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51.
52.
Properties of the real part of the interaction potential between two colliding ions are studied. The calculations are performed in the framework of the energy density formalism, using the sudden approximation. In particular, we show that the potential can be written as the product of a “universal” function and of a geometrical factor. The universal function itself can be parametrized in a simple way. Connections with the proximity theorem of Randrup, Swiatecki and Tsang are discussed in detail. Comparisons with other available potentials are made for a typical example. 相似文献
53.
The vocal signal emitted by a human operator is characterized by a high degree of variability. Therefore, the fuzzy-set theory can be successfully applied to vocal patterns the contours of which differ from one speaker to another and even for the same one vary with his state of tiredness and humour, and with many other factors [1]. 相似文献
54.
Quintanilla E Dávalos JZ Abboud JL Alcamí M Cabildo MP Claramunt RM Elguero J Mó O Yáñez M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(6):1826-1832
Fourier transform ion cyclotron resonance spectroscopy (FT ICR) techniques, including collision-induced dissociation (CID) methodology, were applied to the study of the gas-phase protonation of pivalaldehyde (1) and 1-adamantanecarbaldehyde (2). A new synthetic method for 2 was developed. The experiments, together with a thorough computational study involving ab initio and density functional theory (DFT) calculations of high level, conclusively show that upon monoprotonation in the gas phase, compound 1 yields monoprotonated methyl isopropyl ketone 3. The mechanism of this gas-phase acid-catalyzed isomerization is different from that reported by Olah and Suryah Prakash for the reaction in solution. In the latter case, isomerization takes place through the diprotonation of 1. 相似文献
55.
R. Quintanilla 《Applied mathematics and computation》2010,216(9):2759-2765
In this note we investigate the continuous dependence of the solutions for a theory of heat conduction with a delay term. We use energy arguments to obtain the continuous dependence results and spectral arguments to prove the non-uniqueness result. The extension to the thermoelastic problem is also pointed out. 相似文献
56.
57.
Bazarra Noelia Castejón Alberto Fernández José R. Quintanilla Ramón 《Meccanica》2021,56(12):3025-3037
Meccanica - In this work we study, from the numerical point of view, a one-dimensional thermoelastic problem where the thermal law is of type III. Quasi-static microvoids are also assumed within... 相似文献
58.
The auto triple correlation has several fundamental advantages over the ordinary autocorrelation of second order. We present an optoelectronic processor for the computation of the auto triple correlation. 相似文献
59.
Alicja Kowalska Krystian Pluta Andrzej Masślankiewicz Roman Luboradzki 《Journal of chemical crystallography》1999,29(1):103-106
The title compound (C8H10N4O2) is monoclinic, with a = 7.740(2), b = 17.044(7), c = 6.992(3) Å, = 100.60(1)°, and space group P21/c. Two O-methyl groups are coplanar with the pyrimidine ring. Whereas, the O(6)-methyl group is directed away from the imidazole ring toward the N(1) atom, the O(2)-methyl is pointed away from the N(1) atom toward the N(3) atom. Two intermolecular hydrogen bonds H(8)···N(1) and H(711)···O(2) of 2.48(2) and 2.58(3) Å make a linear arrangement of the molecules. The conformation of the O-methyl groups explains some results of thermal rearrangement of 2,6-dialkoxy-7-methylpurines and differences in alkylations of 2,4-dialkoxypyrimidines and 2,6-dialkoxy-7-methylpurines. 相似文献
60.
R Quintanilla 《Mathematical Methods in the Applied Sciences》2001,24(2):93-102
This paper derives spatial decay bounds in a dynamical problem of thermoelasticity defined on a semi‐infinite cylindrical region. Previous results for isothermal elastodynamics and the parabolic heat equation lead us to suspect that the solution of the thermoelastic problem should tend to zero, faster than a decaying exponential of the distance from the finite end of the cylinder. We prove that an energy expression is actually bounded above by a decaying exponential of a quadratic polynomial of the distance. This is reminiscent of the decay rate in the second‐order parabolic problems. Similar arguments are sketched for the case of a non‐prismatic cylinder, and a non‐linear heat conduction problem for a rigid body is considered. Some extensions and generalizations are indicated in the final section. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献