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芈书贞 《河南水利与南水北调》2010,(2):71-72
文章简单介绍了混凝土材料的细观结构层次、性质及其初始细观裂纹产生原因。在对混凝土的损伤机理进行分析的同时,简单介绍了混凝土细观力学的方法及研究进展。最后对混凝土试件在简单受力情况下的变形与损伤的规律进行了描述。 相似文献
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徐文秀 《水利水运工程学报》2007,(1):70-73
简单介绍了弧形坡脚梯形渠道实用经济断面的计算式和计算方法.详细叙述了改进计算式的推导过程及计算方法.对改进计算式的验证结果表明,改进计算式的计算简单、可行. 相似文献
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近年来随着有限元法在工程上的广泛应用,ANSYS软件凭借建模简单、快速、方便的特点,成为了大型通用有限元软件的代表。文章对ANSYS软件作了简单的介绍,通过对水利大坝的简单分析来阐述ANSYS的分析过程。可以看出,ANSYS软件的确可以在水利工程中发挥有效作用。 相似文献
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简要地介绍了多种地下工程围岩稳定性分析方法,对它们进行了简单的讨论,分析了目前方法的不足和今后的发展趋势。 相似文献
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在对低压断路器结构和工作原理进行简单介绍后,对断路器合理选型与应用技术要点进行了探讨,尤其对断路器的通用选择原则和保护配合推荐系数进行了认真分析研究。 相似文献
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简单分析了新疆自然地理概况和区域水文地质特征,论述了新疆地下水资源及可开采量,并对地下水开采潜力做了分析。 相似文献
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Meteorological data gathered by buoys in Lake Erie and recorded at overland weather stations were used to test three different methods for determining overlake wind speed as a function of overland wind speed and the difference between overland air temperature and water temperature. The overall root mean square differences between estimated and observed overlake wind speed ranged from 2.02 to 2.11 m s?1. Overall correlation coefficients ranged from 0.63 to 0.69. These values are close to the best values possible for a simple statistical formula relating overlake wind speed to overland wind speed and air-water temperature difference. The conclusion is that statistical methods for determining overlake wind speed from overland wind speed have not improved markedly in over a decade and new methods are called for. It is also shown that for the Great Lakes, as opposed to the open sea, air-water temperature difference is a significant factor in determining overlake from overland wind speed. 相似文献
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John T. Beebe 《河流研究与利用》1996,12(1):63-79
To properly manage streams for fish habitat it is necessary to move beyond standard evaluations and the acceptance of relationships between variables that are derived either from rivers of much greater scale or those which are based on time-averaged conditions. Clearly, the relationship between moving fluid and channel boundary is the most important in smaller streams that are used as habitat by fish, as variations in speed patterns causing erosion or sedimentation of the bed will determine the success of spawning activity. To this end, an evaluation of fluid speed profiles is presented using field data collected from spawning streams in Ontario, Canada. The data have been subjected to an interpolation algorithm, minimum curvature, to deliver a more accurate view of fluid speed patterns. The results show that fluid speed patterns vary completely within the same cross-section under different flow regimes, even when the mean depth and mean speed of the flow are virtually unchanged, and that mean speed depiction of flow is inaccurate when considering particle transport/deposition. A comparison of data collection practices is presented which shows that flow measurement from the common 60% of the depth at mid-channel produces large errors in speed prediction on moving towards the bed and surface of the channel. Errors in the prediction of near-bed fluid speeds can result in the entrainment of particles within the preferred spawning range of salmonids, which was not predicted through the use of mean fluid speed for the cross-section or through the less intense data collection technique. The minimum curvature technique of data interpolation is shown to be an accurate method for visualizing fluid speed patterns. 相似文献
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水泵全性能曲线的计算机仿真 总被引:14,自引:0,他引:14
以可靠的实测水泵Suter全性能曲线为基础,利用矩形域正交多项式最小二乘曲面拟合数学模型和计算机仿真技术,以相对流动角x和比转速ns为自变量的分区域的曲面方程来描述任意比速水泵通用全性能曲线,从而提出了一种新的计算机仿真预测水泵全性能曲线的方法。 相似文献
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本文研究了设计风速与喷灌工程费用和设计风速与喷灌均匀度,作物产量之间的关系,应用自然风速的统计分析资料推求设计风速对工程效益和费用的影响,从而提出了用边际分析理论推求最优设计风速的方法,最后通过实例验证了这一方法是切实可行的。 相似文献