Banach空间中非线性Volterra型积分方程解的存在性

利用凸幂凝聚算子的不动点定理研究了Banach空间中一类非线性Volterra型积分方程u(t)=h(t)+∫t0g(t,s)f(s,u(s)ds t∈J=[0,a](∩)R获得了解的存在性结果.定理1 设f满足:(H1)对任给R>0,f在J×BR上一致连续,且存在连续函数α(s)≥0和常数b>0,使得(＝)f(s,u(s)(＝)≤a(s)(＝)u(＝)+b,∨u∈E,并且M∫a0a(s)ds<1,其中M=max{(－)g(t,s)(－):(t,s)∈D}.(H2)存在常数L>0,使得对C(J,E)中等度连续有界集B,有a(f(t,B(t))≤La(B(t)),t∈J.则方程(1)在C(J, E)中至少存在一个解.     

Banach空间中非线性积分-微分方程的正解

利用正锥的概念及近似方法,对抽象空间中的非线性Volterra型积分-微分方程x′=f(t,x,Tx),x(t0)=x0,这里f∈C[J×E×E,E],J=[t0,t0+α],(Tx)(t)＝∫t t0 h(t,s)x(s)ds,h(t,s)∈C[J×J,R+],h0=max t,s∈J h(t,s)进行了讨论,得到了两个比较定理,并以此为工具,给出其正解的存在性,推广了文献[1]中的结果.     

Banach空间二阶积-微分方程两点边值问题解的存在性

利用上下解的单调迭代技巧讨论了Banach空间二阶积-微分方程两点边值问题-u″(t)=f(t,u(t),Su(t)),t∈I,u(0)=u(1)=θ解的存在性.其中f∈C(I×E×E,E),I=[0,1].在非线性项f满足一定的非紧性测度条件和单调性条件下,利用相应的线性方程解算子的谱半径,通过非紧性测度的精细计算,获得了其在上下解之间的最小、最大解的存在性以及在上下解之间解的唯一性.     

有序Banach空间二阶常微方程的非平凡周期解

讨论了有序Banach空间E中的非线性二阶微分方程-u″(t)+au(t)=f(t,u(t)),t∈R非平凡ω-周期解的存在性,其中a0,f:R×E→E连续.在较一般的非紧性侧度条件与序条件下用凝聚映射的不动点指数理论获得了该问题非平凡ω-周期解的存在性与多重性结果。     

抽象微分—积分方程解的混合单调迭代求法

首次应用混合单调方法,研究了Banach空间中二阶微分-积分方程边值问题u~n(t)=-f(t,u(t),Tu(t)),t∈I=[a,b]u(a)=u(b)=0解的存在与唯一性,获得了新的结果.     

非紧半群情形下时滞发展方程周期问题解的存在性

在Banach空间X中研究半线性时滞发展方程周期问题:u′(t)+Au(t)=f(t,u(t),u_t),t∈R,其中A:D(A)?X→X为闭线性算子,且-A生成X中的C_0-半群T(t)(t≥0),f为连续映射,关于t以ω为周期,u_t定义为u_t(s)=u(t+s),s∈[-r,0].应用Kuratowski非紧性测度理论及相应的不动点定理,获得了非紧半群情形下周期mild解的存在性.最后,给出了例子说明主要结果的应用.     

模糊滞后积分微分方程解的性质

讨论了一类模糊滞后积分微分方程u(t)=∫^t0g(t,s,u(s))ds f(t,xt)的性质，利用Banach不动点定理和模糊集度量空间的性质证明了这类方程解的存在性、惟一性和连续依赖性。     

关于一类带积分边值条件的二阶边值问题解的存在性结果推广

研究了如下一类带积分边值条件的二阶边值问题u″(t)+a(t)u’(t)+b(t)u(t)+λf(t,u(t))=0,t∈(0,1)11u(0)=∫u(s)φ(s)ds,u(1)=∫u(s)(s)ds应用Banach压缩映像原理和不动点指数定理及Schauder不动点定理,分别获得解的存在与唯一性,推广和扩展了相应文献的结果。     

Banach空间一类非线性分数阶微分方程边值问题解的存在性

考虑Banach空间E中一类非线性分数阶微分方程边值问题{-Dα0+u(t)=f(t,u(t))t∈Iu(0)=u'(0)=u'(1)=θ解的存在性,其中2σ≤3是实数,I=[0,1],Dα0+是标准的Riemann-Liouville导数,f:I×E→E连续,θ为E中的零元.用新的非紧性测度估计技巧,在f满足比较一般的增长条件和非紧性测度条件下,通过凝聚映射的不动点定理获得了该边值问题解的存在性.     

一类延迟积分不等式的推广及其应用

研究了一类新的非线性延迟积分不等式φ(u(t))≤n(t) ∫0α(t)'(u(s))[f1(s)w1(u(s)) g1(s)u(s) h1(s) ]ds ∫0tφ'(u(s))[f2(s)w2(u(s)) g2(s)u(s) h2(s)]ds, t∈R ,得到了新的结论,推广了已有的若干结果.     

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