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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 Solar time？

又称： apparent solar time · mean solar time · equation of time

Definition 1.15 University Earth and Space Sciences — Year 1 · 第 1 章 — Spherical Astronomy

Apparent solar time is the hour angle of the Sun plus 12 hours: a sundial shows it, and it is noon when the Sun crosses the meridian. Mean solar time is the hour angle, plus 12 hours, of a fictitious mean Sun that moves along the celestial equator at a uniform rate, completing a turn in a tropical year. Their difference, apparent minus mean, is the equation of time.

The equation of time through the year (apparent minus mean solar time): a sundial is up to 16.4\, min fast in early November and 14.2\, min slow in mid-February. Computed from a Kepler orbit with the eccentricity 0.0167, the obliquity 23.44, the longitude of perihelion and the date of the 2026 March equinox. — The equation of time through the year (apparent minus mean solar time): a sundial is up to $16.4\,\mathrm{min}$ fast in early November and $14.2\,\mathrm{min}$ slow in mid-February. Computed from a Kepler orbit with the eccentricity 0.0167, the obliquity $23.44{}^{\circ}$ , the longitude of perihelion and the date of the 2026 March equinox.

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