一类具有逐段常变量微分方程的渐近概周期解

通过构造差分方程的渐近概周期序列解,讨论了具有逐段常变量的微分方程x（t）=ax（t）＋bx（[t]）＋F（t,x）的渐近概周期解的存在性．     

广义渐近拟非扩张型映象不动点的逼近

本文讨论了Banach空间中非空闭凸子集上的广义渐近拟非扩张型映象的迭代逼近问题,给出了具误差的修改的Ishikawa迭代序列{xn}强收敛到广义渐近拟非扩张型映象T不动点的充要条件：设E是Banach空间,C是E中的非空闭凸子集,T∶C→C是广义渐近拟非扩张型映象,其渐近系数kn满足∑∞n=1（kn-1）〈∞,又设F（T）有界,且T在F（T）中的点处一致连续。任取一点x0∈C,{xn}是根据xn＋1=αnxn＋βnTnyn＋γnunyn=ξnxn＋ηnTnxn＋δnvn定义的具误差的修改的Ishikawa迭代得到的,其中{un},{vn}是C中的两个有界点列,{αn},{βn},{γn},{ξn},{ηn},{δn}是[0,1]中的6个数列且满足αn＋βn＋γn=1,ξn＋ηn＋δn=1,∑∞n=1βn〈＋∞,∑∞n=1γn〈＋∞。则{xn}强收敛于T的不动点的充要条件是limn→∞infd（xn,F（T））=0,其中d（x,A）为x到集合A的距离。本文的结果推广改进了文献[1-7]中的结论。     

隐格式组产生迭代序列逼近Lipschitz映像族公共不动点

设K是Banach空间E中非空闭凸集．{Ti}i-1^N是K中具公共不动点集F=∩i-1^NF（Ti）的Lipschitz映像族，其中F（Ti）=（x∈KiTix=x}，{αn}n-1^∞}，{βn}n-1^∞包含[0，1]是实数列，且∑n=1∞（1-αn）〈＋∞，（1-αn）L^2〈1，这里L是{Ti}i=1^N的公共Lipschitz系数．对任意x0∈K，{xn}n-1^∞由文中隐格式组（2）和（3）产生，则（i）{xn}在K中收敛；（ii）{xn}收敛于{Ti）i=1^N公共不动点的充分必要条件是lim d（xn,F）=0．对于（2），如聚βn=0。隐格式组变为xn=αnxn-1＋（1-αn）Tm^2xn,如果βn=1，隐格式组变为Xu与Or1的形式xn=αnxn-1＋（1-αn）Tnxn，对于（3），如果βn=1，隐格式组变为显格式xn=αnxn-1＋（1-αn）Tnxn-1．对于这三种特殊迭代格式，结论（i）（ii）自然成立．     

非线性强增生算子方程解的迭代逼近定理

设1〈P≤2,X是实P-一致光滑的Banach空间,T：X→X是强增生算子．研究了用带误差的Ishikawa迭代程序：（xn＋1）=（1-αn）xn＋αn（f-Tyn＋yn）＋un, yn=（1-βn）xn＋βn（f-Txn＋xn）＋υn,n≥0,）来逼近方程Tx=f解的问题,其中x0∈X,｛un｝｛υn｝是X中的有界序列,｛αn｝,｛βn｝,是[0,1]中的实数列．在无需假设条件αn→0之下,证明了,当T连续时,迭代序列{xn}强收敛到方程Tx=f的唯一解。     

一类差分方程概周期解的存在性和稳定性

通过构造离散形式的Liapunov函数,研究了一类形如x(n+1)=α(n)c(n)/(1+β(n)x(n))的差分方程的概周期解的存在性,得到了不同于已有文献的新结论.     

关于二元函数的三角插值逼近

目的为克服Lagrange插值多项式不能对任意连续函数都一致收敛的问题,构造了一类二元乘积型三角插值多项式算子使得该算子在全平面上能够一致收敛到每个以2π为周期的二元连续函数。方法通过对Lagrange插值三角多项式的平移与组合,在已有成果的基础上做了推广,构造了一类形式较为广泛的二元乘积型三角插值多项式Tmn（f;x,y）=∑k=0^2m∑l=0^2nf（xk,yl）mα^k（x）mβ^l（x）,进而讨论了该算子的逼近性质。结果／结论证明了该算子在全平面上一致收敛到任意以2π为周期的二元连续函数,并且对C2π,2π^s,r（s≤α,r≤β）函数类的逼近均达到最佳收敛阶,即,当f（x,y）∈C2π,2π^s,r,s≤α,r≤β,成立｜Tmn（f;x,y）-f（x,y）｜=O{Emn^＊（f）＋1/m^sω（ ^sf/ x^s;1/m,0）＋1/n^rω（ ^rf/ y^r;0,1/n）＋1/m^s1/n^rω（ ^s＋rf/ x^s y^r;1/m,1/n）}。     

用待定系数法求非齐次欧拉方程的特解

直接用待定系数法详细地讨论了两类常见的二阶非齐次欧拉方程x2y＇＇＋axy＇＋by=xαPm（lnx）,x2y＇＇＋axy＇＋by=xα[Px（lnx）cos（βlnx）＋Pn（lnx）sin（βlnx）],特解的求法,并对求n阶非齐次欧拉方程的特解作了必要的说明.     

一类非线性奇摄动问题边界层与边值的关系

利用匹配渐近展开法,讨论了一类二阶非线性奇摄动问题εy″＋yy＇＋xy＋y^2=0,x∈（0,1）,y（0）=α,y（1）=β,通过匹配方程的内层解、外部解及边界层解,得出解的层性态与边界条件的关系,并给出了解的渐近表示.     

赋范空间中有限个渐近一致φ2 伪压缩映象公共不动点的迭代逼近

设X是一实赋范空间,D是X的非空凸子集．Ti：D→D（i=1,2,…,m）是m个渐近一致φ-伪压缩的一致L-Lipschitzian映象．证明了在一定条件下,关于{xn}的迭代：xn＋1=（1-α1,n）xn＋α1,n T1^ny1,n;y1,n（=1-α2,n）xn＋α2,nT2^ny2,n;…;ym-1,n=（1-αm,n）xn＋αm,n Tm^xxn, n≥0强收敛于有限个渐近-致φ-伪压缩的一致L—Lipschitzian映象Ti（i=1,2,…,m）的公共不动点．     

赋范空间中有限个渐近一致φ-伪压缩映象公共不动点的迭代逼近

设X是一实赋范空间,D是X的非空凸子集．Ti：D→D（i=1,2,…,m）是m个渐近一致φ-伪压缩的一致L-Lipschitzian映象．证明了在一定条件下,关于{xn}的迭代：xn＋1=（1-α1,n）xn＋α1,n T1^ny1,n;y1,n（=1-α2,n）xn＋α2,nT2^ny2,n;…;ym-1,n=（1-αm,n）xn＋αm,n Tm^xxn, n≥0强收敛于有限个渐近-致φ-伪压缩的一致L—Lipschitzian映象Ti（i=1,2,…,m）的公共不动点．     

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