2304-9782, 2618-8686, 2405-7223
St. Petersburg Polytechnic University Journal. Physics and Mathematics
13
4
2020
1-218
RAR
RUS
9-27
Vaganov
Sergei
Ioffe Physical-Technical Institute of the Russian Academy of Sciences
SV.Exciton@mail.ioffe.ru
Panfilov
Andrei
Ioffe Physical-Technical Institute of the Russian Academy of Sciences
a.panfilov@mail.ioffe.ru
Seisyan
Ruben
Ioffe Physical-Technical Institute of the Russian Academy of Sciences
rseis@ffm.ioffe.ru
An exciton in the superstrong and hyperstrong magnetic fields
The transformation of excitonic states in the raising magnetic field has been investigated beginning with the diamagnetic exciton (strong field) through excitonic magnetopolymer (superstrong field) to the QEL exciton (hyperstrong magnetic field). The effects induced by this transformation was considered. The capability of the exciton as a model object to study the hydrogen and positron atoms in superstrong and hyperstrong magnetic fields was also analysed.
10.18721/JPM.13401
537.6, 538.9, 539.1
diamagnetic exciton
excitonic magnetopolymer
superstrong magnetic field
quantum electromagnetic limit
hyperstrong magnetic field
https://physmath.spbstu.ru/article/2020.50.1/
01_9-27_13(4)2020.pdf
RAR
RUS
28-38
Vanina
Polina
p.yu.vanina@gmail.com
Silin
Nikita
Peter the Great St. Petersburg Polytechnic University
silin.ns@edu.spbstu.ru
Bosak
Alexei
Chernyshov
Dmitry
Peter the Great St. Petersburg Polytechnic University
chernyshov65@gmail.com
Naberezhnov
Alexander
Ioffe Physical Technical Institute of the Russian Academy of Sciences
alex.nabereznov@mail.ioffe.ru
Temperature evolution of diffuse scattering in the strontium-barium niobate SBN-60 single crystal in the relaxor state
Temperature dependences of synchrotron radiation diffuse scattering on the model relaxor single crystal Sr0.6Ba0.4Nb2O6 (SBN-60) have been studied in the temperature interval from 90 to 290 K in the vicinities of lattice points (332), (412) and (002) in the [001], [010] and [1 0] directions. This diffuse scattering (DS) has been shown to be a strongly anisotropic with intensity IDS(T, q) proportional q–α where q is a reduce wavevector. The temperature dependences of the parameters α have been obtained, and it is established, that the microscopic modification of structure in the SBN-60 continues on cooling below the temperature of transition to the relaxor state.
10.18721/JPM.13402
538.911, 539.26
diffuse scattering
synchrotron radiation
relaxor
strontium-barium niobate
crystal structure
https://physmath.spbstu.ru/article/2020.50.2/
02_28-38_13(4)2020.pdf
RAR
RUS
39-46
Gorokhovatskiy
Yuriy
Herzen State Pedagogical University of Russia
yurig@fromru.com
Temnov
Dmitry
Herzen State Pedagogical University of Russia
tde@herzen.spb.ru
Sotova
Yulia
Herzen State Pedagogical University of Russia
juliasotova1992@mail.ru
Rheological parameters’ effect on the electret properties of polyvinylidene fluoride
It is known that polymer films based on a copolymer of polyvinylidene fluoride and tetrafluoroethylene P(VDF-TFE) have piezoelectric properties, and these properties appear only after preliminary stretching of the films. The polar crystalline β-phase of the copolymer is responsible for the piezoelectric properties in the P(VDF-TFE), the percentage of this phase in the polymer can vary. In this work, we have studied the influence of the orientational stretching rate on the stability of the electret, and, as a consequence, the piezoelectric state. The influence of rheological parameters on the polymer structure and the parameters of electrically active defects responsible for polarization processes is shown.
10.18721/JPM.13403
538.9
electret state
polyvinylidene fluoride
tetrafluoroethylene
piezoelectric effect
thermostimulated spectroscopy
https://physmath.spbstu.ru/article/2020.50.3/
03_39-46_13(4)2020.pdf
RAR
RUS
47-60
Bulovich
Sergei
Peter the Great St. Petersburg Polytechnic University
bulovic@yandex.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
An implicit economical algorithm for numerical integration of the equation system describing a multiphase flow state with common pressure
An economical scheme for numerical integrating the system of differential equations has been proposed for the model of a multiphase medium with a common pressure (in the barotropic approximation) in liquids. The algorithm allows us to consider an arbitrary number of liquids and admits the possibility of degeneration of this parameter to one liquid in the calculation process. The equations of states for liquids have no restriction related to the finite compressibility of the medium, i.e. the liquid can be incompressible. An implicit method for generating a solution is used. The efficiency is ensured by the fact that the algorithm for constructing the inverse matrix is based on the splitting scheme for physical processes and the solvability of equations within scalar runs. As an example, the flow variant for three liquids is considered.
