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921.
The infrared spectrum of allene has been recorded with high resolution (0.002-0.004 cm?1) on a Fourier transform instrument in the region 730 to 1170 cm?1 containing the perpendicular bands, ν9 and ν10. A total of 21 subbands with KΔK ranging from ?6 to +14 have been assigned in the ν9 band, and 26 subbands with KΔK = ?10 to +15 have been assigned in the ν10 band. The bands are affected by a combination of a Jz-Coriolis and a quartic anharmonic interaction between their upper states ν9 and ν10. In addition, several other more localized perturbations are found in the spectrum. The nature of the interactions responsible for these perturbations is discussed, and five of the strongest perturbations are quantitatively accounted for by constructing a Hamiltonian matrix which includes five different perturbing states and their Coriolis and anharmonic resonances with the ν9 and ν10 upper states. A set of spectroscopic constants for the ν9 and ν10 states and for some of the perturbing states is reported. 相似文献
922.
[4+2] Cycloaddition reaction of 1-(cyclopenten-1-y1)-1-morpholino ethene with β-nitrostyrene leads to tetrahydroindan and tetrahydroindanone derivatives. A [4+2] adduct of interest is also obtained in the reaction of the same substrate with mesyl chloride. Reactivity of the same electrophiles with the morpholino enamine of cyclopentyl-methyl ketone is also examined. Some stereochemical aspects of the above mentioned reactions are discussed. 相似文献
923.
Valentin Savin 《Comptes Rendus Mathematique》2002,334(10):885-888
We study the stability of the Picard bundle on the moduli space of stable vector bundles of fixed rank and determinant, over an irreducible, smooth, algebraic curve of genus g?2. To cite this article: V. Savin, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 885–888. 相似文献
924.
J. Badier J. Boucrot J. Bourotte G. Burgun O. Callot Ph. Charpentier M. Crozon D. Decamp P. Delpierre B. Gandois R. Hagelberg M. Hansroul Y. Karyotakis W. Kienzle P. Le D? J. Lefran?ois Th. Leray J. Maillard A. Michelini Ph. Miné G. Rahal O. Runolfsson P. Siegrist A. Tilquin J. Timmermans J. Valentin S. Weisz NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1983,20(2):101-116
A detailed study ofJ/ψ hadronic production has been performed in a high statistics experiment (more than 1.5 106 J/ψ observed in their dimuon decay mode). Data have been taken with incident π±,K ±,p ±, on hydrogen and platinum targets, at 150, 200 and 280 GeV/c. We find from the observed nuclear dependance of the cross sections, that about 18% of theJ/ψ are produced diffractively. Using known structure functions of the quarks in the nucleon and in the pion, we derive estimations for the gluon structure functions. 相似文献
925.
Valentin Rodriguez Marc A. Nicolet 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1967,18(2):280-289
Zusammenfassung Die Zeitabhängigkeit des Stromstossesi(t) wird berechnet, den eine kleine Ladung beeinflusst, wenn sie sich durch das elektrische FeldE(r) bewegt, das ein stationärer, raumladungsbegrenzter Strom in drei verschiedenen Medien und in Strukturen von ebener, zylindrischer und sphärischer Geometrie erzeugt. Die drei betrachteten Medien sind das Vakuum, und zwei Festkörper, in denen entweder die Beweglichkeit oder die Bahngeschwindigkeit der Ladungsträger von der Feldstärke unabhängig ist. Man findet, dass für die beiden Festkörperi(t) undE(r) zwei eng verwandte Funktionen sind, deren Zusammenhang beschrieben wird. Eine experimentelle Bestimmung der Feldverteilung nach diesem Verfahren erscheint knapp durchführbar und würde direkte Einsicht in den Vorgang des Stromflusses vermitteln. 相似文献
926.
927.
Beck TJ Klust A Batzill M Diebold U Di Valentin C Selloni A 《Physical review letters》2004,93(3):036104
A combined experimental and first principles study of the (2x1)-reconstructed rutile TiO2(011) surface is presented. Our results provide evidence that the surface structure is described by a model that includes onefold coordinated (titanyl) oxygen atoms giving rise to double bonded Ti=O species. These species should play a special role in the enhanced photocatalytic activity of the TiO2(011) surface. 相似文献
928.
Zhigulin VP 《Physical review letters》2004,92(23):238701
Spatiotemporal network dynamics is an emergent property of many complex systems that remains poorly understood. We suggest a new approach to its study based on the analysis of dynamical motifs-small subnetworks with periodic and chaotic dynamics. We simulate randomly connected neural networks and, with increasing density of connections, observe the transition from quiescence to periodic and chaotic dynamics. This transition is explained by the appearance of dynamical motifs in the structure of these networks. We also observe domination of periodic dynamics in simulations of spatially distributed networks with local connectivity and explain it by the absence of chaotic and the presence of periodic motifs in their structure. 相似文献
929.
Operator-valued Fourier multiplier theorems are used to establishmaximal regularity results for an integro-differential equationwith infinite delay in Banach spaces. Results are obtained undergeneral conditions for periodic solutions in the vector-valuedLebesgue and Besov spaces. The latter scale includes in particularthe Hölder spaces C, 0 < < 1 . 相似文献
930.
Let A and B be non-negative self-adjoint operators in a Hilbert space such that their densely defined form sum obeys dom(Hα)⊆dom(Aα)∩dom(Bα) for some α∈(1/2,1). It is proved that if, in addition, A and B satisfy dom(A1/2)⊆dom(B1/2), then the symmetric and non-symmetric Trotter-Kato product formula converges in the operator norm:
||(e−tB/2ne−tA/ne−tB/2n)n−e−tH||=O(n−(2α−1))||(e−tA/ne−tB/n)n−e−tH||=O(n−(2α−1)) 相似文献