大型散热设备安装工艺探索——超临界间接空冷“三塔合一”大型散热设备安装工艺

本文介绍在干旱地区建设的超临界间接空冷"三塔合一"大型散热设备的安装工艺,此工艺不仅提高散热设备吊装效率和安装质量而且缩短安装工期,达到降本增效的目的。     

胶东半岛国际航空货运物流系统分析

随着全球经济的逐渐恢复,航空物流市场越来越受到人们的关注,尤其是发展最快的亚太市场,而中国成为世界航空货运最具发展潜力的市场。本文将对胶东半岛国际航空货运物流系统发展进行分析。     

西南地区环境空气质量影响因素研究

环境问题是目前国内外关注的热点问题,我国经济的粗放型增长对环境已造成一定损坏。西南地区近年经济增长迅速,保护环境甚至提高环境质量势在必行,因此本文以西南地区的空气质量为研究对象,根据现有统计数据资料,对西南地区的空气质量影响因素作统计分析。     

防空导弹垂直发射技术的现状及趋势

本文介绍了防空导弹发射技术的现状,垂直发射技术的特点、发射方式和关键技术,国外采用垂直发射技术的几种防空导弹型号以及垂直发射技术的发展趋势。     

汽车空调风道出风情况的CFD分析与优化

文章建立了某车型汽车空调风道结构的三维数学模型,利用商业软件Fluent进行模拟,得到了风道出风口风量大小和风量的分配情况,并与设计值进行了比较;在此基础上,分析了风道出口扫风情况,提出了解决方案,对改进和优化风道结构,提高汽车空调整体性能具有一定的参考价值。     

对于空调系统节能技术的几点思考

随着国民经济的发展,民用、公用及商用建筑中空调的普及,带来了一个严重的能量消耗问题。本文从围护结构、空调的冷热源、空调机组及末端设备、空调水系统及空调新能源几个方面提出了一些节能措施和方法。     

Optimal route decision with a geometric ground-airborne hybrid model under weather uncertainty

Adverse weather is the dominant cause of delays in the National Airspace System (NAS). Since the future weather condition is only predictable with a certain degree of accuracy, managing traffic in the weather-affected airspace is a challenging task. In this paper, we propose a geometric model to generate an optimal combination of ground delay and route choice to hedge against weather risk. The geometric recourse model (GRM) is a strategic Probabilistic Air Traffic Management (PATM) model that generates optimal route choice, incorporating route hedging and en-route recourse to respond to weather change: hedged routes are routes other than the nominal or the detour one, and recourse occurs when the weather restricted airspace becomes flyable and aircraft are re-routed to fly direct to the destination. Among several variations of the GRM, we focus on the hybrid Dual Recourse Model (DRM), which allows ground delay as well as route hedging and recourses, when the weather clearance time follows a uniform distribution. The formulation of the hybrid DRM involves two decision variables - ground delay and route choice - and four parameters: storm location, storm size, maximum storm duration time, and ground-airborne cost ratio. The objective function has two components: expected total ground delay cost and expected total airborne cost. We propose a solution algorithm that guarantees to find the global optimum of the hybrid-DRM. Based on the numerical analysis, we find that ground-holding is effective only when combined with the nominal route. Otherwise, it is optimal to fly on the route determined by the DRM without ground delay. We also find the formula of the threshold ground-airborne cost ratio, which we call the Critical Cost Ratio (CCR), that determines the efficacy of ground delay: the higher the CCR, the more effective the strategies involving ground delay. We conclude that both ground delay and route hedging should be considered together to produce the best ATM decisions.     

道夫墙板钻孔工装的设计

道夫墙板是梳棉机道夫部件的重要组成部分,属于梳棉机主关键件,其质量好坏对梳棉机整机质量影响较大。文章设计了专用工装进行外圆丝孔加工,分度准确,质量达到了设计要求,而且定位迅速,大大提高了生产效率,解决了生产瓶颈问题。     

地下人防工程结构内力计算的特点

简要介绍了人防结构的设计特点,分析了关于等效静荷载的设计概念,并探讨几种人防结构构件上的荷载取值方法。     

THE INTERNALISATION OF ENVIRONMENTAL EXTERNALITIES AFFECTING DWELLINGS: A REVIEW OF COURT CASES IN HONG KONG

In 1960, Ronald Coase suggested that there are many methods to solve the problem of externalities apart from imposing Pigovian taxes. Internalisation is one of those noted in his classic paper, ‘The Problem of Social Cost’. This paper studies the possibility of residents receiving compensation from pollutant generators. Data collected from Hong Kong law reports over the past 20 years show that there is forty‐fold increase in number of water seepage court cases since the first case in 1994. The total amount of compensation has also increased greatly. There are, however, far fewer court cases where residents seek compensation from generators of noise and air pollution. This may reflect a combination of high transaction costs and low expected benefits from such cases.