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1.
Infiltration and localization of preferential infiltration zones at the dam abutment are measured using radioactive tracer tests of flow in boreholes,meanwhile interconnection between boreholes and the energing water points is analysed.The theory and practice of radioactive tracer synthetic detective method are described to give methods and calculation formulae used under the condition of stable flow in single well to measure permeability coefficient and hydrostatic heads.Major single hole techniques including measurement for seepage line,velocity,rate of seepage flow and relationship of recharge of groundwater in aquifers are introduced briefly.The possibilities offered by natureal tracers are analysed,uincluding electric-conduct,pH-value and temperature of water as well as stable isotopes(D,^18O) and tritium.Furthermore,the sensibilities of this theory and methods were confirmed by detecting seepage flow field of Xinanjiang Dam. 相似文献
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Gas migration in coal bed is a multiple-physical process, of which not only includes gas desorption/diffusion through coal matrix and gas Darcy flow through the cleat system, but also results in deform... 相似文献
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The effect of compressive stress on the stability of reversed austenite in 9Ni steel was investigated by uniaxial and hydrostatic compression.It was found that the uniaxial compressive pressure promoted the γ→α transformation,while the hydrostatic pressure suppressed the γ→α transformation.The pressure dependent transformation behavior can be explained according to thermodynamic analysis. 相似文献
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This paper presents an advanced design methodology for electric power generation from the vast ocean wave energy. A novel single-buoy heaving device called wave energy converter (WEC) based on hydrostatic transmission (HST), or can be shortened as HSTWEC, is proposed to convert mechanical energy generated by ocean waves into electric energy. Modeling and simulations with both regular and irregular waves were then carried out to investigate working performances of the designed HSTWEC. The results showed that more than 78% of wave energy can be absorbed. In addition, an adaptive controller was designed to improve the performance of the suggested device. Effectiveness of the overall HSTWEC control system was finally proved by simulations. 相似文献
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Present paper presents the application of pressure grouting in hydraulic tunnels subjected to high internal pressure of water. Structural analysis of the pressure grouting used for pre-stressing of concrete lining is shown along with the methods used to control the pressure grouting effects. The paper also presents a new experimental method for measuring the loss of water along the complete tunnel under operating conditions and a mathematical model for the evaluation of tunnel impermeability and functionality. All presented test methods have been developed and all measurements were performed by the “Jaroslav Cerni” Institute for Development of Water Resources in Belgrade (Serbia). These methods are presented on the example of a hydraulic tunnel of the “Bajina Basta” pumped storage plant in Serbia, during the stages of its construction and operation. 相似文献
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实现数控机床自适应控制的前提条件是有相关的动力学模型。建立带有载荷、温度等非线性因素的油膜厚度动力学模型是实现重型精密数控机床垂直位移自适应控制的关键。针对没有适用于静压导轨油膜厚度的自适应控制模型,基于Navier-Stokes方程,提出了静压导轨油膜厚度的非线性动力学模型及其简化模型,两者都可用于自适应控制。该模型能体现导轨承受负载变化与油膜厚度变化关系,并包含油膜厚度变化的速度和加速度项,适用于精密液体静压数控设备。经过Simulink tools工具仿真模拟,精度达到10~(-4)的数量级,验证了非线性模型和近似模型的准确性。 相似文献
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简要介绍了车辆静液压储能传动这一新型动力传动系统的基本组成、工作原理及其特点,详细分析了系统中关键元件之一的储能元件——气囊式蓄能器的各参数之问的关系以及蓄能器的充气容积、有效容积和压力、多变指数等参数的变化对车辆制动能量回收以及对车辆性能的影响,并以某型公共汽车为例,通过分析计算和实验得出了系统的能量回收率为38.46%-61.55%,该车具有良好的使用性和经济性及实际应用前景。 相似文献