一类非线性Volterra-Fredho''''m型积分方程解的存在性

本文在Banach空间X中考虑以下非线性Volterra-Fredholm型积分微分方程其中t_0≤t≤t_0+T.我们所得主要结果如下:定理 设y(t)∈C＇([t_0,t_0+T];X),K~i,K_t~i∈C(t_0,t_0+T]×[t_0,t_0+T]×X×X;X)(i=1,2).又设这里i=1,2.并且对(?)x_i,y_1∈X(i=1,2)及t,s∈[t_0,t_0+T]有其中i=1,2,0<σ≤1/(2T+1),则方程(*)在C’([t_0,t_0+T];X)中存在唯一的解x(t),且迭代序列 X_0(t)=y(t)n=0,1,2,…依C′([t_0,t_0+T];X)中的范数收敛于X_*(t).     

一类三阶周期边值共振问题解的存在性

本文研究了三阶周期边值共振问题{v'(t)=f(t,v(t)),t∈[0,T],v~(i)(0)-v~(i)(T)=0,i=0,1,2解的存在性,其中函数f:[0,T]×R→R连续且有界.当非线性项f满足适当条件时,本文发展了上下解方法并得到其解的存在性.主要结果的证明基于Lyapunov-Schmidt过程和解集连通理论.     

带耗散的气体动力学方程组的广义解存在性定理

关于一维均熵气体动力学方程组vt-ux=0,ut+[p(v)]x=0,在p(v)=k2v-γ时,(1970),T.Nishida(1968)及T.Nishida和J.A.Smoller(1973)分别就0<1,y />0,张同和郭于法(1968)就一类初值获得初值问题广义解的整体存在性。本文将上述结果推广到带耗散的气体动力学方程组vt-ux=0,ut+[p(v)]x=-A2u的情形,这里A=const。     

概率度量空间的若干结果

本文给出文献[1]中定理8.15及8.25的逆定理,并证明其中的条件是最佳的.为方便计,我们将所得的逆定理与原有结果适当修正综合起来以充要条件的形式叙述.引理1 设T是左连续t-范数,且L是满足交换律、结合律的算子,并满足若u_1a+b,由于L(a,b)≤Sum(a,b)≤a+b相似文献   

关于L~2(Ω,R~3)中方程div b=0

对于b∈L~2(Ω,R~3),v·b|аΩ=0,运用一个初等方法我们证明方程div b=0有一个解b=cur|φ,其中φ属于Sobolev空间H_0~1(Ω,R~3).     

非线性积分微分方程广义解的存在性与唯一性

在可测向量函数空间讨论了形如x(t)=F(t,x(t),T_x(t)),x(t_0)=x_0的积分微分方程所描述的不连续系统广义解的存在性,建立了较一般的唯一性的定理。进而讨论了广义解对参数和扰动的连续依赖性,对算子T的不同性态给出了一些实用的结果。     

非线性一阶周期边值问题解的分歧结构

利用分歧理论和解集连通理论,研究非线性一阶周期边值问题{u'+λu+f(t,u)=h(t),t∈[0,T],u(0)=u(T),在λ=0附近解的个数的变化情况,其中h∈C[0,T]且∫_0~Th(s)ds=0,非线性函数f∈C([0,T]×R,R)并满足广义符号条件,T0,λ∈R是一个参数.证明存在λ_+,λ_-0,当λ∈[0,λ_+]时,该问题至少有一个解;当λ∈[-λ_-,0)时,该问题至少有3个解.     

二次规划矩阵分解算法一文的更正

本学报1991年第1期上刊出的“二次规划的矩阵分解算法”一文有一个错误,那就是矩阵广义逆的性质2)对于 Moore-Penrose 广义逆不成立,这样算法求出的解不是二次规划的解.现在特作修改如下:1)将定理6中的 A 改为 A~T.2)将55页倒数第1行至56页第5行改为:对(QP)~*中的 L~(-1)A 进行QR 分解(?)则 A(L~(-1))~T 的 Moore-Penrose 广义逆为〔A(L~(-1)~T)〕~+=(L~(-1)A~T)〔(A(L~(-1))~T)(L~(-1)A~T)〕~(-1)=Q(?)(〔R~T,0〕Q~TQ(?))~(-1)     

关于一类含自然增长条件的变分不等式

该文讨论如下的含自然增长条件的变分不等式:求u∈K∩L~∞(Ω),使得∫_Ωa_(αβ)(x,u)D_αuD_β(v-u)dx+1/2∫_Ω(v-u)D_ua_(αβ)(x,u)D_αuD_βudx≥0,?v∈K∩L~∞(Ω)其中K={v∈H~(1,2)(Ω),v≥Ψa.e.于Q,v|?Ω=u_0},得到了其解的存在性。     

具有变号位势的二阶Hamilton系统周期解的存在性定理

Hamilton系统是动力系统的特例,Hamilton系统的研究对气体力学、流体力学、相对论力学和核物理等学科起着重要作用.研究具有变号位势的非自治二阶Hamilton系统ü(t)+b(t)▽(u(t))=0,a.e.t∈[0,T]在满足边界条件u(0)-u(T)=u(0)-u(T)=0下周期解的存在性,其中,T>0,b∈C(0,T;R)满足b■0,∫T0b(t)dt=0并且V∈C1(RN,R).利用Rabinowitz的广义山路引理,证明了系统至少存在一个非平凡的解,推广了一些文献的结论.     

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.     

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-