近似求解Cahn-Hilliard方程的拟谱方法

利用拟谱方法研究了非线性Cahn-Hilliard方程解的近似, 分析了半离散与全离散近似解的收敛性和稳定性, 并给出收敛速度的估计. 同时还讨论了半离散问题解的爆破现象.     

四阶非线性奇异抛物方程的有限元方法的误差估计

考虑了一类四阶非线性奇异抛物方程,给出了其变分问题及半离散和全离散格式;给出了半离散解的加权L2模及加权H2模误差估计;然后又给出了全离散解即C-N方法的加权L2模误差估计.     

具有非线性传导率的麦克斯韦方程的一个保能量混合有限元

本文针对具有非线性传导率的麦克斯韦方程构造了一个保能量的混合有限元. 其中，对麦克斯韦方程的一阶形式, 本文直接使用有限元外微分去离散空间变量, 得到保能量的半离散格式，进而通过一个二阶连续时间Galerkin方法 (CTG) 去离散半离散格式的时间变量，得到保能量的全离散格式. 本文中的半离散和全离散格式能够精确地保持磁场的严格无散条件，具有最优收敛阶. 数值算例验证了理论结果.     

广义Ginzburg-Landau方程的Legendre拟谱方法

利用Legendre拟谱方法对广义Ginzburg-Landau方程的Dirichlet问题构造了半离散和全离散逼近格式,并对半离散和全离散格式的解给出了误差估计.     

一类半线性波动方程的整体吸引子

本文考虑了一类一维带阻尼的半线性波动方程,建立了半离散的Legerldre谱格式,分析了由这种谱格式生成的离散系统的动力性质,在有限时间段（0,T],证明了这个离散动力系统的整体吸引子的存在性,并证明了半离散的Legendre谱格式解的稳定性和收敛性。     

中立型延迟抛物方程的有限元分析

考虑一类中立型延迟抛物方程的有限元分析.基于线性有限元空间,构造中立型延迟抛物方程的半离散和两个全离散有限元格式.借助投影算子作为分析工具,证明了半离散和全离散有限元格式解的L~2范数误差估计.通过数值实验验证了理论分析结果.     

具有软硬件可修复计算机系统解的半离散化

为了解决利用数值计算研究具有软硬件可修复计算机串联系统模型的问题,利用半离散化逼近方法将一个抛物型偏微分方程化为矩阵常微分方程,且后者在许多问题上可以作为原问题的近似.将半离散算法应用到具有软硬件可修复计算机系统模型中,对系统中的修复率进行离散,得到了该系统的半离散化模型,运用泛函分析理论证明了半离散算法的收敛性,结果表明:离散后方程的解收敛于原方程的解,从而为该模型进一步的数值计算提供了理论基础.     

半线性带阻尼波动方程的有限元方法

给出了半线性带阻尼波动方程的半离散和全离散有限元逼近格式,并对其进行了理论分析,得到了最优Ｌ＾２和Ｈ＾１误差估计。     

一类半线性波动方程的整体吸引子

本文考虑了一类一维带阻尼的半线性波动方程,建立了半离散的Legendre谱格式,分析了由这种谱格式生成的离散系统的动力性质,在有限时间段(0,T],证明了这个离散动力系统的整体吸引子的存在性,并证明了半离散的Legendre谱格式解的稳定性和收敛性。     

均匀棒纯纵向运动方程的半离散有限元方法

研究了均匀棒纯纵向运动方程半离散有限元法,利用椭圆投影,获得了半离散有限元逼近的一些最优误差估计。     

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)

正~~     

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.