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11.
以3种典型热轧H型钢截面简支梁为研究对象,分别采用初等梁理论模型和考虑剪切变形及转动惯量影响的高等梁理论模型,分析在不同长细比情况下H型钢截面简支梁前3阶自由振动频率的差异,得出了初等梁理论进行H型钢梁自由振动分析的适用条件,该结论可供结构动力分析及动力设计参考。 相似文献
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Ridesharing has been attracting increasing attention from both academia and industry. One of the challenges posed by the study of ridesharing is to identify the most valuable information for improving the ridesharing decisions taken by participants. Another challenge is to use harvesting techniques to extract specific types of travel-related information. Many methods have been developed by the community in order to solve these issues. However, due to a lack of information sharing between different transit authorities and the difficulty of identifying subjective perceptions of the experience of ridesharing, understanding and evaluating how social media data might support or obstruct goals for mobility, safety and environmental sustainability in ridesharing is a difficult task. In this survey, we first analyze the literature on ridesharing with a focus on the properties and model of service, and introduce a framework to describe the major components required for a ridesharing service. Then, we illustrate the potential value of information extracted from social media and present the rationale for harvesting travel-related data. Finally, we detail some possible directions and different approaches for using social media data, and highlight their assets and drawbacks. 相似文献
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The paper aims at the problem of multi-targets threat degree being hard to be evaluated accurately in complex air defense battlefield environments. Combined with multi-sensors information fusion and interval-valued intuitionistic fuzzy sets (IVIFS) theories, the target priority determination is studied. The score and accuracy functions of IVIFS are improved with thinking about the hesitating information in order to increase the rationality. Then, the influence factors of target priority and the nonlinear relationship between the influence factors and target priority are analyzed. Next, the algorithms for calculating the factor weights and sensor weights are given. Based on the theory of IVIFS and technique for order preference by similarity to an ideal solution (TOPSIS), two methods of target priority determination based on the IVIFS and TOPSIS are proposed. At last, an application example verifies the effectiveness and flexibility of the proposed algorithms. 相似文献
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目前,传统的铁路专用线建设模式是铁路专用线自接轨站接轨,通过区间正线引入厂区的建设模式,这种模式的区间正线受地形条件、厂区位置和沿线规划影响较大,这些影响将不可避免地导致铁路专用线建设工程投资的增加,如能根据运输性质考虑缩短区间正线长度,在接轨站旁边设装车作业站,将大大减少专用线工程投资.以乾元公司铁路专用线建设模式为例来研究铁路专用线场站模式,就如何在接轨站旁边设装车作业站,实现接轨站设备与铁路专用线共用进行探讨. 相似文献
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1Extranet简介
Extranet是Internet的一种应用,是将Internet的构建技术应用于企业间的系统.它是企业与其客户和其他企业相连来完成其共同目标的交互式网络,通过向一些主要的贸易伙伴添加外部链接来扩充内联网,这些贸易伙伴不限于原有组织的成员,可超出组织之外,特别是包括那些想与之建立联系的供应商和客户.
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Wei X.Liu X.Duan Y.Feng J.Qiao N.Guo L. 《现代隧道技术》2018,(3):220-228
Water-sealed underground oil tank projects are quite different from traditional underground projects since the water-sealing conditions are very strict and the difficulties caused by the geological specificity, structural specificity and construction specificity are key factors affecting the project. In light of the significant early initial setting time and rapid temperature increase of sulphoaluminate cement-based grouting material for a large domestic water-sealed underground oil tank with pressurized cyclic grouting, a laboratory grouting simulation is conducted. It is found that the properties of the sulphoaluminate cement-based grouting material are quite different under different pressure cycles, the hydration exothermic peak time gets shorter with an increase of circulation time, the compressive strength decreases with an increase of circulation time, and the longer the circulation time the more obvious the de-crease of compressive strength. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献