特钢精炼中的多路喂丝机PLC控制系统

为实现特钢精炼中对喂丝长度、速度和线卷状态等参数的实时控制,设计了基于现场总线技术的多路PLC控制系统.该系统采用PROFIBUS-DP协议实现管理站与现场PLC操作柜之间的分布式远程通讯.为使喂丝机可靠工作,还设计了一套能自动检测喂丝线卷用完自动报警停机的计长完线测控装置.该系统在多家特钢精炼工程应用后取得较好效果.     

发泡成型生产线微机控制系统

介绍了发泡成型工艺过程的微控制系统。该系统采用AT89C5 1为主机 ,辅以适当的接口和外设 ,实现了对发泡成型生产线的微机控制。运行结果表明 ,该系统具有可靠性高、使用和维修方便 ,功耗低、精度高等特点。     

超临界溶剂精密分离装置自动升压系统的设计

超临界精密分离装置以升压梯度△P均匀升压作为提高产品质量的重要一环.本文采用计算机和二位电磁阀组成的非线性采样控制系统,用脉宽调制方法解决了该装置中的自动升压问题.分析了自动升压控制系统的设计原理,介绍了硬件设计和软件设计要点.     

基于AT89C51单片机的半导体管自动涂胶机的控制系统设计

详细阐述了基于单片机AT89C51的Ф4×2半导体管自动涂胶机控制系统的设计.该自动涂胶机控制系统采用单片机控制,实现自动涂胶、故障报警、自动计数、振动料斗频率的数字化控制等功能,保证各动作的协调一致性,正确完成半导体管点胶.     

基于定量反馈理论的AMT离合器接合控制研究

研究机械式自动变速器(AMT)离合器的接合控制.通过对离合器传动系动力学分析,建立了车辆起步时变速器输入轴速度与离合器接合位移之间的传递函数模型.由于模型中存在参数的不确定性,利用定量反馈理论原理,设计了变速器输入轴速度鲁棒控制系统.仿真研究表明,当车辆起步时的挡位和载荷变化时,该控制系统满足给定的性能指标.     

基于PLC和变频器的海绵发泡控制系统

一套可靠的自动控制系统对于连接、稳定地生产高质量的海绵起着重要作用。主要介绍使用三菱FX2N系列PLC和FR－A500系列变频器设计海绵发泡自动系统的方法，并给出了该系统的硬件结构框图和软件功能。     

国产预涂覆膜机上料卷装置的自动化改造

为了提高国产1200型预涂覆膜机上料卷速度,减轻工人劳动强度,在原有的人工上料基础上进行适当改造,设计成自动上料卷装置。运用solidworks软件对自动上料卷装置进行结构设计和工作模拟,增加电气控制系统,实现机电一体化的给料传动。改造后的自动上料卷装置在实际生产中明显改善了给料速度。有效节约了上料辅助时间,促进了生产率的提高。     

Ω型无缝接合件的设计与应用

针对现有国内外公路桥梁伸缩缝接合件的局限性,研制了一种新颖实用、性能优越的Ω型承重封闭式弹性接合件(简称Ω型无缝接合件)。阐述了Ω型无缝接合件的结构组成与工作原理,分析了在环境温度变化下接合件的受力、应力及其变形情况,并以此提出设计无缝接合件的计算方法。最后,介绍了无缝接合件的拓展应用。     

一种废烟条切碎装置的设计及应用

为解决ZJ17卷接机组采用人工处理启动和停机阶段产生的废烟条和废烟纸的问题,设计了一种废烟条切碎装置,其能自动对废烟条和废烟纸进行在线切碎处理.通过对装置的功能和工况进行分析,采用滚动剪切的方式,将烟条和烟纸切碎成大致均匀的小段,以便废烟输送带能自动完成废烟收集工作.根据设计方案制作了样机,并进行了实验验证.用户试用结果表明,该装置能在线有效地切碎废烟条和废烟纸,有效地提高了卷接机组的自动化水平.     

平面凸轮机构的设计方法与动态特性分析

建立平面闭环机构的运动学方程,根据轨迹上给定点构造从动件位移的三次样条函数,进而确定了最小基圆半径的方程.另外,运用集中参数法建立了摆动从动件盘形凸轮机构的等效动力学模型.根据平面机构的设计方法并结合动态特性分析,采用气动控制和凸轮式机械手相结合的方式来设计纱管抓手装置,实现自动接头机械手在落筒动作过程中纱管的自动抓取和放置过程,并对纱管抓手进行了仿真运动分析.     

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.     

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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