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J. W. Thomas Max Liebig D. Amato und P. Figueara 《Fresenius' Journal of Analytical Chemistry》1881,20(1):260-262
Ohne Zusammenfassung 相似文献
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Mariateresa Giustiniano Sveva Pelliccia Luca Sangaletti Fiorella Meneghetti Jussara Amato Ettore Novellino Gian Cesare Tron 《Tetrahedron letters》2017,58(45):4264-4268
A novel interrupted Ugi reaction between ortho-sulfonylaminated aryl aldehydes, secondary amines, and isocyanides affords in good to high yields N-alkyl-2,3-diaminoindoles, providing access to a so far unexplored area of the indole chemical space. With only one single chemical operation, this novel reaction affords a broad gamma of substituted 2,3-diaminoindoles with five points of diversity. The success of this novel multicomponent transformation lies in presence of the amphoteric sulfonylamino group, which sequentially acts as a Brønsted acids and as a nucleophile the lack of need for additional catalysts and the high atom economy, with the loss of only one molecule of water, renders this approach a very effective one. 相似文献
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L.P. Le R.H. Heffner J.D. Thompson G.J. Nieuwenhuys D.E. Maclaughlin P.C. Canfield B.K. Cho A. Amato R. Feyerherm F.N. Gygax A. Schenck 《Hyperfine Interactions》1997,104(1-4):49-54
The muon‐spin‐relaxation technique has been utilized to characterize the magnetic properties of the borocarbide compounds
RNi2B2C ( R=\,Tm, Er, Ho and Dy), which exhibit coexistence of superconductivity and magnetism. Some general features of their magnetic
ground‐state and unusual results obtained in the Ho, Tm and Dy systems are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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A. Grayevsky I. Felner T. Tashma N. Kaplan F. Gygax A. Amato M. Pinkpank A. Schenck 《Hyperfine Interactions》1997,104(1-4):73-78
As part of an ongoing μ+SR study on cubic van‐Vleck paramagnets of the PrM3 series ( M\ =\ In,Pb,Tl,Sn), in which the CEF level scheme varies systematically, we present preliminary static μ+SR results on a single crystal of PrIn3.
From the angular dependence and from the appearance of the μSR spectra, we could determine that stopped μ+ occupy octahedral sites of the (1/2, 0, 0) type, i.e. sites with 2 Pr and 4 In atoms as neighbors. The spectral frequency
shifts can be accounted for by assigning to the Pr sites essentially unperturbed 4f dipole moment values, as derived from
bulk magnetization measurements. The temperature dependence of the shifts scales to a good accuracy with the bulk susceptibility.
It is concluded that unlike previous observations with PrNi5, the local perturbations induced by an interstitial μ+ on the CEF levels of neighboring Pr in the PrIn3 system are small compared with the unperturbed level splitting itself.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
29.
Daniela Amato 《Journal of Combinatorial Theory, Series A》2011,118(2):403-424
The descendant setdesc(α) of a vertex α in a digraph D is the set of vertices which can be reached by a directed path from α. A subdigraph of D is finitely generated if it is the union of finitely many descendant sets, and D is descendant-homogeneous if it is vertex transitive and any isomorphism between finitely generated subdigraphs extends to an automorphism. We consider connected descendant-homogeneous digraphs with finite out-valency, specially those which are also highly arc-transitive. We show that these digraphs must be imprimitive. In particular, we study those which can be mapped homomorphically onto Z and show that their descendant sets have only one end.There are examples of descendant-homogeneous digraphs whose descendant sets are rooted trees. We show that these are highly arc-transitive and do not admit a homomorphism onto Z. The first example (Evans (1997) [6]) known to the authors of a descendant-homogeneous digraph (which led us to formulate the definition) is of this type. We construct infinitely many other descendant-homogeneous digraphs, and also uncountably many digraphs whose descendant sets are rooted trees but which are descendant-homogeneous only in a weaker sense, and give a number of other examples. 相似文献
30.
Summary The striking optical properties of porous silicon (PS) show a twofold aspect typical of an ordered and a disordered material,
respectively. Raman, electron microscopy, and resonant photoluminescence studies indicate that the light emission originates
from crystalline regions. On the contrary, several features, like the non-exponential decay of photoluminescence (PL), the
broad emission spectrum, the photoluminescence fatigue under light exposure etc. are typical of a disordered material and
reminiscent of similar effects founde.g. in amorphous semiconductors. These twoapparently conflicting aspects have for a long time hindered the understanding of the basic light emission mechanism. In this paper
we report new optical data showing that disorder in porous silicon leads to strong carrier localisation. Light emission in
PS is suggested to occur through transitions involving localized states.
Paper presented at the III INSEL (Incontro Nazionale sul Silicio Emettitore di Luce), Torino, 12–13 October 1995. 相似文献