可编程控制器控制系统的计算机辅助设计

针对可编程控制器控制系统设计过程中的关键性技术问题，提出并实施了计算机辅助设计方法．通过对梯形图的分析比较，得出了逻辑表达式的评价指标及逻辑变换方法．通过使用模块化和计算机编译技术，实现了电气图向梯形图逻辑表达式的自动转换，以及梯形图的自动绘制和可编程控制器指令的自动编程     

PLC的SFC图在编写顺序控制梯形图中的应用

为了解决应用可编程控制器(PLC)的基本逻辑指令编写顺序控制梯形图时所存在的编程复杂、不易理解等问题,采用PLC的顺序功能图来编写顺序控制梯形图是一种非常有效的方法,该方法具有编程简单而且直观等特点.以送料小车的控制为例,采用顺序功能图的方法编写其控制梯形图,从编程结果可以看出,与应用PLC的基本逻辑指令方法相比具有简单、直观、逻辑性强等特点,提高编程的效率.     

可编程控制器的顺序和逻辑控制实验

文本通过以可编程控制器取代继电接触控制的实验，介绍了可编程控制器的基本使用方法，利用梯形图编制的程序清单，以及可编程控制器在顺序和逻辑控制中显示出的优越性。     

采用普通Petri网的自动化立体仓库系统的PLC程序设计

以一个实际立体仓库系统的出库流程为例,给出利用普通Petri网设计其可编程逻辑控制器(PLC)程序的方法.首先,根据自动化立体仓库系统的出库流程,提出其对象Petri网的设计方法;然后,根据系统工艺流程对应的顺序控制规范,在对象Petri网的基础上增加执行机构的变迁,最终得到闭合Petri网(监控器);最后,给出将闭合Petri网转化成PLC梯形图的方法,实现自动化立体仓库系统的形式化建模和PLC程序设计.研究结果表明:所提出的设计方法更容易自动实现系统的控制器设计及转化为梯形图语言.     

软PLC梯形图向指令表转换新算法的研究与实现

通过对软PLC梯形图和指令表的分析,提出一种梯形图向指令表转换的新算法.该算法先将梯形图映射成AOV图,再用串并联扫描的方法化简AOV图,并转换成逻辑树,最后通过后序遍历逻辑树生成指令表.文中给出了一个转换实例,详细介绍了算法的使用及实现步骤,证明了该算法对于复杂的梯形图也能准确快速地生成指令表,具有实用价值.     

工业洗衣机的 PC 控制

介绍可编程控制器（简称ＰＣ），在工业洗衣机控制中的应用实例。给出了控制系统流程图及对应的梯形图程序，并提出了其控制功能的扩展方法。     

工业洗衣机的PC控制

介绍可编程控制器（简称ＰＣ）,在工业洗衣机控制中的应用实例。给出了控制系统流程图及对应的梯形图程序,并提出了其控制功能的扩展方法。     

PC在水塔水位控制中的应用

介绍了可编程控制器在水塔水位控制中的应用和本系统所具有的特点,并给出了I/O端子接线图,梯形图以及程序执行过程.     

自动剪板机的PLC控制

以工业用剪板机为对象,采用了工业顺序控制过程中广泛使用的可编程控制器（ＰＬＣ）对之进行控制,先后给出电气传动部分设计方案和采用ＰＬＣ控制的状态转移图及步进梯形图。     

可编程序控制器梯形图编程的一种通用方法

本文针对可编程序控制器用户程序的编制问题,给出了一种用阶段过渡控制图作为桥梁来编制梯形图的通用方法,并对若干实例在PLC-2/30可编程控制器上全部验证通过,说明这种方法正确无误。该方法严密清晰,简单实用,有规可循,因此是解决PC用户编程很有实用价值的一种通用方法。     

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。     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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     

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