An example of the interactive teaching test is presented. As a task in investigation we consider the classic kinematic problem — the problem of body moving at an angle to the horizon in the gravity field. The structure of the teaching test is suggested
Show AbstractThe history of the basic concepts of mechanics and establishment its laws is investigated. A causal link of this process has been noted.
Show AbstractThe technique of observing the interference rings of equal inclination with a laser and lenses of glasses is suggested. The calculations of the size of the rings depending on the lens parameters are given. This experiment can be used as a lecture demonstration at the school and in high school, for laboratory work as well as students research work.
Show AbstractThe circumstances of demonstration equipment modernization had been formulated. The key features of light sources for demonstration experiments had been distinguished. Some illustrations of their modernization using up-to-date components are given.
Show AbstractWe consider how computer–based tests can be utilized to rate educational groups of students at the faculty of Physics at MSU and what information can be obtained from this.
Show AbstractMinimizing methods for different functionals is widely used in physical problems. Modern computers let use them even the pupils of secondary school. We have described them the least square method. As an example we used a problem of approximation the resistance temperature dependence for the thermistors. The studied material was used for doing research works that were presented on different conferences and competitions.
Show AbstractSpin–electron acoustic waves exist in the spin imbalanced electron gas. Quantum of these waves is called spelnons. The Coulomb exchange interaction decreases the area of their existence by the rather small spin polarization. It is demonstrated that the electronspelnon interaction forms the Cooper pairs of electrons. This mechanism of the Cooper pair formation leads to the high-temperature superconductivity in materials with the partially spin polarized carriers at high temperatures up to 300 K.
Show AbstractThe position of the supercritical triangle is found for the system with Lennard-Jones interaction potential. The virial coefficients currently known and the accelerated method of convergence of the series of the perturbation theory for such system is used. The obtained results suggest that the method used makes it possible to determine with high accuracy the position of the three vertices of the supercritical triangle.
Show AbstractFor the class of evolutionary systems of two nonlinear differential equations describing the nonlinear diffusion processes, heat and mass transfer, admissible transformations are constructed.
Show AbstractThe paper is dedicated to logical means of knowledge representation and processing on computers. We consider the problems of automated theorems synthesis and proving for the class of theorems on mathematical models analogies.
Show AbstractMode matching method application is considered for waveguide resonance scattering and mode localizationproblems in the domain with barrier. The resonance character of scattering in the waveguide with two barriers is proved.
Show AbstractWe consider a nonlinear boundary value problem for an equation of reaction- diffusion-advection type whose solutions have boundary and internal transition layers (contrast structures). We prove the existence of such solutions, construct their asymptotics, and estimate its accuracy. The analysis is carried out with the use of the asymptotic method of differential inequalities and permits one to prove the Lyapunov stability of the contrast structures.
Show AbstractMonitoring of the earth’s surface by remote sensing in the short-wave band can provide quick identification of some characteristics of natural systems. This band range allows one to diagnose subsurface aspects of the earth, as the scattering parameter is affected by irregularities in the dielectric permittivity of subsurface structures. This method based on the organization of the monitoring probe may detect changes in these environments, for example, to assess seismic hazard, hazardous natural phenomena such as earthquakes, volcanic eruptions, as well as some man-made hazards and etc. The problem of measuring and accounting for the scattering power of the earth’s surface in the short-range of radio waves is important for a number of purposes, such as diagnosing properties of the medium, which is of interest for geological, environmental studies. In this paper, we propose a new method for estimating the parameters of incoherent signal/noise ratio. The paper presents the results of comparison of the measurement method from the point of view of their admissible relative analytical errors. The new method is suggested. Analysis of analytical error of estimation of this parameter allowed to recommend new method instead of standard method. A comparative analysis and shows that the analytical (relative) accuracy of the determination of this parameter new method on the order exceeds the widely-used standard method.
Show AbstractMode matching method application is considered for waveguide resonance scattering and mode localizationproblems in the domain with barrier. The resonance character of scattering in the waveguide with two barriers is proved
Show AbstractThe aim of this work is the application of the system of Navier–Stokes equations to the study of oscillation parameters of the gas, determining the frequency of the acoustic radiation, as well as the spectrum of acoustic oscillations of a single cylindrical vortex in a viscous heat–conducting gas (air). Axis of vortex is fixed on the plane. The problem is solved in the approximation of small initial vorticity.
