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1.
水锤涌浪联合试验的变态模型相似律 总被引:1,自引:0,他引:1
该文详细推导了在同一个物理模型中同时模拟调压室涌浪和压力钢管中的水锤时应满足的变态模型相似律,结果应用于电站模型试验中。 相似文献
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Zhang Sheng-ming Yangtze River Scientific Research Institute Wuhan Hubei P. R. China 《水动力学研究与进展(B辑)》1992,(2)
Through a series of model tests of five scales for 2-D free hydraulic jump, the da-ta of fluctuating pressure acting on the floor level within the hydraulic jump were obtained. Dur-ing the experiments, Froude number varied from 2.94 to 8.61, and Reynolds number rangedfrom 2×10~4 to 6×10~5. Experiment results indicate that the amplitude scale of fluctuating pres-sure is the length scale of model, i. e. P'=L, which agrees with gravity similarity law: Thefrequency scale of the fluctuating pressure is a unity i. e., f=1, which does not satisfy thegravity similarity law. 相似文献
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闫建勍 《山西财经大学学报》2005,27(4):43-46
中国与东盟建立了“10+1”自由贸易区,近期内由于产业结构相似度高,会对自由贸易区内各国的经济造成一定的影响,尤其是会加大中国对东盟的贸易逆差。但从长期来看,双方相似的产业结构形成了共享的劳动力市场,贸易区内劳动力的国际流动,会促进贸易区内各国经济的发展。 相似文献
5.
消化吸收是我国技术引进后实现良性循环的重要环节,但目前一直存在效果不佳的问题。为了充分发挥技术引进的后发优势,通过应用相似系统理论,从我国青少年成长过程期间可能遇到的问题及预防措施来类比我国技术引进消化吸收工作中存在的不足,并给出相应的建议措施。 相似文献
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本文是我国半个多世纪来火,核电厂冷却水运动模型试验研究的一个简要历史回顾。在整体分析水力热力模拟难点和解决途径的基础上,对此领域中常遇见的比较复杂的物理模拟问题所做的一些理论探索、工程模型实践和原体检验作了概括性阐述,包括分别含有风吹、冰冻、波浪、喷气防沙等环境效应的冷却水运动模拟。介绍重点放在实现这种复杂模拟的指导思想和具体措施上,伴以工程实际应用实例说明。 相似文献
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Travel mobility has attracted considerable attention from tourism scholars. Studies have extensively discussed discovering key (i.e., collective) movement patterns. Recently, the advancement of information technology has allowed tourism researchers to obtain detailed information regarding travel digital footprints. This study, which analyzes mobile sensor big data, proposes a data mining approach to measure the similarity of travel trajectories by performing a pair comparison of individual trajectory. This method considers the spatial and temporal dimensions of travel flow to help identify trajectory similarity across individual travelers. Considering graph theory, this research also applies graph-based spatiotemporal analytics to identify important insights from complex travel mobility networks. As a result, this study suggests an innovative approach to assess travel trajectory similarity, which can be regarded as a type of data-driven clustering method. This paper also demonstrates the applicability of network science in travel mobility. 相似文献
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Traditional internationalization models suggest multinational companies (MNCs) can exploit their accumulative experience to facilitate their sequential entries. However, experience may depreciate over time. Thus, obtaining benefits from prior experience for MNCs is based on two critical premises, i.e., interpreting and applying experience correctly. We argue that there is a need to study the newness dimension of experiential learning. In doing so, we aim to explore to what extent the newness of experience matters in overseas sequential entries for MNCs. Moreover, we expect that the benefits from recent experience in guiding sequential entries are contingent on the extent of context similarity between the most recent entry location and sequential entry location and the outcome expectancy of focal entry. With a sample of 112 Chinese listed firms and 410 observations during the period of 2000–2012, we find that else being equal, the newness of experience of MNCs is positively associated with sequential entry and such a relationship is positively moderated both by context similarity in institutional environment and the outcome expectancy of the focal entry. We also compare the effects of the newness of different types of experience and find that the newness of the most recent experience has a larger influence on sequential entry than location-specific experience and general experience. 相似文献
10.
Most small-scale social economies are characterised by their deficiency, lack, and/or difficulty in matching natural data. Against this backdrop, this paper builds a relatively uniform theoretical framework and designs a more economical and objective method for demarcating ecological conservation redlines (ECR) based on sensitivity assessment of ecosystem services. The results show that the sensitivity assessment model designed in this study can identify sensitive zones effectively, and that the ECR in Hubei Province are well within the sensitive zones so identified. The delimited areas based on the sensitive assessment of ecosystem services have great similarities (95%) with the actual ECR areas in Hubei Province. The most ecologically important functional zones (EIFZ) can also be identified using the regional ecological sensitivity coefficient. When the threshold of EIFZ is set higher, the probability that it falls within the ecologically sensitive areas is greater and the ECR delimited by the method proposed in this study will be more reliable. Theoretically, the delimitation of ECR can be inserted at any evaluation level with a grid resolution higher than that of the land use data, which can be used as a supplement to the ECR delimitation method in ecology or geography. 相似文献