Convective heat transfer and flow characteristics of Cu-water nanofluid

An experimental system is built to investigate convective heat transfer and flow characteristics of the nanofluid in a tube. Both the convective heat transfer coefficient and friction factor of Cu-water nanofluid for the laminar and turbulent flow are measured. The effects of such factors as the volume fraction of suspended nanoparticles and the Reynolds number on the heat transfer and flow characteristics are discussed in detail. The experimental results show that the suspended nanoparticles remarkably increase the convective heat transfer coefficient of the base fluid and show that the friction factor of the sample nanofluid with the low volume fraction of nanoparticles is almost not changed. Compared with the base fluid, for example, the convective heat transfer coefficient is increased about 60% for the nanofluid with 2.0 vol% Cu nanoparticles at the same Reynolds number. Considering the factors affecting the convective heat transfer coefficient of the nanofluid, a new convective heat transfer correl  

基于鼓励性的水价体制模式的探讨

随着我国经济的迅猛发展,水资源短缺现象呈加剧趋势.虽然各项节水措施和技术相继提上了日程,但由于人们的节水意识淡薄,还不能达到节水的理想效果,只有制定合理的水费体制体现水资源的真正价值,运用经济杠杆来调动民众参与的积极性,才能最大限度地节约和保护水资源.  

品牌管理中的品牌价值评估方法探讨

回顾了国内外主要品牌价值评估方法的缺陷,提出从品牌运营成本、品牌当期收益贡献和品牌未来收益3个方面综合评估品牌价值。在构建直接品牌价值评估模型基础上,给出了间接品牌价值评估法。  

CBR方法中的案例表示和案例库的构造

基于案例的推理即CBR（Case—Based Reasoning）是人工智能研究的传统领域，它的智能性很大程度取决于案例表示和案例库构造的好坏。本文介绍了CBR方法中案例表示和案例库构造方法，着重描述了框架表示法，并且结合snort规则的案例化进一步作了实例分析。  

基于嵌入式网络视频服务器的远程监控系统

介绍了视频监控系统的发展和现状，提出了一种基于嵌入式网络视频服务器的远程监控系统设计，阐述了视频服务器的结构体系和客户端实时软件系统的设计方案。并就视频数据网络传输中的数据处理等关键技术进行了分析，给出了实现远程视频监控系统的应用实例。  

助剂对Cu-ZnO-Al2O3-SiO2催化剂性质和催化性能的影响

研究了助剂MgO、TiO2、ZrO2等对CO2直接加氢合成二甲醚的Cu-ZnO-Al2O3-SiO2催化剂性质和催化性能的影响,并用XRD、XPS、H2-TPD、CO2-TPD、H2-TPR等手段进行了表征.结果表明,助剂不同程度地促进了CuO和ZnO的分散;降低了Cu-ZnO-Al2O3-SiO2催化剂的TPR还原温度;加入的助剂富集于催化剂表面,除ZrO2以外的其他助剂均降低了催化剂表面Cu原子的浓度;助剂对H2、CO2吸附中心有调变作用;活性评价结果表明,CO2的转化率与表面Cu原子的浓度和催化剂吸附氢的能力有关,ZrO2是CO2加氢制二甲醚Cu-ZnO-Al2O3-SiO2催化剂的优良助剂.  

基于改进蚁群算法的无人机三维航路规划

研究了一种基于改进蚁群算法的无人机三维航路规划方法,以保证在敌方防御区域内以最小的被发现概率以及可接受的航程到达目标点。首先对无人机三维航路规划模型进行分析,在此基础上采用蚁群算法对三维航路进行优化。将最短路径的信息反馈到系统中作为搜索的指导信号,并改进节点选择方法,以提高应用蚁群算法搜索无人机三维航路的效率。最后将所研究的方法应用于无人机的三维航路规划,仿真结果表明本文方法是有效的。  

微机原理与接口技术课程的改革与实践

为适应新世纪对电气信息类人才培养的要求,在分析了微机原理与接口技术课程特点及教学状况的基础上,从教学目标、教学内容入手,介绍了微机原理与接口技术课程改革的思路和方法.从适应科技发展的角度,对该课程的教学内容进行了调整,构建了微机原理与接口技术多媒体教学平台系统.同时还探讨了课程考试方式的改革.  

JAPS: an automatic parallelizing system based on JAVA

JAPS is an automatic parallelizing system based on JAVA running on NOW. It implements the automatic process from dependence analysis to parallel execution. The current version of JAPS can exploit functional parallelism and the detection of data parallelism will be incorporated in the new version, which is underway. The framework and key techniques of JAPS are presented. Specific topics discussed are task partitioning, summary information collection, data dependence analysis, pre-scheduling and dynamic scheduling, etc.  

Using genetic algorithm based simulated annealing penalty function to solve groundwater management model

The genetic algorithm (GA) is a global and random search procedure based on the mechanics of natural selection and natural genetics. A new optimization method of the genetic algorithm-based simulated annealing penalty function (GASAPF) is presented to solve groundwater management model. Compared with the traditional gradient-based algorithms, the GA is straightforward and there is no need to calculate derivatives of the objective function. The GA is able to generate both convex and nonconvex points within the feasible region. It can be sure that the GA converges to the global or at least near-global optimal solution to handle the constraints by simulated annealing technique. Maximum pumping example results show that the GASAPF to solve optimization model is very efficient and robust.