现场总线技术应用于煤矿监控系统探讨和实践

根据煤矿监控系统技术现状,讨论了应用于煤矿监控的设备级现场总线的性能要求,分析、比较了几种主要的现场总线的技术性能以及它们对煤矿条件的适应性,并结合煤矿井下设备级现场总线的供电方式在实践中的应用,论证了将先进的现场总线技术应用于煤矿监控可行性.     

CAN总线技术在矿井综合调度系统的应用

提出了一种基于现场总线技术的矿井综合调度网络。利用现场总线结构灵活、通讯高效的特点，将矿井各生产、运输、安全检测等各个环节构成一个有机的综合调度网络，并在地面调度中心实现集中监控，重点以CAN总线技术为例，提出了现场总线技术在煤矿综合调度系统使用中需要解决的几个问题及方案。     

基于现场总线的煤矿提升信号设备的研制

目前煤矿提升信号装置基本采用PLC为控制核心,提升信号为并行传输,可靠性低,安装、维修困难。本文提出了采用CAN现场总线技术进行煤矿提升信号传输新方法,指出了CAN总线技术在煤矿井下环境使用的优点,介绍了应用单片机及CAN总线新技术实现煤矿提升信号装置实现方法。     

Profibus总线在煤矿井下供电监控系统的应用

煤矿要实现高产、高效、安全地生产，井下供电系统的自动化和信息化势在必行。根据煤矿井下供电系统多分散、实时性和可靠性要求高的特点．提出了一套基于Profibus现场总线的煤矿井下供电监控系统的设计方案。     

现场总线技术及其发展趋势

１现场总线的产生传统的工业自动化测控系统一般是基于ＤＯＳ（分散式控制系统）和ＰＬＣ（可编程逻辑控制器）的，属于封闭式的控制系统。一个系统不经过网关等接口无法实现和其他系统的通信。由于控制器与现场设备的连接是点对点的，即一个Ｉ／Ｏ点对现场设备的一个测控点，这种连接需要铺设大量的线缆，成本高，结构复杂，可靠性差，维护不方便。而且由于ＤＣＳ不是开放系统，互操作性差，难以实现数据共享。为了解决这些问题，现场总线（Ｆｉｅｌｄｂｕｓ）技术应运而生。现场总线技术是计算机技术、通信技术和控制技术发展的产物；是连接智能现场设备和自动化系统的数字式、双向传输、多分枝结构的通信网络，它的关键标志是支持全数字通信。它可以把所有的现场设备（仪表、传感器与执行器）与控制器通过一根线缆相连，形成现场设备级、车间级的数字化通信网络，可完成现场状态监测、控制、远传等功能。现场总线技术使企业网（Ｉｎｔｒａｎｅｔ）的信息采集延伸到了工业现场。它代表了当今自动化的发展方向，是工业现场级设备通信的一场数字化革命。由于现场总线技术明显的优越性，在国际上成为一个研究开发的热点。各大公司都开发出了自己的现场总线产品，形成了自己的标准。目前常见的标准有数十种...     

现场总线技术及其发展趋势

１现场总线的产生传统的工业自动化测控系统一般是基于ＤＯＳ（分散式控制系统）和ＰＬＣ（可编程逻辑控制器）的，属于封闭式的控制系统。一个系统不经过网关等接口无法实现和其他系统的通信。由于控制器与现场设备的连接是点对点的，即一个Ｉ／Ｏ点对现场设备的一个测控点，这种连接需要铺设大量的线缆，成本高，结构复杂，可靠性差，维护不方便。而且由于ＤＣＳ不是开放系统，互操作性差，难以实现数据共享。为了解决这些问题，现场总线（Ｆｉｅｌｄｂｕｓ）技术应运而生。现场总线技术是计算机技术、通信技术和控制技术发展的产物；是连接智能现场设备和自动化系统的数字式、双向传输、多分枝结构的通信网络，它的关键标志是支持全数字通信。它可以把所有的现场设备（仪表、传感器与执行器）与控制器通过一根线缆相连，形成现场设备级、车间级的数字化通信网络，可完成现场状态监测、控制、远传等功能。现场总线技术使企业网（Ｉｎｔｒａｎｅｔ）的信息采集延伸到了工业现场。它代表了当今自动化的发展方向，是工业现场级设备通信的一场数字化革命。由于现场总线技术明显的优越性，在国际上成为一个研究开发的热点。各大公司都开发出了自己的现场总线产品，形成了自己的标准。目前常见的标准有数十种...     

Profibus总线在煤矿井下供电监挖系统的应用

煤矿要实现高产、高效、安全地生产,井下供电系统的自动化和信息化势在必行。根据煤矿井下供电系统多分散、实时性和可靠性要求高的特点,提出了一套基于Profibus现场总线的煤矿井下供电监控系统的设计方案。     

浅析现场总线在电厂辅助车间的应用

随着控制，计算机．通信．网络．信息等技术的飞速发展，产生了现场总线技术，并且其在人们的生产生活中发挥着越来越大的作用。该文主要介绍了现场总线控制系统的特点，以及其较与DCS的优点；对在过程控制领域中应用广泛的基金会现场总线和过程现场总线作了简要介绍。继而讨论了现场总线在电厂中的适用范围。并结合平顶山鲁阳发电厂2X1000MW机组主厂房外水系统的工程应用实例，提出了目前现场总线在电厂应用中需要注意的一些问题，展望了现场总线的发展。     

基于现场总线的煤矿供电监控系统

针对煤矿井下的特殊环境,提出了一套基于PROFIBUS总线并满足本安特性要求的的煤矿供电监控系统,它能够对地面35KV变电站、井下中央变电所及采区变电所供配电设备的状况进行实时监测和控制。采用现场总线技术后,供电系统的稳定性和可靠性显著提高,有效减少了矿井无计划停电事故的发生。     

现场总线研究及其一个实验室模型的实现

现场总线研究及其一个实验室模型的实现张大波，赵海，王光兴分析了工厂自动化网络系统的组成和特点，着重讨论了工业环境下的通信需求．具体研究了现场总线（ＦＩＥＬＤＢＵＳ）的体系结构，设计并实现了一个现场总线网络的实验室模型．在这个模型中，采用了非反相归零线...     

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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