Issue 4, 2012
Strings, anisometric gels, and solutions in chemical and biological systems
Strings, anisometric gels, and solutions in chemical and biological systems
S.V.Stovbun, A.A. Skoblin
This article presents a review of the works that are devoted to the formation of supramolecular anisotropic structures in a wide class of model solutions of homochiral compounds and biological fluids. Spontaneous formation of crystalline rigid strings takes place in the study solutions at low concentrations ($10^{-3}\mbox{-}10^{-2}$ M) and continues to the stage of solution solidification. This is preceded, as revealed by dynamic light scattering, by the formation of linear associates, isometric granules, and strings themselves, which strongly and nonmonotonously affect chiroptical properties and the IR and UV absorption in solutions. Strings and similar objects can be considered as model elements of intercellular switches. The described structure apparently characterizes many biological fluids.
Show AbstractThe investigation of equations for the generalized order parameter in magnetic systems
The investigation of equations for the generalized order parameter in magnetic systems
M.K. Bakhnyan, A.M. Savchenko, B.I. Sadovnikov
Equations for the generalized order parameter in the presence of a disordered magnetic system are obtained in the framework of the exchange interaction model. The possibility of the occurrence of a superconducting state upon the destruction of an unstable soliton near the phase transition is considered.
Show AbstractAnalysis of the features of energy spectra of excited states in their intersection region based on the exactly soluble quantum-mechanical problem
Analysis of the features of energy spectra of excited states in their intersection region based on the exactly soluble quantum-mechanical problem
D.Yu. Cherkasov
Modification of the structures of the spectra of excited states of a quantum system that is associated with the intersection (or approaching) of their energies and is revealed based on exactly soluble quantum-mechanical problem is illustrated based on the example of the model Landau representation of the mutually independent character of photon-roton excited states in degenerate liquid helium-II.
Show AbstractSimulation of two-level systems
Simulation of two-level systems
A.V. Ustinov
WA macroscopic model of a two-level system that contains only classical components but reproduces quantum states is constructed using numerical methods. A computer analog of the measuring procedure is developed. The analysis of the single-particle state distribution makes it possible to compare the results with quantum mechanical results. In the modeling of a two-particle singlet state, the probability and correlation functions distributions and restrictions on the Bell’s parameters are obtained. The results agree with the quantum-mechanical results.
Show AbstractA finite-element method for solving a scalar problem of diffraction by two-dimensional scatterers of complex structure
A finite-element method for solving a scalar problem of diffraction by two-dimensional scatterers of complex structure
D.A. Konyaev
A scalar problem of diffraction by two-dimensional domains of complex form is solved by the finite-element method. The good agreement of the numerical results with the exact solution to the problem of plane wave diffraction by an infinite cylinder is demonstrated. In conclusion, examples of the capabilities of the program are demonstrated.
Show AbstractPion condensation in a medium with massive quarks in an external spherically symmetrical non-Abelian chromomagnetic field
Pion condensation in a medium with massive quarks in an external spherically symmetrical non-Abelian chromomagnetic field
A.M. Shchelkachev
We consider pion condensation in a flavor asymmetric quark medium with massive quarks in the external spherically symmetric non-Abelian chromomagnetic field. It is shown that the external field is a catalyzing factor for the occurrence of pion condensation, while the finite quark masses prevent the emergence of this phenomenon.
Show AbstractThe Dirac particle in a one-dimensional “hydrogen atom”
The Dirac particle in a one-dimensional “hydrogen atom”
K.A. Sveshnikov, D.I. Khomovskii
Specific features of the behavior of the spectrum of steady states of the Dirac particle in a regularized “Coulomb” potential $V_\delta(z)={-}q/(|z|+\delta)$ as a function of the cutting parameter of $\delta$ in $1+1$ D are investigated. It is shown that in such a one-dimensional relativistic “hydrogen atom” at $\delta\ll1$, the discrete spectrum becomes a quasi-periodic function of $\delta$; this effect depends on the bonding constant analytically and has no nonrelativistic analog. This property of the Dirac spectral problem clearly demonstrates the presence of a physically containable energy spectrum at arbitrary small ${\delta>0}$ and simultaneously the absence of the regular limiting transition to $\delta\to0$. Thus, the necessity of extension of a definition for the Dirac Hamiltonian with irregularized potential in $1+1$ D is confirmed at all nonzero values of the bonding constant $q$. It is also noted that the three-dimensional Coulomb problem possesses a similar property at $q=Z\alpha>1$, i.e., when the selfconsistent extension is required for the Dirac Hamiltonian with an irregularized potential.
Show AbstractInvestigation of structural evolution of hydrogen-bond networks of water clusters at 1 and 300 K
Investigation of structural evolution of hydrogen-bond networks of water clusters at 1 and 300 K
A.V. Khakhalin$^{1,2}$, A.V. Koroleva$^1$, V.T. Shalabaeva$^1$, Ya.N. Shirshov$^1$
Computer simulation of water clusters (H$_2$O)$_n$, Na$^{+}$(H$_2$O)$_n$ and K$^{+}$(H$_2$O)$_n$ (${n\le8}$) at temperatures of 1 and 300 K was carried out using the Monte Carlo method. All the types of the hydrogen-bond network structures at equilibrium configurations of the water clusters and, among them, the most probable ones at temperatures of 1 and 300 K, were detected. The analysis of the most probable types of hydrogen-bond networks at equilibrium configurations of water clusters revealed that clusters with $n$ water molecules inherit the configuration of clusters with ${n-1}$ water molecules with an accuracy of one hydrogen bond.
