-neutral limit of compressible Euler-Poisson equations in plasma physics in the torus T^d. For well prepared initial data the convergence of solutions of compressible Euler-Poisson equations to the solutions of incompressible Euler equations is justified rigorously by an elaborate energy methods based on studies on an λ-weighted Lyapunov-type functional. One main ingredient of establishing uniformly a priori estimates with respect to λ is to use the curl-div decomposition of the gradient.     

Lyapunov-type inequality for a class of even-order differential equations

In this paper, we generalize the well-known Lyapunov-type inequality for second-order linear differential equations to a class of even-order linear differential equations, the results of this paper are new and generalize some known inequalities in the literatures.     

Computational Study of MHD Equilibrium of Noncircular Tokamak Reactor Plasmas

The MHD equilibrium and stability of noncircular tokamak plasmas limited by a separatrix is studied for reactor size systems. A typical example with a plasma current of 15.8 MA and major radius of 8.1 is presented. The required vertical field is generated by a set of discrete external coils and no conducting shell is included. The detailed equilibrium shape is calculated numerically for a vertical elongated plasma with two stagnation points symmetrically located above and below the midplane as would be required for a system with a poloidal divertor. The plasma height to width ratio is 2, the plasma shape factor is 1.6 and poloidal ? is 2.2. The plasma is locally stable. The general stability criteria with respect to quasi-rigid motions (special kink modes) are calculated numerically and found to be satisfied. Size scaling and the engineering constraints are discussed.     

Design of a Rectangular to Circular Groove Waveguide Transition by Finite Element Method

A rectangular to circular groove waveguide transition is described in millimeter-wave band. The transition maintains a constant cutoff wavelength. Using the Finite Element Method, the size of the variable cross-section throughout the transition are calculated and the transition is designed.     

Synthesis and Raman scattering of GaN nanorings, nanoribbons and nanowires

Low-dimensional GaN materials, including nanorings, nanoribbons and smooth nanowires have been synthesized by reacting gallium and ammonia using Ag particles as a catalyst on the substrate of MgO single crystals. They were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). EDX, XRD indicated that the low-dimensional nanomaterials were wurtzite GaN. New features are found in Raman scatterings for these low-dimensional GaN materials, which are different from the previous observations of GaN materials. Received: 16 November 2000 / Accepted: 17 November 2000 / Published online: 21 March 2001