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171.
For a double channel Markovian queue with finite waiting space the difference equations satisfied by the Laplace transforms of the state probabilities at finite time are solved and the state probabilities are obtained in a simple closed form which can be easily used to find the important parameters of the system. 相似文献
172.
173.
Virendra Singh 《Pramana》1985,24(1-2):31-37
We propose an analytic perturbative approach for the determination of the Feigenbaum-Cvitanović function and the universal
parameterα occurring in the Feigenbaum scenario of period doubling for approach to chaotic behaviour. We apply the method to the caseZ=2 whereZ is the order of the unique local maximum of the nonlinear map. Our third order approximation givesα=2.5000 as compared to “exact” numerical valueα=2.5029 ... We also obtain a reasonably accurate value of the Feigenbaum-Cvitanović function. 相似文献
174.
175.
S. Franchetti 《Il Nuovo Cimento D》1987,9(8):915-925
Summary On the basis of the results obtained by methods of molecular dynamics by Rahman on liquid Ar, it is empirically shown that
the harmonic spectrum of the atomic motion can be interpreted as a sum of two contributions. A ?preliminary? frequency spectrum,
obtained by considering every possible (practically harmonic) motion of an atom in the field of its nearest neighbours, duly
transformed to take account of the very short duration of the single monochromatic oscillations, constitutes one of the contributions
interpretable as a superposition of disordered ?local oscillations?. The other contribution, interpretable as a superposition
of travelling waves, is given by a sum of two bands having some analogy with Rayleigh-Debye bands, but having the customary
cut replaced by a factor of the form exp [−(ω/ω0)2] whose physical meaning is that only oscillations having an amplitude larger than a minimal value appear as travelling waves.
These bands come into evidence when the spectrum of the local oscillations is subtracted from the harmonic spectrum. The lower
frequency band is quite small (area about 2% of the total area of the spectrum) and suggests the existence of transverse waves
(in the field of 1012 Hz.)
Riassunto Sulla base dei risultati ottenuti con metodi di dinamica molecolare applicati da Rahman al caso dell’argon liquido, si mostra empiricamente che lo spettro armonico dei moti atomici in questo liquido si può interpretare come somma di due contributi. Uno spettro di frequenza ?preliminare? ottenuto considerando tutti i possibili moti di un atomo nel campo dei suoi vicini piú prossimi, debitamente transformato per tener conto della brevissima durata delle singole oscillazioni, costituisce uno dei contributi, interpretabile come sovrapposizione disordinata di ?oscillazioni locali?. L’altro contributo, interpretabile come sovrapposizione di onde viaggianti, risulta formato da due bande aventi una certa analogia con le bande di Rayleigh-Debye nelle quali però l’abituale taglio discontinuon è sostituito da un fattore exp [−(ω/ω0)2] il cui significato fisico è che soltanto oscillazioni con un’ampiezza superiore ad un minimo (legato al valore di ω0) appaiono come onde viaggianti. Queste bande di onde viaggianti si evidenziano quando lo spettro delle oscillazioni locali è sottratto dallo spettro atomico. La banda di frequenza minore è molto piccola (area di circa il 2% dell’area totale dello spettro) e suggerisce l’esistenza di onde trasversali (nel campo di 1012 Hz).相似文献
176.
M. K. Baloch 《Rheologica Acta》1989,28(4):316-320
177.
178.
On application of dc electric fields to a sample of KNO2 (99.9% pure) fused between two heavily nickel plated copper plates the sample does not acquire the potential difference equal
to the applied emf even though there is no external potential drop in the circuit. Also a very large capacitance of the order
of 3000μF is obtained for this sample which is attributed to interfacial polarization effect. An equivalent circuit is given to explain
the dc electrical behaviour of the sample. The idea of solid state battery does not seem to be applicable in the case of fused
KNO2. The large value of the capacitance for dc fields in series with large voltage-dependent resistance is the cause of the slow
discharge of the condenser. 相似文献
179.
180.
Ana Brăileanu Susana Mihaiu Margit Bán J. Madarász G. Pokol 《Journal of Thermal Analysis and Calorimetry》2005,80(3):613-618
Summary Oxide materials belonging to the Sn-Ce-O system are very interesting due to their use as solid electrolytes in fuel cells, catalysts, sensors and photoanodes in solar cells. The aim of the present work is to investigate the thermal behaviour of some tin and cerium salt mixtures. Mixtures with different representative Sn:Ce atomic ratio were prepared by classical ceramic method using SnC2O4, Ce(SO4)2·4H2O and (NH4)2Ce(NO3)6 as starting compounds. The samples were investigated by means of TG/DTA methods in flowing and static air atmosphere. SnO2 and/or CeO2 were identified by X-ray diffraction and IR spectroscopy in the final decomposition products, depending on the initial composition of the both series. A different crystallinity degree of the solid products was observed depending on the Ce precursor. 相似文献