一类非Shil’nikov型四维超混沌系统的最终有界

针对3D Lorenz型系统,提出了具有唯一平衡点或两个平衡点的四维超混沌系统,在两种不同平衡点情形下可分别发现超混沌吸引子。通过构造恰当的Lyapunov函数严格证明同宿轨与异宿轨的不存在性,表明此系统的超混沌是非Shil'nikov意义下的混沌;进一步将Lyapunov函数和优化方法有机结合证明超混沌吸引子的最终有界性,并数值模拟验证超混沌吸引子的最终有界;运用相图、Lyapunov指数谱、分岔图和Poincaré映射分析系统随参数变化的复杂动力学。     

多边时滞脉冲反馈方法控制开关到达系统的混沌

选择边界作为Poincar截面定义周期轨,通过在每个边界(n=3)实施时滞脉冲反馈控制来控制混沌,同时对该方法的收敛性进行了理论分析以及数值验证,最后分析了多边控制与单边控制的收敛性。     

耦合的非线性振动子的周期运动和同宿运动

在强迫激励作用下的耦合的非线性振动子的动力学行为是非常复杂的，而理论分析是非线性振动研究的最基本方式．Melnikov方法是研究系统混沌运动的解析方法之一，笔者正是利用Melnikov方法研究了具有Van der pol阻尼的这类振动子周期运动、同宿运动和混沌运动，得出这类振动系统产生次谐周期轨和Smale马蹄意义下的混沌的条件,并通过数值模拟说明了这类系统的混沌．     

一类2个自由度Hamilton系统的动力学性质

主要考虑了一类耦合二阶常微分方程组在参数b{12},b{21}均大于零的情形下,通过适当的尺度变换将此方程组变成具有2个自由度的Hamilton系统,利用Hamilton系统的相关知识分析了系统的平衡点、周期轨、同宿轨,并且运用Melnikov方法研究了系统的混沌性.     

Yang系统中同宿轨存在性研究

关于混沌系统中同宿轨的知识目前还知之甚少。在"捕鱼准则"的帮助下,通过对Yang混沌系统的深入研究,获得了Yang系统中同宿轨的存在性条件。为了更直观的验证理论分析结果,通过数值的方法,获得了一些适当的分岔参数以及它们所对应的同宿轨。     

一类离散神经系统中的混沌存在性

研究了离散FitzHugh-Nagumo神经系统的混沌现象。从理论上严格证明了在一定参数条件下系统存在Marotto意义下的混沌,并通过数值计算模拟出该混沌吸引子,以及周期14轨、周期16轨等其他复杂动态。此外,通过Lyapunov指数的计算对Marotto混沌吸引子的存在性加以验证。     

三阶非线性电容电路中的闭轨分岔与混沌

选取一个含非线性负电容的三阶自治电路,对其状态方程所描述的向量场的特征空间进行分析与计算,根据闭轨产生的条件,求出了闭轨存在的解析式.据此计算并模拟出一条可演化成同宿轨道的闭轨,谊闭轨进而分岔形成双涡卷混沌.     

扰动Sine-Gordon方程的横截异宿轨

本文研究了sine-Gordon方程的异宿轨在扰动下的保持性．利用无穷维Melnikov分析,证明了横截异宿轨的存在性,进而扰动系统有混沌发生．     

Devaney混沌的等价刻画

本文将Devaney混沌定义从度量空间推广到一般拓扑空间．在一般拓扑空间中分别得到了Devaney混沌的两组等价刻画．作为这两组等价刻画的推论：如果实数区间,或紧度量空间X上的连续自映射f对于任意两个非空开子集都共享同一周期轨,则f是Li-Yorke混沌映射．最后的两个例子部分地说明本文所得结果在应用中的有效性．     

圆周自映射的混沌与伪轨跟踪性质(英文)

设f:S1 →S1 是圆周S1 上的连续自映射 ,本文证明 :如果f是 2 ∞ 型的混沌映射 ,那么f不具有伪轨跟踪性质     

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