基于CFD的电子主板模块散热模拟

针对一种机柜内部主板模块的散热系统进行CFD散热模拟,采用Flotherm软件进行散热系统的仿真并对比实验进行分析,结果表明基于Flotherm软件平台对主板散热系统进行散热模拟的结果与实验比较接近,而且可以更直观地得到实验所不能详细测得的速度场和温度场,散热模型的正确建立能指导散热结构的后续优化设计。     

大功率半导体组件的散热系统设计

文章介绍了一种在工程中比较实用的大功率半导体组件的系统设计计算方法,利用散热系统热阻等效电路求出散热器热阻,进而设计出符合高电压、大电流的水风冷却、水电隔离的散热冷却系统,最后通过ANSYS对该散热系统进行了散热仿真及试验验证,为处于封闭空间的高电压、大电流变流器提供可借鉴的散热系统解决方案。     

隧道通风设计排烟口形状研究

针对排烟风道的排烟口断面的特殊性,有必要对其结构形式进行研究,以确定合适的结构形式,从而减少排烟风道的沿程压力损失。文章依托国内某沉管隧道,运用数值模拟软件AnsysFluent对排烟风道的沿程阻力进行计算,以期在不影响总体结构安全的情况下,对排烟口的形状进行适当的优化,从而提高排烟通道的排烟效率。     

浅析风冷散热对器件散热的应用

随着工业产品的快速发展,产品的散热显得尤为重要。文章选择风冷散热器来进行研究,简单阐明了散热设计中的散热计算、散热器选择、风冷散热计算和风扇选择等步骤,完成简单的风冷散热器设计。     

某户外机柜散热过滤风扇设计

户外机柜由于其封闭的运行环境、阳光辐射及内部设备耗散的热量,会使机柜内部设备长时间处于超负荷高温运行状态,导致装置故障,进而影响系统稳定性。因此合理的散热方案对户外机柜是至关重要的,文中对比了过滤风扇、热交换器、空调散热各自优缺点及适用场合,发现过滤风扇为最经济可行的散热途径。并针对某智能变电站户外机柜进行了散热过滤风扇方案设计及散热过滤风扇所需流量的理论计算,最后以浙江金华变电站运行产品实测数据为例,验证了该理论计算方法是可行的、正确的。     

散热功能通信机柜的研究

随着电力电子技术和通信技术的飞速发展,用户对通信机柜的散热功能也提出了更高的要求。由于散热功能和机柜设计结构密不可分,所以在通信机柜设计前就需要根据用户需求确定散热方式。本文从通信机柜的如何散热的原理出发,就目前企业常用的通信机柜通风散热方式进行了介绍与分析,提出了各种散热功能的选取原则与本案的设计要点。     

基于CFD分析与实车测试结果相结合的汽车空调风道设计

汽车空调风道是整车空调系统的组成部件之一,其送风性能的好坏直接影响乘客驾车的舒适性。为了提高风道送风性能,文章从影响风道系统的设计要素分析空调风道设计的具体要求和方法,并基于某车型空调风道设计结构的CFD模拟仿真分析结果及实车测试结果优化前后的流场特性结合验证,结果表明正确计算风道截面积及风向线,有助于降低空调风道空气阻力,提高风道送风性能,该方法对今后汽车空调风道系统设计具有一定的参考价值。     

电器散热罩

电器的散热与防尘是一对矛盾,为解决这个问题,我设计了一种新型的电器散热罩。     

基于计算流体力学的汽车制动盘散热特性研究

文章基于计算流体力学的方法,数值模拟了气流在车轮拱轮中的运动轨迹,分析了导流通道对制动盘散热特性的影响,结果表明:开设导流通道可在保持风阻系数基本不变的情况下,增强制动盘的散热效果。     