Show AbstractThe behavior of the electromagnetic field near a corner point of a line of discontinuity of the permittivity is studied. Using asymptotic methods, we construct an asymptotic representation of the electromagnetic near a corner point of a line of discontinuity of permittivity. The representation obtained imply that, in the vicinity of the corner point of the line of discontinuity of permittivity, the main singularity is in the electric field. The longitudinal component itself is bounded in the neighborhood of the corner point, and its derivative has a power singularity; the form of the function describing the singularity is as that in the scalar case, considered earlier.
Show AbstractThe approach to parallel implementation of low-frequency PIC–algorithms is proposed, taking into account peculiarity of the nonradiative (Darwin) field approximation. Its advantages and specifics of adaptation to the base computer types for high performance calculations are discussed.
Show AbstractFor the FDTD method, we describe an order of accuracy increasing procedure which does not require any modification of the standard equations. The method is demonstrated on a problem of the pulse propagation in free space. Calculations with obtaining a posteriori asymptotically precise estimate and increasing the order of accuracy up to six are carried out.
Show AbstractMathematical modeling methods are subjective. Characteristics Adequacy Model SPS allow us to estimate the quality of the model, its feasibility and consider the model as independent from the researcher.
Show AbstractIn the simulation of physical processes and phenomena in radio physics, optics, we propose to use Finite SamplingTheorem (FST) instead theorem of Wiener–Kotelnikov and methods based on the difference schemes. FST operations are compatible with the convolution, analytical calculations, estimation of multiple integrals.
Show AbstractFor a system of two nonlinear differential equations describing the nonlinear filtering, a geometric method of solving the Cauchy problem was constructed.
Show AbstractThe work is devoted to modeling the interaction of solar cosmic rays (SCR) with the heliospheric current sheet (GTS) in the solar wind (SW). The proposed kinetic self-consistent model GTS dynamics of ions is considered quasi–adiabatic, and GTS is considered as the equilibrium current nested structure with low-energy background plasma SW and the high–energy plasma SCR. The numerical experiment shows that the GTS is the current structure of the multi–thin embedded in a wider plasma layer. Thus, in the GTS typically present shear (along the flow) of the magnetic field component. The presence of high-energy particles in cosmic rays SCR changes GTS structure. The solutions for different temperatures of SCR and the high–energy plasma concentrations at which there may be significant in satellite studies thickening GTS.
Show AbstractWe analyze the content of the information portal «Acoustics» (http://akdata.ru). It is a complex of a single information search system and two information systems that are closely related to each other and providing access to both Russian and foreign users to the Russian–language sources of information on acoustics. Creating a portal pursued goal: to create a user–friendly search tools for researchers and specialists; ensure the fullest coverage by source (journals, books, conferences, etc.) in the field of acoustics; facilitate navigation on Russian–language sources, which all articles have index and are hyperlinked; provide access to full–text versions of «Acoustical Physics» with the ability to easily search; provide access to current information in the field of acoustics. The portal can also be useful to researchers who study the trends in the development of Russian-speaking part of the world of science.
Show AbstractEnergy dissipation on the example of the contact spot between the ball bearings of the pendulum tribometer with flat pieces is considered. The slope of the contact spot lead to storage the elastic energy of the system. Measuring the quality factor of the pendulum tribometer makes it possible to determine the coefficient of hysteresis losses in materials and thin coatings without destroying their structures.
Show AbstractThe application of the piezo quartz resonators (PQR) in liquid media has found a strong dependence of changes in their frequency of oscillation from liquid media permittivity. The present work shows theoretical calculation and experimental research of influence of resonator’s geometrical parameters and permittivity of liquid media on frequency shift of PQR. The effect of sensor’s capacity with different geometrical parameters of capacitor and various permittivity coefficients of liquid media was experimentally determined.
Show AbstractA new principle of the electron beam grouping with cyclotron rotation in inhomogeneous magnetic fields is proposed. It is shown that the electron 3D grouping may not be accompanied by an increase in space charge density in contrast to the electron bunching during the one-dimensional motion of the electrons.
