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991.
Michael Ruzhansky Mitsuru Sugimoto Joachim Toft Naohito Tomita 《Mathematische Nachrichten》2011,284(16):2078-2092
In this paper various properties of global and local changes of variables as well as properties of canonical transforms are investigated on modulation and Wiener amalgam spaces. We establish several relations among localisations of such spaces and, as a consequence, we obtain several versions of local and global Beurling–Helson type theorems. We also establish a number of positive results such as local boundedness of canonical transforms on modulation spaces, properties of homogeneous changes of variables, and local continuity of Fourier integral operators on ${\mathscr F}L^q$. Finally, counterparts of these results are discussed for spaces on the torus. 相似文献
992.
The use of COMU®, as a non-hazardous partner, in the coupling of N-protected α-amino acids to N-methoxy-N-methylamine to afford the corresponding Weinreb amides is discussed. From a practical point of view the reaction can be monitored visually by virtue of the colour change associated with the conversion of substrates (yellow) into the products (orange). As the by-products of the reaction are conveniently water-soluble the products are isolated relatively pure and with minimal racemisation. These factors coupled with the short reaction time make this a very useful procedure. 相似文献
993.
Jelena S. Kiurski Dušanka Ž. Obadović Radmila P. Marinković‐Nedučin Miroslav J. Cvetinov 《Surface and interface analysis : SIA》2011,43(6):971-975
The behavior of the NiO? Al2O3 catalysts is strongly dependent on the preparation method and pretreatment conditions. In the present work, we investigate the influence of Ni(II) content and various treatment temperatures on the properties of NiO? Al2O3 catalysts prepared by impregnation method. On the basis of experimental diffuse reflectance spectroscopy data of electronic d–d transitions of Ni(II) promoter ion, the energies of electronic states in spinel‐like structure were calculated and the most probable scheme of molecular orbital have been proposed. The results of studying the system model allowed the conclusion that the type of contact between the starting phases has a decisive influence on the coordination of Ni(II) ions. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
994.
We propose a new procedure of partial cyclic reduction, where we apply a 2d‐color ordering (with d=2, 3 the dimension of the problem), and use different operators for different gridpoints according to their color. These operators are chosen so that the gridpoints can be readily decoupled, and we then eliminate all colors but one. This yields a smaller cartesian mesh and box‐shaped 9‐point (in 2D) or 27‐point (in 3D) operators that are easy to analyze and implement. Multi‐line and multi‐plane orderings are considered, and we perform convergence analysis and numerical experiments that demonstrate the merits of our approach. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
995.
996.
In 2003, O. V. Borodin and A. Raspaud conjectured that every planar graph with the minimum distance between triangles, dΔ, at least 1 and without 5‐cycles is 3‐colorable. This Bordeaux conjecture (Brdx3CC) has common features with Havel's (1970) and Steinberg's (1976) 3‐color problems. A relaxation of Brdx3CC with dΔ?4 was confirmed in 2003 by Borodin and Raspaud, whose result was improved to dΔ?3 by Borodin and A. N. Glebov (2004) and, independently, by B. Xu (2007). The purpose of this article is to make the penultimate step (dΔ?2) towards Brdx3CC. © 2010 Wiley Periodicals, Inc. J Graph Theory 66: 1–31, 2010 相似文献
997.
用P(G,λ)表示简单图G的色多项式.设G是一个给定的简单图,若对任意简单图H,当P(H,λ)=P(G,λ)时都有H和G同构(记为H≌G),则称图G是色唯一的.本文证明了以下结果:设n,k,△都为非负整数,其中k≥0,△∈{4,5},若n≥1/3k~2+1/3△~2-1/3k△-1/3k-1/3△+4/3,则完全三部图K(n,n+△,n+k)是色唯一的.同时还给出了一个猜想. 相似文献
998.
The oscillator strength and the linear and third order nonlinear refractive index changes of a cylindrical quantum well wire under intense non-resonant laser field have been investigated within the effective mass-approximation by using a finite element method. We found that the laser amplitude, the incident light and the intersubband relaxation time have an important influence on the refractive index changes. 相似文献
999.
P. TankamP. Picart 《Optics and Lasers in Engineering》2011,49(11):1335-1342
This paper presents the experimental optical analysis of the crack inside an electronic component. The optical setup is used to carry out multidimensional deformation measurements using digital color holography and the spatial multiplexing of holograms. Since the Fresnel transform method depends on wavelength, a wavelength-dependent-zero-padding algorithm is described and results in a rigorous sizing of each reconstructed monochrome image. The criterion to optimize the parameters is presented and is based on minimizing the widening of the impulse response of the full recording/reconstruction process. The application of the proposed method is illustrated through the analysis of the mechanical deformation of the electronic component, and offers keys to understand its failure mode in industrial conditions. 相似文献
1000.
夸克-夸克通过单胶子交换的相互作用在其反对称态上是相互吸引的,在致密夸克物质里,这种吸引相互作用会导致费米面上的双夸克凝聚,这就是所谓的夸克配对或色超导现象。本文介绍了夸克配对或色超导现象的基本知识和一些新进展。色超导是一个对称性自发破坏现象,有非常丰富的破缺方式,我们介绍了色超导对称性及其自发破坏模式的分析方法,介绍了怎样计算色超导体两个最基本的变量:能隙和迈斯纳质量。然后我们介绍了描述色超导现象的有效理论。最后是这些理论的一个应用,即计算色超导体里的中微子发射率以及其它输运性质。本文可以作为研究夸克物质理论的入门参考资料。 相似文献