Show AbstractCollapse of hydrogels based on copolymers of N-isopropylacrylamide and sodium vinylsulfonate
Collapse of hydrogels based on copolymers of N-isopropylacrylamide and sodium vinylsulfonate
E.Yu. Kozhunova$^1$, E.E. Makhaeva$^1$, N.V. Grinberg$^2$, T.V. Burova$^2$, V.Ya. Grinberg$^2$, A.R. Khokhlov$^1$
This paper describes the investigation of the behavior of polyelectrolyte thermosensitive hydrogels based on copolymers of N-isopropylacrylamide and sodium vinylsulfonate at different temperatures. The influence of ionogenic groups on the swollen gel-collapsed gel phase transition was studied by means of highly sensitive differential scanning calorimetry. It was demonstrated that the presence of ionogenic groups in the thermosensitive copolymer influences the reversibility and the amplitude of gel collapse, as well as the temperature, enthalpy, and increment of the transition heat capacity.
Show AbstractCycles of solar activity and the configurations of planets
Cycles of solar activity and the configurations of planets
V.P. Okhlopkov
In this paper, using the parameter—the average difference between the heliocentric longitudes of the planets Venus, Earth and Jupiter—the strong link found 22-year and 11-year cycles of solar activity with the lowest values of the parameter. The envelope curve of the minimum values of this parameter is well described as the conjunctions of the three planets, when they are almost in a straight line from the sun, which causes the maximum of solar activity, and the conjunctions in the larger longitudinal sector (25–30 degrees), which occur much more frequently and are accompanied by different combinations of planets on the opposite side of the Sun, which also cause the maximum of solar activity. Location of these planets on opposite sides of the Sun in various combinations is very well compatible with the parameter used.
Show AbstractThe structural function of entropy and turbulence scales
The structural function of entropy and turbulence scales
V.P. Yushkov
Structure functions of sound speed and local entropy in the turbulent atmosphere are analyzed. By long-term measurements in the atmospheric boundary layer the power dependence of these characteristics in the inertial sub-range is significantly diverged from the “2/3 law”. Behavior of structure functions indicates deviation from the asymptotic Kolmogorov-Obukhov law on scales, which significantly exceed Taylor microscale. The exponent of 2/3 is regarded as the limit value, which can be reached under different synoptic conditions. Analytical expressions for the internal and “energy” scales of entropy fluctuations, as well as for relation of these scales with entropy dissipation rate and energy of adiabatic fluctuations are proposed.
Show AbstractThe peculiarities of admixture transport in a stationary vortex flow
The peculiarities of admixture transport in a stationary vortex flow
T.O. Chaplina$^1$, E.V. Stepanova$^2$, Yu.D. Chashechkin$^2$
We consider the pattern of species transport in a compound vortex flow contacting with a free surface. The evolution of a compact marker stain (aniline ink or sunflower oil) is traced in spiral arms on the vortex surface created by a uniformly rotating disk in a cylindrical container. The parameters of the structural elements of currents are determined. The geometry of the spiral flow is structurally stable for a wide range of experimental parameters.
Show AbstractProfiles of the turbulent-exchange coefficient and suspension concentration in a system of stratified currents
Profiles of the turbulent-exchange coefficient and suspension concentration in a system of stratified currents
B.I. Samolyubov
The theoretical distribution of the turbulent-diffusion coefficient for a system of stratified currents is presented taking the specific features of exchange in boundary layers and in zones with a zero vertical-velocity gradient into account. The suspension-diffusion equation is solved using the obtained turbulent-viscosity distribution. The theoretical solution is tested against field measurements of the suspension-concentration distribution over the entire depth of a water body in four systems of currents.
Show AbstractExperimental modeling of the shifting of floating objects in “garbage islands”
Experimental modeling of the shifting of floating objects in “garbage islands”
A.A. Budnikov$^1$, P.V. Zharkov$^1$, Yu.D. Chashechkin$^2$
We studied the movements of polypropylene markers in a composite vortex as a model for the transport of garbage in the ocean in the laboratory setting. We showed that when in motion a marker rotates around the center, as well as around its own axis. We determined the dependence of the angular velocities of marker rotation on the distance to the center of a vortex, whose values depend on the size of the markers at fixed permanent conditions. We found the separatrix that divides the areas of the initial positions, from which the marker is displaced upon further movement to the center of the vortex or to the container walls.
Show AbstractThe photoluminescence kinetics of oligothiophene-phenylenesilane crystalline films
The photoluminescence kinetics of oligothiophene-phenylenesilane crystalline films
A.Yu. Pereverzev$^1$, A.V. Iovlev$^2$, N.S. Vlasova$^1$, Yu.N. Luponosov$^3$, A.V. Bogdanov$^4$, V.A. Postniko$^5$v, S.A. Ponomarenko$^3$, D.Yu. Parashchuk$^2$
Poly- and single crystalline films of 5,5′-bis(4-trimethylsilylbenzene-1-yl)-2,2′-bithiophene were grown for the first time and their photoluminescent properties were studied. Single crystalline films show exponential photoluminescence kinetics with a lifetime of 0.97 ns. Polycrystalline films demonstrate more complex photoluminescence kinetics. The relationship between the film structure and the photoluminescence kinetics is discussed.
Show Abstract