基于改进观测器的分数阶超混沌Chen系统广义同步

基于分数阶微积分的预估-校正算法,研究了分数阶超混沌Chen系统,并进行了数值仿真.仿真结果表明,分数阶超混沌Chen系统存在超混沌的最低阶数为 3.8 阶.根据分数阶稳定性理论,设计了一种改进的状态观测器,利用解析的方法求得广义同步的响应系统,从理论上证明了广义同步方法的可行性.最后,利用该同步方法实现了 3.8 阶超混沌Chen系统的广义同步,数值仿真结果证实了它的有效性.     

广义Lorenz和Chen系统混沌同步控制算法

借助李雅普诺夫稳定性理论提出了一种自适应混沌同步控制方法.该方法通过构造适当的控制函数,从理论上保证了混沌同步控制的稳定性.MATLAB仿真实现了Lorenz系统和Chen系统的混沌同步以及广义Lorenz系统和广义Chen系统的混沌同步控制.     

一个新四维超混沌系统的计算机仿真及同步控制

在Chen氏三维混沌系统的基础上构造了一个四维系统,对系统进行了动力学理论分析和计算机数值仿真研究。发现构造出的系统可以随系统参数的变化而产生周期、准周期、混沌和超混沌运动。详细分析了四维系统的特性,设计了超混沌系统的自同步控制器和异结构同步控制器,并通过计算机数值仿真证实了此同步控制方法的有效性。     

超混沌Chen系统的自适应同步与电路实验研究

研究了超混沌Chen系统的自适应同步问题,基于Lyapunov稳定性理论,设计了参数未知结构相同的2个超混沌Chen系统自适应同步控制器和同步控制器电路,该控制器结构简单,不需要知道系统参数,就可实施控制.数值仿真和电路实验仿真证实了该方法的有效性.     

分数阶Chen系统的分析、同步及其保密通信实现

首先分析分数阶Chen系统的混沌行为,给出系统随参数变化的Lyapunov指数谱图和分岔图,从数值分析上说明了其混沌特性.然后基于一类混沌系统的观测器设计方法,给出了分数阶Chen系统的混沌同步控制策略,并分析和验证了该同步方法的有效性.另外,用模拟电路实现了该同步控制.示波器观测结果表明,该同步方法能够使驱动系统和响应系统达到很好的同步效果.在上述研究的基础上,利用分数阶Chen系统的同步电路进行了模拟信号的保密通信研究,结果表明,该同步控制及其保密通信方法是可行的.     

连续混沌系统的全状态混合投影同步

介绍了全状态混合投影同步,并给出其定义.基于混沌同步误差系统反馈线性化思想设计同步控制器,以 Lorenz系统、超混沌Chen系统为例,同时采用Matlab进行数值仿真,实现了连续混沌系统全状态混合投影同步.数值模拟证明了该方法的有效性和可行性.     

基于输出反馈的分数阶混沌系统的异结构同步

研究了分数阶混沌系统的异结构同步问题.基于反馈控制理论和分数阶线性稳定性理论,提出了一种基于输出反馈的方法来设计同步控制器,实现了分数阶混沌系统的异结构同步.并以超混沌Chen系统和超混沌New系统为例,运用MATLAB软件仿真,证明了该方法的有效性和可行性.     

基于改进观测器的分数阶超混沌Chen系统广义同步

基于分数阶微积分的预估-校正算法，研究了分数阶超混沌Chen系统，数值仿真结果表明，分数阶超混沌Chen系统存在超混沌的最低阶数为3．8阶，并根据分数阶稳定性理论，设计了一种改进的状态观测器，利用解析的方法求得广义同步的响应系统，从理论上证明了该同步方法的可行性．最后，利用该同步方法实现了3．8阶超混沌Chen系统的广义同步，数值仿真结果证实了它的有效性．[第一段]     

不同维异结构混沌系统的有限时间同步

本文考虑两个维数不同和结构不同的混沌系统,在给定时间内实现快速同步的热点问题．基于有限时间稳定性理论,设计出一个非线性开关控制器,通过这个控制使得两个维数不同甚至内部结构都不一样的混沌系统在事先给定的时间内达到完全快速同步．将理论结果应用到Chen—Lee混沌系统,成功实现了三维Chen—Lee混沌系统和四维Chen—Lee超混沌系统以及三维Chen—Lee混沌系统和四维Rabinovich超混沌在给定有限时间内的快速同步．最后,数值结果证实了方法的可行性和控制器的有效性．     

分数阶超混沌系统的耦合广义投影同步及其在保密通信中的应用

研究了分数阶混沌耦合广义投影同步及其在保密通信中的应用问题.提出了一种分数阶混沌系统耦合广义投影同步方案,基于分数阶系统稳定性理论,通过设计同步控制器,使得分数阶超混沌Chen系统达到了耦合广义投影同步;并结合混沌掩盖方法,通过引入可逆转换函数,设计了一种分数阶超混沌保密通信方案.数值仿真结果进一步验证了同步方法的有效性和保密通信方案的可行性.     

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.     

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