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1.
基于径向基函数的点插值(RPIM)无网格法   总被引:1,自引:1,他引:1  
基于径向函数的点插值法(RPIM)是一种新型无网格法。它有效地解决了点插值法(PIM)中遇到的最大困难:系数矩阵奇异性问题。此外,由于插值具有巧函数的性质,从而克服了以往无网格法中难以实现的位移边界条件的难点。本文简单介绍了PIM,重点阐述了RPIM的基本原理,并用算例表明了该法具有效率高、精度高和稳定性好等优点,在工程中具有广阔的应用前景。  相似文献   

2.
在网格法的基础上,根据均匀设计法原理,提出一种解决非线性规划的新的直接法.并给出了Matlab源程序,实例表明该方法是简单和可行的.  相似文献   

3.
提出了求算段法中辐射直接交换面积的数论网格法,并用数论网格最优系数了实例计算,计算结果表明,此法比逐次局部再分法计算简单而且精度高。  相似文献   

4.
无网格法作为一种新型的数值方法,因其近似函数不依赖于网格而受到广泛关注。基于无网格法对油藏渗流问题的求解进行了研究。对无网格法的基本原理进行了详细的阐述;并针对油藏单相渗流问题推导了无网格法计算格式,通过实例计算验证了该方法的有效性。  相似文献   

5.
楔形基无网格法解的存在惟一性   总被引:1,自引:1,他引:0  
将楔形基函数与配点法结合构造了一种新的无网格法。该方法无需背景积分网格,是一种真正的无网格法。将该方法应用于求解椭圆型方程问题,给出了解的存在惟一性,并通过数值算例验证了该算法的可行性。  相似文献   

6.
针对现有固定网格法确定渗流自由面存在穿过自由面的单元等效渗透矩阵和积分域难以确定等问题,提出了加权截距法确定渗流自由面的新型有限元分析方法,解决了相应渗流溢出点的确定方法问题,并在此基础上,开发了相应的渗流有限元分析程序.该方法具有穿过自由面的单元等效渗透矩阵及其积分域易于确定和分析过程简单等优点,应用于工程实例分析,并将理论与试验结果进行比较分析,表明加权截距法确定渗流自由面的有限元分析方法可以满足工程要求,进一步完善了固定网格法确定渗流自由面的有限元分析理论与方法.  相似文献   

7.
针对以往无网格法中本征边界条件处理困难的问题,本文采用滑动Kriging插值技术代替以往无网格法中滑动最小二乘法构造无网格形函数.结果表明:与其他无网格法不同,由此方法所构造的无网格法形函数具有Kronecker δ-函数属性,从而使得本征边界条件处理非常容易.数值算例结果证明该法构造的形函数具备过点插值性质并且具有很好的曲线拟合特性,是一种非常好的无网格法形函数.  相似文献   

8.
建立了拟直接网格优化法,导出了评估该法计算量的公式,从而为避免当维数n较大时网格法所存在的组合爆炸问题提供了一个可行途径。实例计算证明,拟直接网格法特别适用于复杂结构的优化设计计算,并能在大幅度减少计算量的同时找到近似的全局最优方案。  相似文献   

9.
基于楔形基函数的一种新型无网格法   总被引:2,自引:0,他引:2  
无网格法中的近似函数大都不是插值函数,在处理本质边界条件时较为困难.通过楔形基函数插值理论来构造满足插值要求的近似函数,并通过加权最小二乘法来离散控制方程,在此基础上提出了一种新型的无网格方法--基于楔形基插值函数的加权最小二乘无网格法.该方法是一种基于节点信息的纯无网格法.将该方法应用于弹性静力学问题的求解,得到了满意的结果.  相似文献   

10.
二维弹性静力学的奇异杂交边界点法   总被引:1,自引:0,他引:1  
杂交边界点法是一种边界型的无网格法,它以修正变分原理和移动最小二乘近似为基础,同时具有边界元法和无网格法的优良特性。本文在原有杂交边界点法的基础上,借鉴了边界元法处理奇异积分的方法,避免了正则杂交边界点法中计算结果对于标量因子的依赖性。数值结果表明,奇异杂交边界点法具有较高的精度和数值稳定性。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
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   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
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   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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