一类Boussinesq方程的Sobolev指数

研究了如下Boussinesq方程Cauchy问题的整体解：utt-aΔutt-2bΔut=-cΔ2u+Δu-αu+βΔ(up),u(x,0)=ε2(x),ut(x,0)=ε2ψ(x). 其中x∈Rn, n≥2, t>0, a, b, c, α是正常数,β∈R, ε>0是小参数, p≥2是正整数. 当a+c-b2>0时,得到了上面问题整体解的存在性, 而且得到方程的Sobolev指数是n2-1p-1.     

一类半线性Boussinesq方程Cauchy问题的渐近近似解

研究如下Boussinesq方程的整体解utt-2butxx=-αuxxxx+uxx+β(u2)xx,这里,x∈R1,t>0,b,α,β是正常数.假设α-b2>0时,在Sobolev空间C([0,+∞),L2([0,+∞)))∩C1([0,+∞),H-1([0,+∞)))中,得到了上面问题整体解的适定性及长时间渐近解.     

一类非线性波动方程的柯西问题

文章主要考察一类非线性波动方程uu+uxxxx+λu=σ(ux)x,λ>0的柯西问题解的存在性和唯一性.当σ(ux)x=-β(|ux|pux)x,β>0,p>0时,通过构造稳定集(位势井)W={u∈H2(R)|‖uxx‖2+λ‖u‖2<2(p+2)/pd}和不稳定集V={u∈H2(R)|‖uxx‖2+λ‖u‖2>2(p+2)/d},得到了W和V在上述方程的流下是不变的,并证明了如果初始能量E(0)≤d,那么当初值u0∈(-W)时,问题存在惟一整体解u∈C1([0,∞);H2);当初值u0∈V时,问题的解在有限时刻T1∈(t1,t1+4φ(t1)/pφ'(t1))发生爆破.     

一类Kirchhoff方程解的爆破

讨论来自研究一根具有弹性的皮筋的小振幅振动的一类Kirchhoff型方程的整体解的性质。考虑了定义在具有光滑边界Ω的有界区域Ω上的Kirchhoff型方程初边值问题。utt-M(‖u‖22)Δu+δ|ut|q-1ut=μ|u|q-1u,t≥0,x∈Ω,其中δ>0,μ∈R,p>1,q<1,γ≥1;当s≥0时,M(s)是空间C1中的非负函数,且满足M(s)≡α+βsr2,其中α,β>0,γ≥2。对解的爆破结论的证明主要采用能量方法。     

RN上奇异非线性P--调和方程的正整体解

本文研究形如△((△u)p-1*)=f(|x|,u,|(△)u|)u-β的奇异非线性p-调和方程在RN上的正整体解,此处1＜p≤N/2,β≥0是常数,N≥3,f-R+×R+×-R+→R是一个连续函数,ξa*=|ζ|α-1ξ,ξ∈R,α＞0,给出了该类方程具有无穷多个(1)有界的,(2)其渐进阶刚好为|x|(2p-N)/(p-1)(当p＞N/2)或logt(当p=N/2)的正整体解的条件.     

一类半线性热方程耦合系统的整体解

研究一类半线性热方程耦合系统带Dirichlet边界条件的问题 ,ut =vα1 uα2 (△u+u) ,　vt=uβ1 vβ2 (△v+v) ,　u =v Ω =0 ,u(x,0 ) =u0 (x) ,　v(x ,0 ) =v0 (x) (x∈Ω ,t>0 ) ,用正则化和上下解方法证明了该系统解的局部存在性 ,同时讨论了整体解的存在性 .     

障碍带条件下二阶差分方程边值问题的可解性

在障碍带条件下讨论了二阶差分方程边值问题Δ２u(k)=f(k,u(k),Δu(k)), k∈0,T,u(0)=A,Δu(T+1)=B解的存在性, 其中T ≥1是一个固定的自然数, f:0,T+2×R2 →R是连续函数.     

二维非线性Schrdinger方程平衡解的稳定性分析

讨论了非线性Schro。dinger方程:iut=-Δu-λu2u-(1+iα)u,α≠0,λ∈R.平衡解的稳定性,并应用行波解的方法证明了:当α>0时相应的平衡解是不稳定的;当α<0时,相应的平衡解是渐近稳定的.     

RN上半线性椭圆方程的正整体解

设fRn×R+×RN→R为连续函数.本文研究形如△u+f(x,u,▽u)=0,x∈RN(N≥3)的半线性椭圆方程的非径向正整体解,给出了该类方程存在衰减(即当x→∞时趋于0)的正整体解的充分条件.     

R~N中带冲突非线性项的拟线性椭圆方程的多解性

考虑 RN中含正参数 μ的拟线性椭圆方程- div(| u| p -2 u) + | u| p-2 u=q(x) | u| α-2 u-μr(x) | u| β-2 u,u∈ W1,p(RN) ,其中 :10 ,r∈ L∞ (RN) ,r(x)≥ d>0 .证明了当 μ充分大时该方程无非零解 ,而当μ充分小时该方程有足够多的分别具有正能量与负能量的解 .     

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.     

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.     

A computer generator for randomly layered structures

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

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。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

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     

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

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.