使用连接池技术优化系统的整体性能

主要介绍数据库连接池技术的基本原理，分析了数据库连接池的优势，并比较了连接池技术与传统的数据库连接的区别。最后结合JSP技术列举了应用连接池的实例。     

CORBA中间件的实时扩展

从体系结构、关键技术等方面阐述了实时CORBA技术。对实时CORBA的各组件进行了分析和探讨，论述了实时CORBA的总体框架。     

基于B/W/D结构的高考网上报名系统设计及其关键技术实现

介绍了系统的功能模型及其采用的B/W/D结构,并重点阐述了系统采用的连接池、高速缓存和在线摄像等关键技术。     

Mechanism of pool separation and stratification in laser remelting and cladding

1INTRODUCTIONInrecentyears,agreatdealofattentionhasbeenfocusedon1aserreme1ungandcladdingtechnique,whichhavebeenusedextensivelyinindustriesbecause0fimprovingwear-resistance,corrosionresistanceandthermal-barrierofthematerial,.,f...[1'2].Inordert0obtainagoodsurfacecoating,experimentalandnumericalin-vestigationsoncharacteristicsoflaserPOOlwerecarriedonbymanyresearchers.Zax Nicom-positecoatingwasproducedbylasercladdingon4Cr13steelsubstrateandstratifiedstructureincladhasbeenobservedbyPeiet.l[…     

波高传感器的数学模型

通过对波高传感器的实验测试和研究,建立了波高传感器的输出电压与水深及水温的数学模型。这个数学模型,适宜于波浪高度的数据采集,可以提高波高传感器的测试精度。     

HEAT TRANSFER FROM A HORIZONTAL BUBBLING SURFACE TO AN OVERLYING WATER POOL†

An experimenl was performed to study the effects of bubbling from a circular, horizontal, fiat plate on the heat transfer to an overlying water pool. The plate had drilled orifices through which nitrogen was injected into an overlying pool of water at atmospheric pressure. For “deep” pools, the heat transfer coefficient was found to increase only about 20% over a range of superficial gas velocities from 0.6 to 8.5cm/s, A turbulent heat transfer model developed by Konsetov was found to agree well with the data from this experiment. This model and the experimental data suggest that under certain conditions the heat transfer coefficient is similar for both horizontal and vertical surfaces. These conditions are, that the bubbles only contribute to the stirring action in the pool and only when the bubbling pool is considered “deep”. When the pool height fell below 60% of its diameter, the heat transfer coefficient decreased almost linearly with pool height. This suggests that there occurs a reduction in the turbulent fluctuations or in the characteristic length scale based on the average turbulent eddy size as the pool height decreases.     

双带式非晶薄板连铸熔池流动传热数值模拟

以非晶合金新型双带连铸工艺为研究对象,考虑气体层与自由液面之间的交互作用,建立了熔池流动传热三维VOF两相流模型,通过对比分析,验证了新型布流器结构设计的合理性,考察了布流器水口倾角和浸入深度对熔池流场和温度场分布的影响。结果表明,新型布流器能够有效地降低熔池侧封区自由液面的波动程度;随着水口倾角和浸入深度的变化,熔池自由液面的波动速度和温度分布,均表现出强烈的"双波峰"现象;布流器水口倾角每增加15°,液面波动速度波峰约减小0.015m/s,温度波峰约减小10℃;水口浸入深度每增大5mm,液面速度波峰约减小0.01m/s,温度波峰约减小15℃;当水口倾角为30°,浸入深度为25mm时,熔池流场和温度场分布最为合理。     

A numerical simulation of pool boiling using CAS model

This paper presents a new numerical model, called the CAS model, for boiling heat transfer. The CAS model is based on the cellular automata (CA) technique that is integrated into the popular SIMPLER algorithm for CFD problems. In the model, the CA technique deals with the microscopic nonlinear dynamic interactions of bubbles while the traditional CFD algorithm is used to determine macroscopic system parameters such as pressure and temperature. The popular SIMPLER algorithm is employed for the CFD treatment. The model is then employed to simulate a pool boiling process. The computational results show that the CAS model can reproduce most of the basic features of boiling and capture the fundamental characteristics of boiling phenomena. The heat transfer coefficient predicted by the CAS model is in excellent agreement with the experimental data and existing empirical correlations.     

池式高通量研究堆气载放射性流出物的释放量计算

本文给出了池式高通量研究堆正常运行工况下气载放射性流出物向环境释放的三种主要途径及相应的计算方法，它们是：（１）堆芯水池上方气空间中放射性核素的通风排放，（２）重水系统的泄漏排放，（３）实验孔道中被活化的空气及微尘的排放．对一座热功率为２０ＭＷ的池式高通量研究堆，经计算得到每年向环境的释放量很小，主要核素为４１Ａｒ，年释放量约８×１０１２Ｂｑ；其次是氚，年释放量约２×１０１１Ｂｑ．     

基于B/S/S架构的高校教务管理系统的应用与研究

文章的研究来源于广西某师范成教学院的教务管理系统,针对成教学院的教务管理工作强度高、效率低等特点,系统采用B/S/S架构,运用了分页、数据库连接池、内存缓存等技术,开发的教务管理系统满足了用户的需求,具有很大的实用性和推广性.