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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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