GMRES(m)算法在弹性边界元法中的应用

将基于Galerkin原理的GMRES(m)算法应用于边界元法求解大型弹性问题的计算中,使边界积分节点的划分更具任意性,实例计算结果表明,该算法比有限元法求解更精确,高效.     

Stokes方程的边界元区域分裂算法及其应用

用边界元求解不规则凹凸区域时,积分误差很大,区域分裂法是将不规则凹凸区域上的求解问题化的多个不重叠凸区域上的求解问题,在公共的边界上用Dirichlet条件,Neumann条件交替迭代得到全区域上的解。该方法计算精度高、适用于并行计算。作者给出了Stokes方程边界元求解不规则凹凸区域的区域分裂算法,并给出了将该算法用在贵阳市阿哈水库的流场计算的算例。     

波动方程的自然边界元与有限元耦合法

本文对波动方程初边值外问题提出一种有效的数值算法，首先将控制方程对时间进行离散化，得到时间步长离化格式，进而对每一时间步长求解一椭圆型外问题。引入一条圆周人工边界Г0，通过自然边界归化导出Г0的外部无界区域的自然积分方程及Poisson积分公式，讨论算法的有限元离散化及计算问题，概述了求解过程，并对此算法作了简要的评述。     

椭圆-椭圆静动态不适合边界算法

目前，计算二维几何图形是否干涉的不适合多边形(NFP)算法，针对的是多边形，尚未涉及椭圆一椭圆不干涉计算问题．因此，基于NFP法概念，提出椭圆-椭圆之间的不干涉算法，称之为不适合边界算法；进而给出了既相对平动又相对转动的椭圆-椭圆间任一时刻的动态不干涉边界算法．该法可应用于求解Packing问题、机器人路径规划、虚拟装配、医疗内外科手术等领域．     

椭圆单侧问题的边界元计算方法

单侧问题是一类重要的数学物理问题，它可以转化为互补问题进行求解。由于单侧问题的互补条件位于边界之上，特别适用于边界元法。基于Aitchison提出的关于Laplace算子的开关算法，笔者将之拓广到一般的椭圆型算子，并基于边界元方法应用开关算法，对这一问题给出了简单高效的计算方法，并进行了算法的收敛性分析，最后给出了相应的数值算例。此种算法的优点在于只须在原有的边界元程序巾．做少量的改进．并且迭代效率极高．产生的计算误差很小．结果表明．算法简明高效．     

区域分裂方法应用于屏蔽门的电磁泄漏分析

电大尺寸和复杂物体的电磁泄漏分析是计算电磁学的一个重要的研究课题，区域分裂方法（DDM）作为微分方程数值求解的新技术十分适宜求解电大尺寸的电磁场问题。提出了一种基于区域分裂方法和有限元方法（FEM）的混合算法来分析电磁防护中的电磁屏蔽门问题，在屏蔽门的边界和区域分裂的虚拟边界上分别利用吸收边界条件和传输边界条件，具有良好的收敛性质，数值结果表明了这一混合算法的有效性，同时区域分裂方法十分适合于计算机的并行计算，所以这里给出的方法适合于计算电大尺寸物体的电磁计算问题。     

快速多极虚边界元法实施过程分析

快速多极算法的主要思想在于变革计算结构,采用该算法和广义极小残值法对传统虚边界元形成的方程组求解,可使得计算复杂度和存储量与自由度数成线性比例.为便于工程推广应用,本文对快速多极虚边界元法中的树结构、上行遍历和下行遍历等关键问题进行了细致讨论,同时完整的介绍了该方法的实施步骤.采用该算法可求解大规模复杂问题.     

应用Krylov子空间方法求解边界元方程组

利用Ｋｒｙｌｏｖ子空间方法，文中给出一种适应于大型边界元方程组求解的实用迭代算法，对二维，三维弹性问题，利用这一迭代算法实现了其方程组求解的迭代过程，并与相关算法做了比较，结果初步显示了所给方法应用于边界元方程组求解的优越性。     

周期性热源下焊接温度场的边界元计算

采用边界单元法对周期性焊接热源作用下的三维焊接温度场在傅立叶变换空间域进行了求解，在计算中利用局部影响原理，大大减小了快速傅氏变换的计算工作量，使得本文算法的工程应用成为可能。     

结构网格下求解非规则区域流场的一种差分法

对于粘性不可压缩流场的计算，提出一种标识边界的差分方法，对不规则区域的流场边界做标记，应用SIMPLE算法在直角坐标系的结构网格下离散求解N-s方程；对圆柱绕流，不规则腔体流等问题进行数值模拟，取得了较好的效果。     

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.     

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.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.