2304-9782, 2618-8686, 2405-7223
St. Petersburg Polytechnic University Journal. Physics and Mathematics
4
253
2016
RAR
RUS
9-21
Chikova
Tamara
t.chikova@grsu.by
Bashmakov
Victor
chts@tut.by
Reversible plasticity of metallic single crystals at the stage of their residual twinning
The work studies regularities of the formation of wedge-shaped twins under growing concentrated load in single crystals of bismuth, zinc and bismuth-antimony alloy. It was established that the twinning, detwinning and stopping of the twin deformation near the stress concentrator can take place simultaneously with the load growth. Reversibility of plastic deformation during twinning in metals at the stage of residual twinning development were discovered. Various manifestations of spontaneous detwinning of wedge-shaped twins which emerge at stress concentrators when indenting Bi, Zn, Bi-Sb single crystals with increasing load are quantitatively studied. Depending on the value and the sign, local fields of elastic stress can encourage or discourage twinning, or cause detwinning.
10.5862/JPM.253.1
548.24: 539.21
twinning
detwinning
plastic deformation
reversible plasticity
bismuth
zinc
https://physmath.spbstu.ru/article/2016.34.1/
01_9_21_4_253_2016.pdf
RAR
RUS
22-32
E-4237-2014
12784708700
0000-0001-9050-4453
Kapralova
Victoria
Peter the Great St. Petersburg Polytechnic University
kapralova2006@yandex.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
Ilinskiy
Alexander
ilinskiy@mail.ioffe.ru
Castro Arata
Rene
Herzen State Pedagogical University of Russia
recastro@mail.ru
Nabiullina
Lilia
Shadrin
Evgeniy
shadr.solid@mail.ioffe.ru
An effect of optical radiation on charge and magnetic states of the iron ions in the sillenites
The silico-sillenite single crystals with various concentration of impurity iron ions have been studied. An effect of light on the charge state of iron ions has been found involving the transition of Fe3+ to Fe2+. The transition was recorded by means of ESR signal intensity measurement. The parameters of the ESR absorption lines were obtained and analyzed. The nature of chemical bonds between iron ions and surrounding ligands was shown to be changed by the laser-induced recharge. A consistent model for optical recharge process and magnetic properties modification of iron impurity centers in the silico-sillenite single crystals has been suggested.
10.5862/JPM.253.2
537.226.33
silico-sillenite
optical recharge
ESR spectroscopy
ligand
iron ion
https://physmath.spbstu.ru/article/2016.34.2/
02_22_32_4_253_2016.pdf
RAR
RUS
33-47
Ganesh
N.
Ganga
B.
gangabhose@gmail.com
Hakeem
Abdul
abdulhakeem6@gmail.com
Saranya
Sarani
Kalaivanan
Raja
Hydromagnetic axisymmetric slip flow along a vertical stretching cylinder with a convective boundary condition
Steady axisymmetric laminar boundary-layer slip flow of a viscous incompressible fluid and heat transfer towards a vertical stretching cylinder in the presence of a uniform magnetic field is investigated. It is assumed that the left surface of the cylinder is heated by a hot convective flow. Using a similarity transformation, the governing system of partial differential equations is first transformed into a system of coupled nonlinear ordinary differential equations. The resulting intricate nonlinear boundary value problem is solved numerically by the fourth-order Runge – Kutta method with the shooting iteration technique. The analytical solutions are presented for a special case. The effects of various physical parameters on the velocity and temperature profiles are discussed through graphs. The values of the skin friction coefficient and the Nusselt number are tabulated and examined. It is found that the thermal boundary layer thickness increases with an increase in the velocity slip, the magnetic field, the surface convection parameter and the curvature parameter and decreases with the Prandtl number.
