Model of the vertical distribution of temperature and dissolved-oxygen concentration in the convective mixing of the upper layer of a reservoir
Model of the vertical distribution of temperature and dissolved-oxygen concentration in the convective mixing of the upper layer of a reservoir
V.V. Alekseev, Yu.I. Gorbatov, A.Yu. Loskutov
A mathematical model is constructed for the dynamics of water temperature and dissolved-oxygen concentration in the convective mixing of the upper layer of a reservoir. Satisfactory agreement is obtained between the results of the calculation and experimental data. The validity of the theoretical formula for the turbulent transfer coefficient with convection for Grashof numbers of around $10^9$ is verified. The model may be used to predict the water quality of fresh-water reservoirs in the period of autumnal cooling.
Show AbstractSimplest hypernuclear systems with $A\le5$ and $\Lambda N$ potential
Simplest hypernuclear systems with $A\le5$ and $\Lambda N$ potential
N.N. Kolesnikov, V.I. Tarasov
A theoretical analysis of the lightest hypernuclear systems with $A\le 5$ is conducted by means of a multiparticle variational procedure. It is shown that the available experimental data may be described by means of pairwise central spin- and charge-dependent $\Lambda N$ potentials, with possible admixture of the Majorana conponent.
Show AbstractConductivity of bounded two-dimensional systems
Conductivity of bounded two-dimensional systems
I.P. Zvyagin
On the basis of scale theory of localization, it is shown that the activational temperature dependence of the conductivity of two-dimensional systems, usually interpreted by means of the concept of a mobility edge, may be due to the finite value of the characteristic length - the dimension of the system or the diffusional length including the free-path time with respect to inelastic collisions.
Show AbstractAsymptote of the solution of some boundary problems of singularly perturbed systems of differential equations
Asymptote of the solution of some boundary problems of singularly perturbed systems of differential equations
A.A. Shishkin, G.B. Gurov
For a singularly perturbed system of differential equations of the theory of semiconductor instruments, three boundary problems are considered. Asymptotic expansions of the solution of these boundary problems with respect to a small parameter are obtained.
Show AbstractRecording the classical force acting on a quantum oscillator
Recording the classical force acting on a quantum oscillator
B.A. Grishanin, V.N. Rudenko
With the aim of discovering practically realizable operations that satisfy the criterion of a "nonperturbing measurement", quantum analysis is performed of a specific measuring system including a test oscillator and a recording element - an RC sensor. It is shown that the sensitivity to external force may be the best characteristic quantum standard if the oscillator is an excited state. For a vacuum state of the oscillator, quantum fluctuations of the RC sensor limit the sensitivity at the typical level $\tau^{-1}(m\hbar\omega_0)^{1/2}$.
Show AbstractBasic laws of the algebra of parallel compounds of N-poles
Basic laws of the algebra of parallel compounds of N-poles
V.I. Shestakov
Any physical system interacting with the surrounding medium or with N-poles at N points ("poles") is called an N-pole (NP) N(X) in the present work. An autonomous physical system is called a zero-pole (0-pole). Mutually substitutable NP are said to be equivalent NP. Parallel combinations (P combinations) of P are denoted by the previous symbol [1]. On the basis of physical considerations, the basic laws of the algebra of P combinations of NP are taken to be the associative and commutative laws (Al) and (A2), i.e., axioms of each Abelian semigroup. As a consequence of laws (Al) and (A2), formulas analogous to certain axioms of linear algebra are obtained. The relation N(А)$\le$N(В) of shunt neutrality of N(A) with respect to N(B) is determined; a series of formulas expressing its basic properties is presented; it is asserted that they may be used in simplifying P combinations; and it is noted that this ratio is analogous to the inclusion relation $Х\subset Y$ of sets X and Y and also to the relation of partial order in semilattices (semistructures) and, in particular, in Boolean algebra.
Show AbstractDiffraction of laser beams with a smooth profile of intensity variation
Diffraction of laser beams with a smooth profile of intensity variation
P.V. Korolenko, S.N. Markova, A.M. Khapaev
The diffraction of laser beams with a smooth profile of the intensity distribution is investigated using a method based on the representation of the diffracted wave in the form of a superposition of TEM free-space modes. The field distribution of waves diffracted at a "soft" diaphragm and at the end of the gas-discharge capillary of a waveguide laser is calculated. The results of the calculation are verified experimentally.
Show AbstractNonlinear aberrations in the self-deviation of a light beam in a moving medium
Nonlinear aberrations in the self-deviation of a light beam in a moving medium
V.A. Trofimov
A general solution of the problem of optical-radiation propagation in a moving medium is constructed in the approximation of nonlinear geometric optics. The beam distortion is analyzed for homogeneous and bell-shaped intensity distributions.
Show AbstractInvestigation of strontium sulfide in the near-IR regio
Investigation of strontium sulfide in the near-IR regio
M.-L.Yu. Allsalu, V.V. Mikhailin, E.Yu. Pedak, M.A. Rozhdestvenskii, I.V. Tereshchenko
The near-IR luminescence of preliminarily undeformed SrS phosphors is investigated. It is shown that it belongs to the luminescence of $F^+$ centers and near-anionic vacancies. The ignition and extinction times of this luminescence are measured. The dependence of the change in luminescence intensity of $F^+$ centers and near-anionic vacancies under the action of the exciting light is established, and an explanation for the interrelationship between these centers is offered.
Show AbstractInfluence of eddy currents on the time of magnetic-field establishment in band lines
Influence of eddy currents on the time of magnetic-field establishment in band lines
O.S. Kolotov, T.Sh. Musaev, V.A. Pogzhev
The time for magnetic-field establishment in band lines under the action of eddy currents arising when a current difference is applied in a single band is investigated experimentally for the first time.
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