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平原水网地区农田灌溉水有效利用系数测算方法研究 被引量:7
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作者 倪深海 周凌辉 +2 位作者 华幸超 徐文元 潘栋飞 《中国农村水利水电》 北大核心 2018年第2期28-30,36,共4页
为科学评估农田灌溉用水效率与节水潜力,在分析平原水网地区灌溉特点基础上,采用点与面相结合方法测算平原水网地区农田灌溉水有效利用系数。首先进行样点灌区选择的代表性分析,样点灌区的渠首取水量由高精度移动式流量计测量,运用水位... 为科学评估农田灌溉用水效率与节水潜力,在分析平原水网地区灌溉特点基础上,采用点与面相结合方法测算平原水网地区农田灌溉水有效利用系数。首先进行样点灌区选择的代表性分析,样点灌区的渠首取水量由高精度移动式流量计测量,运用水位变化法或水量平衡法进行田间净灌溉用水量测算,采用首尾测算分析方法计算样点灌区的灌溉水有效利用系数,然后由样点灌区灌溉面积加权法推算平原水网地区农田灌溉水有效利用系数,并通过实例进行测算成果合理性分析。测算方法可供其他类似地区测算农田灌溉水有效利用系数时参考。 展开更多
关键词 灌溉水有效利用系数 首尾测算分析 水位变化法 水量平衡 平原水网地区
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Stability and Influence Factors Analysis of Wharf Slope on Slippery Stratum
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作者 LI Peng-fei LIU Ming-wei DAI Ru-lin 《International Journal of Technology Management》 2014年第7期34-37,共4页
With the growing tension of port shoreline resource in Three Gorges Reservoir area, many wharfs can only be constructed on slippery stratum with poor geological condition, which means buckling failure occurs easily. F... With the growing tension of port shoreline resource in Three Gorges Reservoir area, many wharfs can only be constructed on slippery stratum with poor geological condition, which means buckling failure occurs easily. FEM strength reduction method is used in analyzing slope stability of a wharf in Chongqing, and its accuracy is verified by comparing the acquired results with the computation of traditional limit equilibrium method. On this basis, the influences of reservoir water level variation, overload and backfill material behind the retaining wall, and soil share strength of wharf slope on slippery stratum are analyzed. Analysis shows that, there' s a most adverse water level in wharf slope, and the engineering proposals with a certain practical significance such as improve the drainage behind retaining wall, controll overload and improve the strength of backfill soil and subsoil are suggested. 展开更多
关键词 slippery stratum STABILITY factors analysis strength reduction method
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变中有规律(初二、初三)
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作者 孙安同 杨秀英 《数理天地(初中版)》 2004年第10期27-27,共1页
题圆柱形容器内盛有某种液体,液体对容器底的压强是1800Pa,今将12N的均匀木块放入其中,木块有1/3的体积露出液面,此时液体对容器底部的压强是1980Pa.容器内始终无液体溢出.如果将木块露出液面的部分切去再将它放入容器中。
关键词 初中 物理 学习辅导 压强 水位变化 浸物变压
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