LED路灯散热结构分析研究

伴随着经济的发展,LED照明技术也逐步得到完善,大功率LED灯具的功能逐步完善,现在更有把握使城市路灯照明系统变得更加高效节能。目前,LED路灯,尤其是大功率LED路灯在照明系统设备中已经得到了人们广泛认可,有逐渐取代传统的路灯市场的倾向。大功率LED路灯缺陷为灯具内部的能量并不是全部都用于发光,很大一部分能量作为热能造成LED灯具内部温度上升。在大功率LED灯具内部温度过高时,灯具中能量用于发光的效率就会减小,同时灯具内过高的温度会对灯具造成寿命减短,这也对LED灯具的进一步发展造成了严重的阻碍。所以,为了能够让大功率LED灯具更好的发展,首先要着手解决LED的散热问题。文章首先研究了LED路灯散热问题对灯具寿命的影响,然后具体探讨了灯具结构对散热的影响,最后分别从光源的散热和灯具的结构两方面对LED路灯进行了散热设计,成功解决了大功率LED路灯的散热问题。     

Development in Information and Communications Technology (ICT) Statistics at the Australian Bureau of Statistics

This paper outlines the ICT statistical developments that the ABS has undertaken over recent years. These developments have been on both the supply side (ICT industry) and the demand side (use of IT by sector). The content of ABS ICT surveys has changed significantly over the last few years and are expected to develop further in line with industry changes and emerging policy needs.
Recent developments in household collections have been the inclusion of IT use questions in the 2001 Census of Population and Housing and in various ABS social surveys such as Children's Participation in Culture and Leisure Activities. Annual business IT use surveys are now conducted and include topics such as Internet commerce and IT security. Biennial ICT industry surveys are conducted to provide data on ICT production, imports and exports, ICT industry employment, performance and structure information. An Internet activity survey is run every six months and provides regional Internet access details and infrastructure details on Internet service providers.
A major development for 2002–03 will be the compilation of an ICT satellite account. ABS intends to produce an ICT Information Development Plan to guide its future statistical development work in the ICT field.     

Value at Risk in the Suburbs: Eminent Domain and the Geographical Politics of the US Foreclosure Crisis

Several US counties and local governments have recently considered a novel solution to the foreclosure crisis. They plan to use eminent domain to compel the owners of mortgage debt—and specifically of private‐label mortgage‐backed securities—to sell the debt to the government at a price reflecting the loan's market value. The government would then restructure the debt and resell it to new investors. The plans are striking because—in contrast to both development‐driven eminent domain and the federal subprime bank bailout—they would force investors to assume asset devaluation and increased long‐term risk. Notably, the plans have emerged as an instance of financialization‐focused politics in suburbs and suburban cities of color, specifically majority‐black and ‐Latino/a suburbs. Local support for the plans, we argue, is rooted in the long‐term disinvestment of these ‘suburbs of exception', which became targets of subprime lending and eventually sites where the ‘financial exception' has been localized. But these demographic shifts, fragmentation and fiscal pressures have at the same time created a suburban political terrain in which the plans have gained their strongest political support.     

Towards a Theory of Serendipity: A Systematic Review and Conceptualization

Serendipity – the notion of making surprising and valuable discoveries – plays a major role in the success of individuals and organizations alike. Previous research has established the importance of serendipity and identified important individual- and organizational-level antecedents. However, the literature has been dispersed and the boundaries of the concept have been blurry, leading to a lack of conceptual clarity and structure, and thus limiting validity and managerial actionability. Based on a systematic literature review, I synthesize existing management-related research on serendipity and explicate the emergence and composition of serendipity in the organizational context. I first identify three necessary conditions that differentiate serendipity from related concepts such as luck or targeted innovation: agency, surprise, and value. Then, I draw from the literature on sensemaking, event-based theorizing, and quantum-based approaches to management to conceptualize the process of cultivating serendipity in the organizational context as a process of enabling potentiality and materialization, and develop a multi-level theory of (cultivating) serendipity. This conceptualization contributes to our collective understanding of how, why, and when (i.e., under what conditions) organizations can leverage the value in the unexpected, which opens up fruitful avenues for further research.     