10.18721/JPM.13404
519.63:621.039
multi-fluid model
barotropic approximation
implicit algorithm
numerical simulation
Cauchy problem
https://physmath.spbstu.ru/article/2020.50.4/
04_47-60_13(4)2020.pdf
RAR
RUS
61-76
Kovalenko
Anatoliy
Ioffe Physical-Technical Institute of the Russian Academy of Sciences
ras-kan@mail.ru
Koptyuhov
Artem
NRC «Kurchatov Institute» – PNPI
t44h@yandex.ru
Gatchina of Leningrad region, Russian Federation
Meshcheryakov
Dmitry
Peter the Great St. Petersburg Polytechnic University
fess_i@bk.ru
Schuklinov
Alexey
JSC “Atomproekt”;
mupol@mail.ru
Thermokinetic processes in the corium traps of high-temperature melt during the reactor accidents at an a-plant: simulation
The two-stage model of changing the thermal and phase state of the active zone melt in the cooled subreactor crucible trap when interacting with the sacrificial material and when crystallizing the diluted corium after the gravitational inversion of its oxide and metal components is presented. The simulation is based on the generalized formulation of Stefan's task. The results of the end-to-end calculation of the COMSOL Multiphysics package show that the thermokinetic processes examined generally reduce the temperature and density of the corium, reduce heat flows on the trap body, minimize the release of hydrogen and radioactive fission products with their retention in a controlled thermal and phase state until full crystallization.
10.18721/JPM.13405
53.072; 53:004
melt active zone
subreactor crucible trap
sacrificial material
thermal state
https://physmath.spbstu.ru/article/2020.50.5/
05_61-76_13(4)2020.pdf
RAR
RUS
77-88
Khrapunov
Evgenii
Peter the Great St. Petersburg Polytechnic University
hrapunov.evgenii@yandex.ru
195251, St. Petersburg, Polytechnicheskaya St, 29
Chumakov
Yuri
Peter the Great St. Petersburg Polytechnic University
chymakov@yahoo.com
Influence of the slope angle of a locally heated surface on the heat transfer during bifurcation of a pure thermal plume
The results of numerical simulation of the puffing regime of a pure thermal plume, which forms above a slightly inclined (with respect to the horizon) surface have been presented. The flow structure in the near-wall region was investigated and the fields of the velocity components were analyzed. Particular attention was paid to the analysis of the distribution of instantaneous, time- and surface-averaged values of the heat transfer coefficient α. Based on the presented results, it was concluded that there was an optimal angle of inclination of the surface maintaining the most efficient heat transfer with a developed periodic flow regime.
10.18721/JPM.13406
532.5:536.24
natural convection
numerical simulation
bifurcation
heat transfer
puffing
https://physmath.spbstu.ru/article/2020.50.6/
06_77-88_13(4)2020.pdf
RAR
RUS
89-101
Kotmakova
Anna
Scientific Research Institute for Optoelectronic Instrument Engineering
www.anechka_kotmakova@mail.ru
Gataulin
Yakov
Peter the Great St. Petersburg Polytechnic University
yakov_gataulin@mail.ru
Yuhnev
Andrey
Peter the Great St. Petersburg Polytechnic University
a.yukhnev@mail.ru
Zaytsev
Dmitry
Peter the Great St. Petersburg Polytechnic University
zaitsev-aero@yandex.ru
The abdominal aorta bifurcation with iliac arteries: the wall elasticity effect on the flow structure
For the first time, a numerical study of the effect of vascular elasticity on blood flow has been carried out using a model of the abdominal aorta bifurcation with iliac arteries of the average statistical geometry. The greatest effect of elasticity was shown to be observed in the abdominal aorta before bifurcation where an initial oval cross-section shaping into a circle. Taking into account the elasticity of the walls, the flow structure remained unchanged, but the maximum flow rate increased by 40 % in the abdominal aorta. In the abdominal-aortic bifurcation region the cycle-averaged shear stresses decreased by 20%, and their oscillation index increased by 60%.
