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131.
The famous Zlámal’s minimum angle condition has been widely used for construction of a regular family of triangulations (containing
nondegenerating triangles) as well as in convergence proofs for the finite element method in 2d. In this paper we present and discuss its generalization to simplicial partitions in any space dimension. 相似文献
132.
Jan H. Brandts Sergey Korotov Michal K?í?ek 《Linear algebra and its applications》2008,429(10):2344-2357
This paper provides a sufficient condition for the discrete maximum principle for a fully discrete linear simplicial finite element discretization of a reaction-diffusion problem to hold. It explicitly bounds the dihedral angles and heights of simplices in the finite element partition in terms of the magnitude of the reaction coefficient and the spatial dimension. As a result, it can be computed how small the acute simplices should be for the discrete maximum principle to be valid. Numerical experiments suggest that the bound, which considerably improves a similar bound in [P.G. Ciarlet, P.-A. Raviart, Maximum principle and uniform convergence for the finite element method, Comput. Methods Appl. Mech. Eng. 2 (1973) 17-31.], is in fact sharp. 相似文献
133.
134.
135.
Rapid solidification processing (cooling rate from the interval 105–106 K s−1) was used to prepare deeply undercooled cryolite-alumina melts. Such prepared samples were analyzed by the XRD method. Besides
cryolite, XRD patterns belonging to ι-Al2O3 were recorded. The influence of annealing on the XRD patterns of deeply undercooled melts was also investigated. 相似文献
136.
Milan Nádvorník Vratislav Langer Robert Jirásko Michal Holčapek Tomáš Weidlich Antonín Lyčka Alexander Popkov 《Polyhedron》2008
A preparative procedure for the synthesis of an important chiral synthon of side-chain protected tyrosine was developed and optimised for the minimisation of nickel salts waste. While preparing a similar side-chain protected tryptophan synthon, an unexpected low stability was found of the Boc-protective group of the tryptophan aromatic nitrogen during purification on silica gel. X-ray crystal structure determination, tandem mass spectrometry (MS/MS) and NMR were applied for the elucidation of the structures of the prepared complexes and by-products. Stereochemistry of products of α-methylation of the complexes was assessed using a model tyrosine-derived compound. 相似文献
137.
Tyihk Ern Mricz gnes M. Ott Pter G. Hajnos Michal L. Gowniak Kazimierz 《平面色谱法杂志一现代薄层色谱法》2008,21(5):331-336
JPC – Journal of Planar Chromatography – Modern TLC - The accumulation of hydrogen peroxide (H2O2) is an early and crucial step in paclitaxel-induced cancer cell death before commitment... 相似文献
138.
(Dynamic Interpretation of Infrared Spectra) Results of investigation of an algorithm, based on a novel static-dynamic method, for interpretation of infrared spectra are presented. The IRSCAN-D algorithm can recognize 103 infrared-active substructures comprising C, H, N, O, S, halogen, P and Si atoms. The results indicate that the algorithm is efficient; roughly 97% of the substructures are correctly ascribed, with a surprisingly low number (60%) of false recognition. 相似文献
139.
Michal Korenko Marián Kucharík Jozef Vincenc Oboňa Dušan Janičkovič Rosa Córdoba José María De Teresa Blanka Kubíková 《Helvetica chimica acta》2008,91(7):1389-1399
The rapid‐solidification processing (by a cooling rate of 105–106 K/s) was used for the preparation of deeply undercooled cryolite/alumina (Na3AlF6/Al2O3) melts. We found a mass of nanotubes on the surface of these undercooled melts. The nanotubes were preferentially located on the defect places of the surface with the following approximate dimensions: base≈100×100 nm, length≈1000 nm. The solidified samples with the nanotubes on the surface were analyzed by scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), X‐ray diffraction (XRD), and infrared spectroscopy (IR). 相似文献
140.
Pawel G. Parzuchowski Martyna Grabowska Michal Jaroch Monika Kusznerczuk 《Journal of polymer science. Part A, Polymer chemistry》2009,47(15):3860-3868
This article describes the synthesis of a new glycerol‐based AB2 type monomer—ethyl{3‐[2‐hydroxy‐1‐(hydroxymethyl)ethoxy]propyl}thioacetate ( 4 ) and its application for the preparation of hyperbranched polyesters. The polycondensation of 4 has been performed over a wide range of catalysts and reaction conditions leading to polymers containing solely primary hydroxyl groups. The polycondensation progress has been monitored by means of 1H NMR. The degree of branching of the polymers showed to be in the range of 0.5 ± 0.03. The obtained polyesters easily undergo hydrolysis or alcoholysis and may be of interest as recycled materials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3860–3868, 2009 相似文献