一个新的混沌模型及其数字伪随机信号的实现

构造了一个新的混沌系统,对该系统的动力学特性进行了分析,并设计了实现该混沌系统的模拟电路,实验结果与仿真结果完全相符.为产生混沌伪随机数字信号,在此模拟混沌电路的基础上,设计了一个量化电路.EWB仿真表明,该量化电路确实能对模拟的混沌信号进行二值量化.     

一个新混沌系统的混沌分析及电路仿真

提出了一种新型混沌系统,该系统与Lorenz,R sslor,Chen系统不同,每个方程含有一个非线性乘积项,该系统具有较复杂的动力学特性,利用理论推导、Lyapunov指数、功率谱图和相图验证该系统在适当参数下处于混沌运动,随后用数值模拟系统的全局分岔图、全局李雅普诺夫指数谱和庞加莱映射图准确刻画出系统的周期运动和混沌运动,揭示了该系统的全局分岔行为与混沌形成过程,给出运用非线性耦合同步方法实现混沌同步的条件,同时运用Lyapunov方法对所得的条件进行理论证明,运用数值仿真证实控制方法的有效性.最后,通过对实际电路参数的计算以及模型参数的理论分析,验证了实验结果与计算机仿真结果的一致性.     

基于乘法器的混沌系统设计与实现

利用电阻与电容的串并联特性,提出了一种利用乘法器实现混沌系统的方法。利用该方法用一个电路实现2个Lorenz型混沌系统,实现具有3个乘积项的Qi混沌系统,可以通过改变其中一个电阻的阻值实现从单周期、双周期、四周期、多周期、拟周期及单涡卷混沌到双涡卷混沌的不同的动力学行为的转换。电路实验结果、Multism14软件仿真结果与理论分析结果一致,与原有方法相比,元件数量大大减少。     

一个新自治混沌系统的计算机仿真与电路模拟

提出了一个新的三维自治混沌系统.理论分析了该系统的动力学特性,并通过数值计算分析了系统在平衡点处不稳定的参数范围.对该混沌系统的一个混沌吸引子进行了实际电路的设计与实验验证.     

一个双参数恒Lyapunov指数的超混沌系统及电路仿真

提出了一个四维自治超混沌系统,该系统含有两个参数.分析表明,随着参数的变化该系统呈现周期、伪周期、混沌和超混沌运动.在一定参数范围内,超混沌系统的4个Lyapunov指数保持恒定,不随参数的改变而改变.而且系统的两个正的Lyapunov指数都比较大,尤其是第2个Lyapunov指数较已有的超混沌系统都要大,因此,该系统具有更显著的超混沌特征.最后,设计了模拟电路,电路实验结果表明,在电路中分别呈现的周期、伪周期、混沌和超混沌特性与数值仿真完全一致.     

一个混沌电路的特性及其在保密通信中的应用研究

设计了一个实际混沌电路,并用EWB软件对该电路产生的混沌信号特性进行了仿真研究.同时对电路进行了实验研究,并在示波器上观察到了丰富的混沌信号.实验与仿真结果表明:该电路产生的混沌信号稳定,电路处于混沌状态时的参数可调节范围大.另外还用该电路成功地进行了混沌掩盖保密通信的仿真研究与实验研究.     

基于一个可变电阻多功能混沌电路研究

分析了一个新的复杂的四维混沌系统的动力学特性,此系统每个动力学方程中包含三个二次交叉乘积项,通过改变一个参数系统可以产生一涡旋、二涡旋、三涡旋和四涡旋吸引子.最后采用MUTISIM11设计了一个模拟电路来实现这个新的基于一个可变电阻多功能四维混沌系统.     

基于一个可变电阻多功能混沌电路研究

分析了一个新的复杂的四维混沌系统的动力学特性,此系统每个动力学方程中包含三个二次交叉乘积项,通过改变一个参数系统可以产生一涡旋、二涡旋、三涡旋和四涡旋吸引子.最后采用MUTISIM11设计了一个模拟电路来实现这个新的基于一个可变电阻多功能四维混沌系统.     

双圆斑超级混沌吸引系统的数学模型分析及电路实现

为了研究双圆斑超级混沌吸引系统的非线性动力学行为,首先,提出了其数学微分方程,并进行了数值计算.然后,运用EWB电路仿真软件为系统设计了一个可行的实验电路,研究了系统的非线性动力学行为,给出了系统的周期运动和混沌吸引图像.最后,通过硬件电路实现了该混沌振荡电路.实验结果表明,双圆斑超级混沌吸引系统的动力学数学模型正确有...     

一个新的四维超混沌系统及其电路仿真

为产生复杂的超混沌吸引子,基于一个三维混沌系统构造了一个新的四维超混沌系统.分析了该系统平衡点的稳定性、吸引子的相图、系统的分岔图和Lyapunov指数谱等基本动力学特性.结果表明,新的四维超混沌系统随着新引入的参数变化呈现周期、混沌及超混沌动力学行为.最后设计了一个模拟电路,通过实验结果进一步验证了与数值仿真的一致性.     

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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