昌马水库水电站运行管理的实践与探索

对昌马水库水电站自首台机组投产发电以来的运行管理经验、面临的挑战和困难进行了分析和总结,明确了电站运行管理的总体方向和思路,从提高运行管理能力、确保设备健康、破解运行管理难题等方面提出了保障措施,并对相关措施进行了深入思考和探讨。     

论配电变压器的选择

本文作者通过对变压器运行现状、配变运行的认识误区进行了分析。同时结合实例对变压器的选择及运行方式做了阐述。     

浅谈输电线路的安全运行管理与保护

输电线路点多、面广且线路较长,而且长期处到野外的运行环境下,受自然环境影响因素较大,所以对其运行的安全性产生了较大的影响。因此对输电线路安全运行管理和保护工作提出了更高的要求,为了保证输电线路运行的安全性,不仅需要采取必要的预防措施,同时还要做好相应的运行维护工作,从而有效的降低输电线路运行时故障的发生率,保证线路运行时的安全性。该文对输电线路故障的原因及危害进行了分析,同时对输电线路安全运行管理进行了阐述,并进一步对继电保护与自动装置的重要作用进行了具体的介绍。     

10kV配电网运行分析与诊断

利用10kV配电线路上无功补偿装置所记录的历史运行数据,对配电网的运行状态进行分析,提出了配电网运行分析与诊断的功能模式,并对哈尔滨电业局开发区供电局某架空线路2006年度的运行数据进行了分析、诊断和研究。     

自来水厂污泥处理系统运行与管理探究

对自来水厂污泥的来源、运行控制方式进行了说明,并对污泥处理系统的的组成及其运行管理要求进行了较为详细的分析。     

浅谈变电运行设备的维护与管理

随着人们物质文化生活水平的不断提升,对生活质量有了更高的要求,而电力系统安全、稳定的运行直接关系到人们生产生活中正常的电能供应,电能供应的正常与否和人们的生活质量息息相关,所以就要确保电力系统安全、稳定的运行。这就对变电运行设备提出了更高的要求,特别是在当前社会对电能需求量不断增加的情况下,更需要保证变电运行设备运行的稳定性,所以做好变电运行设备的维护和管理至关重要。文中对变电运行常见的故障进行了分析,并进一步对变电运行维护与管理进行了具体的阐述。     

船用电气设备运行状态监测记录仪的设计与实现

针对船舶电气设备进行故障诊断中对设备运行状态数据的需要,设计了一种船用电气设备运行状态记录仪。对电气设备记录电路进行了分析,设计了数据采集电路、时间基准电路、SD卡存储电路和相应软件,实现了对电气设备运行中的模拟量、开关量以及环境参量的监测,采集数据的时间标记和实时存储,存储的数据通过开发的分析软件可直观反映设备运行状态。试验结果表明了电气设备运行状态监测记录仪的可行性和可用性。     

变电运行倒闸操作问题及注意事项探讨

倒闸操作是变电运行的基本工作之一。科学、正确地进行倒闸操作具有重要意义,要求变电运行人员必须正确、严肃、认真地进行工作。本文对变电运行倒闸操作中的问题进行了探讨。首先介绍了电气设备倒闸操作的原则。然后分析了变电运行倒闸操作中的问题与正确程序。最后阐述了倒闸操作的注意事项。     

水轮发电机组中长期稳定运行状态评价研究

讨论了机组中长期运行状态的评价,重点研究机组中长期运行的平稳性问题,以便为保证机组安全、高效运行提供有效的手段．引入机组中长期稳定分析的概念;分别对机组中长期进行了时域、频域评价;并将上述指标在水轮发电机组进行了运行状态评价的实际应用,结果表明此项研究成果对机组的运行稳定评价是有效的．     

多运行水平聚合马尔可夫可修系统可靠性分析

对多运行水平聚合马尔可夫可修系统模型,进行了进一步的可靠性分析,对已有的结论进行了改进,使之更符合系统实际运行的规律及特征.借助生物药理学中的离子通道理论、Laplace变换方法以及矩阵方法得到了表征多运行水平可修系统可靠性的几个关键指标:系统在各个运行水平逗留时间的概率密度函数、平均逗留时间以及在各个运行水平的平均访问次数.最后用数值算例对所得结论进行了模拟实现.      

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

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     

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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