Show AbstractHigh power ultraviolet (UV) and violet spectral region light-emitting diodes (LED) with chips based on p–n InGaN/AlGaN/GaN–heterostructures electroluminescence (EL) spectra have been studied [1, 2]. Experimental equipment based on monochromator MDR–12 has been automated; new software providing fast spectral and electrical measurements has been created. Current voltage characteristics and output radiation power dependencies have been analyzed.
Show AbstractThe results of research of the laser beams in a turbulent medium are made. Wavefront reconstruction algorithm for shear interferograms in the presence of topological phase perturbation is proposed. Testing of the proposed algorithm based on numerical modeling and experimental data has been carried out.
Show AbstractThe results of a series of papers on the influence of hydrogenation on the structural and phase transformations in alloys based on palladium in the course of their long relaxation are presented. It was found that these features are non-monotonic stochastic nature. The model of evolution of structural-phase characteristics of alloys Pd–Me–H is proposed.
Show AbstractIn this work, we show that the use of terahertz laser radiation combined with magnetic field may be an effective tool for detection of topological surface states which is demonstrated for the case of (Bi$_{1−x}$In$_x$)2Se$_3$ solid solutions being either in topological (x < 0.05) or trivial (x > 0.06) phase. It is revealed that for the topological phase, the photoelectromagnetic effect amplitude is defined by the number of incident radiation quanta, whereas for the trivial phase, it depends on the power of a laser pulse irrespective of its wavelength.
Show AbstractThe results from a comprehensive investigation of the structure, phase and chemical composition,and tribological properties of doped with Via group metals (Cr, Mo and W) coatings of hydrogenised amorphous carbon are presented. The chromium doped coatings are deposited via reactive magnetron sputtering in an reactive gas mixture at various volume concentrations of nitrogen and acetylene. The tungsten doped coating is produced via non-reactive magnetron sputtering. The molybdenum doped coating is deposited via plasma-assisted chemical vapour deposition It is found that the type of doped metal has a great influence not only on chemical or phase composition of diamond-like coatings, but also on such of their properties as coefficient of friction and high contact pressure performance. The chromium doped coatings containing large amount of nytrogen atoms have most optimal combination of tribological properties.
Show AbstractThe research value of magnetic losses in the magnetic reversal frequency magnetically bonded magnets and electrical steel industry produces. Samples of bonded magnets produced by pressing with the addition of 1.5-2.0% polymeric ligaments. As the samples of electrical steel were used commercially available steels with a sheet’s thickness from 0.18 to 0.35mm. To measure the static magnetic hysteresis loops was used vibrating magnetometer. To study the processes of magnetization reversal and measurement of magnetic losses in magnetic materials had been developed and created the installation, which allowed measuring these characteristics in a closed magnetic circuit. It was found that losses in the bonded magnets with increasing frequency of magnetic reversal due to Fourier currents are significantly lower than in electrical steels. This advantage makes bonded magnets competitive in a number of technical applications.
Show AbstractThe paper deals with the internal architecture of self-accommodation complexes defined operating twinning planes of martensite crystals. It is shown, that the condition for the closed domain complexes leads to the following requirement: the symmetry operators corresponding to several variants of the orientation relationships, related by the twinning operation in pairs, must form a subgroup of the symmetry group of the cubic austenite lattice.
Show AbstractIn the paper it is discussed the possible ways of the creation of new alloys with shape memory effect. The algorithm of alloys search among the pseudobinary intermetallic compounds of similar properties, but different structure, is proposed. It is made the conclusions about the prospects of alloys of the system Al –Ti –Zr from the point of view of shape memory effect realization.
Show AbstractEffect of hybridization of electronic states on the high-frequency conductivity of disordered semiconductors is studied in the pair approximation with regard to the power dependence of the pre-exponential factors of the resonance $I_{\lambda, \lambda'}$ and overlap $s_{\lambda, \lambda'}$ integrals on the inter-site separation $r_{\lambda, \lambda'}$. It is shown that for $r_{\lambda, \lambda'}< N_{d}^{−1/3}$ ($N_d$ is the site concentration), the region of crossover from almost linear to quadratic frequency dependence of the conductivity is appreciably affected by the hybridization of the electronic states of the resonant pairs.
