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21.
Experimental results on the current-voltage characteristics of polydiacetylene (PDA) single crystals reported by Aleshin et
al [Phys. Rev. Vol. B 69, (2004) art. 214203] are reinterpreted in terms of the phonon-assisted electron tunnelling model. It is shown that
the experimental results, measured in the temperature range from 1.8 K to 300 K are consistent with the tunnelling rate dependence
on field strength, computed for the same range of temperatures. An advantage of this model over that of Aleshin et al, using
the variable range hopping (VRH) model, is the possibility of describing the behaviour of I — V data measured at both high and low temperatures with the same set of parameters characterizing this material. This assertion
is confirmed by comparison of the temperature-dependent current-voltage data extracted from Aleshin et al’s work with tunnelling
rate dependence on temperature, computed using two different expressions of the phonon-assisted tunnelling theory. The temperature
dependence of the conductivity of an ion implanted PDA crystals [B. S. Elman et al, Appl. Phys. Lett., Vol. 46, (1985) p.
100] and polypyrrole [P. Dutta et al, Synth. Met., Vol. 139 (2003) p. 201] are also explained on the basis of this model.
相似文献
22.
We prove a limit theorem in the complex plane for the Hurwitz zeta-function with algebraic irrational parameter.
Received: 14 June 2004; revised: 12 April 2005 相似文献
23.
Ihor Studenyak Yuriy Neimet Csaba Cserháti Sándor K?kényesi Edvardas Kazakevi?ius Tomas ?alkus Algimantas Ke?ionis Antanas Orliukas 《Central European Journal of Physics》2012,10(1):206-209
Structural studies of (Ag3AsS3)
x
(As2S3)1−x
chalcogenide superionic glasses in the compositional range x = 0.3–0.9 were performed by scanning electron microscopy. Temperature and compositional dependences of transmission coefficient,
electrical conductivity, and activation energy were investigated 相似文献
24.
It is well known that the Hurwitz zeta-function ζ(s, α) with transcendental or rational parameter α is universal in the sense that the shifts ζ(s + iτ ),
t ? \mathbbR \tau \in \mathbb{R} (continuous case), and ζ(s + imh),
m ? \mathbbN è{ 0 } m \in \mathbb{N} \cup \left\{ 0 \right\} , with fixed h > 0 (discrete case) approximate any analytic function. In the paper, the discrete universality is extended for some classes
of the functions F(ζ(s, α)). 相似文献
25.
H. Mishou proved that the Riemann zeta-function and Hurwitz zeta-function with transcendental parameter are jointly universal, i.e., their shifts (continuous) approximate any pair of analytic functions. In the paper, a discrete version of the Mishou theorem is presented. In this case, the parameter of the Hurwitz zeta-function and the step of discrete shifts are connected by a certain independence relation. 相似文献
26.
27.
F. Pellegrino D. Wong R. R. Alfano B. A. Zilinskas 《Photochemistry and photobiology》1981,34(6):691-696
Abstract— A detailed experimental study of the effect of intensity of a 6 ps excitation pulse on the decay kinetics and yield from phycobilisomes (PBsomes) is presented. The fluorescence from the c-phycoerythrin (PE) emission from PBsomes was found to decay as a single exponential with a time of 31 ± 4ps for an excitation intensity <1014 photons/cm2 per pulse. The risetime of the c-phycocyanin (PC) and allophycocyanin (APC) emission from PBsomes was found to be 34 ± 13 ps. Therefore, at low excitation intensities, the energy transfer time between the constituent phycobiliproteins, PE and PC, is measured to be 34 ± 13ps from the fluorescence decay time of PE and the fluorescence risetime of the PC and APC emission. The fluorescence yield from the PE emission component in PBsomes was found to be intensity dependent for excitation intensities >1014 photons/cm2. The decrease in yield with increased intensity in this case occurred at a higher intensity than in the isolated phycobiliprotein PE. The fluorescence yield of the PC and APC emission component was also found to decrease markedly with increasing excitation intensity. This is in contrast to the case of the isolated phycobiliprotein APC which showed only a slight quenching of the fluorescence. The higher quenching observed for the APC emission in the PBsome evidences the higher effective absorption of APC via energy transfer from PE to PC and APC. 相似文献
28.
Antonija Dindune Zaiga Kanepe Edvardas Kazakeviius Algimantas Keionis Janis Ronis Antanas Orliukas 《Journal of Solid State Electrochemistry》2003,7(2):113-117
Compounds of the system Li1+
x
M
x
Ti2–
x
(PO4)3 (where M=Sc, Al, Fe, Y; x=0.3) were synthesized by a solid-state reaction and studied by X-ray diffraction. The ceramic samples were sintered and investigated
by complex impedance spectroscopy in the frequency range 106–1.2×109 Hz in the temperature range 300–600 K. Two relaxation dispersions related to the fast Li+ ion transport in bulk and grain boundaries were found. The activation energies of the bulk conductivity and relaxation frequency
were obtained from the slops of Arrhenius plots. The values of the activation energies of the bulk ionic conductivity and
relaxation frequency were found to be very similar in all the materials investigated. That can be attributed to the fact that
the temperature dependences of the bulk conductivity are caused only by the mobility of the fast Li+ ions, while the number of charge carriers remains constant with temperature.
Electronic Publication 相似文献
29.
Antanas Laurinčikas Joern Steuding Darius Šiaučiūnas 《Central European Journal of Mathematics》2009,7(4):635-649
A formula for the mean value of multiplicative functions associated to certain cusp forms is obtained. The paper is a continuation
of [4]. 相似文献
30.