压铸机闭环控制系统设计

本文系统地介绍了压铸机计算机闭环控制系统的设计。在硬件方面，输出输出板均采用了光隔，抗干扰能力强。在软件设计上，采用定时中断，即实现了高速采样，又可周期性地扫描输入输出端口的状态，循环发生动作指令，这种模拟可编程控制器的程序设计方法，大大提高了整个 系统的性能。     

远程操作站在可编程控制器控制系统中的应用

本文阐述了可编程控制器控制系统中，通过ASCII模块，实现远程操作站与可编程控制器的连接，并开发了ASCII模块中的接口通讯程序。     

机器人装配自动线集散控制系统

本文介绍一个用于吊扇电机装配的机器人装配自动线的集散控制系统。该控制系统由一台ＡＳＴ３８６／ＳＸ微型计算机，一台Ｃ２００Ｈ可编程控制器（ＰＬＣ），八台Ｃ系列小型可编程控制器（ＰＬＣ），五台机器人控制器和三台ＭＣｈ－５１单片微机组成。该系统实现了对机器人装配自动线的作业任务的执行控制，作业协调控制，运行状态的监控和生产报表的统计与输出。文中还介绍了集散控制系统的硬件设计和软件设计。     

煤矿巷道风门的自动化控制

针对井下风门的应用现状,研究设计了由可编程控制器控制的液压自动风门系统,重点阐述了自动风门的组成和动作原理及液压系统的控制机构,讨论了可编程控制器实现风门自动控制的可行性方案,并给出了系统控制流程图和梯形图。对煤矿井下风门改造具有一定的参考价值。     

C1000H可编程控制器上位机通讯的开发与研究

可编程控制器联网系统中的上位通讯功能，是实现控制系统上位计算机集中监视、集中控制和集中管理的关键．本文以ＳＹＳＭＡＣ－Ｃ系列中的Ｃ１０００Ｈ可编程控制器上位通讯为例，探讨了有关软件硬件的原理及组成．在通讯协议及网络硬件的基础上，作者通过上位机的可编程异步通讯接口８２５０开发了以查询式和中断式两种方式分别实现的Ｃ１０００Ｈ上位通讯软件．经过系统的调试与运行，证明方法正确、方案可行，可以方便地进一步实现各种上位操作功能．     

监督模糊神经网络控制系统

设计了一个监督模糊神经网络（FNN）控制系统，它可以跟踪周期输入信号，控制系统由永磁（PM）同步伺服电机以及监督FNN位置控制系统组成。监督FNN控制系统由监督控制器和FNN滑式控制器组成。监督控制器可以在指定区域内稳定系统的状态。FNN滑式控制器由滑式控制和FNN组成，滑式控制有较好鲁棒性。FNN具有在线学习能力，作者对监督FNN控制系统进行了详细的理论分析和稳定性研究。仿真结果证明了此系统对参数变化和外部负荷干扰有很好的鲁棒性。     

装载机结构件疲劳试验机的设计

为了查找装载机结构件应力薄弱部位,优化结构设计、提高疲劳寿命,采用电液伺服技术和可编程逻辑控制器(PLC)控制技术设计一套专门测试结构件疲劳强度的试验系统.该系统采用整机正面加侧面的加载方案,由触摸屏和PLC控制器远程控制2个伺服液压缸动作以模拟结构件受载,可实现24 h无人值守试验,适用于各种型号装载机结构件的疲劳试验.试验结果表明:该试验机运转平稳,可靠性高.     

基于人工神经网络的PLC故障诊断系统的研究

本文介绍了一种新的PLC控制系统故障诊断方法。首先建立可编程控制器控制系统的故障诊断模型,然后在对可编程控制器控制系统的故障产生特点进行分析的基础上,阐述了BP神经元网络的原理及如何应用BP神经元网络建立可编程控制器故障诊断系统,最后根据上述分析给出了可编程序控制器故障诊断实例。     

移动滑态变结构控制器设计

给出了移动滑态变结构控制器的设计方法。多变量不确定性变结构控制系统，其能达阶段对控制系统参数摄动较为敏感。为此，设计了移动滑态变结构控制器，使得控制系统在一开始就进入到所设计的滑动模态中并将其保持，从而降低了系统的能达时间，提高了系统抗参数摄动的能力。数字仿真表明，该方案有效地克服了系统参数摄动对控制系统的影响，验证了本文理论的正确性。     

微型 PLC 在跳汰机排料系统中的应用

本文介绍了由可编程控制器（ＰＬＣ）和单片微型计算机所构成的跳汰机自动排料系统，详述了系统硬件、软件的设计和控制器参数的调整方法，并简述了该控制系统的特点。     

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.     

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.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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