10.5862/JPM.253.3
536.24
axisymmetric flow
MHD
slip flow
stretching cylinder
convective boundary
https://physmath.spbstu.ru/article/2016.34.3/
03_33_47_4_253_2016.pdf
RAR
RUS
48-55
Gataulin
Yakov
Peter the Great St. Petersburg Polytechnic University
yakov_gataulin@mail.ru
Zaytsev
Dmitry
Peter the Great St. Petersburg Polytechnic University
zaitsev-aero@yandex.ru
E-5484-2014
56020596900
Smirnov
Evgeny
Peter the Great St. Petersburg Polytechnic University
aero@phmf.spbstu.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
Yuhnev
Andrey
Peter the Great St. Petersburg Polytechnic University
a.yukhnev@mail.ru
Numerical study of spatial-temporal evolution of the secondary flow in the models of a common carotid artery
Numerical study of the secondary flow in the two geometrically different models of a common carotid artery has been carried out. One of the models (Model 1) is characterized by a statistically averaged curvature, and the second one (Model 2) is attributed to the maximal curvature of the artery. It was shown that the most intensive swirl occurred at the phase of flow rate decreasing, the maximum values of the swirl parameters were observed at the interface of the cervical and thoracic segments of the artery. This interface is the place where the Dean vortices are transformed into a single vortex forming a swirling flow. The swirl intensity averaged over the systole and characterized by the ratio of the maximal values of the axial and circumferential velocities was evaluated as 0.20 for Model 1 and 0.25 for Model 2. Generally, it was in accordance with the data of clinical measurements.
10.5862/JPM.253.4
532.5+612.13
common carotid artery
swirling flow
computational fluid dynamics
Navier – Stokes equations
https://physmath.spbstu.ru/article/2016.34.4/
04_48_55_4_253_2016.pdf
RAR
RUS
56-65
Makhov
Ivan
National Research University ‘Higher School of Economics”
imahov@hse.ru
Panevin
Vadim
Peter the Great St. Petersburg Polytechnic University
pvyu@rphf.spbstu.ru
Vinnichenko
Maxim
Peter the Great St. Petersburg Polytechnic University
mvin@spbstu.ru
Sofronov
Anton
sofronov@rphf.spbstu.ru
J-6066-2013
35403302800
0000-0003-3947-4994
Firsov
Dmitry
Peter the Great St. Petersburg Polytechnic University
firsov.da@spbstu.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
Vorobjev
Leonid
Impurity assisted terahertz luminescence in quantum well nanostructures under interband photoexсitation
The results of experimental study of the impurity-assisted photoluminescence in far- (terahertz) and near-infrared spectral ranges in n-GaAs/AlGaAs quantum well structures with different well widths under interband photoexcitation of electron-hole pairs have been presented. In the far-infrared photoluminescence spectra the optical electron transitions between the first electron subband and donor ground state as well as between excited and ground donor states were revealed. Observation of these optical electron transitions became possible because of the depopulation of the donor ground state in the quantum well due to the non-equilibrium charge carrier radiative transitions from the donor ground state to the first heavy hole subband. The opportunity to tune the terahertz radiation wavelength in structures with doped quantum wells by changing the quantum well width was demonstrated experimentally.
10.5862/JPM.253.5
538.958
terahertzluminescence
radiation
quantum well
spectrum
nanostructure
semiconductor
https://physmath.spbstu.ru/article/2016.34.5/
05_56_65_4_253_2016.pdf
RAR
RUS
66-76
Shterengas
Leonid
leon.shterengas@stonybrook.edu
Belenky
Gregory
Vinnichenko
Maxim
Peter the Great St. Petersburg Polytechnic University
mvin@spbstu.ru
Makhov
Ivan
National Research University ‘Higher School of Economics”
imahov@hse.ru
Selivanov
Anatoliy
a_selivanov@mail.ru
Sorokina
Anastasiya
anastasia.sorokina.10@gmail.com
Vorobjev
Leonid
J-6066-2013
35403302800
0000-0003-3947-4994
Firsov
Dmitry
Peter the Great St. Petersburg Polytechnic University
firsov.da@spbstu.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
Auger-recombination effect on the nonequilibrium charge carriers concentration in InGaAsSb /AlGaAsSb quantum wells
The interband photoluminescence spectra of InGaAsSb/AlGaAsSb quantum wells with different well widths have been experimentally studied. The dependence of the concentration of the charge carriers participating in the radiative recombination on the pumping intensity level was calculated. Results of theoretical calculations appeared to be in good agreement with the experimental relationship between the photoluminescence intensity at spectral maxima and the pumping intensity. The resonant Auger recombination involved two holes and one electron and caused a significant decrease in the charge carrier concentration was detected in one of the samples. Recommendations were made to increase the operating efficiency of semiconductor injection lasers at wavelengths of about 3 μm for suppressing the parasitic nonradiative Auger recombination.
