IKBFU's Vestnik

Physics, mathematics, and technology

Theoretical physics

Influence of the Coriolis force on the propagation of displaced long sea waves

Abstract

The influence of the Coriolis force on the peculiarities of the formation and propagation of forced sea waves is studied. The generation of long waves by a focused monochromatic source is observed. Two cases — the low frequency and high frequency waves are investigated.

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Backaction of measuring tunneling current through double quantum dot on it’s dynamics

Abstract

In this paper we study the backaction of measuring tunneling current through double quantum dot on it’s dynamics. We propose a new method for evaluating of measured current operator. Results are demonstrated as a graph representing measured stationary current through double quantum dot as a function of detection performance. It is shown that increasing of detection performance leads to quick decreasing of current through double quantum dot, which is consistent with quantum Zeno effect.

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An application of the Abel equation of first type to the task of solving the Friedman equations

Abstract

An interesting connection between Einstein-Friedmann equations for the models of universe filled with scalar field and the special form of Abel equation of the first kind is presented. In particular, it is shown how, knowing the general solution of the Abel equation (corresponding to the given scalar field potential) one can obtain the general solution of the Friedmann Equation.

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Radiophysics

The decision of the problem of definition of angular coordinates of object by the method of the maximum credibility

Abstract

The new method of processing of the information in location systems is presented. It is based on positions of the theory of optimum reception. As the accepted message dependence of pressure on an exit radar-tracking the receiver from a corner of scanning is used by the diagramme of an orientation of antenna system. Theoretical positions and results of preliminary modeling calculations are resulted. Possibility of increase in the azimuthal permission of two purposes without change of spatial base of a signal is shown.

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The trunced symbolic equations with sources of noise and any unifrequent oscillatory system

Abstract

The trunced symbolic equations with any unifrequent oscillatory system allowing with use of characteristics of transistor-capacitor active one-port circuit are received to find a stationary mode and transients in the  generator at presence of sources of noise.

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Perfection of a principle of base antenna stations placing of a radio communication

Abstract

On the basis of the analysis of principles of antennas’ placing the way of their mutual resistance’s definition taken as a principle the developed device is developed. Introduction of a quantitative estimation of electromagnetic conditions on the basis of an establishment of mutual resistance’s values will allow to solve a problem of electromagnetic compatibility of radio-electronic means.

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The investigation of the conditions of registration of the indirect nuclear quadrupole resonance signals

Abstract

In this work some conditions allows to increase of the indirect nuclear quadrupole resonance are investigated. The proposed method based on the stochastic resonance phenomena in the input electronic circuits of spectrometer. This effect allows provide the essential raise of the signal-to-noise ratio.

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The сross-correlation NMR spectroscopy as the method of study of the guest atom environment

Abstract

In the present paper we focused our attention on problems of property variable of materials by interstitial impurity-induced perturbation of regular structure. This problem may be solve by NMR study of quadrupolar nuclear, that is probe of electronic environment of guest atom embedded in a host lattice. The study of evolution of coherences of quadrupolar nuclear with spin S = 3/2 in the presence anisotropy chemical shift is shown that interference terms between time dependent quadrupolar interaction and anisotropy chemical shift are induce dynamic shifts of satellites and difference broadening line of its. The extraction of Q-CSA interference terms from NMR experimental data give us not only tensor parameters but the information about a location of tensor principal axes.

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The detection of nuclear quadrupole resonance signals with limited data

Abstract

The denoising method of the pulse nuclear quadrupole resonance (NQR) signals was investigated for the case of the small signal to noise ratio. The maximum entropy method of the autoregressive model was applied for the analysis of the experimental NQR data. The obtained results show the efficiency of proposed method in the conditions of the limited sampling rate for the limited time of the detection and digital signal sampling for the NQR detectors.

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Method of the estimation of parameters of signals at change of range to the purpose

Abstract

On the basis of a method of the maximal credibility considers questions limiting accuracy parameters of a signal and the sanction on range at approach of the purpose a locator. It is shown, that due to increase of the attitude the signal/noise essentially increases an opportunity of the sanction of the radio impulses reflected from the purpose. The supersanction on range is provided with a method of the maximal credibility.

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Applied physics

Research of characteristics of nanomodified dry building mixes

Abstract

The article is devoted to the investigation of influence of the nanomodification on physic-technical characteristics of dry building mixes. It was shown that the nanomodification leads to reorganization of structure of front glues, to increase of their durability and to essential reduction of the cost price.

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Temperature evolution of crystal structure of multiferroic Tb0.95Bi0.05MnO3

Abstract

The temperature evolution of crystal structure of multiferroic Tb0.95Bi0.05MnO3 has been studied by powder neutron diffraction in the temperature range 100—450 K. It is shown that the lattice parameters and volume expansion coefficient demonstrate anomalies in the interval 150—250 K. These anomalies could be attributed with a phase separation observed earlier for this compound.

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Study of conditions of electric breakdown in the flow part of electrical insulators of electric propulsion propellant supply systems

Abstract

The results of study of conditions of origination of electrical breakdown of gas in dielectric insulators of anode propellant (xenon) supply lines of prospective high-impulse increased-power electric thrusters intended for spacecraft orientation and stabilization are presented.

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Laboratory practicum

Mathematics

Optimal parameters for consequences of tangential and two-frequency decompositions

Abstract

A preconditioner for large systems of linear equations based on an incomplete block-decomposition for a block-tridiagonal matrices is considered. This method generalizes methods are developed by Buzdin and Wittum [1; 2]. A method of choosing quasioptimal parameters for consequences of tangential and two-frequencies decompositions based on analysis of model problems is developed. It’s convergence rate is better than ADI’s convergence rate in commutational case..

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An mathematical simulation of ionosphere with due regard for its three-dimensional irregularity

Abstract

Difference methods an approximate solution of a three-dimensional equation of ions diffusion with mixed derivatives and divergence first derivatives are considered. The task is reduced to a chain of three two-dimensional parabolic equations on base of the summary approximation method. Difference operators are constructed, and an analysis of its properties, test calculations and an estimate of a mixed derivatives role are carried out.

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A semicanonical normal affine connection associated with the distribution

Abstract

In manydimensional projective space distribution of planes is considered. The way of giving normal generalized affine connection associated with the distribution is proposed. It is shown that this connection is given by connection tensor and normal linear connection object. They define its curvature and torsion tensors. Semicanonical case is investigated when subtensor of the connection tensor vanishes. Two notions are
involved: non-degeneration tensor of torsion and semiholonomical distribution. It is proved that vanishing of non-degeneration tensor implies degenerating to linear connection of the semicanonical normal affine connection. The notion of semiholonomity let us describe semicanonical connection without torsion with non-zero nondegeneration tensor.

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