双向弹簧夹层假定的弹性地基上双层板的解

建立了轴对称条件下,层间有双向弹簧夹层的弹性地基上双层板力学模型,应用Hankel(汉克尔)变换法推演得到了任意轴对称荷载作用下的Winkler(文克勒)地基、双参数地基和弹性半空间体地基上无限大双层板的一般解析解,给出了双层板的挠度、弯矩、剪力,以及层间反力和位移的计算公式.进而,利用该力学模型的解,分析了层间条件对双层板挠度、弯矩的影响规律,计算了上、下层板的中性轴位置,讨论了层间双向弹簧系数的取值方法.结果表明:1)随着层间竖向弹簧参数增大,上层板挠度和弯曲应力减小,下层板挠度和弯曲应力增大;随着层间水平摩阻参数增大,上、下层板的挠度和弯矩均减小;2)当双层板的剪切和压缩效应系数分别取2/3,3/5时,双层板的剪切和压缩效应可较好地被考虑;3)上、下层板的中性轴位置是变化的,它随着距荷载圆中心点的距离增大而向上、下层板各自中面趋近.     

基于互补双对数模型的国际资本流入风险影响因素研究

首先通过理论模型和文献回顾的方式对国际资本流入风险进行定量刻画;其次,运用18个新兴市场国家的样本数据,基于面板互补双对数模型(cloglog)模型实证研究了国际资本流入风险的影响因素,结果表明:外汇储备/GDP和GDP增长率水平越高,发生国际资本流入风险的概率越大,而经常账户余额/GDP和M2/GDP的比率越高,国际资本流入风险水平越低;最后,根据结论,为我国应对国际资本流动风险提出了相关政策建议.     

单位球上星形映射在极值点处的偏差定理

利用多复变数的边界型Schwarz引理,建立了C~n中单位球上正规化双全纯星形映射在极值点处的行列式型偏差定理和矩阵型偏差定理.     

Variations on a theme of Jost and Pais

We explore the extent to which a variant of a celebrated formula due to Jost and Pais, which reduces the Fredholm perturbation determinant associated with the Schrödinger operator on a half-line to a simple Wronski determinant of appropriate distributional solutions of the underlying Schrödinger equation, generalizes to higher dimensions. In this multi-dimensional extension the half-line is replaced by an open set , , n2, where Ω has a compact, nonempty boundary ∂Ω satisfying certain regularity conditions. Our variant involves ratios of perturbation determinants corresponding to Dirichlet and Neumann boundary conditions on ∂Ω and invokes the corresponding Dirichlet-to-Neumann map. As a result, we succeed in reducing a certain ratio of modified Fredholm perturbation determinants associated with operators in L²(Ω;dⁿx), , to modified Fredholm determinants associated with operators in L²(∂Ω;dⁿ⁻¹σ), n2. Applications involving the Birman–Schwinger principle and eigenvalue counting functions are discussed.     

建立在群对称轨道(SMO)及特征组态(CD)基础上的线性分子SMO-CDCI方法

定义和讨论了线性分子的群对称轨道(SMO)及特征组态函数(CD),它能够对线性分子的分子轨道与组态函数进行简单而完全的对称分类.SMO－CDCI方法是一种高效的计算方法,大大节省了线性分子CI计算的机时与内存.     

Rates of Best Uniform Rational Approximation of Analytic Functions by Ray Sequences of Rational Functions

In this paper, problems related to the approximation of a holomorphic function f on a compact subset E of the complex plane C by rational functions from the class of all rational functions of order (n,m) are considered. Let ρ _n,m = ρ _n,m (f;E) be the distance of f in the uniform metric on E from the class . We obtain results characterizing the rate of convergence to zero of the sequence of the best rational approximation { ρ _n,m(n) } _n=0 ^∞ , m(n)/n → θ ∈ (0,1] as n → ∞ . In particular, we give an upper estimate for the liminf _{n →∞} ρ _n,m(n) ^1/(n+m(n)) in terms of the solution to a certain minimum energy problem with respect to the logarithmic potential. The proofs of the results obtained are based on the methods of the theory of Hankel operators. June 16, 1997. Date revised: December 1, 1997. Date accepted: December 1, 1997. Communicated by Ronald A. DeVore.     

考虑在地基固结和流变的上部结构和地基基础的共同作用问题

本文提出一种能同时考虑地基的瞬时变形,团结变形和流变的地基基础与上部结构共同作用的一种新的计算方法,在这种方法中,土的计算考虑了Biot固结理论和流变,上部结构利用子结构法进行凝聚可得边界刚度矩阵和边界力,利用位移协讯条件则可以得到共同作用的控制方程,对上述方程进行Laplace变换,可以得到Laplace变换域内的控制方程,在Laplace变换域内对上述方程进行数值求解并进行相应的Laplace逆变换则可以得到时间境内任意时刻的解。     

A note on Schatten‐class membership of Hankel operators with antiholomorphic symbols on generalized Fock‐spaces

In this paper we investigate Hankel operators with anti‐holomorphic L²‐symbols on generalized Fock spaces A_m² in one complex dimension. The investigation of the mentioned operators was started in [4] and [3]. Here, we show that a Hankel operator with anti‐holomorphic L²‐symbol is in the Schatten‐class S_p if and only if the symbol is a polynomial with degree N satisfying 2N < m and p > . The result has been proved independently before in the recent work [2], which also considers the case of several complex variables. However, in addition to providing a different proof for the result the present work shows that the methodology developed in [4] and [3] can be adopted in order to work to characterize Schatten‐class membership. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)