https://www.elibrary.ru/title_about_new.asp?i
1605-8119
Materials physics and mechanics
13
2
2012
1-101
RAR
RUS
85-116
Melker
A.I.
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Structure of Condensed Solid Matter
In this contribution we have considered the main items of the history of ideas on the structure of condensed solid matter. They are divided into two principal groups; one is based on discreteness (numbers, atoms), the other on continuity (geometrical figures). The evolution of these ideas has led to such notion as crystals, long-range and short-range order, continuous and discrete space, quasicrystals, types of disorder, amorphous structure. In its turn the new notions generated new theories, such as group theory, topology, etc. Significant attention was given to molecular dynamics, a new powerful instrument for solution of many problems connected with the structure of disordered phases. Leaning on a molecular dynamics, we have developed the theory of deformation and fracture for amorphous materials.
crystals; long-range and short-range order; continuous and discrete space; quasicrystals; types of disorder; amorphous structure; molecular dynamics; disordered phases; deformation and fracture of amorphous materials
https://mpm.spbstu.ru/article/2012.21.1/
MPM_2012_13_2_P01.pdf
RAR
RUS
117-123
Sanin
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Bagmanov
Waves in Quantum Systems with Nonlinearity and Walls
The nonlinear cubic Shrödinger equation is integrated numerically for quantum systems confined by potential walls of a well. If nonlinear potential describing nonlinearity is distributed on the whole width of the well, soliton generation is possible. For the nonlinear potential distributed on the right half of the well with free motion on the left one the propagation of waves occurs. Solutions for the probability density, expectation positions and velocities of the wave were analyzed under different initial conditions including the Gaussian and specified wave packets.
the nonlinear cubic Shrödinger equation
soliton
https://mpm.spbstu.ru/article/2012.21.2/
MPM_2012_13_2_P02.pdf
RAR
RUS
124-129
Kozlova
Belarusian State University of Informatics and Radioelectronics
Minsk, Belarus
Lyskouski
Belarusian State University of Informatics and Radioelectronics
Minsk, Belarus
Nelayev
Belarusian State University of Informatics and Radioelectronics
Minsk, Belarus
Electronic Properties of Ternary Compounds with Vacancy Clusters: ab initio Simulation
Electronic and magnetic properties of ternary crystal TlMeX2 compound (TlGaS2 as an example) with alone vacancy or their clusters were studied by means of first-principle (ab initio) approximation. It was shown that presence of S-vacancy clusters narrows the band gap of TlGaS2 crystal significantly while Tl - vacancy clusters increase it slightly. Restructuring TlGaS2 crystal due to vacancy or vacancy clusters presence leads to manifestation of ferromagnetic properties of the compound with the spin polarization value approx. 22 % when the number of vacancies in the cluster increases up to extremely high values. Revealed phenomena may be used in the censoring applications.
ab initio simulation
electronic properties
spin; anisotropy
TlMeX2 compounds
sensory
https://mpm.spbstu.ru/article/2012.21.3/
MPM_2012_13_2_P03.pdf
RAR
RUS
130-142
Savatorova
National Research Nuclear University
Moscow, Russia
Talonov
National Research Nuclear University
Moscow, Russia
Vlasov
Institute of Applied Mechanics Russian Academy of Sciences
Moscow, Russia
Volkov-Bogorodsky
Institute of Applied Mechanics Russian Academy of Sciences
Moscow, Russia
Multi Scale Modeling of Thermoelastic Properties of Composites with Periodic Structure of Heterogeneities
The majority of processes in composite materials involve a wide range of scales. Because of the scale disparity in multi scale problem, it's often impossible to resolve the effect of small scales directly. In this paper we perform multi scale modeling in order to analyze properties of composite materials with periodical structure under temperature and stresses influence. We consider a homogeneous matrix with periodic system of spherical particles separated from the matrix by an interphase. Each component has its own thermodynamic and mechanical (elastic) properties. We replace differential equations with rapidly varying coefficients by homogenized equations having effective parameters, which incorporate multi scale structure and properties of any component. We study, how effective properties of the system "matrix-interphase-inclusion" can depend on sizes of inclusions, thickness of interphase, mechanical and thermodynamic properties of components of a composite material.
multi scale modeling; thermoelastisity; effective thermo mechanical properties; nano composite materials; elastomeric composites
https://mpm.spbstu.ru/article/2012.21.4/
MPM_2012_13_2_P04.pdf
RAR
RUS
143-146
Prozorova
St. Petersburg State University
St.Petersburg, Russia
Dispersion and the Equations of Mechanics
This work is devoted to studying the influence of angular momentum variation in an elementary volume and cross flux on its sides on some equations of continuum mechanics. The self- diffusion effect is investigated for fluctuations of shock waves for the Mach number M≈1. As another example, a beam and a plate are considered.
angular momentum; conservation laws; nonsymmetrical stress tensor; Boltzmann equation; Chapman-Enskog method; the Navie-Stokes equation
https://mpm.spbstu.ru/article/2012.21.5/
MPM_2012_13_2_P05.pdf
RAR
RUS
147-156
Igolkin
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Melker
A.I.
