2304-9782, 2618-8686, 2405-7223
St. Petersburg Polytechnic University Journal. Physics and Mathematics
2
194
2014
RAR
RUS
9-14
Seregin
Maxim
horanzon@gmail.com
Naberezhnov
Alexander
Ioffe Physical Technical Institute of the Russian Academy of Sciences
alex.nabereznov@mail.ioffe.ru
Shaganov
Anton
shaganovanton@gmail.com
Sysoeva
Anna
annasysoeva07@mail.ru
Temperature stability of ferroelectric phase in potassium nitrate nanoparticles
Powder X-ray diffraction spectra of potassium nitrate embedded into porous boron-silicate glasses have been obtained. The temperature range of spectra recording was 100 – 400 K. The phase ratio of samples at various temperatures and its relationship to temperature treatment and to the way of embedding material were analyzed.
538.97
potassium nitrate
porous glass
X-Ray diffraction
ferroelectric phase
https://physmath.spbstu.ru/article/2014.24.1/
01_ph_2_194_2014.9_14.pdf
RAR
RUS
15-29
Semenov
Artem
Peter the Great St. Petersburg Polytechnic University
semenov.artem@googlemail.com
The identification of anisotropy parameters of phenomenological plasticity criterion for single crystals worked out on the micromechanical model basis
The analysis of the predictive ability of the Hill quadratic criterion of plasticity has been carried out for monocrystalline nickel based superalloys. The possibilities of determining the parameters of the quadratic criterion on uniaxial tensile tests for single-crystal samples of different crystallographic orientation were investigated. The experimental results and predictions of micromechanical model with the Schmid criterion were compared. In order to improve the prediction accuracy the phenomenological fourth degree criterion of plasticity was proposed, that allowed taking into account a number of effects that could not be described by a quadratic criterion.
539.3, 624.04
plasticity
single crystal
yield surface
anisotropy
phenomenological criterion
micromechanical model
https://physmath.spbstu.ru/article/2014.24.2/
02_ph_2_194_2014.15_29.pdf
RAR
RUS
30-36
Alekseeva
Olga
blackhole2010@yandex.ru
Naberezhnov
Alexander
Ioffe Physical Technical Institute of the Russian Academy of Sciences
alex.nabereznov@mail.ioffe.ru
Poprawsky
Ryszard
ryszard.poprawski@pwr.wroc.pl
Pecularities of melting and crystallization of low-melting metal nanoparticles
The melting and crystallization processes of low-melting metals (gallium and indium) embedded into porous glasses with average pores diameters of 2 and 7 nm have been studied by differential scanning calorimetry. The applicable Tm and Tcr temperatures and a thermal hysteresis between these processes were determined. The hysteresis values were found to increase with reducing the average pore diameter.
53.096
porous glass
melting
crystallization
metal nanoparticle
thermal hysteresis
differential scanning calorimetry
https://physmath.spbstu.ru/article/2014.24.3/
03_ph_2_194_2014.30_36.pdf
RAR
RUS
37-45
Bakaev
Alexander
bakaev_vic@mail.ru
Zhurkin
Evgeniy
ezhurkin@phmf.spbstu.ru
Characterization of radiation defects in austenitic alloys
Numerical calculation of formation energy of different radiation defects at zero temperature (T = 0 K) in the austenitic Fe0.7Ni0.1Cr0.2 model alloy using classical molecular dynamics method has been carried out. Thermal stability of the radiation defects by means of annealing modeling at different non-zero temperatures was studied.
548.4
radiation defect
annealing
austenitic alloy
modeling
classical molecular dynamics method
https://physmath.spbstu.ru/article/2014.24.4/
04_ph_2_194_2014.37_45.pdf
RAR
RUS
46-53
Bakaev
Alexander
bakaev_vic@mail.ru
Zhurkin
Evgeniy
ezhurkin@phmf.spbstu.ru
Atomic-scale simulation of dislocations in the iron austenitic alloy
We have investigated the movement of dislocations in a model iron alloy with 10 % Ni and 20 % Cr by means of computer simulation in order to study an interaction of dislocations with radiation defects in metals afterwards. Among other things, we tested the model of periodical dislocations and calculated a set of dislocation characteristics.
539.5
dislocation
austenitic alloy
molecular dynamics
modeling
https://physmath.spbstu.ru/article/2014.24.5/
05_ph_2_194_2014.46_53.pdf
RAR
RUS
54-61
Igolkin
S.I.
igolson@gmail.com
Melker
Alexander
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 the opposite direction parallel to the surface; transforming the cavity into a water crater of an arising water volcano; its activity and decay.
538.9
molecular dynamics method
shock wave
underwater disturbance
Lennard-Jones liquid
underwater explosion
https://physmath.spbstu.ru/article/2014.24.6/
06_ph_2_194_2014.54_61.pdf
RAR
RUS
62-68
Pogoda
Anastasiya
Petrov
Victor
The spectral selectivity of reflective holographic gratings in the BaTiO3:Co crystal
The spectral selectivity of refractive-index gratings in the BaTiO3: Co crystal has been investigated. A new technique for the spectral selectivity measurement of thick reflective holograms was suggested. That technique allowed direct measurement of the spectral selectivity of gratings using a tunable wavelength laser reader. A good agreement between experimental data and theoretical calculations was obtained.
621.373.826
holographic grating
spectral selectivity
dynamic holographic medium
https://physmath.spbstu.ru/article/2014.24.7/
07_ph_2_194_2014.62_68.pdf
RAR
RUS
69-74
Semenov
Semen
ussrcom@mail.ru
Vorobyev
Stanislav
s.vorobjev@gmail.com
Dudkin
Valentin
Constructing a microwave image of an object using the inverse diffraction problem
The paper designs a calculation procedure for the electromagnetic field to construct a microwave image of an object. The procedure suggested was tested with the AMu256 experimental setup. We proved it was possible to create the construction required in real-time using this setup.
