三维空间中半线性波方程整体解的渐近性

研究三维空间中半线性波方程utt-△u=εf(u ,ε) ,　t >0 ,u(0 ,x ,ε) =u0 (x ,ε) ,ut(0 ,x ,ε) =u1 (x ,ε) ,(其中 x∈R3 ,u是一个实值未知函数 ,△ =∑3i =1 2 x2 i,ε充分小且 0 <｜ε｜≤ε0 1,)整体解的渐近性 ,得到了在C2 空间中时间T =∞时形式近似解的合理性及适定性 .这一结果描述了形式整体解的渐近行为     

二维空间中半线性波方程整体解的渐近性

研究二维空间中半线性波方程初值问题utt-△u=εf(u,ε), t＞0, x∈R2,u(0,x,ε)=u0(x,ε), x∈R2,ut(0,x,ε)=u1(x,ε), x∈R2,整体解的渐近理论.在古典空间C2中讨论了解的适定性及形式近似解关于时间T=∞时的合理性,并用这些结果描述了形式整体解的合理性.同时给出了该渐近理论的一个应用,在二维空间中分析了一个特殊的波方程.     

一维空间中一类波方程的渐近理论

研究了一维空间中一类非线性波方程初值问题utt-uxx+p2u=εf(t,x,u,ε),t＞0,0＜x＜∞;u(0,x,ε)=u0(x,ε),ut(0,x,ε)=u1(x,ε),的渐近理论.在古典意义上研究了在长时间阶|ε|-(1)/(2)时解的适定性及形式近似解的合理性,并对近似解作了描述.     

一类非线性时滞反应扩散方程的奇摄动问题

讨论了一类具有非线性时滞反应扩散方程的奇摄动问题ε－ (L＋ε L′ )u=f(x,u,u＊ ,ε ). (t,x)∈ [0,T]×Ω, u|t=0=g(x,ε ),x∈Ω ,u=h(t,x,ε ), t∈ [－ε r,0]在一定条件下,利用比较原理得到了问题解的渐近性态 u=(Ut＋ Vi)ε i, 0<ε≤ε0.     

一类弱半线性电报方程解的渐近理论

在区域{（x，t）｜x∈R，0〈t〈L/√｜ε｜}中，研究了一类具有初值问题的弱半线性电报方程解的适定性问题，给出了解在这个区域上形式近似解的渐近合理性，并给出了所得渐近理论的应用．     

一类拟线性奇摄动问题

研究了一类具有拟线性奇摄动问题．在适当的条件下，利用微分不等式理论，讨论了该边值问题解的存在性和渐近性态．给出了渐近估计式：u0(x)-U^i0(x/ε)-u0(0) O(ε)≤u(x,ε）≤u0(x) O(ε),0≤x≤1。     

非线性摄动电报方程初值问题的渐近理论

对一类二阶半线性摄动电报方程,给出了一个渐近方法,证明了解的渐近理论及形式近似解的合理性都在时间变量无穷大时（０≤ｔ≤Ｏ（｜ε｜－１））成立,并推广了赖绍永的工作［应用数学及力学,１９９７,１８（７）：６１１～６１６］．     

退化的粘性守恒律方程解的收敛性估计

主要研究退化的粘性守恒律方程的熵解的收敛性问题.采用Kuznetsov的证明方法,类似于他对非退化的情形的讨论,证明了当‖ε‖C0→0时,粘性守恒律方程utε＋f（uε）x=ε（x,t）uεxx（ε（x,t）≥0）初值问题的解uε（x,t）收敛到无粘守恒律方程ut＋f（u）x=0相应初值问题的解u（x,t）,并给出了收...     

奇摄动拟线性边值问题的高阶近似解

研究了一类具有边界层性质的奇摄动拟线性边值问题。在相对较弱的条件下,利用合成展开法构造问题的形式近似解,然后利用不动点定理证明解的存在性,并给出满足边界层性质的高阶近似解,使得它与精确解之间的渐近估计可达到任意O(ε~n)阶近似。     

多重尺度法的机器实现

应用Mathematica系统的强大的符号运算功能以及该系统提供的控制语句,对一类弱非线性系统ue＋ω0^2u＝εf(u,u）的有效渐近展开式解进行了研究,用Mathematica系统实现了一种有效的奇异摄动方法－－多重尺度法的自动求解问题,并调试通过程序做成了程序包。     

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.     

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.     

A computer generator for randomly layered structures

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

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.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

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.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to