# Search articles

## Scientific and Educational Physical Schools in Saratov (on the 80th Anniversary of the Saratov Region)

We present a brief history of scientific-educational schools in physics in Saratov since the founding of Saratov University (1909). Saratov belongs to Russian industrial centers that have extensive experience of research, development of technology of electronic equipment, training for this field of science and technology. The outstanding scientist Peter N. Lebedev was at the forefront of physical education and science in Saratov.

## Afterword to the Anniversary of the Faculty of Physics of SSU

We present information on the meeting of graduates from physical faculty of Saratov National Research State University, dedicated to the 70th anniversary of the faculty. Physical education in the university was formed under the influence of the greatest Russian physicists Peter N. Lebedev and Nikolai N. Semenov, the winner of the 1956 Nobel Prize. Graduates from the faculty of various specialties (on vacuum and solid state electronics, radiophysics, optics, chemical physics, laser physics and biophotonics) celebrated the anniversary of the faculty on February 19, 2016.

## D. I. Blokhintsev about the Spiritual Foundations of Scientific Creativity

The Corresponding Member of the USSR AS Dmitrii Ivanovich Blokhintsev (10.01.1908 — 29.01.1979), one of the pioneers of atomic science and technology in USSR, the organizer and the first director of the Joint Institute for Nuclear Research in Dubna, has his original opinions about the spiritual foundations of scientific creativity. In this brief paper, we try to treat his opinions and show how they are working in the modern physics and cosmology of the Early Universe.

## Molecular Modeling and Vibrational Spectra of 4,4,’-clorobenzophenone

Vibrational infrared and Raman spectra of 4,4’-chlorobenzophenone have been measured at room temperature in the ranges 400–3200 and 0–3200 cm−1 respectively. Modeling of structure and vibrational spectra has been performed by a density functional theory method B3LYP/6-31+g(d) and 6-31-g(d). Energy, structure, components of the dipole moment and polarizability tensor, force constants, frequencies of normal modes in harmonic approximation and their intensities in the IR and Raman activity have been calculated. Interpretation of measured spectra is given.

## AD HOC Quantization of the Electromagnetic Momentum for a Dispersive Medium

**Background and Objectives:** There are two types of linear field momentum in the macroscopic electrodynamics: Minkowski momentum, and Abraham momentum. The first is conserved inside the uniform substance, the second is included into the momentum balance in relation to the center of energy. These two quantities must comply with two measures of photon momentum. Unfortunately, the ad hoc quantization of the Minkowski momentum in dispersive medium leads to the theoretical photon momentum, which differs from the observed momentum.

## IR Spectra of Triphenyl Phosphite and Their Interpretation by Molecular Modeling

**Background and Objectives: **IR spectra of triphenyl phosphite (TPhPh) were measured in liquid (at 320 K), glassy and glacial phases and in hexagonal (metastable) and monoclinic (stable) crystal phases at 12 K. The observed differences in the spectra is a consequence of the implementation of the conformers of different types in the sample. To substantiate this hypothesis, structurally dynamic models of the three most probable conformers (I –III) were built. The conformers are different in angles of rotation of the phenyl rings around the C-O bonds.

## Modeling of Vibrational Spectra of L-tryptophan in Condensed States

**Background and Objectives: **This work is devoted to the interpretation of IR and Raman spectra of Trp in the condensed states. For this purpose, we calculated the complexes in the zwitterionic form of Trp with the water molecules. Obtained results allow us to determine the influence of hydrogen bonds on the vibrational spectra of Trp in the aqueous solution and solid state.

## Electromagnetic Momenta at Wave Refraction into Dispersive Medium

**Background and Objectives:** There are two types of a field momentum in the classical electrodynamics, namely, the Abraham momentum, and the Minkowski momentum. The question arises how these momenta are conserved in the refraction on the boundary surface of a medium.

**Methods: **The electromagnetic stress tensor and momentum density in a dispersive medium, including the case of negative permittivity and negative permeability, are derived and used in this paper.

## Effect of Secondary Particles with High Linear Energy Transfer on Photon Beam Quality Factor

The energy dependence is investigated for a monoenergetic photon radiation quality factor with energies up to 40 MeV, while passing through a thin layer. The conditions of irradiation simulate radiobiological experiments to determine the relative biological eectiveness. The quality factor is calculated on the basis of data on linear energy transfer of all the particles in the irradiated layer, which are calculated using the Monte–Carlo method using GEANT4 code.

## Calculation and Approximation of Radial Dose Function of Iridium Sources

**Background and Objectives:** The purpose of this paper is to investigate optimal fitting parameters for approximating radial dose function of Iridium sources. Calculations were performed using written by authors source code based on GEANT4 library package designed to simulate particle transport processes using Monte–Carlo method. **Results:** Following parameters of the source were determined: dose rate constant, radial dose function and anisotropy function. Obtained satisfactory coherence with other researchers’ data.

