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131.
We consider a general self-adjoint spectral problem, nonlinear with respect to the spectral parameter, for linear differential-algebraic
systems of equations. Under some assumptions, we present a method for reducing such a problem to a general self-adjoint nonlinear
spectral problem for a system of differential equations. In turn, this permits one to pass to a problem for a Hamiltonian
system of ordinary differential equations. In particular, in this way, one can obtain a method for computing the number of
eigenvalues of the original problem lying in a given range of the spectral parameter. 相似文献
132.
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137.
Yu. D. Varlamov Yu. P. Meshcheryakov M. R. Predtechensky S. N. Ul’yankin 《Journal of Applied Mechanics and Technical Physics》2007,48(1):101-108
Microdroplet absorption by two-layer porous media is studied both theoretically and experimentally. A two-dimensional model
for liquid flow from a droplet into a porous medium is presented and veri.ed based on a simultaneous numerical solution of
the Euler equations taking into account surface tension forces and the unsteady filtration equation. The effect of the structural
parameters of the two-layer porous medium (pore size in the layers, and the thickness and porosity of the layers) on the droplet
absorption is analyzed. It is shown that the presence of the second layer can have a significant effect on the droplet absorption
rate and the liquid distribution in the medium. The pore size is found to be the main parameter that governs the effect of
the second layer.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 1, pp. 121–130, January–February, 2007. 相似文献
138.
T. S. Shamirzaev M. S. Seksenbaev K. S. Zhuravlev A. I. Nikiforov V. V. Ul’yanov O. P. Pchelyakov 《Physics of the Solid State》2005,47(1):82-85
The photoluminescence of quantum dots in Si/Ge/SiO2/Si and Si/Ge/Si structures is investigated as a function of temperature. The low activation energies for the temperature quenching of photoluminescence of germanium quantum dots in both structures are explained in terms of the thermally stimulated capture of holes from quantum dots to the energy levels of defects localized in their vicinity. 相似文献
139.
M. Wasim A. Rahman J. H. Zaidi S. Waheed S. Ahmad 《Journal of Radioanalytical and Nuclear Chemistry》2002,254(1):219-222
The proposed reference material from the International Atomic Energy Agency, namely IAEA-407 (Fish Homogenate) was analyzed using instrumental neutron activation analysis (INAA). 15 elements, Al, As, Cl, Co, Cr, Fe, Hg, Mg, Mn, K, Na, Sb, Se, V and Zn, were determined using two irradiations (5 minutes and 5 hours) and four countings. IAEA-MA-A-1/TM (Copepoda Homogenate), NIST-SRM-1566 (Oyster Tissue), NIST-SRM-1572 (Citrus Leaves) and NIST-SRM-1577a (Bovine Liver) were utilized as standards in the quantification step. 相似文献
140.
From a combined analysis of the stoichiometric composition and Urbach tail in samples of CuInSe2, CuInTe2, and CuGaTe2 of the I-III-VI2 family of chalcopyrite semiconductors, it is found that the energy hνp involved in the electron/exciton-phonon interaction is a linear function of a parameter Δz which is the sum of the deviations from ideal molecularity Δx and anion to cation ratio Δy. It gives evidence that in the copper ternaries hνp is associated to the structural defects caused by cation-cation, cation-anion, and other intrinsic disorders. The high value of hνp found in the studied samples, higher than the highest optical mode, is shown to come from the contribution of the additional phonon energy due to structural defects. This is in agreement with recently proposed models of the temperature dependence of the Urbach energy. 相似文献