浅谈变频螺杆空压机在矿井中的应用

变频调速技术是近年来发展起来的一种先进技术。节能降耗已成为企业降生产成本重要手段之一，空压机在煤矿生产中起重要的作用，提供、保证生产，所以我们对空压机进行技术改造。     

浅谈煤炭企业维简费

维持简单再生产是企业生存发展的基本条件，煤矿维简费主要用于煤矿生产的正常接续、开拓延深、技术改造、设备更新等，以确保矿井持续经营、稳定发展和安全生产，也是企业取得经济效益的重要基础。维简费的计提使用、计划管理、会计核算及账务处理，对煤炭企业维简费使用管理起着关键作用。     

煤矿机电设备的检修与技术改造

由于煤矿生产条件和生产环节的复杂性，这给机电设备管理工作提出了新的课题。因此，应加强煤矿机电设备基础工作，重视煤矿机电设备检修工作。进行机电设备的技术改造，强化质量标准化管理。     

恒源煤矿二水平副暗斜井系统改造

我国目前现有的煤矿矿井大多数在建井时设计标准偏低,当很多煤矿开始逐渐转向中深部煤矿开采时,原来提升能力已经难以甚至不能满足煤矿生产的需要,必须进行必要的技术改造,才能保证正常生产。恒源煤矿二水平副暗斜井通过对车场的技术改造,使生产能力大幅提高,对其他类似提升矿井具有借鉴作用。     

机电一体化技术在煤矿机械中的应用

近年来，我国煤炭行业在利用机电一体化技术改造旧设备和开发新产品方面做了大量的工作，取得一定的成效。它已使人们清楚地认识到，应用机电一体化技术发展煤矿机电产品，是实现高效、安全、机械化生产和煤矿机电产品更新换代的重要途径。本文对机电一体化技术在煤矿机械中的应用进行阐述，并对其发展趋势进行分析。     

水力采煤配套系统设备改造、开发与应用

孔庄煤矿自水采投产以来，煤水提升系统一直运转不正常，经过一段时间的探索与分析，先后对高压供水系统、煤水提升系统及供电系统等进行了一系列的技术改造，确保了孔庄煤矿水力采煤的正常生产。     

大同煤矿集团公司对新参组小煤矿技术改造的实践

针对小煤矿普遍存在安全技术投入欠缺、机械化程度低、采煤方法落后、安全生产无保障等问题，简述了大同煤矿集团公司对新参组小煤矿进行技术改造的必要性、指导思想、改造原则、改造目的、改造内容及改造效果。     

煤矿机械设备维修与管理浅析

煤矿机械设备的维修与管理是保证设备正常运行的主要手段,是提高工作效率和避免恶性事故发生的关键性因素。加强煤矿机械设备的维修与管理是一件相当重要的事情。文章阐述了煤矿机械设备的维修与管理的技术和方法,提出了进行技术改造的重要性,从而提高煤矿企业的生产效率和质量。     

自动化控制系统和隔爆型变频器在井下钢缆皮带中的应用

近阶段煤矿系统进行大范围的技术改造,主要表现在电力提升和电力拖动这一块。包括煤矿皮带运输系统、煤矿提升系统、煤矿地面生产系统等;随着技术改造的进行,PLC可编程控制器和变频器也广泛地进入煤矿系统。煤矿采用的上海普昱矿山设备有限公司KJX—1140自动化控制系统和ZJT3—250/1140变频器。这样就要对钢缆皮带的详细情况和运行要求做细致的了解。下面对PLC可编程控制器和变频器、钢缆皮带现状进行一些详细的介绍。     

有关煤矿瓦斯检测技术应用的浅析

为实现我国经济的可持续稳定发展，必须把企业的安全生产放在首位，因此煤矿企业不断深化体制改革，加快对煤矿瓦斯检测技术的研究，提高煤矿瓦斯检测技术的应用。为煤矿企业的安全生产作贡献，就煤矿瓦斯检测的技术应用进行简要分析。     

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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