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Pier Luigi Barili Giancarlo Berti Giorgio Catelani Felicia D'Andrea Francesco De Rensis Giampaolo Goracci 《Journal of carbohydrate chemistry》2013,32(8):1167-1180
Abstract The unreported title compound and its 2,6-di-O-benzyl derivative have been prepared from methyl β-D-galactopyranoside through a sequence involving the bisglycoside methyl 2,6-di-O-benzyl-5-O-methoxv-β-D-galactopyranoside 8, the precursor of L-orabino-hexos-5-ulose, that was converted to the L-lyxo series by inversion at C-3. The inversion was achieved in acceptable yields by selective triflation, followed by displacement with benzoate, and by an oxidation/reduction sequence. Whereas 2,5-di-O-benzyl-L-lyxo-hexos-5-ulose exists entirely as a mixture of the two anomeric 1,4-furanosic forms, the unprotected hexos-5-ulose involves at equilibrium in CD3CN/D2O at least eight tautomers, one of which is predominant. 相似文献
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Roberto Franzosi Salvatore M. Giampaolo Fabrizio Illuminati Roberto Livi Gian-Luca Oppo Antonio Politi 《Central European Journal of Physics》2011,9(5):1248-1254
The dynamics of repulsive bosons condensed in an optical lattice is effectively described by the Bose-Hubbard model. The classical limit of this model, reproduces the dynamics of Bose-Einstein condensates, in a periodic potential, and in the superfluid regime. Such dynamics is governed by a discrete nonlinear Schrödinger equation. Several papers, addressing the study of the discrete nonlinear Schrödinger dynamics, have predicted the spontaneous generation of (classical) breathers in coupled condensates. In the present contribute, we shall focus on localized solutions (quantum breathers) of the full Bose-Hubbard model. We will show that solutions exponentially localized in space and periodic in time exist also in absence of randomness. Thus, this kind of states, reproduce a novel quantum localization phenomenon due to the interplay between bounded energy spectrum and non-linearity. 相似文献
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Roberto Artuso Giampaolo Cristadoro 《Communications in Nonlinear Science & Numerical Simulation》2003,8(3-4):137
We review how transport properties for chaotic dynamical systems may be studied through cycle expansions, and show how anomalies can be quantitatively described by hierarchical sequences of periodic orbits. 相似文献
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We investigate the transfer of w-stability and Clifford w-regularity from a domain D to the polynomial ring D[X]. We show that these two properties pass from D to D[X] when D is either integrally closed or it is Mori and w-divisorial. 相似文献
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Antonino Lauria Ilenia Abbate Noemi Gambino Giampaolo Barone 《Tetrahedron letters》2008,49(35):5125-5128
Derivatives of the new ring system pyrazolo[3,4-d][1,2,3]triazolo[1,5-a]pyrimidine were synthesized from the corresponding angular isomers, through a Dimroth rearrangement, in quantitative yields. Preliminary computational studies demonstrated that this class of compounds could be a good candidate as DNA intercalating agents. 相似文献
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G. Cicogna 《Letters in Mathematical Physics》1980,4(1):9-13
We examine sequences of linear operators which are an abstract generalization of the classical operators of Sturm-Liouville. We give some hypotheses which ensure the convergence of the eigenvalues and the norm-convergence of eigenvectors of sequences of such operators. A possible application to problems of time evolution is also briefly mentioned. 相似文献
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Giampaolo Giacomelli Luciano Lardicci Carlo Bertucci Anna Maria Caporusso 《Tetrahedron》1978,34(13):2015-2020
The synthesis and the physical properties of some optically active 1,4-dialkylbuta-1,3-dienes are reported. The synthetic processes employed were essentially stereospecific. NMR, UV and CD spectra of these compounds provide information on the main conformation of the conjugated diene system, which was shown to be s-trans planar. 相似文献
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