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1.
用叠加法求Burgers-KdV方程的精确解析解   总被引:3,自引:3,他引:0  
基于对Burgers方程、KdV方程和Burgers KdV方程特点的分析,提出了一种由Burgers方程的解和KdV方程的解构造Burgers KdV方程的解的叠加法,并用该法求得了Burgers KdV方程的解,所得结果与已有结果完全吻合.  相似文献   

2.
利用方程代换思想,对广义Riccati方程作变系数多项式展开,获得了(2+1)维变系数KdV方程的多种新精确解.相应地,亦得到近轴KdV方程的新精确解.  相似文献   

3.
一些非线性发展方程孤立波解的分析   总被引:1,自引:1,他引:0  
通过对Burgers方程和KdV方程解的分析,给出一般非线性发展方程的双曲函数型孤立波解之间的一个重要关系,即tanhα形式的解和(sinh 2α±√r^2-1)/(cosh 2α+r)形式的解在方程中是成对出现的,进而得到KdV-Burgers方程的新精确解,最后说明文献得到的精确解并不是KdV方程和KdV-Burgers方程的新精确解.  相似文献   

4.
RLW—Burgers方程的一类精确解   总被引:1,自引:0,他引:1  
给出了RLW-Burgers方程及Burgers方程的一类精确解析解,包含了某些文献的结果,以及其他文献的部分结果。这些解可以表示为Burgers方程和RLW方程或KdV方程的某种线性组合,修正了某些文献的结论。  相似文献   

5.
具有变系数的广义Burgers-KdV方程新精确解   总被引:2,自引:0,他引:2  
利用截断展开法求得了具有变系数的一类广义Burgers—KdV方程的新的精确解,作为特例,分别获得了具有变系数的广义KdV方程和广义柱KdV方程的精确解,由此发现了Burgers方程的一类新的孤子解。  相似文献   

6.
KdV和二维KdV方程新的双Jacobi 椭圆函数周期解   总被引:2,自引:2,他引:0  
将双Jacobi椭圆函数展开法应用于求解KdV方程和二维KdV方程(KP方程),得到了许多组新的用双椭圆函数表示的准确周期解。应用该方法得到的有些周期解在极限情况下可以退化为相应的孤立波解。这种方法还可以用于求解其它非线性波方程。  相似文献   

7.
通过分析Burgers方程、KdV方程和Burgers-KdV方程的特点,提出了一种由Burgers方程的解和KdV方程的解构造Burgers-KdV方程解的组合法,并由此求得了Burgers-KdV方程的若干显式精确解.  相似文献   

8.
一种构造Burgers和KP方程孤立子解和周期解的方法   总被引:3,自引:3,他引:0  
构造了非线性发展方程的孤立子解和周期解的形式,并且成功的用于求解(2+1)维Burgers方程和(3+1)KP方程,得到了这两个方程的一些行波解.  相似文献   

9.
我们将(1+1)维Korteweg-de Vries(KdV)方程的解,移植到含有5个变系数的广义Kaolomtsev-Petviashvili(KP)方程,成功地获得了19组KP方程的精确解和类孤波解,讨论了类孤波解随时间和边界的变化情况。  相似文献   

10.
用格子Boltzmann方法模拟KdV-Burgers方程的激波解   总被引:3,自引:0,他引:3  
采用单弛豫形式的格子Bohzmann方程,建立KdV—Burgers方程的Boltzmann模型,并数值模拟了KdV—Burgers方程的激波解.  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
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。  相似文献   

15.
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  相似文献   

16.
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  相似文献   

17.
18.
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.  相似文献   

19.
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).  相似文献   

20.
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.  相似文献   

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