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1 Markets I: The Ecosystem and Exchange-Traded Markets市场在线 2 Markets II: Rates, FX and Credit市场在线 3 Markets III: Commodities, Energy and Crypto市场在线 4 Quantitative Methods方法在线 5 Derivatives and Volatility衍生品在线 6 Rates, Credit, XVA and Risk利率、信用与风险在线 7 Research Craft: Predictors, Backtests, Measurement, Portfolios研究在线 8 Strategies I: Equities and Futures策略在线 9 Strategies II: Volatility, Relative Value, Macro and the Bank Desks策略在线 10 Microstructure and Execution交易执行在线 11 Market Making and High-Frequency Trading做市在线 12 Machine Learning for Markets机器学习在线 13 Low-Latency Software技术在线 14 Networks, Hardware and Trading Infrastructure技术在线 15 Research, Data and Risk Platforms技术在线 16 The Desk and the Firm公司运营在线 17 The Industry: Firms, Roles and Careers职业发展在线 18 Interviews I: Maths, Probability and Speed职业发展在线 19 Interviews II: Markets, Trading Games and the Final Round职业发展在线 20 Interviews III: Code职业发展在线

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Earth and Space Sciences · 术语表

什么是 Hydraulic head; hydraulic gradient？

又称： hydraulic head · hydraulic gradient

Definition 23.1 University Earth and Space Sciences — Year 3 · 第 23 章 — Hydrogeology

The hydraulic head at a point of the saturated ground is

h = z + \frac{p}{\rho g} ,

the sum of the elevation head $z$ of the point above a datum and the pressure head $p/(\rho g)$ , $p$ being the pressure of the water above the atmospheric pressure. It is the elevation to which water rises in a tube, a piezometer, open only at that point. The hydraulic gradient is $\nabla h$ ; its size between two points a distance $L$ apart along the flow is $\Delta h/L$ .

A piezometer, a tube open only at its screen. The water stands in it at the hydraulic head of the point P: its elevation z plus its pressure head. Here the level in the tube is above the water table, as it is where the water rises towards a spring or a river. — A piezometer, a tube open only at its screen. The water stands in it at the hydraulic head of the point $P$ : its elevation $z$ plus its pressure head. Here the level in the tube is above the water table, as it is where the water rises towards a spring or a river.

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