Theoretical and experimental research on heat transfer performance of the semi-open heat pipe

This paper focuses on the heat transfer performance of semi-open heat pipe which is a new type of heat pipe. After analyzing its condensation heat transfer mechanisms theoretically, several semi-open heat pipes in different length ratios and upper hole diameters are studied experimentally and compared with the same dimensions closed heat pipes. Experimental results show that the heat transfer performance of semi-open heat pipe becomes better by increasing heat transfer rate. At the first transitional point, the heat transfer performance of semi-open heat pipe approaches the level of the closed heat pipe. It is suitable to choose upper small hole about 1 mm in diameter and length ratio larger than 0.6 for the semi-open heat pipe.     

高危早产儿发生PICC堵管的相关影响因素和临床护理对策

目的分析高危早产儿发生PICC堵管的原因及临床护理对策。方法选取2018年1月~2019年12月我院收治的采取PICC置管的高危早产儿164例,对其PICC堵管发生情况以及原因进行分析,并且找出针对性的临床护理对策。结果高危早产儿发生PICC堵管的原因包括新生儿血管因素、输液护理因素、药物因素以及导管使用与管理因素。结论导致高危早产儿PICC堵管的原因多种多样,临床上要及时采取针对性的临床护理措施进行应对,确保置管安全。     

用最小二乘法估算给水管道造价公式中的参数

将单位管线建造费用公式转化为线性形式,先假设a为已知,根据最小二乘法原理进行线性回归从而确定b,α的值。问题的关键便转化为对a值的确定,通过对回归方程相关指数R的分析,运用消去法找出最优的a值。根据所建的数学模型编写C＋＋程序,并通过算例证明能够准确,快捷的计算,得出较为满意的参数值。     

NT Server系统安装及维护辨析

分析了在不同系统环境和应用需求条件下，WindowsNT网络操作系统的安装及系统维护方案，以NT4．0为核心提出在多种应用条件下的实用安装解决方案。     

Flash电影在PowerPoint中的应用

PowerPoint2000是教师制作课件最常见的软件之一。Flash电影在PowerPoint中得到了广泛的应用，本文着重介绍了FlashActiveX控件的安装步骤，以及在其安装后，Flash电影在PowerPoint中如何进行嵌入操作。     

PRESSURE DROP IN THE VERTICAL PNEUMATIC PIPE FOR POWDER CONVEYING

Based on the former research work of the authors,the resistance of differentsolid particle suspension flow in a vertical pipe is analysed,and investigatedexperimentally.The applicable formulas of pressure drop are presented.Two types of par-ticles,talcum powder and glass beads,are convcyed in the test which has been carried outat various air vclocities of 10 to 28 m/s and at the ratio of solids-air mass flow rateranged from 0 to 2.The experimental results show a good agreement with the calculatedones.     

MTS试验机的安装

对MTS试验机的几种安装方案进行了讨论,确定借助试验大厅墙壁的支承,利用杠杆原理将试验机立起并安装到位的方案。结果显示,该方案原理清晰、安全、简单易行。     

压力流雨水排水系统在实际工程中的应用

结合春兰电子商务有限公司物流配送中心厂房，对重力流和压力流雨水排水系统在工程中的应用进行分析比较。介绍了适用于大屋面雨水排放的压力流雨水排水系统中雨水斗和管道的安装方法。     

构筑安全的网络系统

本文简要地分析了构筑安全的网络系统应注意的几个方面:网络配置、防火墙、防病毒、口令设置、存取控制、数据备份、第三方评估等安全措施,为网络系统的安全保障提供技术上参考。     

Low frequency oscillatory flow in a rotating curved pipe

INTRODUCTIONThemotionoftheflowinarotatingcurvedpipeisafundamentalproblem ,whosesolutionhaspotentialapplicationsingasturbines ,elec tricgenerators ,electricmotorsandsomeequip mentsusedinseparationprocesses.Itisimpor tanttoknowtheflowstructurecharacteristic…