537.876.22
field amplitude
microwave image of object
inverse diffraction problem
calculation of electromagnetic field
https://physmath.spbstu.ru/article/2014.24.8/
08_ph_2_194_2014.69_74.pdf
RAR
RUS
75-85
Miroshnikov
Konstantin
kmi@bk.ru
Simakova
Maria
m_simakova@mail.ru
The structure and properties of gp181 lytic enzyme of phiKZ bacteriophage
In this paper the gp181 peptidoglycan hydrolase (structural lysin) of phiKZ bacteriophage Pseudomonas aeruginosa has been investigated. The study of gp181 was performed using directed deletion mutagenesis. The assumption that the C-terminal part of gp181 may be involved in the infection process as the sensory molecular needle-like cell-puncturing device of phiKZ was experimentally confirmed.
577.322.4
structural lysin
bacteriophage
pseudomonas aeruginosa
gp181 lytic enzyme
deletion mutagenesis
https://physmath.spbstu.ru/article/2014.24.9/
09_ph_2_194_2014.75_85.pdf
RAR
RUS
86-93
Khokhlyuk
Vitaly
The illustration of the calculating partitioning procedures
The present article continues a series of papers devoted to the numerical solution of practical mixed optimization problems. Previously the partitioning theorem of the indicated mixed maximization problem was formulated and proved. In this article some methods for solving problems by partitioning, including the graphical method, a three-step procedure, and the iterative procedures 1 and 2, are shown by a specific example of the solution of the simplest mixed maximization problem. A feasible set of the problem and the convex hull of this set are graphically presented within the framework of solving the problem.
519.854
mixed problem
linear problem
optimization
duality
polyhedral cone
graphical method
partitioning procedure
https://physmath.spbstu.ru/article/2014.24.10/
10_ph_2_194_2014.86_93.pdf
RAR
RUS
94-102
Petrichenko
Mikhail
Peter the Great St. Petersburg Polytechnic University
fonpetrich@mail.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
Extreme properties of solutions of a parabolic equation
Rational procedures and properties of solutions of limiting problems have been considered for equations and limiting problems with partial derivatives of a parabolic type. It was proved that such limiting problems for parabolic equations admitting the group of self-transformations were necessary conditions for a minimum of positive functionals; furthermore, the Crocco equation was proved to be equivalent to a canonical system and its applicable functional was shown to be found at once. It was also demonstrated that someone was able to bring a parabolic equation in its original notation into a canonical form using additive doubling variables.
512.81
TRANSFORMATION GROUP
LAYER
EXTREME
PARABOLIC EQUATION
CROCCO EQUATION
ADDITIVE DOUBLING OF VARIABLES
https://physmath.spbstu.ru/article/2014.24.11/
11_ph_2_194_2014.94_102.pdf
RAR
RUS
103-109
Kachalov
Vasily
kachalovvi@mpei.ru
Holomorphic in the parameter integrals of the second-order equations perturbed singularly and limit theorems
Holomorphic in the parameter integrals of the second-order equations perturbed singularly have been built up on the basis of homomorphisms of algebras of holomorphic functions of different numbers of variables. A limit transition theorem follows from those integrals.
517.928
homomorphism
limit transition
pseudoholomorphic solution
equation perturbed singularly
commutation relation
https://physmath.spbstu.ru/article/2014.24.12/
12_ph_2_194_2014.103_109.pdf
RAR
RUS
110-119
Tikhomirov
Victor
Peter the Great St. Petersburg Polytechnic University
victikh@mail.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
Longitudinal shear crack terminating at a wedge-shaped elastic inclusion
The interaction between a semi-infinite crack of mode III and a wedge-shaped elastic inclusion has been considered. The stress singularity at the crack tip was investigated. It was shown that the stress asymptotics was able, unlike the classical case, to have two singular terms at some parameter values for composite material. A crack deflection by the interface was analyzed.
539.3
longitudinal shear crack
elastic inclusion
stress singularity
crack deflection
https://physmath.spbstu.ru/article/2014.24.13/
13_ph_2_194_2014.110_119.pdf
RAR
RUS
120-136
Tsygan
Anatoly
tsygan.astro@mail.ioffe.ru
Shalybkov
Dmitry
dasha@astro.ioffe.ru
Barsukov
Dmitry
bars.astro@mail.ioffe.ru
Goglichidze
Oleg
An analysis of differential rotation of neutron star polar caps for the case of the anisotropic conductivity of the cap substance
The differential rotation of liquid polar caps caused by magnetospheric currents closing up under neutron star surface has been considered. The anisotropy of cap electric conductivity and viscosity due to magnetic field was taken into account. The rotation velocity was shown to be very slow and almost all electric current was brought out to close up deeper, inside the rigid crust.
524.354.4
radiopulsar
neutron star
magnetic hydrodynamics
polar cap
differential rotation
anisotropic conductivity
https://physmath.spbstu.ru/article/2014.24.14/
14_ph_2_194_2014.120_136.pdf
RAR
RUS
137-144
Belyavsky
Grigoriy
beliavsky@hotmail.com
Misyura
Il’ya
ilya.misyura@gmail.com
Signal filtering with jumps during discrete time and under finite horizon
The problem of filtering signals with jumps occurring at random times on a background of white noise in discrete time and with finite horizon has been considered. Two signal models being discrete analogs of diffusion with jumps were developed.
519.21
signal filtering
jump diffusion
Markov chain
Bellman equations
discrete time
finite horizon
https://physmath.spbstu.ru/article/2014.24.15/
15_ph_2_194_2014.137_144.pdf