Turbulence Characteristics and Interaction between Particles and Fluid in Particle-Laden Open Channel Flows

Mechanism of sediment transport is composed of complicated interactions between turbulent flow, particle motion, and bed configurations. Of particular significance is the interaction between turbulence and particle motion, although turbulence measurements of particle-laden two phase flow have been a problem for a long time, especially in the near-wall region. In this study, simultaneous measurements of both the particles and fluid (water) were conducted in particle-laden two phase open channel flows by means of a discriminator particle-tracking velocimetry. The mean velocity and turbulence characteristics for fluid and particles each were examined in comparison with those in clear-water (particle-free) flow, together with previous existing data measured by laser Doppler anemometer and phase Doppler anemometer. The relative velocity and the turbulence modulation, which are the most important topics in two phase-flow approach, were revealed by varying the particle diameter and specific density. The fluid-sweeps are more contributory to the motion of particles than the fluid ejections in the near-wall region. In turn, the particle-sweeps transport the high momentum to the carrier fluid and enhance the turbulence intensities of fluid.     

UG二次开发工具的使用

通过对UG软件提供的各种二次开发工具进行的研究，分别提出了它们的使用方法、使用特点和相互关系，使得UG开发人员能够对这些工具有较全面的了解，提高UG软件二次开发的效率。     

GL型感应式电流继电器时限特性研究

本文对GL型感应式电流继电器时限特性的数学模型作了理论分析．针对其理论模型存在的问题,通过实验研究给出了GL型电流继电器的实用模型,并通过实例验证了该模型的实用性．     

数学教学中要重视学生发散性思维的培养

论述了发散性思维特点及在数学教学中培养学生发散性思维品质的重要性,介绍了在数学教学中为培养发散性思维经常所采用的一些具体做法,即注重学生发散性思维机智、变换思维机智、创优思维机智的培养。强调在传授知识的同时更要注重培养学生能力的观点。     

基于虚拟化环境下的网络安全监控技术应用

在某大型国企的数据中心虚拟化环境背景下,分析虚拟化与云计算安全在网络接入层的"虚拟以太网交换机"(Virtual Ethernet Bridge,VEB)技术在目前的实现方式中的优缺点,研究业界为解决其不足之处所提出的相关方案,阐述采用基于新型网络架构"软件定义网络"(Software Defined Network,SDN)中OpenFlow框架的可行性,提出采用该框架下的Open vSwitch开源技术来实现虚拟网络隔离、QoS配置、流量监控以及数据包分析等虚拟化网络安全监控工作的应用思路。本研究在虚拟网络交换的数据转发与安全控制的解耦、网络安全服务的独立和虚拟网络的安全控制等方面具有创新性,为采用虚拟化和云计算技术的信息系统在接入安全方面提供了参考价值。     

在VB中快速访问SQL Server数据库的方法

针对SQL Server系统所建立的数据库，分别就DQO、RDO ADO不同机制下的数据源访问列举出采用数据绑定控件和适应动态编程的非绑定控件的应用，着重对ADO方法进行了详解。     

多核CPU下的K-means遥感影像分类并行方法

针对海量遥感影像快速分类的应用需求,提出一种基于K-means算法的遥感影像并行分类方法.该方法结合CPU下进程级与线程级模式的并行特征,设计融合进程级与线程级并行的两阶段数据粒度划分方法和任务调度方法,在保证精度的基础上实现并行加速.利用大数据量的多尺度遥感影像进行实验,结果表明:所提并行方法可大大减少遥感影像的分类时间,取得了良好的加速比(13.83),并可达到负载均衡,从而解决了大区域遥感影像快速分类的问题.     

TWC LOGD: A portal for linked open government data ecosystems

International open government initiatives are releasing an increasing volume of raw government datasets directly to citizens via the Web. The transparency resulting from these releases not only creates new application opportunities but also imposes new burdens inherent to large-scale distributed data integration, collaborative data manipulation and transparent data consumption. The Tetherless World Constellation (TWC) at Rensselaer Polytechnic Institute (RPI) has developed the Semantic Web-based TWC LOGD portal to support the deployment of linked open government data (LOGD). The portal is both an open source infrastructure supporting linked open government data production and consumption and a vibrant community portal that educates and serves the growing international open government community of developers, data curators and end users. This paper motivates and introduces the TWC LOGD Portal and highlights innovative aspects and lessons learned.     

中型矿山小设备开采的经济环境效益分析

以经山寺矿为例,分别从爆破技术、设备选型、开采顺序、道路规划、排水设计、设备利用率等方面综合分析了中小型设备高强度采矿技术的经济效益和环境效益。实践证明,小型设备高强度开采值得在矿体规模小、数量多、厚度薄、产状复杂的中小型露天矿中推广,有利于控制贫化和损失。