液压控制系统建模和仿真方法的研究

利用液压伺服阀频响实验结果建立伺服阀的动态模型，同时采用键合图方法对液压缸进行建模，又利用Simulink工具箱提供的定义子系统和封装的方法，对组成位置伺服控制系统的元件和环节建立了形式统一的仿真模型，在此基础上构建了整个系统的仿真模型并对系统进行了仿真．通过建模和仿真过程说明，与用单一环节建模方法建立的系统模型比较，根据不同元件的频响特性用不同的环节建模方法建立的系统模型容易保证仿真的可靠性；系统仿真模型与用户的良好交互性及本身所具有的通用性，在很大程度上方便了系统仿真模型的构建和仿真的运行．     

面向远程仿真的电阻炉建模研究

实验对象模型的建立是远程仿真系统中极其重要的部分．研究了电阻炉远程仿真与控制实验室系统中远程仿真模块的电阻炉建模方案．分析了远程仿真系统与一般工业过程控制中建模需求的区别．探讨了系统的远程特性赋予建模工作的新的特点．根据实验设备的结构和远程特性设计了建模实验，在尝试并比较了多种建模方案及模型结构之后．提出采用多项式拟合方法获得电阻炉针对远程仿真的二阶模型．为验证仿真模型的有效性．将PID控制典型情况下的实时控制曲线与不同阶次、不同结构模型的仿真曲线进行比较．结果表明，采用多项式拟合方法获得的二阶模型与实时控制曲线最一致．能反映电阻炉控制系统的动态特性．并提出了采用插值方法进一步完善仿真模型的设计方案．     

新型三态滞环电流自适应控制策略

在分析与比较传统两态滞环电流控制和三态滞环电流控制的基础上，利用三态滞环电流自适应跟踪控制方法导出了一种新型环宽计算公式；利用Matlab／simulink工具建立了逆变控制系统仿真模型，使用该模型对并网系统电流控制进行了实验仿真．结果证明，该控制方法稳态性能好，实际电流波形理想，电流误差小．     

基于Matlab的开关磁阻电动机驱动系统非线性建模仿真

在分析开关磁阻电动机数学模型的基础上，借助于Matlab／Simulink建立了电流滞环控制、功率变换器、转子位置角计算等模块，将这些模块有机结合，搭建出了电流斩波控制方式下的开关磁阻电机驱动系统的非线性仿真模型．据此模型，针对一台四相8／6结构样机进行了仿真，仿真结果证明了该模型的有效性．该模型为分析和设计SRM控制系统提供了一种有效的工具．     

基于网络污水处理实时仿真与控制

构建了基于网络的污水处理实时仿真与控制系统的硬件平台，采用C＋＋ Builder语言，利用UML建模方法，开发了基于TCP／IP协议系统仿真与控制软件，实现了污水处理系统的实时仿真与控制。以CSTR工艺为例，以ASM No．1模型和二沉池的沉淀模型，在Matlab／Simulink下建立了系统的仿真模型，利用Matlab／xPC Target生成了控制内核，实现了该工艺的仿真和自动控制。运行结果表明：采用厌氧-好氧生物处理的CSTR工艺中的反应池和二沉池，可以实现实时运行控制和实时仿真，并具有良好的扩充性和移植性；证明了利用网络技术对污水处理过程进行实时仿真和实时控制在技术上是可行的。     

非线性不确定系统的鲁棒拟人控制器设计

尽管拟人智能控制方法自提出以来取得了很多成功应用，但在系统存在不确定性的情况下，如何基于拟人智能控制方法设计系统的鲁棒控制器一直是个难题．针对仿射非线性不确定系统，结合二级倒立摆系统作为设计实例，提出了一种鲁棒拟人智能控制器设计方法．首先，基于被控对象的标称模型设计拟人控制律；然后在采用拟人控制律的基础上，应用积分滑模控制方案设计鲁棒补偿器，用以抑制模型不确定性对系统稳定的不利影响、提高系统的鲁棒性．最后，对二级倒立摆控制系统进行了仿真和实验验证，仿真和实验结果进一步证明了设计方案的有效性．     

基于切换多模型小波网络的非线性动态系统控制

为了提高非线性动态系统的性能，提出了多模型小波网络方法，并详细介绍了多模型小波网络的结构．用多模型小波网络对非线性系统进行建模与控制，在仿真试验中将其与单小波网络进行对比，结果显示多模型小波网络控制的均方差为0．158，单小波网络控制的均方差为0．374．试验结果证明多模型小波网络方法控制精度高，响应速度快，其控制性能优于单小波网络。     

空调水系统实时在线优化控制预测模型的研究

针对集中空调水系统，将模型层次、模型特性及参数辨识有机结合，建立了系统层次实时在线的优化控制预测模型．该模型基于简单物理特性及自适应控制技术的模型参数在线辨识，能通过自校正式的在线仿真对系统的运行特性和控制特性进行实时预测．     

高土石坝施工计算机一体化仿真

采用系统仿真方法对土石坝施工中的两个子系统，即运输上坝子系统和坝面填筑子系统的施工过程进行系统描述，分析了各自的运行特点，阐明内在联系，提出将二者有机结合起来进行一体化仿真，拓展了循环网络模型的概念，精减了现有循环网络模型中的职能节点和控制节点，并增设了一种新的综合节点，实现了面向资源的施工系统仿真建模．编制了仿真软件，并在某高土石坝施工设计中得到应用，仿真成果验证了该建模的有效性及仿真方法的先进性．     

基于Simulink永磁同步电机伺服系统矢量控制

永磁同步电机（PMSM）伺服系统的速度环和电流环具有非线性耦合特性,需要进行电流解耦控制．因此,根据矢量控制的原理实现了该系统的线性解耦．通过对永磁同步电机数学模型分析,建立基于Simulink伺服系统矢量控制仿真模型．仿真结果表明,建立的系统耦合模型具有良好速度控制特性,并对永磁同步伺服耦合系统设计具有指导价值．     

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     

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