两台耦合受调制的激光器的混沌同步

通过数值模拟对两台空间耦合受到涮制的单模激光器系统的动力学行为进行研究。根据激光之间空间耦合作用的凋制频率，讨论并分析了激光系统中强度与调制频率之间的关系。数值研究表明：在一定的参数范围内．尤其是耦合强度在一定频率范围内受到凋制，激光强度可以实现混沌同步。通过对功率谱和李雅普诺犬指数的分析，可以确信所研究的激光系统处于混沌状态。     

环形空间耦合激光阵列的时空混沌同步

通过数值模拟对多台单模Nd:YAG激光器激光环形阵列组成的系统的动力学行为进行了研究.阵列中这些激光束是在光场中空间局部耦合的相互作用和一定参数设置下进行的.数值研究表明,在一些相对小区域的参数范围内,激光之间空间耦合作用的距离一定时,相应激光束的强度之间可以实现混沌同步且具有一定特点.通过对功率谱和李雅普诺夫指数的计算和分析,可以确信所研究的强度同步的激光系统处于混沌状态.     

三台多模激光强度的混沌同步

对空间耦合的三台多模激光阵列的动力学行为进行了理论分析．当系统的泵浦受到调制时，在一定的参数范围内，第一台激光和第三台激光输出的总强度之间会出现很好的混沌同步，两台激光的对应模式之间也出现相应的混沌同步，但不同模式之间则是完全的混沌状态，而第一台、第三台激光与第二台激光的输出强度之间则没有混沌同步现象出现．每台激光的各个模式强度之间存在模式竞争现象，通过李雅普诺夫指数也可以看出系统处于混沌状态，     

混沌系统的双向耦合同步

文章对混沌系统的线性双向耦合同步进行研究，通过选取适当的耦合参数，可以达到混沌系统的全局混沌同步，给出了同步原理．对物理学中的WINDMI系统，采用简单的线性耦合方式，运用双向耦合同步方案，讨论其复杂的混沌同步行为，用Mathematica软件进行仿真实验，理论分析和数值仿真结果都表明了该方法的有效性．     

SCH量子阱激光器的混沌同步通信研究

首先对光电子反馈及光电子注入式SCH量子阱激光器的混沌动力学行为进行了研究,然后采用光电子反馈及光电子注入式SCH量子阱激光器分别作为发射系统和接收系统进行混沌同步及同步通信的数值模拟研究.理论及数值模拟研究表明,利用SCH量子阱激光器进行混沌同步通信,可取得良好的通信效果.另外,采用本激光系统进行通信,有利于克服其他系统只能传输小信号的问题.     

局域速率反馈方法同步时空混沌

在一维的复Ginzburg-Landau方程(CGLE)系统中,提出了时空混沌同步的一种广义反馈方法,称为变量速率反馈方法。研究了利用单个速率反馈信号同步时空混沌的可能性。研究结果表明,选取较大的偏流强度和反馈强度可以使响应系统与驱动系统之间获得较好的混沌同步,并通过数值计算确定出同步参数空间。     

双势阱Duffing-Van der Pol系统反馈同步

用变量反馈方法研究了具有对称双势阱的扩展Duffing-Van der Pol(DVP)系统的混沌同步问题,以及反馈增益强度摄动对同步时间的影响.结果表明,仅需一路反馈信号就能有效实现驱动系统与响应系统的混沌同步,反馈增益强度具有较宽的取值区间,且反馈增益强度的摄动幅度小于0.82时对同步时间没有显著影响.变量反馈控制方法实现DVP系统混沌同步的有效性和稳定性通过数值仿真得到证实.     

双向混沌耦合研究

通过对混沌系统的驱动变量进行相互耦合,使不同初值下的混沌系统达到同步,同步过程不改变原系统的混沌性质,在一定的耦合强度下,对Lorentz混沌系统进行了数值实验,结果在K2＞2的情况下,系统都达到了同步,这一耦合强度明显小于主动－被动同方法中的耦合强度,最后,对主动－动同步方法,连续反馈同步方法及相互耦合谱量同步方法进行了比较,发现在一定的条件下,三种同步方法具有等价的关系。     

典型混沌系统的噪声诱导与增强同步

研究了典型混沌系统在噪声影响下的完全同步问题,包括噪声诱导同步和噪声增强同步两种情形,并以新近提出的Liu混沌系统为例进行了讨论.进一步,本文还在一般的线性耦合框架下,针对混沌系统完全同步问题,详细讨论了噪声强度和耦合强度之间的关系.研究发现:噪声强度和耦合强度两因素对于实现混沌同步均起着积极的作用.数值仿真进一步证明了这一观点.     

一个具有全局吸引混沌吸引子的系统及其混沌同步

报道了一个分段线性离散系统的混沌引子，通过系统对初始条件的敏感依赖性研究，得出此吸引子是全局吸引的。为进一步证实此系统是混沌系统，又对此系统进行了不同初始条件下的混沌同步研究，利用反馈同步方法，很容易地实现了此系统的混沌同步。最后对混沌系统的开关项变化问题进行了研究，通过数值计算，得出不同开关参数下，混沌吸引子的形状是完全一样的，不同的是混沌吸引子在状态空间的形状围成的面积将发生变化。     

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