919 research outputs found
Effective attraction between oscillating electrons in a plasmoid via acoustic waves exchange
We consider the effective interaction between electrons due to the exchange
of virtual acoustic waves in a low temperature plasma. Electrons are supposed
to participate in rapid radial oscillations forming a spherically symmetric
plasma structure. We show that under certain conditions this effective
interaction can result in the attraction between oscillating electrons and can
be important for the dynamics of a plasmoid. Some possible applications of the
obtained results to the theory of natural long-lived plasma structures are also
discussed.Comment: 14 pages in LaTeX2e, two columns, 3 eps figures; minimal changes,
some typos are corrected; version published on-line in Proc. R. Soc.
Observation of superluminal geometrical resonances in Bi2Sr2CaCu2O8+x intrinsic Josephson junctions
We study Fiske steps in small Bi2Sr2CaCu2O8+x mesa structures, containing
only few stacked intrinsic Josephson junctions. Careful alignment of magnetic
field prevents penetration of Abrikosov vortices and facilitates observation of
a large variety of high quality geometrical resonances, including superluminal
with velocities larger than the slowest velocity of electromagnetic waves. A
small number of junctions limits the number of resonant modes and allows
accurate identification of modes and velocities. It is shown that superluminal
geometrical resonances can be excited by subluminal fluxon motion and that
flux-flow itself becomes superluminal at high magnetic fields. We argue that
observation of high-quality superluminal geometrical resonances is crucial for
realization of the coherent flux-flow oscillator in the THz frequency range
Fractional Models of Cosmic Ray Acceleration in the Galaxy
Possible formulations of the problem of cosmic rays acceleration in the
interstellar galactic medium are considered with the use of fractional
differential equations. The applied technique has been physically justified. A
Fermi result has been generalized to the case of the acceleration of particles
in shock waves in the supernovae remnants fractally distributed in the Galaxy.Comment: 10 page
Spin-controlled Mott-Hubbard bands in LaMnO_3 probed by optical ellipsometry
Spectral ellipsometry has been used to determine the dielectric function of
an untwinned crystal of LaMnO_3 in the spectral range 0.5-5.6 eV at
temperatures 50 K < T < 300 K. A pronounced redistribution of spectral weight
is found at the Neel temperature T_N = 140 K. The anisotropy of the spectral
weight transfer matches the magnetic ordering pattern. A superexchange model
quantitatively describes spectral weight transfer induced by spin correlations.
This analysis implies that the lowest-energy transitions around 2 eV are
intersite d-d transitions, and that LaMnO_3 is a Mott-Hubbard insulator.Comment: 4 pages, 4 figure
lmmuno Histochemical Profile of Endometrium in Patients With Genital Endometriosis
The aim of present study was to investigate the occurence of different lymphocyte
subsets in the endometrium of endometriosis patients and in healthy women on every
day of the menstrual cycle with special emphasis to the proliferative activity of
endometrial cells with Ki-S3 antibody. We also conducted immunohistochemical
studies of T-lymphocytes, B-lympho-cytes, macrophages, natural-killer-cells and also
of antigens class II of the histocompatibility complex (HLA-DR) during the different
phases of the menstrual cycle in endometriosis and non-endometriosis patients
The algorithm of interaction of the enterprises of fuel and energy complex in implementation with the use of alternative means of payment
The structure of the algorithm for building a system of payment interaction of enterprises of the fuel and energy complex has been off red. The necessity to include such intangible components as trust, business reputation, transparency of economic relations in the assessment of the value of assets of the fuel and energy complex enterprises has been highlighted. The possibility of wider application of mechanisms of non-monetary trade in the conditions of economy of βdistrustβ and political and economic crisis has been designated. The peculiartities of cooperation between the enterprises of the fuel and energy complex in the conditions of sanctions pressure, turning into a trade war have been revealed. The possibilities of activation and development of resource trade as one of the main factors of increasing the security of the fuel and energy complex and the Russian economy as a whole have been discovered
ΠΠ΅ΡΠΎΠ΄ΠΈΠΊΠ° ΡΡΡΡΠΊΡΡΡΠ½ΠΎ-ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΎΠΏΡΠΈΠΌΠΈΠ·Π°ΡΠΈΠΈ ΠΊΠ°ΡΠΊΠ°Π΄Π½ΡΡ ΡΠΈΡΡΠ΅ΠΌ Π°Π²ΡΠΎΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠ΅Π³ΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΌΠΎΠ΄ΠΈΡΠΈΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΡΠΏΡΠ΅Π΄ΠΈΡΠ΅Π»Ρ Π‘ΠΌΠΈΡΠ°
The paper presents methodology for structural and parametric optimization of cascade ACS Β technological parameters of thermal power processes which has been developed on the basis of a modified Smith predictor. The given methodology permits significantly to improve quality of regulation in comparison with the typical cascade AΠ‘S.Β Π Π°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π° ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ° ΡΡΡΡΠΊΡΡΡΠ½ΠΎ-ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΎΠΏΡΠΈΠΌΠΈΠ·Π°ΡΠΈΠΈ ΠΊΠ°ΡΠΊΠ°Π΄Π½ΡΡ
Π‘ΠΠ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΡΠ΅ΠΏΠ»ΠΎΡΠ½Π΅ΡΠ³Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΡΠΎΡΠ΅ΡΡΠΎΠ² Π½Π° Π±Π°Π·Π΅ ΠΌΠΎΠ΄ΠΈΡΠΈΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΡΠΏΡΠ΅Π΄ΠΈΡΠ΅Π»Ρ Π‘ΠΌΠΈΡΠ°. ΠΠ°Π½Π½Π°Ρ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ° ΠΏΠΎΠ·Π²ΠΎΠ»ΡΠ΅Ρ ΡΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎ ΡΠ»ΡΡΡΠΈΡΡ ΠΊΠ°ΡΠ΅ΡΡΠ²ΠΎ ΡΠ΅Π³ΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΏΠΎ ΡΡΠ°Π²Π½Π΅Π½ΠΈΡ Ρ ΡΠΈΠΏΠΎΠ²ΠΎΠΉ ΠΊΠ°ΡΠΊΠ°Π΄Π½ΠΎΠΉ Π‘ΠΠ
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