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


Физика

The Influence of the Layered Structure Electrodes on the Characteristics of the Surface Acoustic Waves Devices

Effect of the thickness and elastic properties of sublayer chrome and vanadium of two-layer metallic film, from which the electrode structure is formed, on thermostability of SAW devices in the microwave band is investigated. Angles of the thermostable Y-cuts for the frequencies 1 and 2 GHz are found. Also reflection factor of SAW from edges of electrodes IDT is investigated. Thickness of aluminium and chrome in two-layer electrodes at which the reflection factor is equal to zero are found.

Multifractal Analysis of Signals Based on Wavelet-Transform

Main ideas of multifractal analysis based on the wavelet-transform are presented (the wavelettransform modulus maxima method). Possibilities and limitations of the given approach at analysis of complex signals are studied. Advantages of multifractal technique over the classical correlation analysis are discussed for the case of nonstationary and short data. Phenomena of the multifractality loss in the dynamics of different systems are considered.

Using of Method Spectrometric Analysis for Detection Microorganisms

This article presents data on the development of a new tool and method for detection of dangerous infectious diseases agents, which is based on spectrometric analysis. A device for detection of mentioned agents and software for analysis of results have been developed. This device allows to carry out non-specific and specific detection of pathogens with 30 minutes.

Model Potentials of Intermolecular Interaction Pyridine, Skatole and Pyrrole with Water

The calculations of the lengths of hydrogen bridge and frequencies of vibrations of bonds in the formation of hydrogen bonds skatole, pyridine and pyrrole with the water molecules in the approximation of B3LYP/6-31G(d,p). The calculations of model potentials of intermolecular interaction of the molecules on the basis of formulas Lennard–Jones and Morse, allowed to account for changes in the length of hydrogen bonds depending on the number of water molecules participating in the formation of complexes.

Influence of 40%-glucose Solution on a Human Corneal Structure

Effective treatment of the patients with postoperative corneal edema is one of the actual problems in ophthalmology. In this paper results of complex monitoring of influence of 40%-glucose solution on the state of both normal and edematous cornea after a cataract phacoemulsification on the base of date of confocal microscopy and optical coherence tomography have been presented. It has been shown that the glucose solution induces a short-term swelling of the healthy cornea and dehydration of the edematous one, as well as optical clearing of the tissue in the both cases.

Optimization of Phacoemulsification in Different Forms of the Cataract in the Patients with Diabetes Mellitus

In this work, human lens pathology in different forms of the cataract was studied. Two hundred twenty patients with a cataract (220 eyes) were included in the study. Morphological, immunohystological and immunocytochemical investigations of both lens capsule and substance with antibodies to α- (α-А and α-В), β-, and γ- crystallines were carried out. Diabetic patients revealed a more pronounced expression of α- and β-B crystallin compared with a group of patients with age-related cataracts.

Ecological Diagnostics of the Safety of Premises

A study was made of the radiation background of premises of economic and household purposes under various conditions. According to the data obtained, a vertical distribution of the exposure rate of premises was revealed; the influence of external factors on its value was established. Dependences were obtained and features of radiation background changes in the rooms under study were revealed. The contribution of finishing materials to the increase in the exposure rate was found.

Constructive Interference of Optical Solitons in Dispersion Oscillating Fiber

In this article the results of numerical modeling of soliton’s collision in dispersion oscillating fiber are presented. Nonlinear Schroedinger equation for modelling was used. Different propagation regimes of the couple of solitons are considered. One of these results is merging of two solitons into high-intensity pulse.

Thermostable Tunable YIG Oscillator

In the paper the original construction of thermostable electrically tunable microwave YIG oscillator with planar resonator in feedback loop is proposed. PCB of oscillator with tunable coil and thermocompensated system is located inside the screen of the portable magnetic system. Temperature drift YIG resonator frequency compensated temperature demagnetization of permanent magnets.

Numerical Simulation of Vibronic Spectra for Polyatomic Molecules

Algorithms for vibrational analysis of the excited electronic states of molecules and calculations of molecular structure at electronic excitation are described. Algorithms are realized in the form of special programs. Basic data of programs are described. All initial data for this complex are formed on the basis of the molecular dynamics and quantum models.

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