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51.
根据有限元计算原理,结合山西临汾地区浍河水库泄洪洞,对土坝下的大型软基涵洞分层填土施工过程和蓄水对结构的影响进行了模拟计算,得到了更贴近实际的涵洞结构内力和涵洞土压力分布规律,并根据实际地基条件及现有涵洞的两种常见的结构形态对涵洞结构形式进行了优化,其成果已用于设计和施工,证明了该研究方法的科学性和结论的正确性。 相似文献
52.
Trevor Davies Roger Elmer 《International Journal of Technology and Design Education》2001,11(2):163-180
The paper introduces the highly problematic nature of modelling in design and technology education and examines the relationship
between cognitive and concrete modelling. Its aim is to gain insight into what learners do, rather than what others say they
ought to do in their learning activities. The variety of purposes that educators have for learners’ modelling are discussed
through examining the contested curriculum justification for design and technology education itself. The paper proposes that
learners’ modelling cannot be extracted from the social milieu in which they act and it provides some insights of these social
influences through the analysis of two case studies. Their settings are a girls’ secondary school and a college of higher
education. Each case study is presented independently but organised with a common format to consider a) the impact of assessment
on learning intentions and outcomes; b) cultural influences on learning and modelling; c) social influences on learning and
modelling. A discussion of the emergent themes considers implications for teachers.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
53.
宜昌水文站是葛洲坝、三峡水利枢纽的设计依据站。葛洲坝水利枢纽动工修建和运行 ,对该站水位流量关系中低水部分产生了影响。探讨了该河段泄流能力的变化对葛洲坝水利枢纽设计洪水有无影响的问题。用1 967~ 1 999年实测资料对宜昌站以汛期平均水位为参数的水位流量关系曲线簇进行了检验 ,大部分年份最大日平均流量、3、7、1 5、30d洪量的偏差在± 4 %之间 ,说明曲线簇推流具有相当的精度。证明了宜昌河段中低水泄流能力的变化对葛洲坝水利枢纽设计流量和校核流量基本没有影响 相似文献
54.
55.
本文通过最近所作的两个离心模型试验,进一步探讨了用离心机作静力结构模型试验的有关问题,试验结果进一步证明用离心机作静力结构模型试验,无论在理论上和试验技术上都是可行的,最后将有关问题作了进一步的讨论。 相似文献
56.
In this paper we illustrate how certain design problems can be simplified by reparametrization of the response function. This alternative viewpoint provides further insights than the more traditional approaches, like minimax, Bayesian or sequential techniques. It will also improve a practitioner’s understanding of more general situations and their “classical” treatment. 相似文献
57.
58.
Strategic management research has been characterized as placing less emphasis on construct measurement than other management subfields. In this work, we document the state of the art of measurement in strategic management research, and discuss the implications for interpreting the results of research in this field. To assess the breadth of measurement issues in the discipline, we conducted a content analysis of empirical strategic management articles published in leading journals in the period of 1998–2000. We found that few studies discuss reliability and validity issues, and empirical research in the field commonly relies on single‐indicator measures. Additionally, studies rarely address the problems of attenuation due to measurement error. We close with a discussion of the implications for future research and for interpreting prior work in strategic management. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
59.
结合建设项目进度及质量控制理论,从施工方案、进度计划、施工组织及劳动力计划、材料及施工设备、质量保证及安全生产等方面论述了大坝安全监测自动化系统工程的施工组织设计,对提高系统的可靠性、缩短工期、节约投资具有一定的现实意义. 相似文献
60.
William Jack 《Economics of Transition》2002,10(3):619-635
As part of the reforms of their systems for financing and delivering health care, many transition economies, particularly in central and eastern Europe, have adopted national insurance funds that are institutionally separate from ministries of health. Most of these countries have also grappled with the problem of restructuring the delivery system, especially the need to reduce hospital capacity. Although improving the performance of medical care providers through a shift from passive budgeting to explicitly incentive mechanisms is important, why this change in financial relations between the government and providers could not be implemented simply by reforming the role of health ministries is not obvious. This paper presents an explicit rationale for the separation of powers between the regulator (the ministry of health) and the financing body (the insurance fund), based on the inability of a single agency to commit to closing hospitals. JEL classification: L51, P20, P35, I18. 相似文献