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1.
文章利用MQ拟插值构造了求解Burgers-Fisher方程的无网格数值方法。在时间方向,用向前差分法对方程进行离散;在空间方向,用MQ拟插值及其导数逼近函数本身及其空间导数。该方法的特点是操作简单,不用求解大型的方程组,稳定性好。最后,将该方法与精确解的误差和其他方法与精确解的误差进行了比较,结果显示MQ拟插值方法求解此类方程表现更好。  相似文献   

2.
插值具有很高的逼近阶但是需求解线性方程组.拟插值精度较低,但不需求解线性方程组就能直接得到逼近函数.基于径向基Multiquadric(MQ)函数和Inverse multiquadric(IMQ)函数,构造新的高精度拟插值算子L*f(x),并且证明该算子的精度和线性多项式再生性.并且通过数值算例验证该算子具有良好的逼近精度.  相似文献   

3.
针对第一边界条件和周期边界条件的插值问题,给出了一种新的导数恢复格式,并用能量估计法证明了导数恢复格式按照离散L2范数具有四阶收敛精度.利用节点值和恢复出的导数值构造了一种新型的四阶精度分段三次插值函数.数值算例验证了理论分析的正确性和插值函数的实用性.  相似文献   

4.
将2次插值和Kansa方法结合应用于求解时间分数阶扩散方程,选择多重二次函数(multiquadric,MQ函数)作为径向基函数.在离散过程中,将Kansa方法用于离散空间导数,用线性插值和3点2次插值来近似Caputo型时间分数阶导数.最后讨论了数值算例的数值解,通过实验得出数值解与解析解之间的误差较小、整体稳定性好,从而验证了该方法求解分数阶扩散方程的有效性、可行性和准确性.  相似文献   

5.
重心有理插值在整个插值区间上具有足够的光滑性、不存在极点,且具有很高的逼近阶.首先基于给定权构造的重心有理插值来计算导数的近似值,再通过两族参数作为形状调节参数来构造3/1型有理插值样条使得插值函数保单调,保凸,最后分析了误差并给出了数值例子来说明新方法的有效性.  相似文献   

6.
近似特别解(MAPS)是一种基于径向基函数(RBFs)插值的无网格方法.本文采用近似特别解法来解决变时间分数阶扩散方程,在离散过程中,用有限差分法离散时间分数阶导数,用近似特别解法离散扩散项,选择薄板样条函数作为径向基函数,并把所得结果和MQ插值函数进行对比.数值结果表明在解决变时间分数阶扩散方程时,薄板样条函数所得结果比MQ函数结果更稳定,同时避免了形参c的选择,且有较高的精度和计算效率.  相似文献   

7.
介绍了算术均插商的概念,在此基础上构造了一类基于算数均差商分母为线性的有理三次插值样条.利用Peano-kernel定理讨论了此类插值样条的函数值与导数的逼近性质,并且给出了数据分析.  相似文献   

8.
石东伟 《河南科学》2006,24(3):319-321
基于牛顿插值方法,本文提出了构造具有高阶导数插值条件或缺少函数值插值条件的Hermite型插值的新格式,具有构造简单,应用广泛等优点.  相似文献   

9.
利用矩形域上的函数值及偏导数值作为插值数据,构造了一种带6个形状参数、分母为双二次的二元有理三次插值样条,讨论了其C~1连续条件,给出了诸如对称性的一些性质,证明了其有界性并作了误差分析.最后给出了一个数值例子说明了形状参数对于曲面构造的有效性.  相似文献   

10.
基于Hermite插值的高精度数值积分公式   总被引:1,自引:0,他引:1  
构造Hermite插值多项式,得到插值型求积公式.分析积分中值定理中间点的渐近性,得到具有更高精度的数值求积公式.对数值积分公式中的导数进行处理,最终得到不用计算导数值,只需计算节点处函数值的高精度数值求积公式.  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.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
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   

15.
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
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   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
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   

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