Show AbstractSpontaneously formed temperature-frequency zone of negative dielectric permittivity ’<0 was found in polymer–water system «PolyAcrylic Acid + 3 weight % of moisture». Nucleation and evolution of this zone is demonstrated on $\varepsilon ′(f, T)$, $ \varepsilon′′(f, T)$ and $\tg (f, T)$ 3D plots. The release of bound water at $T>65^{\circ}$C is thought to be the reason of this phenomenon. The frequency width of the zone steadily increases with temperature up to $T = 83^{\circ}$C, and then increases sharply from low–frequency side. This effect might be related to the anomalies in temperature dependencies of thermodepolarization currents in water at $T = 83^{\circ}$C. Spontaneous manifestation of $\varepsilon ′ < 0$ phenomenon indicates that one can expect it in natural materials, including biopolymers, i. e. in living organisms.
Show AbstractWe consider combined temperature- and concentration-driven convection in air during evaporation of a substance with molar mass exceeding molar mass of air. It is shown that some substances (butanol, naphthalene) can exhibit both downward and upward convective flow, depending on the surface temperature. Using heat and mass transfer analogy in numerical modeling and for interpretation of experimental results, obtained with background oriented schlieren technique, is discussed. We show that if the analogy conditions are satisfied, it is possible to obtain temperature and vapor concentration fields in good agreement with simulation results. If analogy conditions are violated, e.g. if additional boundary conditions are present, temperature and concentration contributions to measured refractive index field can not be separated.
Show AbstractThis article is devoted to the study of chiral properties of water configurations with achiral ions K$^+$ and Na$^+$ and with chiral biological molecules: L-, D-valin and L-, D–glycerate. Water system with ions was obtained using the Monte–Carlo method, a water shell of biological molecules was obtained using the Avogadro algorithm Conjiugate Gradients. It was revealed that addition of achiral impurities in a model water system does not change the 50/50 distribution of the number of right and left water configurations, and the addition of chiral molecules D-valine leads to the predominance of the left configurations in the sample.
Show AbstractNonstationary velocity fields behind shock (blast) waves in air have been studied experimentally by the particle image velocimetry (PIV) technique. Shock waves have been initiated by surface sliding discharge of nanosecond duration (plasma sheet) in air at pressure of (2÷4)$\times 10^{4}$ Pa. Analysis of the spatial distribution of flow velocities behind shock waves showed that the pulsed energy deposition is homogeneous along the discharge channels of a plasma sheet.
Show AbstractThe model of propagation of strong shock waves (SW) in a gas with inhomogeneous density is proposed. Partial differential equations of this model are reduced to ordinary differential equations. The relation between the speed of the SW $D_{SW}$ and density of the undisturbed medium $\rho_{0}$ is determined. The present results are compared with previous numerical investigations.
Show AbstractThe results of studies of the low-temperature gas discharge plasma influence on the modes of propane-air fuel combustion. Supersonic stationary combustion of propane in the expanding wind channels of various configurations is experimentally realized. The results confirm the efficiency of the low temperature plasma use in a supersonic plasma aerodynamics
Show AbstractThis study showed experimentally the existence of two inertial ranges in the spectrum of a quasi-two-dimensional flow of two intersecting jets in a disc–shaped vessel. The flow was recorded through an infrared transparent wall using a thermal camera at the frame rate of 100Hz in a wide spectral range.
Show AbstractRadiation treatment on food products, especially vegetables, is one of the possible effective ways for extending their period of storage. This article discusses the results of a research on the effects of X-rays on potato tubers. The study estimates the extent of inhibition of sprouting of tubers exposed in the different doses for several types of potato.
Show AbstractNew radionuclides for brachytherapy were selected. To implement selection Brookhaven National Laboratory’s NuDat database was used.
Show AbstractThe paper is about computers imulation of water phantom irradiation by photons with energies up to 40MeV and estimation of quality factor’s mean value depth distribution, taking into account the resulting secondary particles.
Show AbstractIn this paper we have studied an effect of blood glucose concentration on the absorption and reflection spectra of blood components in the frequency range of 0.05÷2.7THz. The observed differences in the experimental spectra were compared with the dielectric function of water in order to identify the parameter that makes the greatest contribution to the change in the dielectric function of sample. It was obtained that the changes of impact of the first Debye term describing «slow» relaxation of water molecules are associated with variations in the glucose concentration in blood samples.