10.5862/JPM.253.6
535.3
auger recombination
quantumwell
semiconductor
photoluminescence
https://physmath.spbstu.ru/article/2016.34.6/
06_66_76_4_253_2016.pdf
RAR
RUS
77-84
Yakovenko
Sergey
ser_mail@poi.dvo.ru
Budrin
Sergey
ss_budrin@mail.ru
Dolgikh
Stanislav
sdolgikh@poi.dvo.ru
Chupin
Vladimir
chupin@poi.dvo.ru
Shvets
Vyacheslav
vshv@poi.dvo.ru
Hydrophysical laser-interference complex
A new hydrophysical measuring complex has been developed on the basis of the laser measuring instrument of hydrosphere pressure variations. The latter was previously engineered and experimentally approbated. The use of this equipment allows solving problems on investigation of the amplitude-phase variations of hydrosphere vibrations and waves in the low-frequency range. All performance data of the complex was considerably improved by virtue of the operating experience obtained previously. Radically new opportunities of the created equipment were provided since the apparatus was rigged with new sensors for accompanying measurements and a container, which allowed working independently. The new hydrophysical measuring complex is easier to operate and maintain, ensures higher quality data obtained and new spheres of its application.
10.5862/JPM.253.7
681.7.08
laser measurer
hydrosphere pressure variation
interferometer
measurement system
hydrosphere
https://physmath.spbstu.ru/article/2016.34.7/
07_77_84_4_253_2016.pdf
RAR
RUS
85-93
Shashkina
Antonina
shashkinaas@ya.ru
Krivosheykin
Anatoliy
Skvortsov
Nicolay
nnskvo@gmail.com
Vorotkov
Mikhail
biser_gao@mail.ru
Fractal properties of the led avalanche breakdown
The conventional model of processes occurring in the course of p–n-junction’s partial avalanche breakdown has been analyzed in this paper. Microplasma noise spectra of industrially produced LE Ds were compared with those predicted by the model. The data obtained experimentally on the reverse-biased LEDs were established not to be described in terms of this model. The degree of pronouncedness of fractal properties was shown to be variable by changing the reverse voltage. Discovered fractal properties of microplasma noise can serve as the basis for further studies which are bound to explain the breakdown characteristics of real LEDs and to correct the conventional model of p–n-junction’s avalanche breakdown.