## Waveguide-dielectric Resonance in Systems with Nanometer Metal Layer on Dielectric Substrate

High sensitivity of an electromagnetic wave transmission spectra to change the thickness of the nanometer metal layers on dielectric plates in the case of the waveguide-dielectric resonance emergence due to the waveguide cross section is partially filled across the width and asymmetrically occupied relative to its middle by the investigated structure has been established.

## From Anosov’s Dynamics on a Surface of Negative Curvature to Electronic Generator of Robust Chaos

**Background and Objectives:** Systems with hyperbolic chaos should be of preferable interest due to structural stability (roughness) that implies insensitivity to variation of parameters, manufacturing imperfections, interferences, etc. However, until recently, exclusively formal mathematical examples of this kind of dynamical behavior were known.

## Poincare Recurrences and Afraimovich–Pesin Dimension in a Nonautonomous Conservative Oscillator

**Background and Objectives: **One of the fundamental features of the temporal dynamics is Poincare recurrence. It have been shown that statistics of return time in global approach depends on topological entropy h. The case of h > 0 (set with mixing) has been already studied theoretically. The theoretical conclusions have been confirmed by numerical simulation. The case of the sets without mixing (h = 0) has been studied theoretically, but recent numerical results shows some special aspects which are absent in theory.

## Two Approaches to the Solution of the Scalar Problem of Diffraction on the Plane Two-periodic Lattice From Bodies of Revolution Located in the Liquid Layer

**Background, Objectives and Methods:** The problem of diffraction of acoustic waves on the lattices located in the layered media is of great scientific interest in hydroacoustics. There are many methods of the solution of this diffraction problem, such as the method of the surface integral equations, finite element method, boundary element method, etc. One of universal method of solution of diffraction problems is the modified method of discrete sources (MMDS).

## Method for Information Transmission Using a Predictive Model in Coupled Time-delay Systems

**Background and Objectives:** The object of our study is a system for secure information transmission based on time-delay generators. The choice of the model is justified by the fact that time-delay systems can be easily realized in experiment and they can exhibit chaotic behavior with a large number of positive Lyapunov exponents (hyperchaos). A transmitter uses the modulation of the delay time of a chaotic generator by a binary information signal.

## Calculation of Focusing Spin Wave Transducers Using the Method of Micromagnetic Simulation

**Background and Objectives:** Researches in the field of electronic circuit development for microwave informational systems based on magnetization oscillations and waves have been performing since the 1960s of the last century. The surge of interest in spin waves (SW) during the last decade is caused by the perspective to use SW as information carriers on the sub-micromagnetic and nanometer scale that leads to the fabrication of devices on magnonic principles and a significant miniaturization of spin-wave devices.

## Synchronization of Chimera States in Ensembles of Nonlocally Coupled Cubic Maps

**Background and Objectives: **Effects of mutual and external synchronization of chimera states are studied in two coupled ensembles of discrete maps. Each of the ensembles is a onedimensional ring of nonlocally coupled cubic maps in the chaotic oscillation mode. In order to create differences in the dynamics of the ensembles when there is no coupling between them, a mismatch is introduced in the parameters of the individual oscillators of the first and second rings. Effects of external and mutual synchronization of chimera states are explored in detail.

## Lorenz Attractor in a System with Delay: an Example of Pseudogyperbolic Chaos

**Background and Objectives:** The work contributes to a research direction aimed at search for and construction of physically realizable systems, which could fill the mathematical theory of pseudo-hyperbolic dynamics with physical content. Chaotic attractors belonging to this class generate genuine chaos that does not degrade under small variations of parameters and functions in dynamical equations.

## Numerical Simulation of a Looped Tube 4-Stage Traveling-Wave Thermoacoustic Engine

**Background and Objectives:** The technology of thermoacoustic energy conversion is one of the most promising technologies for converting thermal energy into electrical one. A brief review of the achievements in development of the multi-stage traveling-wave engines was made. The numerical simulation of a 4-stage engine with a load was done. The aim of research was to determine the engine parameters, required to achieve the maximum of efficiency of the system and the acoustic power on the load.

## Complex Dynamics and Chaos in the Rabinovich – Fabrikant Model

**Background and Objectives:** In the work we consider a finitedimensional three-mode model of the nonlinear parabolic equation. It was proposed in 1979 by M. I. Rabinovich and A. L. Fabrikant. It describes the stochasticity arising from the modulation instability in a non-equilibrium dissipative medium with a spectrally narrow amplification increment. The Rabinovich – Fabrikant system presents some extremely rich dynamics die to the third-order nonlinearities presented in the equations. The considered system is universal.

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