Fe3+对全氟丁酸降解反应影响的理论研究

目的从理论计算的角度来研究Fe3+对全氟丁酸降解反应的影响,为寻找更有效的实验降解方法提供理论依据。方法以全氟丁酸(PFBA)为研究对象,应用Gaussian09程序,采用密度泛函理论B3LYP/6-31+G(d,p)方法对C3F7COOH,C3F7COO-及[C3F7COO-Fe]2+进行几何构型优化,对计算结果进行分析。结果得到C3F7COOH,C3F7COO-及[C3F7COO-Fe]2+3种优化结构的UV-VIS光谱,其强吸收峰对应的吸收波长依次增大,吸收光能依次减小,吸收光强度依次明显降低,表明Fe3+可促进PFBA光催化降解。结论由于形成[C3F7COO-Fe]2+配合离子,电子由基态到激发态跃迁所需的激发能降低,故Fe3+可促进PFBA光催化降解反应的发生。     

近藤格点模型研究的一种新途径

最一般的近藤格点模型(KLM)是一种受到十分重视的理论模型,因为它描述了重费米子体系以及水锰矿等一系列重要物质的物理学.     

变时滞非线性细胞神经网络稳定性分析

通过构造新的Lyapunov-Krasovskii泛函和线性矩阵不等式(linear matrix inequatity,LMI),研究变时滞非线性细胞神经网络渐近稳定性,利用牛顿-莱布尼兹公式,一些参数矩阵表达出系统变量之间的关系。从而得出一个具有变时滞相关的全局渐近稳定性判据,其扩展并改善了以前文献的结果。数值及仿真例子验证了结果的有效性。     

应用PDE方法构造两个代数曲面拼接

应用PDE方法实现两个曲面的C1光滑拼接,并根据实例对算法加以介绍,运用mathematica软件编程运算和处理图像,直观的证明了算法的合理性和可行性。     

DYNAMIC CHARACTERISTICS IN INCOMPRESSIBLE HYPERELASTIC CYLINDRICAL MEMBRANES

In this paper, the dynamic characteristics are examined for a cylindrical membrane composed of a transversely isotropic incompressible hyperelastic material under an applied uniform radial constant pressure at its inner surface. A second-order nonlinear ordinary differential equation that approximately describes the radial oscillation of the inner surface of the membrane with respect to time is obtained. Some interesting conclusions are proposed for different materials, such as the neo-Hookean material, the Mooney-Rivlin material and the Rivlin-Saunders material. Firstly, the bifurcation conditions depending on the material parameters and the pressure loads are determined. Secondly, the conditions of periodic motion are presented in detail for membranes composed of different materials. Meanwhile, numerical simulations are also provided.     

一类高阶线性微分方程的算子解法及其解的稳定性

本文利用微分算子研究一类高阶线性微分方程的解法及其解的稳定性,推广了文[3]的有关结果.     

非线性脉冲扰动下带强迫项的次线性时滞微分方程解的渐近性

讨论了非线性脉冲扰动下带强迫项的二阶次线性时滞微分方程(r(t)x'(t)'+p(t)x'(t)+ ∑n(i=1)qi(t)xθ(t-σi)+h(t)=0,t≠tk,0<θ<1,x'(tk+)+x'(tk)=Ik(x'(tk)),x(tk+)-x(tk)=Jk(x(tk)),t=tk,k=1,2…,t≥t0,解的渐近性.利用脉冲微分不等式和分析技巧获得了该方程所有非振动解或振动解趋于零的一系列充分性条件, 所得结果推广了现有文献中的结论.     

Thin Film Flow of a Second Grade Fluid over a Stretching/Shrinking Sheet with Variable Temperature-Dependent Viscosity

Effects of variable viscosity on the flow and heat transfer in a thin film on a horizontal porous stretching sheet are analyzed. The steady boundary layer equations for momentum and thermal energy are simplified by using similarity transformations. The resulted and coupled nonlinear differential equations are solved by Homotopy analysis method. The results are presented graphically to interpret various physical parameters appearing in the problem.     

ON THE EXPECTED DISCOUNTED PENALTY FUNCTION IN A MARKOV-DEPENDENT RISK MODEL WITH CONSTANT DIVIDEND BARRIER

This article considers a Markov-dependent risk model with a constant dividend barrier. A system of integro-differential equations with boundary conditions satisfied by the expected discounted penalty function, with given initial environment state, is derived and solved. Explicit formulas for the discounted penalty function are obtained when the initial surplus is zero or when all the claim amount distributions are from rational family. In two state model, numerical illustrations with exponential claim amounts are given.