10.5862/JPM.253.8
621.382.23
avalanche breakdown
microplasma; p–n-junction; fractal
led
https://physmath.spbstu.ru/article/2016.34.8/
08_85_93_4_253_2016.pdf
RAR
RUS
94-106
Bondarenko
Vyacheslav
Peter the Great St. Petersburg Polytechnic University
vyacheslav.b.bondarenko@mail.ru
Davydov
Sergey
0000-0002-2519-2577
Gabdullin
Pavel
Peter the Great St. Petersburg Polytechnic University
gabdullin_pg@spbstu.ru
Gnuchev
Nikolay
Peter the Great St. Petersburg Polytechnic University
nmg@rphf.spbstu.ru
Maslevtsov
Andrey
phys-el@spbstu.ru
Arkhipov
Anton
Electron spectrometer for studying field-induced emission from nanostructured objects
A novel electron spectrometer has been designed to study low-voltage field-induced emission of nanostructures such as nanoporous carbon, nanotubes, nanodia-mond and other carbon structures. The estimated high resolving power of the device is mainly achieved by using an original energy analyser of high energy dispersion and by retarding the electron beam by the factor of tens and hundreds in terms of energy. The analyser pass energy governs the absolute energy resolution ΔЕ of the spectrome-ter; ΔЕ value varies approximately in the range of 10 meV < ΔЕ < 300 meV. There are three different working modes adapted for emission of widely variable current. The minimal emission current at which energy analysis is still possible is approximately 0.1 nA. The spectrometer working modes were tested experimentally using a ther-moemitter as the test object. The study then proved that the recorded spectra reflected physical phenomena taking place on the emitter surface.
10.5862/JPM.253.9
53.07
low-voltagefield emission
nanostructure
high resolution
electron spectrometer
https://physmath.spbstu.ru/article/2016.34.9/
09_94_106_4_253_2016.pdf
RAR
RUS
107-120
Ivankov
Alexey
a.vnkv1@gmail.com
Kutuzov
Anton
ka200893@gmail.com
Krivoruchko
Lyudmila
kr@ya.ru
The additive model of usdg records: attractor dimensions of determinated addends
The paper presents the algorithm and the mathematical support to estimate the correlation dimensions of attractors manifested themselves in the most powerful harmonics of spectra retrieved during Doppler sonography assessment of human cerebral circulation. The objective of the present study was to estimate the correlation dimensions for power spectral densities of the most powerful harmonics. The results of real clinical data analysis are given. The estimates of the correlation dimensions were formed for the different examined body’s states: in the rest and under test for hypocapnia. The significant relation was found between those estimates of the correlation dimensions and psychoemotional state of volunteer.
10.5862/JPM.253.10
61:577.3; 004.415.2.031.43
correlation dimension
chaotic attractor
Fourier spectrum
power spectral density
https://physmath.spbstu.ru/article/2016.34.10/
10_107_120_4_253_2016.pdf
RAR
RUS
121-128
Bezrukova
Alexandra
bezr@pb1097.spb.edu
Vlasova
Olga
Peter the Great St. Petersburg Polytechnic University
olvlasova@yandex.ru
Mixtures of 3D disperse systems with nano- and microparticles: optical characterization
The multiparameter analysis of simultaneous optical data for systems of nano- and /or microparticles (3D disperse systems, dispersions, colloids, ensembles) by presentation of system characteristics as N-dimensional vectors of optical parameters (ND-vectors) can help to elucidate changes in the state of the particles in systems. In this paper, the application of ND-vector approach is shown on the examples of dispersion mixtures: mixture of influenza virus particles with albumin proteins (as a model of dispersions at the process of vaccine production); mixture of Coli bacillus and clay dispersions (as natural water model). This approach can serve as the on-line control platform for the management of technological processes with mixtures.
10.5862/JPM.253.11
577.343 (075.8)
absorption
bacteria
clay
3D disperse system
microparticle
nano-particle
https://physmath.spbstu.ru/article/2016.34.11/
11_121_128_4_253_2016.pdf
RAR
RUS
129-138
Smirnova
Natalia
nvsmirnoff@yandex.ru
Petrova
Natalia
nataly_petrova@mail.ru
Lebedeva
Inna
innale@list.ru
Popryadukhin
Pavel
pavel-pn@mail.ru
Dobrovolskaya
Irina
dobrov@hq.macro.ru
Yudin
Vladimir
yudin@hq.macro.ru
Tissue reconstruction of skin failues and soft-tissue injuries using regenerative medicine methods
The electrospinning technique has been used to manufacture the composite material based on nanofibers made of aliphatic copolyamide and composite nanofibers made of chitosan and chitin nanofibrils. Experimental in vivo studies of the material worked out as wound covering were carried out to treat the vast and multilayered wound on the rat’s back. After 28 days and nights of observation the complete epithelialization of the wound surface was established to occur in the experimental rat group. Histological analysis of scar tissue showed the presence of small minority of capillaries and a low amount of infiltrate cells. The survival of animals was 100 %. At the same time, in the control group of animals, the lethality was observed in 11 % of cases, and suppurative complications were observed in 100 % of cases. To increase the rate of tissue regeneration, and to reduce the infection probability the thrombocyte gel prepared from the peripheral blood of the patients was used. The curative effect was proved to increase when applied simultaneously the wound coatings and autologous blood product separation – thrombocyte gel and platelet-rich plasma.
