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281.
L. P. Falaleev 《Mathematical Notes》2000,67(4):505-511
We obtain a sharp value for the constant in the leading term of the deviation of a function belonging to the class Lip1 α from the generalized Abel-Poisson operators specified by the summation factors
of the conjugate Fourier series in the case 0 < α <l ≤ 1.
Translated fromMatematicheskie Zametki, Vol. 67, No. 4, pp. 595–602, April, 2000. 相似文献
282.
283.
介绍了小波变换的基本概念和特性.通过对岩石超声波检测信号的小波分析和处理,表明该方法在奇异信号检测和局部化分析方面具有优异特性. 相似文献
284.
285.
In this study, a generalized method based upon nonextensive statistics is presented for nucleation and growth processes in a thin layer between two interfaces. It is shown that the presented mathematical model, which uses an index called the entropic index that measures the nonextensivity of the physical system, successfully deals with the nucleation and growth processes, and works better than Johnson–Mehl–Avrami–Kolmogorov model. The presented model also contains Austin–Rickett model as a special case. 相似文献
286.
Shu-fang Deng 《Physica A》2007,382(2):487-493
Darboux transformations for the isospectral and nonisospectral modified Kadomtsev-Petviashvili (mKP) equations are investigated. In the isospectral case it is an auto-Darboux transformation; however, in the nonisospectral case it is not auto-Darboux tranformation. 相似文献
287.
The photo-detachment cross section of H^- near two parallel elastic interfaces is derived and calculated by using the closed orbit theory. The photo-detachment cross section of H^- near two interfaces is shown to exhibit multi-periodic oscillations when the distance between the H^- and the interface is varied. Each peak in the Fourier transformed photo-detachment cross section corresponds to the length of a closed orbit, which is quite similar to the case of atomic spontaneous emissions in a dielectric slab. This study provides a new understanding of the photo=detachment process of H^- in the presence of interfaces. 相似文献
288.
Jürgen Geiser 《国际流体数值方法杂志》2011,65(8):877-922
We introduce a solver method for mobile and immobile transport regions. The motivation is driven by transport processes in porous media (e.g. waste disposal, chemical deposition processes). We analyze the coupled transport‐reaction equation with mobile and immobile areas. We apply analytical methods, such as Laplace‐transformation, and for the numerical methods we apply Godunov's scheme, see (Mat. Sb. 1959; 47 :271–306; Finite Volume Methods for Hyperbolic Problems. Cambridge University Press: Cambridge, 2002). The method is based numerically on flux‐based characteristic methods and is an attractive alternative to the classical higher‐order TVD methods, see (J. Comput. Phys. 1993; 49 :357–393). In this paper, we will focus on the derivation of analytical solutions for general and special solutions of the characteristic methods that are embedded in a finite‐volume method. At the end of the paper, we illustrate the higher‐order method for different benchmark problems. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
289.
FINE Jason P 《中国科学 数学(英文版)》2012,55(8):1583-1595
We consider the estimation of three-dimensional ROC surfaces for continuous tests given covariates.Three way ROC analysis is important in our motivating example where patients with Alzheimer’s disease are usually classified into three categories and should receive different category-specific medical treatment.There has been no discussion on how covariates affect the three way ROC analysis.We propose a regression framework induced from the relationship between test results and covariates.We consider several practical cases and the corresponding inference procedures.Simulations are conducted to validate our methodology.The application on the motivating example illustrates clearly the age and sex effects on the accuracy for Mini-Mental State Examination of Alzheimer’s disease. 相似文献
290.
The transformation from ferrihydrite to various iron oxides and iron oxyhydroxides has been given much attention not only in environmental science and geochemistry but also in biology and material science. This laboratory study attempted to investigate Fe(II)-induced transformation of ferrihydrite in sulfate-rich medium. The results indicate that the transformation in sulfate-rich medium differs from that in Cl− medium in the species, the amount and the morphology of products and transformation rate. Lepidocrocite is a main ingredient in the product in Cl− medium at room temperature (RT), while goethite is the only product in SO42− medium at RT. Goethite particles obtained in Cl− medium are star-like but rod-like in SO42− medium. The transformation rate in the latter medium is obviously slower than that in the former medium. The formation of lepidocrocite depends on both the ionic strength of the system and the dissolution rate of ferrihydrite. 相似文献