10.18721/JPM.13407
532.5+612.13
abdominal aorta’s bifurcation
numerical simulation
wall elasticity
blood flow structure
https://physmath.spbstu.ru/article/2020.50.7/
07_89-101_13(4)2020.pdf
RAR
RUS
102-109
0000-0003-3514-8577
Solovyev
Konstantin
Peter the Great St. Petersburg Polytechnic University
k-solovyev@mail.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
Ideal focusing systems with homogenous magnetic fields
Cases of charged particle pack ideal focusing in the presence of constant magnetic field have been considered. One-directional ideal space-time focusing was shown to remain only on conditions that a magnetic field being homogenous and its direction being the same as the one of quadratic potential growth. Axially symmetric electrostatic fields with superimposed magnetic field were taken as an example because of their practical importance in the mass spectrometry. It was concluded that at least one equation with separated motion should be linear to maintain the ideal space-time focusing.
10.18721/JPM.13408
537.534.3:621.384.8 (075.8)
spectrometry
ideal focusing
ion trap
homogenous magnetic field
https://physmath.spbstu.ru/article/2020.50.8/
08_102-109_13(4)2020.pdf
RAR
RUS
110-118
Reshetov
Ilya
Alferov University
reshetov_iv@spbstu.ru
Kaasik
Vladimir
Peter the Great St. Petersburg Polytechnic University Alferov University
vkaasik@yandex.ru
Lipovskii
Andrey
Alferov University
lipovskii@mail.ru
Tagantsev
Dmitry
Peter the Great St. Petersburg Polytechnic University
tagan@dt1386.spb.edu
Zhurikhina
Valentina
Peter the Great St. Petersburg Polytechnic University
zhurikhina@mail.edu.ioffe.ru
Thermal relaxation of optical nonlinearity in the poled glasses
The thermal relaxation of second-order optical nonlinearity in the subsurface layer of a poled soda-lime silicate glass has been studied. The glass annealing below glass transition temperature was shown to lead to full relaxation of the nonlinearity. At the same time, the measurements of thermostimulated depolarization current demonstrated that spatial electric charge formed in the course of the glass polarization relaxed above the glass transition temperature. This allowed concluding that the second-order optical nonlinearity in the poled glasses was not induced by the spatial electric charge.
10.18721/JPM.13409
53.097
glass
optical nonlinearity
polarization
poling
relaxation
depolarization
thermostimulated depolarization current
https://physmath.spbstu.ru/article/2020.50.9/
09_110-118_13(4)2020.pdf
RAR
RUS
119-132
Kozhevnikov
Vadim
vadim.kozhevnikov@gmail.com
7006335646
Privalov
Vadim
Peter the Great St. Petersburg Polytechnic University
kafedra@physics.spbstu.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
AAD-9657-2019
57197390995
Fotiadi
Alexander
Peter the Great St. Petersburg Polytechnic University
fotiadi@rphf.spbstu.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
Effective mode volume and estimation of helium-neon laser output power
The relationship between the generated power and the mode volume of the fundamental mode of a plane-sphere resonator is considered in the article exemplified a He-Ne laser. A novel technique based on the volume of the generating mode has been proposed to estimate the output radiation power of a gas-discharge laser with an arbitrary cross-sectional shape of an active element. It was shown that the results of calculations of the generated power, carried out on the basis of the effective mode volume, which took into account the transverse distribution of the population inversion of the active medium, were in better agreement with the experimental data and the results of estimates using other methods.
10.18721/JPM.13410
621.373.8
mode volume
effective mode volume
population inversion
He-Ne laser power
https://physmath.spbstu.ru/article/2020.50.10/
10_119-132_13(4)2020.pdf
RAR
RUS
133-148
Karov
Dmitry
Peter the Great St. Petersburg Polytechnic University
dmkarov@yandex.ru
Puro
Alfred
Euroacademy
alfredpuro@gmail.com
Curved-ray tensor tomography for residual stress measurements in the axisymmetric graded rods
For the first time, an algorithm for reconstructing an arbitrary distribution of residual stresses by the polarization tomography method for cylindrical rod structures with a radial distribution of the refractive index has been presented. The reconstruction took into account the ray refraction. The algorithm is based on the expansion of the tensor stress field in angular harmonics (singular value expansion). The case of an axisymmetric tensor field with an arbitrary stress gradient along the cylinder axis was considered. Numerical calculations were carried out for an axially symmetric stress distribution in a gradan for the case of a plane deformation state. The reconstruction was based on the expansion of the stress tensor in eigenfunctions of the boundary value problem. The regularized solution of the resolving equation (of Abelian type) used the expansion in Zernike polynomials. The results of the reconstruction are given with taking into account the additional term due to the deflection of the transmission rays as well as without this doing.