10.5862/JPM.253.12
544.77.022.823
aliphatic copolyamide
сhitosan
chitin nanofibrilla
electrospinning
wound covering
composite nanofiber
https://physmath.spbstu.ru/article/2016.34.12/
12_129_138_4_253_2016.pdf
RAR
RUS
139-149
Chernyuk
Daria
dashachernuk@gmail.com
Vlasova
Olga
Peter the Great St. Petersburg Polytechnic University
olvlasova@yandex.ru
O-7971-2016
7006214225
0000-0001-7006-6951
Bezprozvanny
Ilya
UT Southwestern Med Ctr, Dept Physiol
mnlabspb@gmail.com
Dallas, USA
Popugaeva
Еlena
lena.popugaeva@gmail.com
Hyperexpression of STIM2 protein lowers the amount of abeta plaques in the brain of alzheimer’s disease mouse model
The role of STIM2 - nSOCE signaling pathway was investigated in model of Alzheimer’s disease (AD), 5×FAD mice, that express amyloid and presenilin toxicity simultaneously. It was observed that expression of STIM2 protein was downregulated in the hippocampus of adult 5×FAD mice at the ages of 4 and 6 months. It was shown that expression of PSD95 protein was downregulated together with STIM2 protein. It was established that hyperexpression of STIM2 protein in the hippocampus of adult mouse was able to lower the amount of amyloid plaques in the cortex of 5×FAD mice by three times. The observed data confirms scientific hypothesis that activation of STIM2-dependent store-operated calcium entry can have therapeutic effect for treatment in AD.
10.5862/JPM.253.13
612.82
Alzheimer disease
amyloid toxicity
neuronal store-operated calcium entry
STIM2
aβ-plaques
https://physmath.spbstu.ru/article/2016.34.13/
13_139_149_4_253_2016.pdf
RAR
RUS
150-162
Pivkov
Andrey
apivkov@gmail.com
Lobachev
Aleksandr
lobachev_am@spbstu.ru
Polyanskiy
Vladimir
Institute for Problems in Mechanical Engineering of the RAS
vapol@mail.ru
Modestov
Victor
Peter the Great St. Petersburg Polytechnic University
modestov@compmechlab.com
Numerical simulation of ultrasonic waves in the isotropic elastic layer with the piezoelectric actuator
This paper is devoted to the finite-element modeling (FEM ) of elastic waves сaused by the work of a piezoactuator. For this purpose, a mathematical model of the ‘elastic layer – piezoelectric element’ system has been developed. In the terms of the model, the simultaneous solution of the piezoelectricity and the solid-mechanics equations was employed. This model allowed us to describe the propagation process of high-frequency mechanical vibrations, caused by the application of the probing electrical pulse to the electrodes of the piezoelectric element (the vibrations occur in the elastic layer) and to reproduce the potential difference arising in the reception of the reflected wave. The influence of t-parameters of the FEM and numerical integration scheme on the calculation results was investigated. The essential sensitivity of the reflected-wave’s delay-time to the integrating time-step was found.
10.5862/JPM.253.14
534.16
numerical modeling
finite element
piezoactuator
piezoelasticity
acoustic wave
https://physmath.spbstu.ru/article/2016.34.14/
14_150_162_4_235_2016.pdf