Vol 18, No 3 (2015)
- Year: 2015
- Articles: 15
- URL: https://journals.ssau.ru/pwp/issue/view/386
Articles
Research of impact of electromagnetic fields of the highest frequencies on properties of agrotsenoz of crops
Abstract
In work researches of possibility agrotsenozy agricultural systems control possibility are conducted under the influence by noninvasive levels of electromagnetic fields energy at the highest frequencies. Results of laboratory and field researches are given. The criterion of an assessment uses effectiveness ratio of an agrotsenoz.
Properties of complexly periodic inhomogeneous systems in radio and optical guiding structures
Abstract
We have considered a questions associated with the analysis of the spectral characteristics of fiber Bragg gratings and periodic radio frequency in coaxial cable systems with uniform periodic structure containing a discrete phase shift. These fiber gratings are designed for measurement of temperature, linear and bending tension and allow by 1-2 orders increase their resolution. Shows the effect of increasing the sensitivity of electrophysical parameters definition using Bragg structures with a phase shift in the coaxial cable.
Antenna arrays focused by broadband signals
Abstract
Broadband and ultra-wideband signals are increasingly used in modern antenna technology, and various radio systems. Traditional performance evaluation antennas operating with narrow band signals are not always adequately reflect the characteristics of broadband antennas, at least in view of the frequency dependence of the antenna pattern. Therefore it is important to evaluate the properties of antennas based on the spectral content of the signal, as well as taking into account the ways of its processing in the receiving equipment. Consideration of this issue is devoted to this article.
Hierarchy of the laser fusion targets processes and inertial stabilizing influence
Abstract
An approach of inertial influences plasma stabilization in the lasers fusion targets is considered in that paper. It is showing that the suggested approach allows to do analyze processes in targets by common positions. For example, the slowdown of local instabilities in the plasma targets, provide the required time laws of energy flux density change for sustained compression and heating of the target, to solve the inverse problem of plasma stability with detection of the desired material density distribution and additives in ablative and working layers of the target.
Mathematical models and experimental research of bifilar logospiral conical antenna with a thinwire finite size reflector of Small spacecraft «AIST-2»
Abstract
The article is devoted to construction of mathematical models of bifilar conical logospiral antenna, part of the small spacecraft «AIST-2». Construction of models is based on the integral representations an electromagnetic field coupling currents on the radiating surface with an electromagnetic field at any point in space. the impact finely stranded reflector size and density of the grid on his chart The antenna is considered. The experimental and numerical results are given.
Optimum and quasi-optimum identification of objects at structural and system monitoring of situation
Abstract
With use of criterion of a minimum of average risk and estimates of maximum likelihood of the same parameters synthesis of optimum algorithm of an identification of the objects revealed by in common functioning monitors in the conditions of aprioristic uncertainty of signs of identification is executed. Its quasi-optimum modification allowing to reduce the sizes of massifs of signs of identification due to establishment of a priority of the purposes with the maximum conditional probability of an identification is received. Statistical characteristics of efficiency of an identification of the purposes by results of an assessment of their coordinates are investigated by various monitors.
Waves described in the adjoint boundary value problem Helmholtz equation
Abstract
The boundary value problem about improper waves of closed waveguide is formulated based on the adjoint of the Helmholtz equation. Shows that this problem is self-consistent, because it takes into account the reverse effect of the field on the source and the wave numbers in the function of the field and in the functions of the same source.
Proton conductivity of boron nanotubular systems
Abstract
We have studied the possibility of using single-layer boron triangular and alpha-structured nanotubes as substances with proton conductivity. Proposed and studied various ways to the migration of a proton on the surface of single-walled nanotubes in the implementation of the two possible mechanisms of migration - hopping and step-by-step. We conducted semi-empirical quantum-mechanical calculations of the proton transfer process on the outer surface of boron nanotubes and constructed surface profiles of potential energy, which allowed us to calculate the activation energy of the proton hopping from one boron atom of the surface to another. This feature can be used to obtain the dependence of the nanotube relative conductivity from the temperature.
The new direction in radio physics: fractal-scaling and scale-invariant radiolocation
Abstract
The new kind and approach of up-to-date radiolocation: fractal-scaling or scale-invariant radiolocation has been proposed. It leads to basic changes in the theoretical radiolocation structure itself and also in its mathematical apparatus. The fractal radio systems conception, sampling topology, global fractal-scaling approach and the fractal paradigm underlies the scientific direction established by the author in Russia and over the world for the first time. The author has been investigating these issues for exactly 35 years. The results of big practical and scientific importance obtained by the author were published in four summary reports of the Presidium of Russian academy of science (2008, 2010, 2012, 2013) and in the report for the Government of Russian Federation (2012).
Feynman integrals as connecting component between radio еngineering, fractal paradigm and quantum mechanics
Abstract
Analysing Feynman integral for one-dimensional harmonic oscillator we have found that it is possible to introduce quasiparticle of radio systems. This quasiparticle we have called «radion». One can understand «radion» as object moving along fractal trajectories in phase space of oscillator. The same arguments have led us to the conclusion about ‘natural’ fractality of all radio systems working with spectrum of signal. Under radiation of electromagnetic wave into medium with arbitrary dielectric permeability radion continues its fractal movement. Interrelations of radion and photon also have been discussed.
The cardinal principles of the designing multi canales microwave switches with semiconductor element are considered
Abstract
The Cardinal principles of the designing multi canales microwave switches with semiconductor element are considered in this article. Value and defect of the different schemes of the switches are given analysis. Using Shunting Structures with short-circuit and open-circuit stub, allows to increase the range a worker frequencies, enlarge the level to power, reduce the weakening in opened and enlarge the weakening in closed channel, reduce the size.
Compensation of nonlinear distortions in multistage amplifiers
Abstract
The paper deals with the methods of nonlinear distortion compensation for even and odd orders in the output of multistage amplifiers for radio receivers. The essence of the method is using the additional re-interactions of the base frequencies with the second harmonics and combinations to neutralize the unwanted spectral components. The optimal configuration of the dual-channel amplifier circuits FET is suggested for the simultaneous suppression of the second and third order intermodulation distortion. The advantages are shown to compensate the third order intermodulation products in the final summator relative to their minimization in separate channels.
Electroacoustic gap waves guided by cross moving crack of piezoelectric crystal
Abstract
The mode properties of electroacoustic gap waves on plane boundaries of a crack, uniformly moving in a piezoelectric crystal of 6mm (4mm) class symmetry are discussed. It is shown that transverse motion of a crack causes noncollinearity of the electroacoustic waves attached by its, leads to parametrical connection of symmetric and antisymmetric modes and is a source of frequency dispersion.
The electromagnetic compatibility specific problems in power supply systems for radar stations
Abstract
The device for leakage current protection in three-phase network without neutral terminal feeding powerful radar station supply system was designed and developed. The device for insulation resistance measuring in three-phase network without neutral terminal with capacitors having 1200 uF at all for asymmetrical interference filtration was designed and developed. There are not such devices in Russia.
Fractal method of calculation whole-cell dimension to identify the risks of recurrent myocardial infarction by analyzing patient’s scattergrams
Abstract
In article we use calculation of the Minkowski’s fractal dimension for a scattergram that are based on pulsograms. The features of the application of fractal techniques to short pulsograms total duration of no more than five minutes. The paper studied the fractal dimension of the two groups of patients: myocardial infarction and with repeated myocardial infarction. It is shown that the statistical relationship between the fractal dimensions scattergram in patients with recurrent myocardial infarction.