这种泵效率高、经济、简单、体积小，可压送压力水头高达250英尺的水量。
This pump is efficient, economical, simple and quite small. It can be built to furnish almost any amount of water against pressure heads of up to 250 feet.
以压力水头为因变量的数学模型可以模拟供水压力和灌水器特性对灌溉效果的影响。
A mathematical model whose variable is water head can simulate the effects of water head and properties of subsurface irrigation pipe on irrigation.
通过摄动方法得到一系列关于水头展开式的偏微分方程，用有限差分法进行求解，获得了压力水头的随机描述，并计算其均值和方差。
The equations are solved by finite difference method and the mean and variance of pressure head are determined from its random expression.
为了提供精确的水头压力参数，管线应该连接到水柱的底部。
To provide accurate reading of head pressure , the line should connect at the base of the water column.
利用支持向量机推求管网节点水头和供水泵站供水量、供水压力的非线性关系。
The nonlinear relation between node pressure head of the pipe network and water capacity and pressure of water supply pump station was deduced by SVM.
随着井深增加，水温对水头高度的影响越来越大，需要采用下井仪器测量井底压力。
The influence of water temperature on water head height becomes bigger as the well depth increases. The pressure at the well bottom has to be measured by instruments in the well.
相应的高水头大直径水工压力隧洞的建设也逐渐增多。并且越来越多的工程采用地下钢筋混凝土岔管。
Building of hydraulic tunnels with high head and large diameter increase gradually, and the underground reinforced concrete branch pipe is adopted in more and more projects.
在高水头引水式水电站中，通常几台机组共用同一调压井，且共用压力主管。
Usually, in the high head hydroelectric power station where long channel has been used as a water conveyance structure one surge tank and one penstock may serve more than one machine.
储层压力的影响因素有构造应力、地下水头高度及埋深、地下水矿化度等。
The major influencing factors are tectonic stress, height and burial depth of groundwater, the mineralization ability in groundwater and so on.
结果表明，土壤孔隙率在毫米尺度上存在较为明显的差异，在水头压力下，孔隙率随着深度增加而变大。
The result showed the evident existences of the variability of porosity in soils on mm-scale. Under the stress of water, pore becomes more and more bigger with the deepne…
结果表明，土壤孔隙率在毫米尺度上存在较为明显的差异，在水头压力下，孔隙率随着深度增加而变大。
The result showed the evident existences of the variability of porosity in soils on mm-scale. Under the stress of water, pore becomes more and more bigger with the deepne…
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