一类不确定组合大系统的输出反馈全息控制

研究一类不确定组合大系统的输出反馈全息镇定问题，设计出一类具有全息结构的线性输出反馈控制器使受控系统在平衡点处渐近稳定，且输出反馈增益矩阵可通过求解代数Ｒｉｃ－ｃａｔｉ方程获得．最后给出一个数值仿真例子验证了本文所给结果的有效性．     

代数Riccati不等式与H∞滤波器

利用代数Ｒｉｃｃａｔｉ不等式技术，给出Ｈ∞滤波器设计方案；还给出卡尔曼滤波器及ＬＱ控制满足Ｈ∞性能指标的充分条件．代数Ｒｉｃｃａｔｉ不等式技术的优点就在于可以兼顾Ｈ∞性能指标与其他性能指标．     

一种基于观测器的分散H∞控制

提出一种基于代数Ｒｉｃｃａｔｉ方程设计分散控制律的方法．该法不仅计算简便，而且可获得较好的Ｈ∞性能指标     

一类可积的Riccati方程

讨论了一类可积的Ｒｉｃａｔｉ方程，给出了可积条件及求解方法．     

应用于离散H^∞控制的共轭化方法

用代数的方法导出Ｈ＾∞控制系统中共轭因子存在的充要条件为一个离散Ｒｉｃｃａｔｉ方程正解存在，为研究（Ｊ，Ｊ′）－无损失矩阵分解和求解Ｈ＾∞控制问题提供了一种有效工具。     

用Riccati方程解一类一阶线性齐次方程组

研究了用Ｒｉｃｃａｔｉ方程求形如（＊）的一类一阶方程组的解的方法,改进了求形如方程组（＊）的解的工作。     

时离散代数Riccati方程正半定解的矩阵界和简单迭代

给出时离散代数Ｒｉｃｃａｔｉ方程正半定解的一个上下界和一个简单迭代，并有数值例子。     

广义系统的Riccati方程

研究了广义系统Ｒｉｃｃａｔｉ方程的结构性质，给出了有关Ｒｉｃｃａｔｉ方程性质的最基本结论。     

关于Riccati方程的代数体解

提出了关于具有亚纯系数的Ｒｉｃｃａｔｉ方程的代数体解增长性和其局部全纯解解析延拓的两个问题，并给出了部分回答。     

Painleve分析产生的Tu系统的精确解

分析了非线性Ｔｕ系统的载断Ｐａｉｎｌｅｖｅ级数，得到了Ｔｕ系统与Ｒｉｃｃａｔｉ型方程φｉ－φｘ＝αφ＋βφ＋γ的关系，并提示Ｒｉｃｃａｔｉ型方程本身的一些性质。最后借助于Ｒｉｃｃａｔｉ型方程给出了Ｔｕ系统的三类显式的精确解。     

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