连接密度对于均匀网络上耦合映象同步方式和同步时间的影响

通过修改随机网络的连接概率,研究了网络的连接密度对于均匀网络上的同步方式和同步时间的影响,发现稠密的网络上同步时间与耦合强度关系是单调的.进一步揭示了连接密度产生这种影响的机制,即在稠密的网络上,弱耦合Logistic映象具有与强耦合Logistic映象相同的同步方式,于是随着耦合强度的变化,不出现两种同步方式的转变以及相应的同步慢化.     

不同超混沌系统广义投影同步

在参数未知的情况下,采用自适应的控制方法实现了两个超混沌系统的广义投影同步.利用Lyapunov方法从理论上证明了这种方法的有效性,最后又对同步系统通过matlab进行仿真,数值仿真的结果表明这种方法是快速有效的.     

一种新的混沌同步方法

首先给出了混沌同步的定义,又简要介绍了两种现有的混沌同步方法,然后提出一种新的混沌同步方法,并针对连续和离散两类混沌系统分别介绍这种混沌同步的设计方法,最后对未来混沌通信研究方向进行了展望.     

分数阶超混沌Lü系统的一步耦合同步研究

主要应用一步耦合法对分数阶超混沌Lü系统的同步进行研究和设计.利用拉格朗日终值定理证明了同步的有效性,并用数值仿真结果验证了同步的可行性.这种同步方法实现了分数阶超混沌系统初值不同的耦合同步.     

基于相关的MIMO-OFDM系统同步方案

提出了一种M IM O(m u ltip le inpu tm u ltip le ou tpu t)-OFDM(orthogona l frequency d iv is ion m u ltip lex-ing)系统前导结构以及基于相关的帧/符号同步、载波频率同步方案,详细介绍了同步算法,并给出高斯白噪声信道和频率选择性衰落信道中的仿真结果.结果表明,这种同步方案算法复杂度低,具有较高的精度和较大的实用价值.     

耦合映象格子系统中的刚性同步

提出了一个新的反馈项，实现了两个耦合映象格子系统的时空混沌同步。讨论了这同步的特点，指出这种同步是刚性同步，并给出模拟结果。     

一种改进的参考点同步模型多媒体同步控制方法

首先介绍了多媒体同步的分类，并指出了实现多种媒体同步的关键就在于建立适当的同步控制模型；接着分析了现在浒的３种单一同步模型以及二级同步模型，评价了它们各自的优点与缺陷；在此基础上，提出了一种改进的参考点同步模型多媒体同步输出控制方法，这种折衷的同步控制方法，在一定程度上弥补了单一同步模型和二级同步模型各自的缺陷。     

径向励磁低速同步电动机的电路模型

用电势法建立了径向励磁低速同步电动机的电路模型,包括:电势方程、参数计算式和等效电路图.提出了同步后的这种电动机可等效于一台异步电动机的观点,在此基础上得到了电磁转矩及最大转矩的表达式,为分析和研究这种电动机奠定了基础.     

分布式多媒体系统中连续媒体的同步方案

随着各种新的网络设备、视频点播以及新的应用的大量出现,多媒体信息在网络传播信息中的比重越来越大,而多媒体同步作为多媒体系统的一个关键技术,其重要性越来越体现出来.无处不在的分布式网络更是对分布式多媒体同步提出了新的要求,因此针对分布式多媒体系统的复杂结构以及分布式网络中出现的越来越多的各种类型的连续媒体,提出一种不需要全局时钟的连续媒体的同步方案.这种方案设置一个信宿对信源的简单的反馈信息,利用这个反馈信息和巧妙的缓冲区的设计,克服了网络时延抖动对不同信宿之间数据同步回放的破坏;利用多个连续媒体之间的内在关系实现连续媒体间的同步,从而实现各种结构下的分布式网络中多媒体信息的完整同步.仿真表明这种同步方案能够保证多点对多点结构下多个信宿保持回放多媒体数据的同步.并且这种方案适用于各种不同结构的、传输不同类型连续媒体的分布式网络.     

一种应用层数据同步方法的设计和实现

为实现在复杂网络和异构数据库环境下的数据同步,在分析基于触发器的数据同步机制的基础上,设计了一种应用层数据同步机制.这种机制在应用层利用数据库和XML的映射来封装和解析同步数据,同时针对数据传输和数据库更新在应用层引入了可靠性机制.该同步机制具有与平台耦合度小、功能分层易于复用的优点,能够根据应用需求有效解决跨平台的数据同步问题.实践证明,该应用层数据同步机制达到了设计要求.     

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.     

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