k-边覆盖对策及其核心

本文针对从图的k-边覆盖问题引出的合作对策模型，利用线性规划对偶理论得到了其核心非空的一个充分条件和构造核心分配的多项式时间算法，并将这一结果推广到了一般的k-集合覆盖对策模型中．     

Assembly of ϵ-Keggin Polyoxometalate from Molecular Crystal to Zeolitic Octahedral Metal Oxide

Zeolitic octahedral metal oxides are inorganic crystalline microporous materials with adsorption and redox properties. New ϵ-Keggin nickel molybdate–based zeolitic octahedral metal oxides have been synthesized. ³¹P NMR spectroscopy shows that reduction of Mo^VI-based molybdates forms an ϵ-Keggin polyoxometalate that immediately transfers to the solid phase. Investigation of the formation process indicates that a low Ni concentration, insoluble reducing agent, and long synthesis time are the critical factors for obtaining the zeolite octahedral metal oxides rather than the ϵ-Keggin polyoxometalate molecule. The synthesized zeolitic nickel molybdate with Na⁺ is used as the adsorbent, which effectively separates C₂ hydrocarbon mixtures.     

On <Emphasis Type="Italic">k</Emphasis>- critical 2<Emphasis Type="Italic">k</Emphasis>- connected graphs

A graph G is called an (n,k)-graph if κ(G-S)=n-|S| for any S ? V(G) with |S| ≤ k, where ?(G) denotes the connectivity of G. Mader conjectured that for k ≥ 3 the graph K_2k+2?(1-factor) is the unique (2k, k)-graph. Kriesell has settled two special cases for k = 3,4. We prove the conjecture for the general case k ≥ 5.     

一类新的k-次增生型变分包含解的存在性及其具有混合误差项的Ishikawa迭代逼近

在实自反Banach空间中,引入和研究了一类新的k-次增生型变分包含问题,证明了这类变分包含解的存在性、唯一性及其具有混合误差项的Ishikawa迭代程序的收敛性.本文结果本质地改进、发展和统一了张石生和曾六川等人的一系列相关结果.     

On Boundary Conditions for Wedge Operators on Radial Sets

We present a theorem about calculation of fixed point index for k-ψ-contractive operators with 0 ≤ k < 1 defined on a radial set of a wedge of an infinite-dimensional Banach space. Then, results on the existence of eigenvectors and nonzero fixed points are obtained.     

无限展长后掠翼边界层定常横流不稳定转捩分析

采用γ-Re_θt横流转捩拓展模型对NLF （2）-0415无限展长后掠机翼进行数值模拟,重点分析来流雷诺数、机翼表面粗糙度及后掠角对边界层横流不稳定性的影响.研究发现γ-Re_θt横流转捩拓展模型能够准确预测边界层定常横流不稳定转捩,计算结果与试验数据吻合较好.结果表明来流雷诺数越大、机翼表面越粗糙,横流转捩位置越靠前;随着机翼后掠角的增加,转捩位置先前移随后逐渐靠后.     

Optimal convergence rates for three-dimensional turbulent flow equations

In this paper,the convergence rates of solutions to the three-dimensional turbulent flow equations are considered.By combining the Lp-Lq estimate for the linearized equations and an elaborate energy method,the convergence rates are obtained in various norms for the solution to the equilibrium state in the whole space when the initial perturbation of the equilibrium state is small in the H3-framework.More precisely,the optimal convergence rates of the solutions and their first-order derivatives in the L2-norm are obtained when the Lp-norm of the perturbation is bounded for some p ∈[1,6/5).     

非正交网格控制容积法分析复杂形状池内的流动

介绍一种基于非正交网格控制容积法的数学模型，及其在圆形沉沙池流动研究中的应用．该模型求解轴对称流动的连续方程及时均Ｎ－Ｓ方程，并采用标准ｋ－ε紊流模型，模拟圆形池内的流动．由于采用非正交网格，此计算模型可精确模拟几何形状较复杂的沉沙池内的流动，利用上述模型对某实际沉沙池进行了流场计算，计算所得流场与模型试验实测值符合良好．     

Enhanced near-field distribution inside substrates mediated with gold particle: optical vortex and bifurcation

We present new results for laser excited semiconductor crystals probed by ultrashort x-ray pulses diffracted by the crystal lattice. First we discuss acoustical phonons of semiconductors, i.e. indium antimonite and germanium, and then we describe the temporal evolution of the laser-induced metal–semiconductor phase transition of samarium sulfide.