具分布参数的广义随机神经网络的镇定

研究具分布参数的Cohen—Grossberg广义随机神经网络的镇定性。将所考虑的系统的解随机场关于空间变量的积分视为相应的由随机常微分方程描述的神经网络的解过程来讨论其镇定性。具体实施方法是运用Ito↑^微分公式沿系统对构造的关于空间变量平均的Lyapunov函数进行微分，从而克服了研究具分布参数随机系统无相应Ito↑^公式的困难。     

变时滞随机模糊细胞神经网络的均方指数稳定性研究

研究变时滞随机模糊细胞神经网络的均方指数稳定性,利用Ito公式及Lyapunov泛函方法得到其均方指数稳定的判据,并举例说明了理论结果的有效性.     

线性随机分布参数系统均方稳定的充要条件

基于线性随机分布参数系统新的数学描述形式,给出了相应的均方稳定定义．考虑边界条件及散度定理,将偏微分方程转化成常微分方程,基于常微分方程的稳定性条件给出了相应偏微分方程的稳定性条件,从而得到了该类线性随机分布参数系统均方稳定的充要条件．最后通过仿真实例证明了结果的正确性.     

一类随机的SIR流行病模型的动力学行为分析

首先对受参数扰动的具有阶段结构的SIR流行病模型引入随机项,建立了具有阶段结构的随机SIR流行病模型的非线性微分方程,应用随机中心流形定理和随机平均法相关定理将其化为Ito微分方程。然后,基于Oseledec乘性遍历理论,应用最大Lyapunov指数和奇异边界理论分别分析了该随机系统的局部随机稳定性和全局随机稳定性;利用拟不可积Hamilton系统随机平均法对系统的随机Hopf分岔行为作了分析。最后,选取其中的某些参数作为分叉参数得到相应的平稳概率密度函数图和联合概率密度函数图,对发生分岔的概率和位置进行了验证。     

随机时滞Hopfield型神经网络的几乎指数稳定性

利用Lyapunov泛函和Ito公式，研究了具有时滞的随机Hopfield型神经网络的几乎指数稳定性，证明了一个定理和两个推论．当随机扰动为0时，得到确定性的时滞神经网络指数稳定性的结果．     

关于随机Riemann和的均方收敛性

本文给出随机Riemann和在闭区间上一致均方收敛的充分性条件,并把所得结果应用于随机积分,高阶随机积分,同时还得到一类Ito随机微分方程在均方收敛意义下的解。     

随机变时滞递归神经网络的几乎指数稳定性

研究了一类随机变时滞递归神经网络的几乎指数稳定性问题。利用Lyapunov函数方法和Ito公式,结合矩阵分析技巧,给出了系统几乎指数稳定的判别准则。数值例子说明了该结果的有效性。     

It型随机微分方程解的有界性

关于确定性微分方程解的有界性,Antosiewicz在[2]中作了概括和研究。在本文中,我们利用停时、强马氏性和随机Lyapunov函数等概念,把在[2]中有关的定义和定理推广到Ito型随机方程上去,从而研究了Ito型随机方程解的随机有界性。     

具有比率型功能反应函数的随机恒化器系统的渐近性态

考虑到流出率受随机噪声的干扰,研究了一类具有比率型功能反应函数的随机恒化器系统,详细讨论了系统解的长期渐近性态。利用随机微分方程比较定理,证明了系统正解的全局存在惟一性。通过构造Lyapunov函数,利用Ito公式证明了系统的绝灭平衡点是全局随机渐近稳定的,研究了随机系统在确定性系统正平衡点附近解的渐近行为。     

线性随机系统基于观测器的反馈镇定

针对控制系统测量输出产生的乘性噪声问题,提出基于观测器的反馈控制设计算法.首先,引入状态误差变量,导出反馈控制下It8型随机微分方程描述的闭环系统.其次,运用复合Lyapunov函数方法并结合随机分析技术,分析闭环系统的均方指数稳定性和几乎必然稳定性,并建立输出反馈控制器存在的充分条件.基于此条件给出了控制增益矩阵和观测器增益矩阵的参数化设计算法.最后,通过倒立摆模型的数值仿真,验证所提出控制策略的有效性.     

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