10.18721/JPM.13411
536.421
residual stress
integrated photoelasticity
transverse translucence
GRIN rod lense
https://physmath.spbstu.ru/article/2020.50.11/
11_133-148_13(4)2020.pdf
RAR
RUS
149-161
Pashkevich
Dmitrii
Peter the Great St. Petersburg Polytechnic University
pashkevich-ds@yandex.ru
St. Petersburg, Russian Federation
Zimin
Arseniy
Peter the Great St. Petersburg Polytechnic University
fz1min@yandex.ru
Alexeev
Yury
«New Chemical Products» Ltd.
alexeev-588@yandex.ru
St. Petersburg, Russian Federation
Mukhortov
Dmitrii
FSUE RSC "Applied Chemistry"
St. Petersburg, Russian Federation
Kambur
Pavel
Russian Scientific Center "Applied Chemistry"
pavel.kambur@mail.ru
Petrov
Valentin
FSUE RSC "Applied Chemistry"
valentinpetrov46@mail.ru
St. Petersburg, Russian Federation
Bazhenov
Dmitrii
JSC "Siberian Chemical Plant"
dmitriy_bazhenov@mail.ru
Smolkin
Pavel
JSC "Siberian Chemical Plant"
spa-net@mail.ru
Kapustin
Valentin
Peter the Great St. Petersburg Polytechnic University
Valentin.Kapustin.2014@yandex.ru
St. Petersburg, Russian Federation
Hydrogen fluoride obtaining from uranium hexafluoride in the combustion mode
Currently, there are no effective industrial technologies to return fluorine into a technological cycle. The authors have proposed a method for processing uranium hexafluoride depleted in the U-235 (DUHF) isotope in a hydrogen-oxygen flame that can be used as a basis for obtaining hydrogen fluoride and uranium oxides. Using own devising program code and complex ASTRA.4, performed thermodynamic calculations in the U-F-H-O elements system and it was shown that if the number of hydrogen atoms exceeds the number of fluorine atoms, then at temperatures above 1150 K, the only fluorine-containing substance in the thermodynamically equilibrium mixture was HF, while the main uranium-containing was UO2. The proposed method was experimentally investigated at a pilot plant and it showed that the composition of its products was close to thermodynamic equilibrium. The results can become the basis for industrial technology of the hydrogen fluoride production from DUHF.
10.18721/JPM.13412
544.3:544.45:661.487:621.039.1
depleted uranium hexafluoride
uranium dioxide
hydrogen fluoride
combustion
https://physmath.spbstu.ru/article/2020.50.12/
12_149-161_13(4)2020.pdf
RAR
RUS
162-175
Pashkevich
Dmitrii
Peter the Great St. Petersburg Polytechnic University
pashkevich-ds@yandex.ru
St. Petersburg, Russian Federation
Mukhortov
Dmitrii
FSUE RSC "Applied Chemistry"
St. Petersburg, Russian Federation
Kapustin
Valentin
Peter the Great St. Petersburg Polytechnic University
Valentin.Kapustin.2014@yandex.ru
St. Petersburg, Russian Federation
Kambur
Pavel
Russian Scientific Center "Applied Chemistry"
pavel.kambur@mail.ru
Kurapova
Ekaterina
Russian Scientific Center "Applied Chemistry"
e_kurapova@mail.ru
Zimin
Arseniy
Peter the Great St. Petersburg Polytechnic University
fz1min@yandex.ru
Maslova
Anastasia
Peter the Great St. Petersburg Polytechnic University
anastasiiamaslova5@gmail.com
The stability of flame front and the composition of combustion products of ammonia in oxygen in the presence of hydrogen fluoride
The authors have proposed a way for producing hydrogen fluoride (the major fluorinating agent in the modern industry) from ammonium bifluoride (by-product in the production of extraction phosphoric acid, tantalum, niobium, etc.) by burning up NH4F∙HF in oxygen. Calculations performed via program complex ASTRA.4 showed that the only fluorine-containing substance was hydrogen fluoride, whereas nitric fluorides and oxyfluorides being absent under the ratio of chemical elements N-1.0; H-5.0; F-2.0; O-1.5 (according to the proposed process), in the temperature range 600 – 2500 K, in thermodynamically equilibrium mixture. The combustion of ammonia in oxygen in the presence of hydrogen fluoride was experimentally investigated and it was found the feasibility of forming a stable flame, where a molar ratio of ammonia/hydrogen fluoride consumptions was 1: 2, only by using methane as a fuel. The conditions for the ratio of component consumptions were determined.
