黄土斜坡最危险滑裂面的遗传算法确定及稳定性分析

黄土滑坡尤其是地震作用下的黄土滑坡历来是我国西部广大地区一种突出而严重的地质灾害。本文研究了一种采用遗传算法基本思想和原理确定黄土斜坡“最危险滑裂面”、并以此为基础进行稳定性分析的新方法。实例的验证表明,与传统方法相比,该方法更准确、更高效,具有较好的实用性。     

Banach空间中n阶非线性微分积分方程初值问题解的存在与唯一性

用压缩映象原理研究Banach空间中定义在无界域上的n阶非线性Volterra型微分积分方程初值问题,获得了解的存在与唯一性及其迭代逼近新结果。     

Dynamic characteristics and simulation of traffic flow with slope

This paper proposes a new traffic model to describe traffic flow with slope under consideration of the gravity effect. Based on the model, stability analysis is conducted and a numerical simulation is performed to explore the characteristics of the traffic flow with slope. The result shows that the perturbation of the system is an inherent one, which is induced by the slope. In addition, the hysteresis loop is represented through plotting the figure of velocity against headway and highly depends on the slope angle. The kinematic wave at high density is also obtained through reproducing the phenomenon of stop-and-go traffic, which is significant to explore the phase transition of traffic flow and the evolution of traffic congestion.     

Short Tm3+-doped fiber lasers with watt-level output near 2 μm

High-power operation of diode-pumped fiber lasers at wavelength near 2μm are demonstrated with short length of heavily Tm3 -doped silica glass fibers. With 7-cm long fiber, a laser at near 2 μm is obtained with the threshold of 135 mW, maximum output power of 1.09 W, and slope efficiency of 9.6% with respect to the launched power from a laser diode at 790 nm. The output stability of this fiber laser is within 5%.The dependence of the performance of fiber lasers on the operation temperature and cavity configuration parameters is also investigated.     

基于布拉格光栅的边坡监测实验研究

提出了一种基于分布式光纤光栅的边坡监测与报警系统.根据强度折减法,利用ANSYS软件分析出边坡的软弱面及滑体所在的具体位置,从而在该处安装经过特殊封装的拉线式光纤光栅位移传感器.滑体的位移通过拉线转换为作用在光栅上的应力,而光纤光栅反射波长与应变具有良好的线性关系,因此通过检测光栅反射光的中心波长的偏移量,就可以解调出...     

基于相平均方法的折射绕射联合波浪模型

近岸带波浪运动的研究具有很重要的工程意义,近年来已获得了较丰硕的研 究成果并发展了许多波浪模型,而基于不同理论的波浪模型往往具有特定的适用性. 在海岸 工程中应用比较广泛的一类波浪模型以波能(波作用量)守恒为基本依据,如SWAN模型. 该 类模型在实际工程中已经得到了大量的应用,但该类模型未计及波浪绕射效应,成为其突出 的缺陷之一. 如何对模型做适当的改进,使之适用于波浪绕射的模拟,从而在原有基础上拓 广模型的应用范围是一项具有实际意义的研究工作. 该文采用波能(波作用量)守恒方程描 述近岸带波浪运动,通过引入绕射因子,得到折射、绕射联合波浪模型,从而拓广了模型的 应用范围. 通过实际算例验证,表明所建立的模型计及了波浪折射、绕射作用,对相平 均波浪模型在波浪绕射效应模拟方面的改进具有一定的意义.     

Singular properties of solutions for a parabolic equation with variable exponents and logarithmic source

This paper deals with a parabolic $p\left(x\right)$-Laplace equation with logarithmic source $u^{q\left(x\right)}logu$. The singular properties of solutions are determined completely by classifying the initial energy. Moreover, we obtain a new extinction rate of solutions, where the order of the extinction rate is greater than the maximum of variable exponent $q\left(x\right)$. This kind of extinction rate could reflect the influence of logarithmic functions on the extinction of solutions more reasonably.     

Existence and uniqueness of positive solutions to a linear transport equation in a metric space

The linear functional equation ∂_tz = L(z) − rz is considered. The linear operator L acts on a linear metric space of real functions z depending on t and on a parameter ω belonging to a subset of ^m. The existence and uniqueness to a nonnegative solution of the initial value problem is shown. An application to a kinetic equation is performed.     

On Gabay’s algorithms for mixed variational inequalities

Iterative numerical algorithms for variational inequalities are systematically constructed from fixed-point problem characterizations in terms of resolvent operators. The applied method is the one introduced by Gabay in [Ga], used here in the context of discrete variational inequalities, and with the emphasis on mixed finite element models. The algorithms apply to nonnecessarily potential problems, generalizing primal and mixed Uzawa and augmented Lagrangian-type algorithms. They are also identified with Euler and operator splitting methods for the time discretization of evolution first-order problems.