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试析中国古代的航海计程单位“潮” 被引量:2
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作者 何沛东 《自然科学史研究》 CSSCI CSCD 北大核心 2018年第4期438-447,共10页
"潮"是中国古代一个重要的航海计程单位,潮汐"自涨而落或自落而涨"称为"一潮",古人以两地航道沿途潮汐相继发生的次数(或需要候潮的次数)表示航程的远近。宋代至清代,以"潮"计程之法经常被运... "潮"是中国古代一个重要的航海计程单位,潮汐"自涨而落或自落而涨"称为"一潮",古人以两地航道沿途潮汐相继发生的次数(或需要候潮的次数)表示航程的远近。宋代至清代,以"潮"计程之法经常被运用到东南沿海的短距离近岸航海活动中。以"潮"计程是古人对于潮汐充分认知和熟练运用的一个重要例证。 展开更多
关键词 古代航海 计程单位
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Simulation Based Synthesis, Design and Optimization of Actual Pressure Swing Adsorption (PSA) Unit
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作者 Rajasree Retnamma Arun Sadashio Moharir 《Journal of Chemistry and Chemical Engineering》 2012年第4期336-345,共10页
The present study demonstrates the potential of the simulation based on-line synthesis, design and optimization strategy for pressure swing adsorption (PSA) processes developed in our earlier study by implementing o... The present study demonstrates the potential of the simulation based on-line synthesis, design and optimization strategy for pressure swing adsorption (PSA) processes developed in our earlier study by implementing on an actual two-bed unit. The unit is very flexible and allows process synthesis from the PSA cycle configuration point of view. The model parameters are regressed and updated using live experimental data. The on-line monitoring and controlling of the operating parameters and operating configurations are done by multi-loop processor programmable logic controller. Separation of air into nitrogen free oxygen as raffinate stream and enriched nitrogen as extract stream using 5A zeolite as adsorbent has been chosen as a specific system for implementing the strategy. The philosophy of the typical optimization and process synthesis exercise implemented on the unit is described. The results show the successful implementation of the developed strategy on the two-bed O2-PSA unit and the application of this general approach to commercial PSA processes. 展开更多
关键词 PSA process synthesis DESIGN OPTIMIZATION simulation.
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Unit Commitment with Production Cost Uncertainty: A Recourse Programming Method
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作者 H. Borsenberger Ph. Dessante G. Sandou 《Journal of Energy and Power Engineering》 2011年第2期164-172,共9页
Many studies have considered the solution of Unit Commitment problems for the management of energy networks. In this field, earlier work addressed the problem in determinist cases and in cases dealing with demand unce... Many studies have considered the solution of Unit Commitment problems for the management of energy networks. In this field, earlier work addressed the problem in determinist cases and in cases dealing with demand uncertainties. In this paper, the authors develop a method to deal with uncertainties related to the cost function. Indeed, such uncertainties often occur in energy networks (waste incinerator with a priori unknown waste amounts, cogeneration plant with uncertainty of the sold electricity price...). The corresponding optimization problems are large scale stochastic non-linear mixed integer problems. The developed solution method is a recourse based programming one. The main idea is to consider that amounts of energy to produce can be slightly adapted in real time, whereas the on/off statuses of units have to be decided very early in the management procedure. Results show that the proposed approach remains compatible with existing Unit Commitment programming methods and presents an obvious interest with reasonable computing loads. 展开更多
关键词 Unit Commitment dynamic programming stochastic programming UNCERTAINTY energy management systems RECOURSE Lagrangian relaxation.
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