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91.
The extended Förster theory (EFT) of electronic energy transport accounts for translational and rotational dynamics, which are neglected by the classical Förster theory (FT). EFT has been developed for electronic energy transfer within donor-acceptor pairs [Isaksson, et al, Phys. Chem. Chem. Phys., 9, 1941(2007)] and donor-donor pairs [Johansson, et al, J. Chem. Phys., 105, 10896 (1996); Norlin, et al, Phys. Chem. Chem. Phys., 10, 6962(2008)]. For donors that exhibit different or identical non-exponential fluorescence relaxation within a donor-donor pair, the process of reverberating energy migration is reversible to a higher or lower degree. Here the impact of the EFT has been studied with respect to its influence on fluorescence quantum yields, fluorescence lifetimes as well as depolarisation experiments. The FT predicts relative fluorescence quantum yields which usually agree with the EFT within experimental accuracy, however, substantial deviations occurs in the steady-state and in particular the time-resolved depolarisation data. 相似文献
92.
K. R. Allakhverdiev M. ?. Yetis S. ?zbek T. K. Baykara E. Yu. Salaev 《Laser Physics》2009,19(5):1092-1104
We present an overview of the current state of the literature and research performed by the authors of the present paper on the experimental and theoretical results on the structural-, optical-, nonlinear optical (NLO)-properties (including two-photon absorption (TPA) and the terahertz (THz) range of spectra) and practical applications of a highly anisotropic Gallium Selenide (GaSe) semiconductor with emphasis on the ?-GaSe. Physical properties of ?-GaSe are important to researchers and designers developing different devices by using this material. This crystal possesses an outstanding NLO properties: high optical birefringence Δn ~ 0.3 at 700 nm; high transparency range (0.7?18.0 μm) with low absorption coefficient (α ≤ 0.3 cm?1); very high nonlinear susceptibility χ(2) (d 22 ≈ 86 ± 17 pm/V, corresponding to (2.0 ± 0.4) × 10?7 esu) that is used for phase matched second harmonic generation (SHG) in a wide transparency range; high power threshold for optical damage; possibility to perform optical frequency conversion under phase-matching conditions in the near- to mid-IR and THz range of spectra, etc. The domain structure of crystal in connection with the NLO properties is discussed as studied by confocal Raman microscopy experiments. Perspectives for future research of GaSe are considered in the present article, which does not pretend to be one reflecting all existing papers on GaSe crystal and discussed subjects. 相似文献
93.
N. Bo?kovi?-Vragolovi? R. Gari?-Grulovi? ?. Grbav?i? R. Pjanovi? 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(9):1550-1553
Mass transfer coefficient (j
D
) between fluid and column wall in liquid packed and fluidized beds of spherical inert particle has been studied experimentally
using adsorption method. Experiments were conducted in column 40 mm in diameter for packed and fluidized beds. In all runs
mass transfer rates were determined in presence of spherical glass particles 2.06 mm in diameter. This paper introduced adsorption
method as very suitable method for studies of mass transfer and for fluid flow visualization. The adsorption method is based
on the dynamic adsorption of an organic dye onto a surface covered with a thin layer of a porous adsorbent. Local and average
mass transfer coefficients were determinated from the surface color intensity of the foils of silica gel. Correlation j
D
= f(Re) was derived using mass transfer coefficients data.
The article is published in the original. 相似文献
94.
95.
96.
C. Güzeli? S. Karamamut ?. Gen? 《ARI - An International Journal for Physical and Engineering Sciences》1999,51(4):296-309
A supervised learning algorithm for obtaining the template coefficients in completely stable Cellular Neural Networks (CNNs) is analysed in the paper. The considered algorithm resembles the well-known perceptron learning algorithm and hence called as Recurrent Perceptron Learning Algorithm (RPLA) when applied to a dynamical network. The RPLA learns pointwise defined algebraic mappings from initial-state and input spaces into steady-state output space; despite learning whole trajectories through desired equilibrium points. The RPLA has been used for training CNNs to perform some image processing tasks and found to be successful in binary image processing. The edge detection templates found by RPLA have performances comparable to those of Canny's edge detector for binary images. 相似文献
97.
98.
Yasemin ?. ?iftci Kemal ?olako?lu Cansu ?oban Engin Delig?z 《Central European Journal of Physics》2012,10(1):197-205
The structural, elastic and thermodynamic characteristics of CeGa2 compound in the AlB2 (space group: P6/mmm) and the omega trigonal (space group: P-3m1) type structures are investigated using the methods of density
functional theory within the generalized gradient approximation (GGA). The thermodynamic properties of the considered structures
are obtained through the quasi-harmonic Debye model. The results on the basic physical parameters, such as the lattice constant,
the bulk modulus, the pressure derivative of bulk modulus, the phase-transition pressure (P
t
) from P6/mmm to P-3m1 structure, the second-order elastic constants, Zener anisotropy factor, Poisson’s ratio, Young’s modulus,
and the isotropic shear modulus are presented. In order to gain further information, the pressure and temperature-dependent
behavior of the volume, the bulk modulus, the thermal expansion coefficient, the heat capacity, the entropy, Debye temperature
and Grüneisen parameter are also evaluated over a pressure range of 0–6 GPa and a wide temperature range of 0–1800 K. The
obtained results are in agreement with the available experimental and the other theoretical values. 相似文献
99.
In this paper, we establish several inequalities for some differantiable mappings that are connected with the Riemann-Liouville fractional integrals. The analysis used in the proofs is fairly elementar... 相似文献
100.
Nebojša ?. Din?i? 《Linear algebra and its applications》2011,435(11):2658-2673
We present new results related to the mixed-type reverse order law for the Moore-Penrose inverse of various products of three operators on Hilbert spaces. Some finite dimensional results are extended to infinite dimensional settings. 相似文献