Accountability of NGOs in Bangladesh A critical overview

NGOs in Bangladesh have been recognized as effective change agents in the socio-economic arena throughout the world. Their contributions in micro credit, non-formal education and primary health care are widely known. NGOs play a significant role in society. NGO accountability, as a result, has become a critical issue. NGO accountability in Bangladesh has been examined here in relation to patrons, clients and themselves. Of the three relationships only accountability to patrons is in a near satisfactory state. Accountability to clients is handicapped by lack of opportunities of beneficiaries to participate meaningfully in NGO policy making. Accountability to themselves is adversely affected due to the adherence to a strictly hierarchical system and the influence of founding and charismatic NGO leaders.     

Towards an Asian model of human resource management? A comparative analysis of China,Japan and South Korea

There has been much discussion regarding the possible decline and weakening of national systems of human resource management (HRM). Yet, culture and institutions are often cited as the major stumbling blocks to this outcome. Such constraints may dissipate in the analysis, particularly if ‘regional clusters’ are considered where geographic and cultural closeness and ‘openness’ to similar economic pressures exist. In such cases, it might be postulated that convergence in HRM will occur. We argue that China, Japan and South Korea represent such a cluster. This article examines these countries, to see if a degree of convergence is taking place and if it is towards an identifiable ‘Asian’ model of HRM. A model of change is presented that distinguishes between levels of occurrence and acceptance. Details of the development and practice of HRM in each country are then set out. The article ends with a discussion and implications section and a brief conclusion.     

Ansätze und Ergebnisse anglo-amerikanischer M&A-Forschung

Based on a review of established U.S. management journals (1995–2003), six schools of thought are identified within the Anglo-American M&;A research: “Capital Market”, “Principal/Agent”, “Industrial Organization”, “Organizational Behavior”, “Human Resources” and “Strategic Management”. The literature review shows that the definition of M&;A success, the methods applied, and insights from empirical research differ according to the respective school of thought. Empirical studies focus on the resource combinations of merger partners, the specific circumstances of merger negotiations, and on integration management as antecedents of merger performance. Unfortunately, empirical findings have not yet provided reliable explanations for M&;A success. Based on the current state of Anglo-American M&;A research, the authors discuss implications for business practice, identify research gaps, and propose areas for future research.     

Introduction of New Technology with a Sound Transition of the Input-Output Structure

We examine the general equilibrium repercussions associated with the introduction of new technologies, using the generalized Leontief system that allows technological substitutions. We show that an untested introduction of cost-increasing technologies in any industry may result in creating a non-productive technological structure that does not satisfy the Hawkins-Simon condition, following the autonomous dynamic adjustment process with structural transitions in the economic system. Therefore, we propose a practicable control scheme of introducing cost-increasing technologies that strictly avoids the creation of non-productive structures in all periods of structural transition, using the available information on the ex ante technological structure.     

The Creation of the Office for National Statistics

A new Office for National Statistics was created in the United Kingdom in 1996 following a series of developments designed to strengthen the relevance and integrity of statistics. This paper describes these fundamental changes and sets out a blueprint for future progress. It also sets current developments in the United Kingdom in an historical and international context.     

What helps? Women engineers' accounts of staying on

We have considerable understanding of the obstacles that women engineers encounter and the reasons that they leave the field, but we know less about what enables them to remain. Adopting an interpretivist approach, this article examines how a group of British women engineers in two FTSE 100 companies account for “staying on” in their male‐dominated work settings. We delineate four specific forms of help that facilitate women's retention in the field. We argue that exposure to help leads to women developing a habitus that enables them to continue working in engineering. To conclude, we draw on our findings to outline HR practices that will facilitate supportive relationships in the workplace and pave the way towards developing more positive organisational climates.     

论现代物流企业的发展观

物流业经过诸多年的发展目前已经成为最热门的行业之一,物流企业的注册数量也与日俱增,达到前所未有的规模。毋庸置疑,任何企业都希望自己迅速做强做大,并成为真正现代物流企业的典型代表,要实现这一目标一个首要问题就是要解决现代物流企业的发展观问题。