某一类平面上E_3动力系统的全局结构

本文证明了Ｅ３系统ｄｘ／ｄｔ＝Ｐ３（ｘ，ｙ）ｄｙ／ｄｔ＝ｘ有的定曲线Ｆ（ｘ，ｙ）＝ｘ～２＋ｙ～２－１＝０为特解当且仅当 它具有形式： ｄｘ／ｄｔ＝ａ１ｘ＋ａ２ｙ－ａ１ｘ～３－（１＋ａ２）ｘ～２ｙ－ａ１ｘｙ～２－（１＋ａ２）ｙ３，ｄｙ／ｄｔ＝ｘ，进而讨论了系统的所有 有限远奇点和无限远奇点的性质，并且利川Ｄｕｌａｃ函数证明了ｘ～２＋ｙ～２＝１是它唯一可能的极限环。 最后我们得到由图（１）－（１０）说明的所有可能的全局结构．     

一类动力系统的大范围定性研究

本文考虑动力系统：ｄｘ／ｄｔ＝Ｐ３（ｘ，ｙ），ｄｙ／ｄｔ＝ｘ（１（．研究系统（１）具有代数曲线解：Ｘ２一ｋｙ２＝１ （ｋ＞０）（２）全局结构。 容易得到这时系统（１）等价于系统,ｄｘ／ｄｔ＝ａ１ｘ＋ａ２ｙ－ａ１ｘ３＋（ｋ－ａ２）ｘ２ｙ＋ｋａ１ｘｙ３＝ｋ（ａ２－ｋ）ｙ３，ｄｙ／ｄｔ＝ｘ（３）．由（３）我们得到所有奇点（有限远和无穷远）的类型。并用Ｄｕｌａｃ函数证明 （３）不存在极限环。进而得出（３）的所有可能的全局相图（ｌ）－（１３）．     

一类线性方程可化为常系数方程的条件

ｎ阶线性方程ｄ＾ｎｙ／ｄｘ＾ｎ＋Ｐｎ－２（ｘ）ｄ＾ｎ－２ｙ／ｄｘ＾ｎ－２＋…＋Ｐ１（ｘ）ｄｙ／ｄｘ＋ｐ０（ｘ）ｙ＝０在变换ｘ＝φ（τ）下可化为常系数线性方程当且仅当Ｐｉ（ｘ）＝Ｓｉ／（Ｃ１ｘ＋Ｃ２）＾ｎ－ｉ（ｉ＝０，１，…，ｎ－２）。     

以广义Logistic方程为基础的两种群互惠共存数学模型

以广义Ｌｏｇｉｓｔｉｃ方程ｄｘ／ｄｔ＝μｘｘｍ－ｘ／ｘｍ＋（ｋ－１）ｘ（μ,ｋ,ｘｍ为常系数）为基础,推广了Ｍａｙ－两种群互惠模型ｄｘ／ｄｔ＝μ１ｘ「１－ｘ／ｘｍ＋α２ｙ」 ｄｙ／ｄｔ＝μ２ｙ「１－ｘ／ｙｍ＋α１ｘ」用方程ｄｘ／ｄｔ＝μ１ｘｘｍ＋α２ｙ－ｘ／ｘｍ＋α２ｙ＋（ｋ１－１）ｘ ｄｙ／ｄｔ＝μ２ｙ／ｙｍ＋α１ｘ－ｙ／ｙｍ＋α１ｘ＋（ｋ２－１）ｙ描述两种群互惠共存,当ｋ１＝ｋ２＝１时,该方程     

一多项式系统的极限环

讨论了系统ｄｘ／ｄｔ＝－ｙ（１＋ｙ）＾ａ＋ｄ·Ｘ＾ａ＋ｘ＾ａ＋１＋ｄｘ＾２ｙ ｄｙ／ｄｔ＝ｘ＾２（１＋ａｘ＋ｙ）的极限环。彻底解决了该系统极限环存在的个数和分布问题。讨论的结果包含了文「１」。（α为正的奇数）。     

一多项式系统极限环的存在性和唯一性

讨论了多项式系统ｄｘ／ｄｔ＝－ｙ＾ａ（１＋ｙ）＋ｄｘ＾α（１＋ｙ）ｘ＾α＋,ｄｙ／ｄｔ＝ｘα（１＋ａｘ＋ｙ）极限环的存在性和唯一性,其中α为正的奇数,彻底解决了（１）的极限环个数和分布问题。     

具有三次曲线解的二次系统的极限环的唯一性

本文研究一类以三次曲线ｘｙ＾２＋２ｙ－１＝０为不变集的二次系统,除去明显不存在极限的情形外,该二次系统可化为ｄｘ／ｄｔ＝（ａ－１）－（１＋β）ｘ－βｘ＾２＋αｘｙ,ｄｙ／ｄｔ＝－β２＋（β＋１／２）ｙ＋β／２ｓｙ－１＋α／２ｙ＾２,经一系列变换,将上述方程化为广义Ｌｉｅｎａｒｄ方程,证明此方程最多只有一个极限环,从而完整地解决了此类二镒系统的极不的个数问题。     

多项式自治系统的极限环的唯一性

该文将下列二阶ｎ次多项式自治系统｛ｄｘ／ｄｔ＝１ａ（ｘ）｜ｈ１（ｘ）ｙ，ｄｙ／ｄｔ＝ｇ２（ｘ）＋ｈ２（ｘ）ｙ。其中ｇ１（ｘ）＝Σ（ｎ，ｉ＝０）ａｉｘ＾ｉ，ｈ１（ｘ）＝Σ（ｎ－１，ｉ＝０）ｂｉｘ＾ｉ，ｇ２（ｘ）＝Σ（ｎ，ｉ＝０）ｃｘ＾ｉ，ｈ２（ｘ）＝Σ（ｎ－１，ｉ＝０）ｄｉｘ＾ｉ，变换成Ｌｉｅｎａｒｄ方程、再利用所给引理得到二阶ｎ次多项式自治系统的极限环唯一性的几个充分条件。     

一类Lienard方程的极限环

证明了Ｌｉｅｎａｒｄ方程｛ｄｘ／ｄｔ＝Ｆ（ｘ）－ｙ ｄｙ／ｄｔ＝ｇ（ｘ）当Ｆ’（ｘ）具有两个零点时在原点外围最多有一个或两个极限环，依据Ｆ（ｘ）有一个或三个零点。并由此证明（Ⅱ）（ｍ＝０）当ａ２＋ａ４〈０，２ｓ／ａ〉１时在原点外围最多有两个极限环。     

一类具有二阶细焦点的二次系统

对如下一类具有二阶细焦点的二次系统进行了研究， ｄｘ／ｄｔ＝－６＋ａｘ＾２， ｄｙ／ｄｔ＝ｘ＋ｌｘ＾２＋ｍｘｙ＋ｎｙ＾２，其中ｗ１＝－２ａｌ－ｍ（ｌ＋ｎ）＝０，ｗ２＝ａ（２ａ＋ｍ）（３ａ－ｍ０［ｎ（ｌ＋ｎ）＾２－ａ＾２（ａｌ＋ｎ）］≠０。证明了当－１＜ｌ／ｎ≤时，系统（１）在０外围     

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.