微机辅助设计加热炉炉衬

本文从技术经济学的角度出发,分析了加热炉炉衬的最优设计问题,建立了数学模型,并给出了计算机运算程序框图。     

Can a Shorter Workweek Induce Higher Employment? Mandatory Reductions in the Workweek and Employment Subsidies

This paper presents a unified model of the impact on employment of a mandatory reduction in work hours in combination with an employment subsidy to reduce quasi-fixed costs of employment, while attempting to maintain worker's take-home pay or welfare level. Achieving the dual policy objectives of enhancing employment and maintaining worker income is not necessarily feasible. Nevertheless, a reduction in the legal workweek may induce a degree of downward wage flexibility, while an employment subsidy to firms accommodates downward wage rigidity. It may be possible, therefore, to increase employment with a policy that combines a reduction in the workweek with an employment subsidy. In general, however, the long run employment outcome is ambiguous, and a decline in output cannot be ruled out. More direct policy measures whose impact can be assessed with greater certainty—in particular, removing structural rigidities in the labor market—should be given priority to decrease long term unemployment.     

CAXA电子图板的特点及功能分析

结合多年使用 CAXA电子图板的经验 ,重点对该软件的功能、特点进行了分析和总结 ,并与软件 Auto CAD的功能进行了比较     

Realising the Potential – and Lost Opportunities – for Peer Collaboration in D&T Setting

This paper follows up our theoretical discussion of the potential for collaborative problem solving in Design and Technology (Hennessy and Murphy, 1999). In this paper we report our empirical investigation of peer collaboration in a setting where we identified the presence of significant pre-conditions for productive collaboration. The study investigated the participation of two boys aged 13 who worked together with their teacher over 8 weeks in designing and making an aid for a child with a disability. We analysed their participation using a framework of key features derived from the research literature. Our analyses yielded evidence of effective collaboration in the early design stage, but the students' collaboration and their progress were subsequently undermined. The reasons related to the students' ability to collaborate and the tension for the teacher between students' learning needs and client needs within an authentic activity. The outcome was a successful product but a wealth of lost opportunities – and lack of support – for the students' collaborative problem solving and Design and Technology (D&T) learning. Our observations confirm that despite little evidence of collaboration in D&T, this setting offers extensive resources for supporting collaboration in joint design, planning and problem-solving activities. We also identify impediments to collaboration as a learning mechanism. This revised version was published online in July 2006 with corrections to the Cover Date.     

固液两相流离心泵磨损机理和叶轮的设计

本文研究了固液两相流离心泵磨损机理，指出离心泵内叶轮出口附近的射流 尾流结构是离心泵内的局部磨损的重要原因。理论分析、试验结果及工业应用表明：采用小叶片出口角β2、少叶片数Z和大出口宽度b2的叶轮能减轻泵的磨损。     

管理信息系统中在线帮助子系统设计

在线帮助是数据库管理系统的重要组成部分。本文以 Foxpro2.0为基础讨论了面向应用的在线帮助子系统的几种设计方法。     

水轮机导叶双列叶栅的水力优化

以水力损失为目标函数，对固定导叶，活动导叶叶型及周向相对位置进行了优化，计算结果表明：与常规方法相比，本文方法用于水轮机导叶双列叶栅的水力设计能提高其水力效率。     

农产品自主品牌塑造探究

本文采用SWOT分析法进行农产品分析,从美学体验、象征性体验及情感体验来解析品牌表现的多种可行性,对农产品资源的特点进行品牌设计体验特征解析,从而得到从生态特点、旅游产业、历史文化中塑造自主品牌的途径。     

彭水水电站勘测设计过程及主要技术问题研究

彭水水电站的勘测设计与科研工作始于上世纪70年代初,30多年来,针对坝址地形、地质条件及水文特性,对枢纽布置、坝型及泄水建筑物、电站主厂房轴线、尾水洞体型和通航建筑物型式等主要技术问题开展了多方案研究,确定了长溪坝址及河床泄洪、右岸地下厂房、左岸通航建筑物的枢纽布置格局,以及大坝采用碾压混凝土弧形重力坝、主厂房采用与岩层走向呈0°角布置、电站尾水采用变顶高隧洞、通航建筑物采用船闸加升船机的建筑物型式方案.这些研究较好地解决了彭水水电站设计中的主要技术问题.     

我国出口产业结构优化问题探讨

我国在外贸上长期处于顺差,但外贸增长主要还是依靠数量上的扩张,出口产业结构普遍存在着档次低、区域雷同化现象严重等问题。本文在对我国出口产业结构现状进行分析的基础上,结合出口产业结构发展规律,提出了我国出口产业结构优化的原则,并提出了相关对策建议。