基于Terminal滑模的Hindmarsh Rose神经元放电同步控制

基于Terminal滑模控制方法, 实现了单向耦合HindmarshRose神经元之间的同步控制. 仿真结果表明, 该控制策略不但可完成神经元内部参数变化而导致不同放电状态的同步控制, 还可完成由于外部干扰导致不同放电状态的同步控制, 并证明了该控制策略的有效性.     

基于内模与偏差耦合复合的舞台调速吊杆群同步控制方法

以舞台调速吊杆群高精度协调同步运行为目标,针对吊杆运行过程中易受负载扰动和电机参数摄动影响同步效果的问题,在并联同步控制的基础上,用内模控制器取代常规PI跟踪控制器,并与偏差耦合控制方法相结合,构建了基于内模与偏差耦合复合的舞台调速吊杆群同步控制方案,以内模控制增强系统的鲁棒性、位置均值偏差耦合补偿控制改善系统的精度.最后选用3组调速吊杆的同步控制对文中方法进行有效性仿真验证,结果表明,该方法在保证系统具有优良抗干扰性能的同时,较传统PI位置耦合控制具有更好的跟随性能及同步精度.     

升降舞台多电机同步系统的预测函数控制

针对升降舞台系统中升降台因负载扰动、机械间隙等因素造成的不同步现象,提出一种基于预测函数控制与位置偏差耦合的复合同步控制策略.结合预测函数跟踪速度快、鲁棒性好的特性,与并联同步下位置偏差均值补偿同步控制结构来协同改善舞台升降台的同步控制性能.仿真研究表明,升降舞台预测函数控制系统能够确保多电机高性能同步运行,与PI控制系统相比,对参数摄动和外部干扰鲁棒性更强,控制精度更高.     

基于改进型偏差耦合结构的多电机同步控制

针对现有的多电机同步控制方案难以满足高精度控制的要求和不能实现比例同步控制的局限性，提出一种带PI补偿控制的改进型偏差耦合控制结构，可适用于多电机完全同步和比例同步控制.针对永磁同步电动机非线性和强耦合特性，设计了自适应模糊滑模变结构控制器来实现永磁同步电动机的跟踪控制.建立了4台永磁同步电动机的同步控制仿真模型，仿真实验表明，所提出的多电机同步控制结构相对于带固定增益补偿的控制结构具有更高的同步控制精度.与PID和常规滑模控制算法相比，自适应模糊滑模控制策略具有更高的同步稳定性和更强的鲁棒性.     

变形Liu混沌系统的同步控制及电路实现

针对一种变形Liu混沌系统,研究其驱动与响应的单向耦合同步控制问题.基于李雅普诺夫稳定性理论,分析研究该变形Liu混沌系统稳定性,提出系统的单向耦合控制系数建构方法,通过Matlab软件进行数值研究该系统的驱动、响应系统的误差系统同步控制问题,数值结果显示有效实现该系统的同步控制目标;设计出同步控制电路原理,并用Multisim电路仿真软件对其进行同步控制验证;数值分析和电路仿真软件实验结果一致,相互验证其正确性与有效性.     

基于平均场的全局耦合神经集群的去同步控制

针对一些疾病中出现的神经元放电的病理性同步,本文提出了一种去同步控制方法.在神经元受到电流和噪声的刺激引发放电时,引入平均场对神经元集群进行点对点的全局耦合,将会使神经集群达到同步状态.在此过程中将平均场进行滤波以及线性处理反馈回神经集群,可以控制集群去同步.通过对集群参数与控制器参数分别研究,表明这种控制方法对噪声,耦合强度,控制器参数都具有鲁棒性.而且此方法有实用性,易临床实现,可以用作深度大脑刺激的新颖控制方法来治疗精神疾病.     

多电机同步控制方式的研究

本文针对多电机同步控制问题,研究了多电机同步控制系统,通过对系统中常用的各种多电机同步控制方式的分析和比较,选择了主从同步控制方式和偏差耦合同步控制方式;结合综合指标优的无刷直流电机作为执行电机。在建立无刷直流电机数学模型的基础上,对双电机主从控制和偏差耦合控制分别进行了数学建模,并用MATLAB对其进行仿真,仿真结果验证了采用偏差耦合控制具有更好的跟随性能。     

风电叶片两点疲劳试验系统激振器加载控制

基于电驱动惯性式激振装置,构建了一种风电叶片两点激振疲劳试验系统,并提出了虚拟主令同步控制算法.以PID算法设计误差补偿器,利用李雅普诺夫函数证明虚拟主令同步控制算法的稳定性,并建立控制仿真模型,数值仿真分析虚拟主令同步控制算法的收敛性及鲁棒性.最后,试验验证了耦合下虚拟主令同步控制算法的有效性.结果表明:虚拟主令同步控制算法能使激振器快速跟随,激振器之间相位差的波动很小,叶片振幅稳定,实现了风电叶片的平稳有效加载.     

桩锤同步振动系统的机电耦合特性及同步控制

控制同步是实现多锤联动的有效方式之一.针对目前存在的两台桩锤控制同步时出现的机电耦合现象,建立了打桩过程中的"锤-桩-土"系统的动力学数学模型,并构建了两桩锤同步振动系统的机电耦合模型,在此基础上进行了数值仿真分析,发现机电耦合的结果是在一定的条件下出现自同步现象.对机电耦合下的同步控制策略与算法进行了研究,确立了"虚拟主令+比例-积分-微分算法(PID)"的控制方式,最后通过试验验证了机电耦合规律的正确性及同步控制策略与算法的有效性,控制同步的精度可以满足工程应用.     

复杂网络中众多混沌运动电机的同步控制研究

以混沌运动的永磁同步电机作为节点构建线性耦合的复杂动力网络,研究了网络中众多电机的同步控制方法.该方法根据线性耦合网络全局同步的牵制控制条件,设计出电机交轴和直轴电压的比例调节控制器,并给出施加牵制控制后电机网络的状态方程.模拟结果表明:在网络耦合强度、电机节点参数时变情况下,对于小世界拓扑或无标度拓扑构建的电机网络,一个电机节点的线性反馈牵制控制就能实现网络所有电机同步,控制方法具有控制效率高、代价小、可调节等优点.     

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.     

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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