10.18721/JPM.13413
544.3:544.45:536.7:661.487:536.464
ammonium bifluoride
ammonia
hydrogen fluoride
combustion
tunnel burner reactor
https://physmath.spbstu.ru/article/2020.50.13/
13_162-175_13(4)2020.pdf
RAR
RUS
176-184
Babich
Ekaterina
Peter the Great St. Petersburg Polytechnic University
babich.katherina@gmail.com
Reduto
Igor
University of Eastern Finland
igor.reduto@uef.fi
Finland
Alexey
V.
Institute for Problems of Mechanical Engineering RAS
red-alex@mail.ru
Reshetov
Ilya
Alferov University
reshetov_iv@spbstu.ru
Zhurikhina
Valentina
Peter the Great St. Petersburg Polytechnic University
zhurikhina@mail.edu.ioffe.ru
Lipovskii
Andrey
Alferov University
lipovskii@mail.ru
Modification of glass surface by a high electric field
The work has studied an effect of a high DC field on the composition and properties of the subsurface region of a multicomponent silicate glass. The concentration of alkali ions in the subsurface glass region was shown to drastically decrease under the high electric field. This led to a change in the ion-exchange characteristics of glasses and their resistance to etching. The effect allows employing the poled regions of the glass surface as dielectric masks in the formation of gradient optical structures, as well as relief microstructures, e.g., channels for microfluidics, in glass substrates. The advantage of this approach is that there is no need in multiple lithography using liquid chemicals. This reduces the cost and makes this technological process environment friendly.
10.18721/JPM.13414
538.958
high electric field
chemical etching
ion etching
ion exchange
https://physmath.spbstu.ru/article/2020.50.14/
14_176-184_13(4)2020.pdf
RAR
RUS
185-202
0000-0001-5988-1429
Liokumovich
Leonid
Peter the Great St. Petersburg Polytechnic University
leonid@spbstu.ru
Kostromitin
Aleksey
Concern CSRI “Elektropribor”
kostromitin.aleksei@yandex.ru
Skliarov
Philip
Kotov
Oleg
Peter the Great St. Petersburg Polytechnic University
kotov@rphf.spbstu.ru
An output power level of the fiber-optic interferometric schemes with fiber Bragg gratings for multiplexing the sensitive elements
The paper continues a series of articles devoted to the procedure proposed by the authors how to calculate the required elements’ parameters and the output optical power level of the fiber-optic interferometric schemes with time-division multiplexing (TDM) of sensing elements. In particular, the schemes based on fiber Bragg gratings have been analyzed. The proposed method enables to ensure uniformity of powers of optical signals from individual sensing elements, as well as to evaluate how the deviations of elements’ parameters from the nominal ones influence the optical powers. According to the calculation methodology, a sequence of applying the required expressions was substantiated and some obtained results and an analysis of characteristic behaviors for the considered optical fiber circuits were exemplified. The proposed approach was recommended for design of interferometric optical fiber sensors with multiplexed sensing elements.
10.18721/JPM.13415
535.3, 535-15, 535.417
fiber-optic interferometric sensor
Bragg grating
optical power
time-division multiplexing
https://physmath.spbstu.ru/article/2020.50.15/
15_185-202_13(4)2020.pdf
REV
RUS
203-215
Valdman
Jan
University of South Bohemia in České Budejovice
jan.valdman@gmail.com
Česká Republika
Frolov
Maxim
Peter the Great St. Petersburg Polytechnic University
frolov_me@spbstu.ru
St. Petersburg, Russian Federation
Functional-type a posteriori error estimates for solutions of problems in deformable solid mechanics
The paper provides a historical review and recent developments on theoretical justification and numerical implementations of functional a posteriori error estimates and adaptive algorithms for approximate solutions to problems in deformable solid mechanics. The efficient practical implementation of such methods is a relevant objective, including for modern engineering practice.
10.18721/JPM.13416
519.63: 539.3
error estimates
finite element method
adaptive algorithms
solid mechanics
https://physmath.spbstu.ru/article/2020.50.16/
16_203-215_13(4)2020.pdf