Izvestiya of Saratov University.
ISSN 1817-3020 (Print)
ISSN 2542-193X (Online)


Физика

Temperature Effects in Vibronic Intensity of Absorption and Resonance Fluorescence Spectra

Algorithms and program for calculation of the vibronic absorption and fluorescence molecular spectra are described taking into account the dependence of intensities on temperature. The algorithms are based on the construction of molecule’s quantum models in ground and excited electronic states with application of ab initio and density functional methods. The theoretic study of excited electronic states for polyatomic molecules, prediction of electronic absorption and fluorescence spectra of polyatomic molecules, the temperature dependence of intensities are described.

Surface Acoustic Wave Propagation in Two-dimensional Phononic Crystal on Piezoelectric Substrate

Using finite element method analysis of surface acoustic wave (SAW) propagation in the phononic crystal in a form of periodic lattice from nickel pillars, located on a piezoelectric substrate of Y + 128°-cut LiNbO3, has been conducted. Amplitude and phase characteristics of SAW propagation through said structure have been numerically studied and the change in the formed stopbands width and center frequency, related with geometric parameters of the phononic crystal changing, was analyzed. The numerical results were compared with the experimental measurements.

Analysis by Finite Element Method of Integral Antenna of RFID Tag at 5.5–6.5 GНz

Numerical analysis effective integral antenna of acoustoelectronic RFID tag was accomplished. Optimal parameters of the antenna compatible with interdigital transducer on a range of 5.5–6.5 GHz were obtained.

Methods for Enhancing Emissive Ability of the Carbon Nanotubes

The analysis of papers devoted to study of the emission properties of the carbon nanotubes and to revealing ways for the control of these properties has been performed. Five main methods for enhancing emissive ability of the carbon nanotubes have been singled out.

Structural-dinamics Models and Spectral Identification of Monohydroxysubstituted Flavone

On based of the calculations for parameters of adiabatic potential by method DFT/b3LYP are proposed the structural-dinamics models for monohydroxyflavones. The indications of spectral identification are revealed.

Instanton for the Maxwell–Einstein Equations

In this article instanton solution for the Maxwell–Einstein equations is investigated. Equations for the field of instanton and metrics are derived. Metrics of pseudoeuclidean space which is corresponding to transition between degenerate classical vacua of problem and is connected with presence at the space infinity divergent and convergent spherical electromagnetic waves is studied. An expression of the instanton is received and it’s size is found. Value of pseudoeuclidean action is calculated.

Dispersion Characteristic Calculation of Photonic Crystal Fiber Guided Modes

Dispersion characteristic of photonic crystal fiber guided mode is calculated. Numerical modeling based on the Maxwell equation for magnetic components for field of the photonic crystal is obtained. It is shown, that slot photonics crystal waveguides can be used to tailor dispersion.

Influence of Water and Biology Active Media on Silicon Nanostructures

The obtained results of comparative study of solubility, optical properties and morphology of silicon nanoparticles and nano porous Si before, during and after interaction with distilled water and the biology active medium- yeast (Saccharomycetes cereviseae) show the significant dependence of the interaction between water and BAM on structure of the researched materials.

The Effect of Illumination on Conformation of Polyelectrolyte Molecules During Adsorption onto Semiconductor Substrate

The analytical model describing the influence of illumination of semiconductor substrate during polyelectrolyte adsorption onto it, which results in different deposited organic layer thickness, was suggested. The both changes of non-equilibrium charge carriers concentrations and surface charge density under illumination of semiconductor were considered, which allows one to explain changing of adsorbed layer thickness due to molecule conformation changes because of their electrostatic interaction with photosensitive substrate.

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