拉模在甘肃引洮总干渠出口段混凝土轨道床的应用

甘肃省引洮总干渠9号隧洞工程出口段底拱混凝土轨道床全长810 m,为C20混凝土;圆弧型混凝土薄壁结构,宽度为3.26 m,半径R=2.905 m,衬砌厚度仅为27 cm(最薄处22 cm).在出口段底拱混凝土轨道床的施工中,为了有效解决薄壁混凝土浇筑、I43重轨的安装及有渗水地段的黏土基础处理,采用了相应的施工措施,其混凝土是利用拉模浇筑的.文中简要介绍了有关的内容.     

基于投影寻踪的水利工程项目决策模型研究

决策问题是水利工程项目管理过程中的关键问题,由于水利工程项目的独特性,其决策问题受到多方面因素的综合影响,是一个综合评价问题.然而,用于解决水利工程项目决策问题的现有数学模型方法,多数受到人为因素的干扰,存在缺点和不足.因此,在分析现有方法存在问题的基础上,构建了基于投影寻踪的水利工程项目决策模型,并将其应用到一个水利工程项目的经济财务决策问题中.     

TURBULENCE TRANSPORT OF SURFACTANT SOLUTION FLOW DURING DRAG REDUCTION DEGENERATION

Turbulence transport of surfactant solution flow during drag reduction degeneration is investigated experimentally in a two-dimensional channel.Particle Image Velocimetry (P1V) system is used to take t...     

MOTION OF TRACER PARTICLES IN A CENTRIFUGAL PUMP AND ITS TRACKING CHARACTERISTICS

The Basset-Boussinesq-Oseen (BBO) equation can be used for most flows to trace the motion of a particle, but in a centrifugal pump, among the forces that act on the particles, one should also include those due to the impeller rotation, as additional effects. This paper firstly reviews various approximations of the BBO equation for the motion of dispersion particles in a viscous fluid. Then based on the motion equation for particles in low Reynolds number centrifugal pumps, a formula for calculating the tracking characteristics of tracer particles is deduced through the Fourier integral transformation. After that the deviations of the particle motion from the fluid motion, as predicted by the various approximations, are discussed and compared. At last, with an emphasis on the Particle Image Velocimetry (PIV) results, the tracking characteristics of particles are estimated. Also, advantages and disadvantages of different tracer particles are discussed and suitable tracer particles for application in PIV studies for flow fields in centrifugal pumps are suggested.     

湖南株溪口水电站一期百吨级门机轨道梁吊装技术

本文介绍了一种新的闸坝式水电站坝顶门机轨道梁的施工方案,结合确定的方案着重介绍了轨道梁吊装机具的设计和吊装施工情况。该方案不但成本低而且能够满足质量工期要求,实施后取得了显著的经济效益。     

大伙房模型在石佛寺流域洪水预报方案中的应用

为了提高辽河流域洪水预报精度,缓解流域下游的防洪压力,为水库防洪调度提供科学依据,现以水文自动测报系统为技术支持,以大伙房模型为例研究了石佛寺水库的洪水预报方案,并使用粒子群算法对大伙房模型进行了参数优选。计算结果表明,模拟预报结果都属于甲级方案,预报方案合理,并且符合石佛寺流域的结构特点,充分反映了洪水的时空变化,可用于石佛寺水库的预报调度。     

粒子群优化算法惯性权重的一种动态调整策略

为了有效地调整粒子群优化算法的全局开拓和局部搜索能力,提出一种基于Logistic模型动态调整惯性权重的粒子群优化算法.该算法在初期保持较大的惯性权重,使其具有较大的全局开拓能力,在进化后期保持较小的惯性权重,有利于局部搜索,加速算法的收敛.通过标准测试函数的仿真实验表明：该调整策略优于线性递减的调整策略,且对于优化多峰值函数具有一定的优越性.