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951.
地铁列车振动对精密仪器和设备的影响及减振措施 总被引:2,自引:1,他引:2
轨道交通对环境产生的振动问题已引起人们的重视,但是关于对精密仪器造成影响的研究成果非常少。随着城市轨道交通的快速发展和地面机构的修建,便捷的轨道交通与精密仪器的使用将形成无法回避的矛盾。因此,关于振动对精密仪器、设备影响的研究具有重要的现实意义和科研价值。为此,笔者探讨地铁振动对精密仪器和设备影响的表现,详细介绍仪器和设备允许振动的含义及影响因素等,建议采用综合减振措施,并提出综合治理及减振措施设计原则,为减振措施的选取和设计提供了参考,同时还指出了该领域中还需进一步研究的几个问题。 相似文献
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Nageshwar Rao Bhaskar Elbert E. Whitlatch 《Journal of the American Water Resources Association》1980,16(4):587-593
ABSTRACT: The HEC-4 monthly stream flow simulation model, developed by the Hydrologic Engineering Center, Davis, California, is used to extend the available historical stream flow records in the Central Ohio area. The principal objective of this paper is to examine the effectiveness of the HEC-4 model in generating synthetic monthly flows. Important statistical parameters are evaluated in order to relate the statistical properties of the historical and generated flows. In doing so, it is observed that the mean, standard deviation, and skewness of the generated flows are consistently larger than the corresponding estimates based on historical flows. However, results show that these statistics, as well as the lag-1 serial correlation, are generally well maintained by the generated sequences. The degree to which any statistical dissimilarities would be critical, from an engineering design point of view, is demonstrated by utilizing their low flow characteristics. Estimates of reservoir safe-yields, based on a nonsequential mass-curve analysis of the historical and generated low flows, indicate a nominal difference in this particular study. 相似文献
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John W. Labadie John M. Shafer Robert Aukerman 《Journal of the American Water Resources Association》1980,16(3):477-485
ABSTRACT: There is considerable misconception about the dangers of opening to a recreating public in great need of additional open areas. A systematic procedure for identifying the factors essential to the selectio, planning, and management of reservoirs for recreation is described. A detailed case study conducted by an interdisciplinary project team is presented to demonstrate the feasibility fo maintaining storage levels in recreation-conductive high country reseroirs without unduly injuring downstram water users. The idea is to trade water with reservoirs having less recreation potential. The optimal means of doing this is found via a river basin simulation model with quasi-optimizing capability. Results of the case study show that this strategy is indeed feasible. Applicable to other areas may require analysis of tradeoffs if at least some damage to downstream users is unavoidable. 相似文献
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M. A. Collins 《Journal of the American Water Resources Association》1977,13(1):57-70
ABSTRACT: A deterministic dynamic programming optimization model with a refining sectioning search procedure is developed and implemented to find least cost withdrawal and release patterns for water supple from a multiple reservoir system serving a metropolitan area. Applications are made to teh four reservoir system operated by the city of Dallas, Texas. A realistic cost structure, including nonlinear power consumption, block rate unit power costs, and flow dependent power consumption for intracity water distribution, is utilized. Applications are made to find least cost operating patterns and, as well, by inclusion of a water loss penalty function, supply patterns which will reduce evaporation water losses for the Dallas system. 相似文献
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因油漆属易燃易爆物品 ,在涂饰作业中有较多的危险危害因素。本文从防火、防毒两个方面对涂饰施工提出了注意事项 ,并对涂饰作业环境提出了具体要求。 相似文献
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