一类高阶奇异左定微分算子的谱

利用谱曲线的方法研究了一类带有不定权函数的高阶奇异左定微分算子的谱,结果表明,自伴边界条件的高阶奇异左定微分算子有可数多个特征值,而且均为实数,上下无界,算子的特征值可以排序为 …≤λ-2≤λ-1≤λ-0<0<λ0≤λ1≤λ2≤…     

两个序数μ，V的乘积空间是有小于λ=min{cfμ,cfv}点可缩性质的空间

日本数字家Nobuyuki Kemoto在1996年论证了两个序数的乘积是遗传可数亚紧间空间。本文是在这个性质的基础上进行了进一步的研究，定义了点可缩性质，并得到了两个序数的乘积空间是有小于λ=min{cfμ,cfv}点可缩性质的空间，这是对Kemoto结果的更进一步的推广。     

关于相对可数紧度空间

为了得到相对可数紧度空间的映射及嵌入性质,借助映射方法和紧化理论讨论了相对可数紧度空间被闭映射逆保持问题及嵌入紧空间问题,得到了相对可数紧度空间被闭映射逆保持的一个充分条件、局部紧的可数紧度空间可嵌入紧空间的几个充分条件以及某一类局部紧空间在任意紧化中不具有可数紧度等结果．文章进一步刻画了相对可数紧度空间的性质。     

关于正规可数中紧空间在逆极限运算下的保持问题

设X是逆系统{Xα,πα^β,∧}的逆极限,｜∧｜=λ,假设每个投射πα：X→Xα以是开且到上的,X是λ-仿紧的,如果每个Xα是正规可数中紧的,则X是正规可数中紧的．进一步,还得到了关于遗传性质的类似结果．     

L-fuzzy保序算子空间的ω-Lindelf可数性

在L-fuzzy保序算子空间中引入一种新的ωLindelf可数性概念.系统地讨论了ωLindelf可数性的基本性质以及与第二ω可数空间之间的关系.得到ωLindelf可数性是ω闭遗传的,是弱拓扑不变的,第二ω可数空间是ωLindelf空间等结论.     

几乎可数仿紧空间的性质与刻画

在Elise Grabner定义几乎亚紧空间的基础上,引入了几乎可数仿紧空间,得到了一个关于它的等价刻画定理:X为几乎可数仿紧空间当且仅当X的每个可数散射分解有一个几乎局部有限的开膨胀。讨论了几乎仿紧空间、几乎可膨胀空间、几乎可数仿紧空间三者之间的关系:几乎κ-仿紧空间是几乎κ-可膨胀的。空间X是几乎可数仿紧的当且仅当X是几乎可数可膨胀的。     

L-fuzzy保序算子空间的ω-Lindel(o)f可数性

在L-fuzzy保序算子空间中引入一种新的ω—Lindeloef可数性概念．系统地讨论了m—Lindeloef可数性的基本性质以及与第二ω-可数空间之间的关系．得到m—Lindeloef可数性是ω-闭遗传的，是弱拓扑不变的，第二ω-可数空间是m—Lindeloef空间等结沦．     

m-半格中的滤子及其相关拓扑性质

首先, 通过在m-半格中引入滤子的概念, 讨论m-半格中滤子的若干性质, 进而构造m-半格上的滤子拓扑, 得到了滤子空间的一系列性质; 其次, 证明每个滤子空间是连通的, 且双侧m-半格上的滤子空间满足第一可数性公理, 并分别给出其为T₀空间及满足第二可数性公理的充要条件; 最后, 通过引入m-半格中素滤子的概念, 讨论m-半格上的对偶素谱空间, 证明双侧m-半格上的对偶素谱空间是T₀空间, 并给出其为T₁空间的等价刻画.     

L—fuzzy拓扑的λ—截拓扑(Ⅱ)

讨论了各种可数性和分离性与λ-截拓扑的关系.特别是,若(L~X,δ)是λ-弱诱导空间,则(L~X,δ)是Hausdorff空间或强Hausdorff空间,当且仅当λ-截拓扑空间(X,ι_λ(δ))是Hausdorff空间,因此对λ-弱诱导空间来说,Hausdorff分离性与强Hausdorff分离性是等价的;又若(L~X,δ)是满层的λ-弱诱导空间,则(L~X,δ)是ST_1的(ST_2的),当且仅当λ-截拓扑空间(X,ι_λ(δ))是T_1的(T_2的),于是对满层的λ-弱诱导空间来说,ST_2分离性与强Hausdorff分离性及Hausdorff分离性是等价的.     

L-fuzzy保序算子空间的ω-Lindel(o)f可数性

在L-fuzzy保序算子空间中引入一种新的ω-Lindel(o)f可数性概念.系统地讨论了ω-Lindel(o)f可数性的基本性质以及与第二ω-可数空间之间的关系.得到ω-Lindel(o)f可数性是ω-闭遗传的,是弱拓扑不变的,第二ω-可数空间是ω-Lindel(o)f空间等结论.     

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