Show AbstractFeatures of a thermal bar development in fresh water reservoir during ice cover melting are investigated using mathematical modelling. It is shown that the anomalous feature of water (maximum density at 4 ◦C) at given hydrometeorological conditions leads to two hydrodynamic effects which have opposite influence on the thermal bar movement. On the one side the thermal bar is formed near the shore and moves to the center of the reservoir, and on the other side vortex is arisen near the ice edge slowing down this process.
Show AbstractAnalysis of the strongest deep earthquakes of the Okhotsk Sea has shown that these events are confined to the central part of the subduction beneath the continent cold oceanic plate with a weak plasticity at the edges. Mechanisms of sources is normal and discharges focus on several areas of a rupture. High rupture velocity and big values indicate stress drop developing process of destruction in this part of the transition zone from the upper to the lower of the Earth’s mantle.
Show AbstractWe present the results of the comparison of ionospheric satellite UV-spectrometry and radiotomography data as well as the modelling of the direct and inverse problems of low–orbital satellite UV-tomography of volume emission rate of ionospheric OI 135.6 nm emission.
Show AbstractThe numerical model is described for the simulation of dispersive gravity waves and hydroacoustic waves generated by seismic ocean-bottom motions. The model consists of two dynamically coupled modules. Deep-water module employs 3D equations of linear potential theory of compressible liquid. Shallow-water module employs 2D equations of linear long-wave theory. The numerical model is used for simulation of the 2007 Central Kuril Island tsunami. Manifestations of water compressibility in the vicinity of the tsunami source and phase dispersion of tsunami waves are discussed.
Show AbstractHistory of development of the deep-water observatories intended for registration of earthquakes and tsunamis is briefly presented and advantages of deep-water registration of a tsunami in comparison with coastal measurements are described. Features of manifestation of the catastrophic 2011 Tohoku earthquake and tsunami according to observatories of DONET and DART are discussed.
Show AbstractSome examples of radiotomographic reconstructions of main ionospheric trough over Europe using navigational satellite systems (low-orbital and high-orbital) data are considered under different geomagnetic conditions. A complicated structure of the main ionization trough with its polar wall moving equatorwards was observed during the geomagnetic storms. The trough position, depth and width vary within a wide range depending on geomagnetic activity.
Show AbstractThe article describes the mechanism of wind wave trains in the ring aerohydrobasin. It is shown that at a certain value of the wind speed and the liquid depth the final stage of formation was a solitary wave that meets the criterion of rogue wave.
Show AbstractExtraterrestrial materials in space are subjected to shocks and particle radiation by cosmic rays. We present here the results of experimental investigations of hydrostatic pressure, shock and particle irradiation (by protons, argon and lead ions) effects on the magnetic properties of extraterrestrial materials — meteorites and lunar samples — and their terrestrial analogs. We also justify via numerical modeling a possibility and present a physical mechanism of shock-induced and irradiation-induced self–reversal of magnetization of ferrimagnets, which represent the major carrier of rock and meteorite magnetic properties.
Show AbstractThis article describes the technique for estimating integrated water vapor content of the atmosphere by analyzing received signals of satellite navigation systems. Computed data series of integrated water vapor content are compared with NCEP reanalysis data and AERONET photometer measurements.
Show AbstractThe study of geomagnetic field paleointensity has been conducted from northern (Reykjanes Ridge) and the southern Mid- Atlantic Ridge segment (MAR) basalts with different ages by Tellier–Coe method. The Earth virtual axial magnetic dipole moment (V ADM) value was calculated and ranged between: 3.3–8.0$\times 10^{22}$ Am$^2$ for the MAR basalts and 3.7–8.0$\times 10^{22}$ Am$^2$ for basalts of the Reykjanes Ridge. The V ADM values were complied with an international data bank of the geomagnetic field intensity changes over the last 1.2myr. The age of the rocks was determined by the spreading rate of ocean crust and the analysis of the geomagnetic anomaly. It is concluded that the magnetization fluctuations of the various blocks of the magnetically active layers in the MAR rift and AGF zone features can be explained by the changes in geomagnetic field intensity with time.
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