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991.
M. A. Elkin B. S. Ishkhanov I. M. Kapitonov E. I. Lileeva E. V. Shirokov 《Physics of Atomic Nuclei》2004,67(4):653-661
An isotopic effect in the widths of giant dipole resonances is established on the basis of an analysis of the latest systematics of photoabsorption cross sections for nuclei containing 12 to 65 nucleons. This effect arises owing to isospin splitting of a giant resonance and is enhanced by its configuration splitting. 相似文献
992.
An experimental Dalitz plot distribution for the decay η → π
+
π
−
π
0 is fitted by the theoretical one obtained in chiral perturbation theory with unitarity corrections taken into account. The
fit shows that the difference of light-quark masses is larger than is expected from electromagnetic mass differences of neutral
and charged kaons.
From Yadernaya Fizika, Vol. 67, No. 2, 2004, pp. 443–445.
Original English Text Copyright ? 2004 by Martemyanov, Sopov.
This article was submitted by the authors in English. 相似文献
993.
B. A. Belyaev N. A. Drokin V. F. Shabanov V. A. Baranova 《Physics of the Solid State》2004,46(3):574-578
This paper reports on the results of investigations into the influence of variations in the chemical composition of the aromatic core of cyano-containing molecules of liquid crystals on their dielectric properties in the frequency range 1–2000 MHz. It is shown that the dispersion of the longitudinal permittivity is adequately described by the sum of two Debye processes with different weighting factors and relaxation times. The frequency dependence of the transverse permittivity is well approximated by the Debye process with a continuous distribution of relaxation times in a specified range. It is established that the replacement of one benzene ring in the biphenyl core of the 5CB liquid-crystal molecule by a cyclohexane (or bicyclooctane) fragment leads to a considerable decrease in both relaxation times for the longitudinal permittivity, a change in the low-frequency limit of the relaxation time range for the transverse permittivity, and the evolution of the frequency dependence of the dielectric anisotropy. 相似文献
994.
B. K. Kardashev Yu. A. Burenkov B. I. Smirnov A. R. de Arellano-Lopez J. Martinez-Fernandez F. M. Varela-Feria 《Physics of the Solid State》2004,46(10):1873-1877
The effect of the vibration strain amplitude on the Young modulus and ultrasonic absorption (internal friction) in biomorphic SiC ceramics is investigated in the temperature range 116–296 K. The biomorphic SiC ceramics is prepared through pyrolysis of eucalyptus with subsequent infiltration of silicon. It is demonstrated that the vibration loading of samples in air and under vacuum is accompanied by a number of unexpected effects. The behavior of the studied ceramics is governed by at least two mechanisms, which, to a large extent, are responsible for the elastic and inelastic properties of the material. One mechanism is associated with the adsorption-desorption of environmental molecules (hypothetically, owing to the presence of pores and residual carbon), and the other mechanism involves microplastic deformation due to the motion of dislocations or other (similar) structural units. 相似文献
995.
Boriskin A. I. Eremenko V. M. Pavlenko P. A. Skripchenko A. N. Khomenko S. N. 《Technical Physics》2004,49(6):770-774
A REMMA 102 scanning electron microscope equipped with semiconductor and wave spectrometers is applied to measure the copper
and zinc concentrations in the surface layers of an M161 brass sample and the same sample subjected to a focused laser radiation.
The results are compared with the results obtained with an MS3101 laser mass spectrometer having a laser-plasma ion source.
The laser-assisted erosion of the surface layer in the brass is shown to significantly change the copper and zinc concentrations.
It is found that, when the craters produced by laser pulses on the initial surface do not overlap, the copper and zinc contents
in the laser-induced plasma correspond to their contents in the sample. 相似文献
996.
The phenomenon of spatial deterministic chaos is described. A transition from an ordinary differential equation to a discrete map is justified for modeling of the chaos. Methods of studying the chaos dynamics in this model are suggested. It is established how the physical properties of a nonlinear ring interferometer influence the structure of charts of the Lyapunov exponents. The approaches developed in the present study allow an optical cryptosystem to be optimized.__________Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 65–71, December, 2004. 相似文献
997.
Special features of the absorption and fluorescence spectra of phenols (phenol and para-chlorophenol) in alkalized and acidified aqueous-micellar solutions are studied. It is established that the absorption band of the anionic phenol form is formed in aqueous-alkali media in the presence of ionogenic surfactants. The fluorescence intensity of the anionic phenol form solubilized in micelles is higher than that in water.__________Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 76–80, November, 2004. 相似文献
998.
Computer models belonging to the class of models of growth controlled by a gradient are investigated. A theoretical approach to the construction of model algorithms of this class allows us to obtain a wide variety of clusters with different structures, including fractal ones. A consideration of gradient increments to the potential leads to the formation of vertical, nonbranching, and insulated clusters corresponding to a long-range potential with large gradient. 相似文献
999.
N. V. Boev 《Acoustical Physics》2004,50(6):651-656
This study is devoted to the development of the ray theory of diffraction in application to arbitrary (nonconvex) smooth obstacles in the scalar case. A three-dimensional problem is considered. An asymptotic method of estimating the diffraction integrals is described. The method is based on the multidimensional stationary phase approach. The diffraction integrals are obtained on the basis of the generalization of the Kirchhoff physical theory of diffraction. Explicit expressions are derived for the pressure in the reflected wave in the cases of its single and double reflections. 相似文献
1000.
N. A. Zimbovskaya 《Journal of Experimental and Theoretical Physics》2004,98(6):1231-1236
We present theoretical studies of the temperature and magnetic field dependences of the Coulomb drag transresistivity between two parallel layers of two-dimensional electron gases in the quantum Hall regime near half-filling of the lowest Landau level. It is shown that Fermi-liquid interactions between the relevant quasi-particles can significantly affect the transresistivity, providing its independence of the interlayer spacing for spacings that take values reported in the experiments. The obtained results agree with the experimental evidence. 相似文献