一类分数阶微分方程多点边值问题的多解性

本文主要研究一类Riemann-Liouville分数阶微分方程多点边值问题:{D_(0+)~αu(t)+f(t,u(t),u′(t))=0,u(0)=u′(0)=u″(0)=…=u~(n-2)(0)=0,u′(1)=∑m-2i=1β_iu′(ξ_i),其中0≤t≤1,n-1α≤n,n≥2,0β_i1,0ξ_i1,i=1,2,…,m-2。a_i0,∑m-2i=1β_iξ_i~(α-2)1。先利用Schauder不动点定理得到边值问题解的存在性,再由Leggett-Williams不动点定理证明边值问题至少存在3个正解的存在性,所得结论更为丰富,推广了已有文献的结果,最后举例子说明本文结论的正确性。     

一类二阶非线性四点边值问题正解的存在唯一性

运用单调迭代方法讨论二阶非线性常微分方程四点边值问题u″(t)+f(t,u(t))=0,t∈(0,1),u(0)=βu(ξ),u(1)=αu(η)正解的存在唯一性,其中ξ,η∈(0,1),0≤β(1-ξ)<1,0≤αη<1.推广和改进相关文献的结果.     

变号二阶四点奇异边值问题正解的存在性

运用上下解方法和拓扑度理论研究了变号二阶四点奇异边值问题u″+h(t)f(t,u)=0,0＜t＜1,u′(0)=αu(ξ),u(1)=βu(η)至少一个正解的存在性.     

一类二阶常微分方程组多点边值问题多个正解的存在性

利用不动点定理,并赋予f,g一定的增长条件,讨论了一类二阶常微分方程组u″(t)+f(t,v(t))=0,0≤t≤1;v″(t)+g(t,u(t))=0,0≤t≤1;u′(0)=∑i=1 m-2 biu′(ξi),u(1)=∑i=1 k aiu(ξi)-∑i=k+1 m-2 aiu(ξi),v′(0)=∑i=1 m-2 diu′(ηi),v(1)=∑i=1 l civ(ηi)-∑i=l+1 m-2 civ(ηi),多个正解的存在性,其中f,g∈C([0,1]×[0,∞),[0,∞)).     

一类非线性分数阶微分方程边值问题正解的存在性

本文运用Schauder不动点定理和Krasnoselskii’s不动点定理获得了非线性分数阶微分方程边值问题~CD■u(t)=f(t,u(t),u′(t),u″(t)),t∈(0,1),u′(0)+u″(0)=0,u′(1)+u″(1)=0,u(0)=0正解的存在性,其中2α≤3,~CD■是Caputo分数阶导数.     

三阶无穷多点边值问题正解的存在性

本文研究了如下三阶微分方程的无穷多点边值问题{u'+λa(t)f(u)=0,t∈(0,1),u(0)=βu′(0),u(1)=∑∞i=α1u(ξi),u′(1)=0正解的存在性,其中参数λ0,ξi∈(0,1),αi∈(0,∞],且满足∑∞αi i=1 1,0∞∑αiξi(2-ξi)1.a(t)∈C([0,1],[0,∞)),f∈C([0,∞),[0,∞)),运用锥拉伸与压缩不动点定理,在f满足超线性和次线性的情况下,本文不仅得到了该边值问题正解的存在性,同时还得到了使得问题有解的特征值λ的取值范围.     

一类分数阶非线性系统正解的存在性

研究了分数阶非线性系统D_(0+)~αu(t)+f(t,u(t),u′(t))=0,t∈(0,1),和边值u(0)=0,D_(0+)~β(1)=aD_(0+)~βu(ξ)的正解存在性问题。并且根据不动点理论得到其正解的存在性定理。     

奇异分数阶微分方程三点边值问题

研究了一类奇异分数阶微分方程的三点边值问题~cD_0~α+u(t)+a(t)f(t,u(t),~cD_0~μ+u(t))=0,0t1,u(0)=0,u′(1)=u′(η),u′(0)=J_0~μ+u(1),其中2α≤3,1μ=α-12是实数,~cD_(0~+)~α,~cD_(0~+)~μ是标准的Caputo阶导数,f在t=0处奇异,并利用Leggett-Williams不动点定理得到该边值问题正解的存在性.     

一类半线性分数阶微分方程解的存在性（英文）

本文考虑如下含有两项分数阶导数的半线性分数阶微分方程解的存在性问题:{~cD_t~αu(t)+λ~cD_t~βu(t)=f(t,u(t)),0t≤h,u(0)=x_0,u′(0)=y_0,其中1α≤2,αβ0,~cD_t~α为Caputo分数阶导数.利用Schauder不动点定理,作者证明了在适当条件下解存在.所得结果改进了已有结论.     

四阶四点奇异边值问题的可解性

利用Leray-Sachuder原理研究了一类四阶四点边值问题:{u(4)(t)+f(t,u(t),u″(t)=0,t∈(0,1);u(0) = 0,u(1) = au(η),u″(0) = 0,u(1) = bu(ξ).其中,η,ξ∈[0,1],a,b≥0且满足0≤aη≤1,0≤bξ≤1,得到其解的存在性,放宽利用上下解时对函数f(t,u,v)单调性的限制,并且在t=0或t=1有奇异性.     

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