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Molecular Hydrodynamics of Underwater Explosion
In this contribution we report on modeling underwater explosion in the framework of molecular dynamics. We have developed a computer program which allows studying the underwater explosion in two dimensional Lennard - Jones liquid. Calculations of the dynamical structure of underwater explosion displayed the striking resemblance of the underwater-explosion evolution obtained and the real process; namely, generation of a shock wave and its expanding; formation of a cavity; disintegrating the shock wave, when reaching a surface, into two parts which begin to move in opposite direction parallel to the surface; transforming the cavity into a water crater of an arising water volcano; its activity and decay.
underwater explosion; molecular dynamics; two dimensional Lennard - Jones liquid; dynamical structure; generation of a shock wave; formation of a cavity; water crater
https://mpm.spbstu.ru/article/2012.21.6/
MPM_2012_13_2_P06.pdf
RAR
RUS
157-161
Burkov
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Melker
A.I.
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Molecular Hydrodynamics of Tsunami Waves
We have developed a molecular dynamic approach for studying tsunami generation. In a two-dimensional model developed a force, which models the generation of disturbance, was incorporated into the water after reaching thermodynamic equilibrium. The temporal evolution of an arising wave shows that at first the disturbance creates the wave of large amplitude which propagates with a significant velocity and a cavity at the site of disturbance. When the wave reaches shallow water, the amplitude and velocity decreases, and the wave changes its shape that is consistent with observations for areas with a large angle of bank. As the bank is approached, the wave density decreases, and foam formation takes place. From the very beginning the surface layer has a lesser density, as if one has "rarefied" water. During the wave propagation the rarefied water penetrates deeper.
molecular dynamic; tsunami generation; two-dimensional model; temporal evolution; large amplitude wave; cavity; bank; foam formation; rarefied water
https://mpm.spbstu.ru/article/2012.21.7/
MPM_2012_13_2_P07.pdf
RAR
RUS
162-174
Bezrukova
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Vlasova
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Optical Characterization of 3D Disperse Systems with Nano- and Micro- Particles: Polymodality of Size Distributions
Natural (including biomedical) 3D disperse systems (DS) with nano- and/or microparticles are inherently polycomponent polymodal polydisperse systems. Characterization of such systems by different compatible non-destructive optical methods (refractometry, absorbance, fluorescence, light scattering: integral and differential, static and dynamic, unpolarized and polarized) is desirable because of feasibility to organize the on-line testing of their state. At this road it is necessary to take into account peculiarities of inverse optical problem solution for such complex systems (so called “three ill”: "ill-defined" 3D DS, "illposed" problems, "ill-conditioned" systems of equations). At the information–statistical approach to the optical characterization and control of 3D DS it is possible to go round these peculiarities and to qualify the 3D DS state changes.
biomedical and mineral particles; 3D disperse systems; inverse problem; light scattering; mixtures of nano- and micro- particles; on-line control; optical methods; polymodal size distributions
https://mpm.spbstu.ru/article/2012.21.8/
MPM_2012_13_2_P08.pdf
RAR
RUS
175-180
Rackauskas
Aalto University
Finland
Talka
Aalto University
Finland
Kauppinen
Aalto University
St.Petersburg, Russia
Nasibulin
Aalto University
Finland
Zinc Oxide Tetrapod Synthesis and Application for UV Sensors
Zinc oxide tetrapods (ZnO-Ts) were synthesized by air oxidation of zinc vapor. For stable production of the ZnO-Ts at the furnace temperatures of 900 °C, the lowest evaporator temperature was found to be 480 °C. Aerosol measurements showed that the fraction of naturally charged particles decreased with evaporator temperature from 89 % at 480 o C to 43 % at 420 o C. Various UV sensors were prepared to study the response and reset times and the On/Off ratio as a function of the ZnO-T concentrations, interelectrode distance and air humidity conditions. The presence of humid air was found to increase the conductivity of the ZnO-T sensors and to lower the response and reset times as well as On/Off ratio to 98, 96 and 88 %, respectively.
ZnO; tetrapod; synthesis; UV sensor
https://mpm.spbstu.ru/article/2012.21.9/
MPM_2012_13_2_P09(1).pdf
RAR
RUS
181-185
Gerasimov
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Matuzenko
St.Petersburg State Technological Institute
St.Petersburg, Russia
Proskurina
St.Petersburg State Technological Institute
St.Petersburg, Russia
Purity Analysis of Trade Produced C-60 Fullerene
The article compares the product purity of fullerene C-60, synthesized in different laboratories. The content of main product impurities was determined by liquid chromatography, infrared spectroscopy and mass spectrometry. It is shown that only one method of chromatographic analysis, the results of which are given in the certificates of goods, is not enough for detecting detect impurities.
fullerene C-60
product purity
https://mpm.spbstu.ru/article/2012.21.10/
MPM_2012_13_2_P10.pdf