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971.
K. A. Barantsev A. N. Litvinov E. N. Popov 《Journal of Experimental and Theoretical Physics》2017,124(1):1-9
The variational Monte Carlo method is applied to investigate the ground state and some excited states of the lithium atom and its ions up to Z = 10 in the presence of an external magnetic field regime with γ = 0–100 arb. units. The effect of increasing field strength on the ground state energy is studied and precise values for the crossover field strengths were obtained. Our calculations are based on using accurate forms of trial wave functions, which were put forward in calculating energies in the absence of magnetic field. Furthermore, the value of Y at which ground-state energy of the lithium atom approaches to zero was calculated. The obtained results are in good agreement with the most recent values and also with the exact values. 相似文献
972.
V. V. Popov T. S. Orlova A. Gutierrez-Pardo J. Ramirez-Rico 《Physics of the Solid State》2017,59(4):703-709
The effect of partial graphitization on electrical and galvanomagnetic properties of BE-C(Fe) biomorphic carbons produced by beech wood carbonization at temperatures of 850–1600°C in the presence of an iron-containing catalyst is studied. The use of an Fe catalyst at Т carb ≥ 1000°C leads to the formation of nanoscale graphite-phase inclusions; its total volume and nanocrystallite sizes increase with Т carb. The data on the carrier concentration and mobility are obtained. It was shown that partially graphitized BE-C(Fe) carbons with Т carb ≥ 1000°C in the conductivity type and magnetoresistance features relate to highly disordered metal systems whose conductivity can be described taking into account the contribution of quantum corrections, mainly the correction caused by the electron–electron interaction. It is shown that nonmonotonic dependences of the Hall constant R on the magnetic field are characteristic of BE-C(Fe) samples with 1000 ≤ Т carb < 1600°C, which is most probably caused by the contribution of various carrier groups, i.e., electrons and holes. In BE-C(Fe) samples with Т carb = 1600°C, the Hall coefficient corresponds to the metal state, which is associated with conducting medium homogenization resulting from the formation of a significant graphite phase volume. 相似文献
973.
Technical Physics - A method that enables the online processing of the experimental field emission data for the large-area emitters has been developed. This is based on an analysis of the SK... 相似文献
974.
A. S. Gogolev M. A. Kazaryan A. V. Obkhodsky A. S. Popov R. O. Rezaev E. A. Smirnova 《Bulletin of the Lebedev Physics Institute》2017,44(12):350-352
This study is devoted to the analysis of the plane-wave approximation applicability to X-ray radiation incident on an object. Based on simple calculations, it is shown that an X-ray tube focal spot 0.4 × 0.8 mm in size at distances of ~1 m can be considered as a point source; however, the plane-wave approximation for such X-ray radiation with energy E = 22keV is valid for radiation source–object distances much longer than 10 m. 相似文献
975.
S. P. Savin V. V. Lyahov V. M. Neshchadim E. Amata J. L. Rauch V. P. Silin V. Yu. Popov V. P. Budaev S. I. Klimov A. A. Skalsky L. A. Legen J. Blecki 《Bulletin of the Lebedev Physics Institute》2017,44(4):99-105
The theory of charged current sheets is compared with plasma data of Prognoz-8, Interball-1, Polar, and Cluster satellites. The possibility of momentum and energy transfer into the magnetosphere, irrespective of magnetic field line reconnection, as a specific dynamo effect, is shown. This relates statistical properties of the turbulent boundary layers with the character of the transfer through thin boundaries. 相似文献
976.
Analytical expressions and numerical results describing ionization of atoms by intense linearly polarized ultrashort laser pulses are obtained in the frame of the Keldysh approach. Photoelectron spectra and total ionization probabilities are presented for several analytical models of a single-cycle laser pulse. In particular, strong left-right asymmetry of the spectra is shown for the case of odd pulses. 相似文献
977.
978.
An exact analytic solution of the problem of the right circular cylinder in a rarefied molecular gas is constructed in the
isothermal approximation. An expression for the velocity of a rarefied molecular gas entrained by the cylinder rotated therein
is obtained in the regime of a flow with slip accounting for the second-order correction in terms of the Knudsen number. A
generalization of the BGK model of the Boltzmann kinetic equation accounting for the rotational degrees of freedom of gas
molecules is used as the governing equation, and the diffuse reflection model is used as a microscopic boundary condition
on the cylinder surface. The given approach is shown to enable the consideration of the gas flow dependence on the Prandtl
number and the gas temperature. 相似文献
979.
V. G. Arakcheev V. N. Bagratashvili A. A. Valeev V. B. Morozov A. N. Olenin V. K. Popov D. V. Yakovlev 《Russian Journal of Physical Chemistry B, Focus on Physics》2009,3(7):1062-1066
Coherent anti-Stokes Raman scattering spectra measured within the Q-branch of the vibrational transition ν1 are used to gain insights into the state of carbon dioxide molecules in nanopores of Vycor™ glass at room temperature (20.5°C)
and a subcritical temperature of 30.5°C and gas pressures up to the saturation point P
sat for each temperature. Along with the main spectral component, belonging to gaseous CO2 molecules, the spectra recorded at pressures close to P
sat feature a second (low-frequency) component. The second component is associated with the contribution from the CO2 molecules trapped inside pores. A spectral deconvolution with account for the interference of these two bands makes it possible
to estimate the spectral characteristics of the second (low-frequency) component at each temperature. At 20.5°C, the bandwidth
of the low-frequency component decreases with CO2 pressure, a behavior that can be explained by the transition of CO2 from the adsorbed to the condensed state in the pore. At the subcritical temperature of 30.5°C, the spectral width of the
second component is pressure-independent and close to the value measured in the bulk of the supercritical fluid, a result
likely associated with a low-temperature shift of the critical point of the substance trapped in nanopores. 相似文献
980.
We investigate the ground states of a Bose-Einstein condensate of indirect excitons coupled to an electron gas. We show that in a properly designed system the crossing of a roton minimum into the negative energy domain can result in the appearance of the supersolid phase, characterized by periodicity in both real and reciprocal space. Accounting for the spin-dependent exchange interaction of excitons we obtain ferromagnetic supersolid domains. The Fourier spectra of excitations of weakly perturbed supersolids show pronounced diffraction maxima which may be detected experimentally. 相似文献