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991.
Florin Ambro 《manuscripta mathematica》2003,111(1):43-49
We prove a precise inversion of adjunction formula for the log variety (ℂ
d
+1,X), where X is a non-degenerate hypersurface. As a corollary, the minimal log discrepancies of non-degenerate normal hypersurface singularities
are bounded by dimension.
Received: 17 September 2002 / Revised version: 22 November 2002
Published online: 14 February 2003
Current address: DPMMS, CMS, University of Cambridge, Wilberforce Road, Cambridge CB3 0WB, England. e-mail: f.ambro@dpmms.cam.ac.uk
Mathematics Subject Classification (2000): Primary 14B05; Secondary 14M25, 52B20 相似文献
992.
In this paper, we use weighted modules ω(?)(f,t)w to study the pointwise approximation on Szasz-type operators, and obtain the direct and converse theorem, as well as characterizations of the pointwise approximation of Jacobi-weighted Szasz-type operators. 相似文献
993.
E. Rebollar M. Oujja M. Castillejo S. Georgiou 《Applied Physics A: Materials Science & Processing》2004,79(4-6):1357-1360
Optical emission and laser-induced fluorescence spectroscopies (OES and LIF) are employed to examine the plume ejected into vacuum upon UV pulsed laser ablation (248 nm, 20 ns, and 266 nm, 5 ns) of poly(methyl methacrylate) PMMA films doped with photostable compounds naphthalene (NapH) and phenanthrene (PhenH), and their photolabile iodide derivatives iodonaphthalene (NapI) and iodophenanthrene (PhenI). Spontaneous emissions observed in the irradiation of NapI and PhenI sensitised films can be assigned to excited products resulting from photodissociation of the dopants and to excited C2, CH, and CN radicals. The presence in the plume of ground state products is revealed by LIF upon excitation at 266 nm. Measurements of the dependence of the spontaneous and LIF emissions on distance to the surface, ablation fluence, and flight velocities of species are discussed with reference to the mechanistic implications derived from the measurements. PACS 52.38.Mf; 61.82.Pv; 82.50 相似文献
994.
Monika Goikoetxea María J. Barandiaran José M. Asua 《Journal of polymer science. Part A, Polymer chemistry》2007,45(24):5838-5846
The mechanisms involved in the formation of n‐butanol during the synthesis of butyl acrylate containing latices were investigated. The experimental results showed that neither the hydrolysis of butyl acrylate nor of the ester bond in the butyl acrylate segments of the polymer played a major role in the formation of n‐butanol, which was mainly generated from the polymer backbone, by transfer reactions to polymer chain followed by cyclization. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5838–5846, 2007 相似文献
995.
Christiane Albrecht 《Analytical and bioanalytical chemistry》2008,390(5):1223-1224
996.
997.
C. Foces‐Foces M. Lpez‐Rodríguez C. Prez 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(2):o95-o97
The title compound, C12H21NO3, crystallizes in two polymorphic forms, viz. the tetragonal form described here and the monoclinic form described previously [Foces‐Foces, López‐Rodríguez, Pérez, Martín & Pérez‐Hernández (2007). Cryst. Growth Des. 7 , 905–911]. The differences in the conformations of the hydroxymethyl and methylaminocarbonyl substituents have important consequences in the hydrogen‐bond interaction motifs and, therefore, in the packing arrangements. These forms are concomitant polymorphs with melting points differing by 3 K. 相似文献
998.
Gujie Qian S. Baccaro M. Falconieri Jiafang Bei A. Cecilia Guorong Chen 《Journal of Non》2008,354(40-41):4626-4629
Glasses in SiO2–ZnO–BaO system with the different ZnO/BaO ratio were studied. In some cases, BaF2 was introduced to substitute for BaO on the equal base. Photoluminescent spectra showed that ZnO in glass matrices behaved somewhat differently from ZnO crystals. Especially, the introduction of fluorine ions led to dramatic shift of UV emission band of glasses closer to that of ZnO crystals. Raman spectral analysis provided consistent results. In particular, Raman bands in the high frequency region are sensitive to effects of different ZnO/BaO or BaF2/BaO ratio on structure of glasses. 相似文献
999.
A. P. Voronov G. N. Babenko V. M. Puzikov A. D. Roshal’ V. I. Salo 《Crystallography Reports》2008,53(4):708-712
The features of doping of KDP crystals with cerium ions and organocerium complexes with alizarin complexon and arsenazo III have been investigated. It is established that “direct” doping by introducing cerium salts into the initial solution cannot be implemented. The effect of organometallic complexes of cerium on the crystal growth has been studied. Organocerium complexes predominantly enter the prismatic or pyramidal growth sectors. It is shown that the complex arsenazo III + Ce blocks the growth of the prismatic sector. Cerium-doped KDP crystals exhibit a photoluminescence band peaking at the wavelength λmax= 350 nm. 相似文献
1000.
O. M. Ostrikov 《Mechanics of Solids》2008,43(5):793-797
We propose a dislocation model of a nanotwin, which is used to calculate the stress fields in the nanotwin. We consider the role of these stresses in the process of interdislocation interaction and nanotwin growth. 相似文献