关于稳定范畴的一个注记

设C是abelian范畴,Ω■■X是反变有限子范畴,则加法范畴(C/Ω)/(/Ω)≈X/有左三角结构,从而也是一个左三角范畴.     

变分不等式的新的外梯度方法

本文引入了一个新的求解非扩张映射的不动点集和具有单调及Lipschitz连续映射的变分不等式的解集的公共元素的近似算法。这一算法是建立在外梯度方法和粘性逼近方法基础上的。在Hilbert空间上得到了这一算法产生序列的强收敛性定理。其内容如下：设C是实Hilbert空间H中的非空闭凸集,映射A：C→H是单调和k-Lipschitz连续的,S：C→H是非扩张映射满足Fix（S）∩VI（C,A）≠Ф,其中Fix（S）和VI（C,A）分别是S的不动点集和变分不等式的解集f：H→H是压缩映射,序列{xn}和{γn}由下列算法产生的：{x1=x∈C γn=Pc（xn-γnAxn） xn＋1=αnf（xn）＋βnxn＋（1-αn-βn）SPc（xn-γnAγn）,n=1,2,…,其中{γ},{αn}和{βn}是满足条件limαn n→∞=0和∑n=1^∞αn=∞,1〉lim n→∞ sup βn≥lim n→∞ inf βn〉0和limγn n→∞=0的数列,则{xn}和{yn}强收敛到w=PFix（S）∩VI（C,A）f（w）,这里PFix（S）∩VI（C,A）f（w）表示f（w）在Fix（S）∩VI（C,A）上的投影。本文结果推广了文献中的一些著名结果。     

Banach空间中数学规划问题的二阶最优性条件

在无穷维Banach空间建立了非线性规划问题的二阶必要最优性条件，即找到了约束条件Tg^2（x0，h）={w：D^2G（x0）（h，h）＋DG（x0）w∈TC^2（G（x0），DG（x0）h）}，比Robinson约束条件0∈int（G（x0）＋DG（x0）X—C）更弱．     

形如xw的双边无限C∞字的组合

文[1]定理2给出了形如w xw的间隙为x（｜x｜≤4）的双边无限C∞字所确定的无限C∞字w恰有12个.文章在此研究定理2的逆问题,并完全确定了形如wxw的双边无限C∞字的间隙x的取值,其中w是由定理2确定的12个无限C∞字.     

顶点算子代数的模扩张

设（V,Y,1,w）是一顶点算子代数,W是一Z分次V-模,令U=V（＋）W,对任何v,v′∈V,w,w′∈W,定义Yu（v,x）（v′＋w′）=Y（v,x）v′＋Yw（v,x）w′Yu（w,x）（v′＋w′）=e^xDYw（v′,-x）w,其中D=L（-1）,则在线性扩张下（U,Yu,1,w）是一顶点算子代数.     

用非交换图刻画L3(q)

令G是一个有限群,其非交换图▽（G）如下定义：顶点集合▽（G）是G／Z（G）,当两条边x与y的换位子不等于单位元时x与y相连.我们证明了如果G是一个有限群,且▽（G）≌▽（M）,其中M=L3（q）,q=pn,p是素数n∈N,则G≌M.     

无粘性Burgers方程黎曼问题光滑近似解的高阶衰减估计

通过运用特征线法，引入一些非线性函数变换，讨论了无粘性Burgers方程如下柯西问题{w1＋wwx=0，w（x，0）=w0（x）=1/2（w＋＋w-）＋w~Kq∫0^4xdy/（1＋y^2）^q，解的L^p衰减估计，并给出了w（x，t）的高阶L^p衰减估计的证明．[编者按]     

关于周期函数的两个定理

本文绘出两个定理，为判断一元函数的周期性提供了方便。定理1若函数y＝f（x）在R上的图象关于直线x＝a与x＝b（a＜b）对称，则函数f（x）是周期函数。定理2若函数y＝f(x)在R上的图象关于点A（a，y0）和直线x=b（a相似文献   

哈密尔顿连通图和邻域并条件（Ⅰ）

记G=(V,E)是简单图,δ表示图G的最小度,NC=min{|N(x)∪N(y)|：x,y∈V（G）mxt∈E（G）|,NC2=min{|N（x）∪N(y)|：x,y∈V(G),d(x,y)=2},1989年Faudree等证明了：若3连通n阶图G,NC≥(2n 1)／3,则G是哈密尔顿连通图。据此进一步研究NC2≥(2n 1)／3,而且研究到2连通图,得到下面结果：若2连通n阶图G,NC2≥(2n 1)／3,则G是哈密尔顿连通图或G=ψ。     

形如(w)xw的双边无限C∞字的组合

文[1]定理2给出了形如(w)xw的间隙为x(|x | ≤4)的双边无限C∞字所确定的无限C∞字(w)恰有12个,文章在此研究定理2的逆问题,并完全确定了形如(w)xw的双边无限C∞字的间隙x的取值,其中(w)是由定理2确定的12个无限C∞字.     

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