Molecular-dynamic modeling of structural variations in a Ni-P system upon deep cooling and subsequent heating
Molecular-dynamic modeling of structural variations in a Ni-P system upon deep cooling and subsequent heating
V.S. Stepanyuk, O.S. Trushin, A.A. Katsnel'son, A. Sas
The method of molecular dynamics is used to study the structure of the $Ni_{75}P_{25}$ alloy as dependent on the preparation process. The structure is shown to have "thermal hysteresis". The possibility of predicting structural relaxation is discussed in therms of molecular-dynamic modeling.
Show AbstractThe effect of substitutional impurities on the temperature of metal-semiconductor phase transition
The effect of substitutional impurities on the temperature of metal-semiconductor phase transition
V.I. Emelyanov, N.L. Levshin, A.L. Semenov
The effect of substitutional impurities on the temperature of metal-semiconductor phase transition was theoretically studied with consideration for diagonal and off-diagonal matrix elements of the perturbation operator. The results were compared with experiment data.
Show AbstractTemperature quenching of photoconductivity in undoped specimens of amorphous hydrogenated silicon obtained at different deposition temperatures
Temperature quenching of photoconductivity in undoped specimens of amorphous hydrogenated silicon obtained at different deposition temperatures
A.G. Kazanskii, I.V. Klimashin, O.I. Kon'kov, E.I. Terukov
A complex of methods was used to study the following properties of undoped a-Si:H specimens: absorption (by the dc photocurrent technique), concentration of dangling bond (DB) type defects (by the EPR technique), and temperature dependence of dark and photoconductivity. To explain the results obtained, a model was proposed which allows, in addition to the growth of DB defect concentration, also for the growth of concentration of shallow centers with energies near the valence band in the a-Si:H mobility gap.
Show AbstractПамяти Бориса Ивановича Спасского
Памяти Бориса Ивановича Спасского
Редколлегия журнала «Вестник Московского университета. Серия 3, Физика. Астрономия»
12 января 1990 г. скончался Борис Иванович Спасский — ученый, доктор физико-математических наук, профессор Московского университета, чье имя и научные труды по истории и методологии физики широко известны научной и педагогической общественности в нашей стране и за рубежом.
Show AbstractOn a relaxation of normal velocity in a crystal
On a relaxation of normal velocity in a crystal
M.Yu. Kovalevskii, V.A. Krasnikov
Based on two fundamental ideas of N.N. Bogolyubov, namely the concept of quasi-means and the method of reduced description, the effect of crystal lattice on the dynamics of a superfluid is taken into account within the framework of microscopic description. The coefficient of deceleration of normal velocity is expressed in terms of the correlation function. Equations of motion are derived for densities of additive integrals of motion and superfluid momentum. The positive definiteness of entropy production is proved.
Show AbstractOn some a priori estimates for the solution to the nonlinear diffusion problem
On some a priori estimates for the solution to the nonlinear diffusion problem
A.V. Schepetilov
In this paper, under consideration is a boundary value problem for a quasilinear parabolic equation describing the cementation process in the hardening of a steel specimen. Its solution is compared with the solution to an analogous linear problem. It is shown that by selecting a diffusion coefficient and boundary and initial conditions in the linear case it is possible to obtain a two-sided estimate for the solution to the nonlinear problem using the solution to the linear problem.
Show AbstractFermions in the Aharonov-Bohm field: scattering and spin effects
Fermions in the Aharonov-Bohm field: scattering and spin effects
D.V. Gal'tsov, S.A. Voropaev
Particular features of scattering of relativistic particles with spin 1/2 in the Aharonov-Bohm gauge field are considered. For this purpose use is made of the model of a solenoid of radius $a$ with subsequent passage to the limit for $a\to 0$, the magnetic flux being conserved. It is shown that the electromagnetic potential affects the initial spin state of the particle.
Show AbstractOn the ground state of two-dimensional electron gas in a quantizing magnetic field
On the ground state of two-dimensional electron gas in a quantizing magnetic field
V.R. Khalilov
It is shown that the Fermi energy of two-dimensional electron gas in a magnetic field is quantized. Approximate formulas are obtained for the electron ground state energy in weak and strong magnetic fields with consideration for the interaction of electrons at zero temperature. It follows from the results obtained that,depending on the relationship between the problem parameters (electron density, magnetic field intensity, and orbital angular momentum of relative motion), there can occur phase transitions in the electron system. A simple formula is derived, which relates the Landau level occupancy in a strong magnetic field to the orbital angular momentum of the electron pair.
Show AbstractMass generation at finite temperature and density in the Gross-Neveu model
Mass generation at finite temperature and density in the Gross-Neveu model
A.S. Vshivtsev, V.Ch. Zhukovskii, B.V. Magnitskii
The paper examines the effect of finite values of the temperature and chemical potential on mass generation in the Gross-Nevue model. Relations between the mass, chemical potential, and the temperature are found for the fermion gas under consideration.
Show AbstractQuarkonium dissociation in quark-gluon plasma
Quarkonium dissociation in quark-gluon plasma
R.N. Faustov, I.G. Vasilevskaya
Suppression of birth of $J/\Psi$ charmonium in collisions of heavy ions was observed in several experiments. This phenomenon can be a consequence of formation of quark-gluon plasma, charmonium-hadron collisions, and nuclear absorption effects. Therefore, of interest is the dissociation of quarkonium in quark-gluon plasma. In this communication, calculations are carried out for the processes $J/\Psi+g \to c+\bar{c}$ and $\Upsilon + g \to b+\bar{b}$ at various temperatures.
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