陕西交口抽渭多级泵站优化调度研究

泵站工程对工农业生产的发展有着非常重要的作用。根据泵站优化调度数学模型求解方法,结合交口灌区泵站的实际情况,采用动态规划和模拟技术相结合的方法以总能耗最小为目标函数建立数学模型,模型采用站内机组的优选和多级泵站系统的优化进行求解,用动态规划法确定每级泵站的机组最优开机组合,然后模拟了系统的运行,计算出各级泵站之间的优化水位组合,对交口灌区多级泵站实施优化调度,经实践研究表明,模型是可行和实用的。     

泵站优化调度的分解协调模型

针对泰州泵站中转浆式与定桨式轴流泵机组同时并存的情况，依据其常规调度模式和机组布置的特点，引入大系统分解协调技术，建立了两层谱系结构的泵站优化调度模型，并在不同层次采用了合理的优化进行求解，计算结果表明，所提出的模型及优化原则保证了泵站在原有设施条件下能经济高效地运行。     

离心式泵站并联调速运行的优化控制

通过对离心式水泵高效工作区的性能曲线进行二次拟和,分析离心式水泵机组并联调速运行特性.以机组最小功耗为目标函数,以系统流量为约束条件,建立泵站并联调速优化运行控制的数学模型.将不同转速泵并联调速的最优控制问题转化为求解多元函数条件极值问题,采用拉格朗日乘数法和非线性方程的Newton解法求解该模型,得到并联调速机组优化运行时工况点的计算方法.仿真结果证实该模型有效、可行,给出的优化控制方法可以在一定程度上节约泵站的运行成本.     

江都四站站内多机组变角优化运行方式研究

以南水北调东线源头泵站江都四站为例,建立了考虑峰谷电价的站内多机组日变角优化运行非线性规划模型.以站内机组耗电费用最少为目标函数,时段为阶段变量,水泵叶片角、开机机组台数为决策变量,日抽水量为约束,采用动态规划逐次逼近的方法,对江都四站进行计算分析,确定了不同水量约束条件下泵站机组的开机台数与水泵叶片角.结果表明,该模型可有效解决站内机组优化运行问题,效果良好.     

含储能系统及风电的电力系统动态经济调度

风电的随机性和波动性给传统的调度带来困难,为此在模型中引入储能系统,分析了储能系统对含风电的电力系统经济调度的影响,尤其是对系统调峰的影响。将含风电和储能系统的经济调度描述为一个非线性优化问题,建立了一个风电场与储能系统相配合的清洁经济调度模型,其目标函数在传统火电机组运行费用的基础上兼顾了火电的排污成本,寻求经济和环保总成本的最优解,采用粒子群算法对该模型进行求解。通过6机系统算例分析,表明该模型能够有效地控制储能系统的出力;储能系统的引入可明显降低系统的运行费用,尤其是火电机组调峰的费用,且提高了风能利用率。     

含储能系统及风电的电力系统动态经济调度

风电的随机性和波动性给传统的调度带来困难﹐为此在模型中引入储能系统﹐分析了储能系统对含风电的电力系统经济调度的影响﹐尤其是对系统调峰的影响。将含风电和储能系统的经济调度描述为一个非线性优化问题﹐建立了一个风电场与储能系统相配合的清洁经济调度模型﹐其目标函数在传统火电机组运行费用的基础上兼顾了火电的排污成本﹐寻求经济和环保总成本的最优解﹐采用粒子群算法对该模型进行求解。通过6机系统算例分析﹐表明该模型能够有效地控制储能系统的出力;储能系统的引入可明显降低系统的运行费用﹐尤其是火电机组调峰的费用﹐且提高了风能利用率。
     

风火联合系统的多目标随机优化调度方法的研究

考虑到风电场出力的随机性,以常规机组燃煤费用最小、污染气体排放量最小为目标函数,约束条件以概率的形式表示,构建考虑机组组合的风火联合系统的多目标随机机会约束规划模型。结合机组启停优先顺序表,采用启发式搜索策略确定机组组合状态,以避免机组频繁启停或系统容量冗余。采用基于Pareto的多目标粒子群优化算法,结合随机模拟技术和模糊逻辑评价法,对既定机组进行经济负荷分配。以含10机的风火联合系统为算例,验证了所提调度方法的可行性、有效性。优化调度结果表明:1该模型能够充分利用清洁能源,降低系统运行成本,减少污染气体排放量,提高电力系统运行的综合效益;2该算法计算精度高,速度快,避免了基本粒子群优化算法易陷入局部最优的缺点。     

燃气溴化锂吸收式制冷机运行的模拟及优化

结合实际的测试数据，利用神经网络反向传播网络BP算法，辨识出机组的系统模型，对机组的运行特性进行分析，并采用同样的方法对机组的运行费用进行建模和优化．研究结果表明，采用人工神经网络能很好地解决溴化锂机组的建模问题，并可根据模型对机组的运行特性进行分析．     

分区优化模型在山地城市给水管网中的应用

针对山地城市加压泵站多、造价高的特点，对传统的给水管网优化模型提出了改进，增加了中途加压泵站基建及运行管理费用，提出了符合山地城市分区管网特点的经济优化模型．并采用分层求解算法进行求解计算，将优化问题分解成两个子项，即布局优化子项和管径优化子项，最后通过工程实例验证了方法的实用性．     

城市多水源供水系统一级优化调度模型及求解

针对南京市多水源复杂供水系统,建立了以运行费用为目标函数的一级优化调度模型,并采用遗传算法对其进行求解.优化调度结果表明:各泵站供水量、供水压力及A,B测压点的压力在满足用户供水要求的情况下得到了优化,调速泵站的调速作用得到了充分发挥,各泵站供水量得到了重新分配,供水压力及管网测压点的压力随之发生了变化,优化后的压力普遍变小且随时间变化较优化前平稳;为多水源供水系统一级优化调度提供了可行方法,并为泵站二级调度创造了条件.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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