局部对称伪黎曼流形中的伪脐类空子流形

给出了局部对称伪黎曼流形中伪脐类空子流形的一个积分不等式,将局部对称黎曼流形的相应结果推广到伪黎曼流形.     

伪黎曼流形的2-调和类空子流形

研究了伪黎曼流形的2-调和子流形，得到了伪黎曼流形的2-调和类空子流形成为极大的一个充分条件，推广了欧阳崇珍的伪黎曼流形中具平行平均曲率向量的2-调和子流形的相应结果．     

局部对称伪黎曼流形中的伪脐类空子流形

研究局部对称伪黎曼流形N_p~(n+p)中的伪脐类空子流形M~n.当M~n是完备非紧且具有平行平均曲率向量场时,得到M~n的第二基本形式的模长平方的一个拼挤定理.当M~n是紧致且具有平行平均曲率向量场时,证得M~n是全测地的.     

伪黎曼空间形式中的伪平行类空子流形

研究伪黎曼空间形式中的类空子流形.对类空超曲面,得到它是伪平行的充要条件;对伪平行类空子流形,利用约当三角系统得到它是全测地的充分条件.     

关于伪Riemann流形的极大类空子流形

在给出伪Riemann流形中一般等距浸入子流形的基本公式的基础上,证明了极大类空子流形的一个广义Bernstein定理,并研究了这种子流形的稳定性.     

伪黎曼流形中具有平行平均曲率向量的伪脐子流形

研究了伪黎曼流形中具有平行平均曲率向量的伪脐子流形,Npn p为n p维完备连通伪黎曼流形,它的截面曲率KN满足a≤KN≤b,Mn为Npn p中紧致的具有平行平均曲率向量的伪脐子流形.通过利用Green散度定理,得到了一个J.Simons型积分不等式,推广了已有结果.     

指数三分与伪几乎自守解的存在性

考虑具有指数三分性的线性微分方程伪几乎自守解的存在性,应用Leray-Schauder不动点定理证明了对于非线性方程x′(t)=f(t,x(t))+g(t,x(t)),当f和g均为伪几乎自守时存在伪几乎自守解.     

伪黎曼流形中的极大类空子流形

研究了伪黎曼流形中极大类空子流形,得到了这类子流形关于黎曼曲率张量的不等式.此外,在Ricci曲率平行的条件下,得到了Lorentz空间中极大类空子流形关于数量曲率的不等式.     

半局部η-伪线性函数的一些性质

作为半局部伪线性函数和η-伪线性函数的推广,本文利用半可微性提出了一类新的广义凸性函数一半局部η-伪线性函数.同时,本文建立了f在Γ上是半局部η-伪线性的当且仅当存在p:Γ×Γ→R,满足p(x,y)＞0,(V)x,y∈Γ,∫(y)=f(x)+p(x,y)df+(x,η(y,x))等性质.本文的结果是对文献[2]和[4]...     

广义伪Ricci对称Sasakian流形

Chaki引入了非平坦黎曼流形(M^n,g)(n≥2)，并称之为伪Ricci对称流形，记为(PRS)n，在此基础上Chaki和Koley定义了一类非平坦黎曼流形，并称为广义伪Ricci对称流形，记为G(PRS)n。讨论了广义Ricci对称Sasakian流形，证明了如果向量场ρ,λ和μ中任意2个正交于ξ，则第3个也正交于ξ。另外计算了广义伪Ricci对称Sasakian流形的数量曲率的值。     

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