p-群的Burnside环的增广理想的商群的结构

目的 讨论两类由p-群出发构造的Burnside环的增广理想的商群的结构.方法 利用轨道、稳定子和基底的关系,归纳证明.结果 确定了该商群的结构.结论 回答了关于此类Burnside环的Karpilovsky问题.     

悟出的才是自己的

在南北相对的两座大山上,各有一个寺院。他们相互之间的见解、主张不完全相同,这本来是很正常的事情。     

常用的求函数极限的方法的探讨

由于极限在微积分中的基础地位,本文结合实例,重点介绍十二种常用的求极限的方法。     

实正交矩阵的子矩阵的幂的迹的渐进分布

设随机矩阵U属于n阶实正交群O(n),O(n)的分布是单位Haar分布,[U]m表示U的m阶顺序主子矩阵,记Q=n/m～(1/n/m)[U]m.文献(Diaconis P,Shahshahani M.J Appl Probab,1994,A31:49-62.)通过计算TrUj的联合矩得出对固定的整数k,当n充分大时(TrU,TrU2,…,TrUk)渐进于正态分布.利用Jack函数和对称群的特征标的恒等式,推广这一结论到U的子矩阵情形,即证明了随机向量(TrQ,TrQ2,…,TrQk)当m→+∞时依分布收敛于正态分布.对特殊实正交矩阵群SO(n)也有类似的结论.     

改进的UMTS的认证机制的研究

详细分析了UMTS认证和密钥分配协议的过程以及协议的安全性，找出协议中存在的弱点和可能的攻击，提出了公钥加密协议的改进方法。经过分析，这一改进协议不但能满足第三代移动通信的安全需求，而且改善了UMTS在认证过程中在安全上的不足。     

矩阵的行列式的几个不等式的注记

在这篇注记里,我们将文献[1,2]中几个有关矩阵的行列式的不等式作了推广。     

面向对象的专家系统的研究

提出一种知识库独立于程序的面向对象的专家系统的实现方法,介绍了其知识表示及推理机制.该方法将规则技术与面向对象技术相结合,并且不区分事实实例与规则实例,还为用户提供一个函数加载接口,以利于用户使用函数过程且确保知识库的独立性.     

波罗的海三国的直销

波罗的海三国——爱沙尼亚、拉脱维亚和立陶宛地处波罗的海东岸,是东西方交往的天然通道,战略地位十分重要。历史上曾遭多个近邻国家占领,自第一次世界大战以来,波罗的海三国先后处于德国和前苏联的漫长统治之下,经济发展非常缓慢。苏联解体后,1991年,立陶宛、     

伦敦的盛会 英国的难题

当约翰·马克在1948年夏天的那个炎热傍晚点燃圣火时,他也许并不会意识到,圣火在伦敦的下一次燃起将要等待漫长的64年。从温布利球场到"伦敦碗",从战后的获胜者再到欧洲的"边缘人",英帝国经历几度起伏。作为"没落的贵族",伦敦奥运呈现的不只是赛场上的激情洋溢,似乎也有几分说不清、道不明的别样情结。英国与德国:结一对欢喜冤家比起近邻英国、法国在主办奥运会上的无限风光,德国在负责组织、筹办奥运会方面的经历真可谓一波三折。在现代奥林匹克运动兴起以后,世界各大国都把筹办奥运会作为彰显国力的绝好     

冰的熔解热的实验研究

冰在熔解过程中需要吸取热能，根据热力学第一定律，将冰与水混合的过程中系统的总能量守恒，即冰在熔解及升温过程中所吸收的热量就等于水降温放出的热量，最终冰熔解并达到与水相同的温度．考虑到量热器系统的吸热及系统与环境之间的换热损失，对测量结果进行修正，可求出冰的熔解热．     

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).     

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.     

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.