Physics

Complex Waveforms and Synchronization in Functional Model of Vascular Nephron Tree

Authors: Scherbakov P. A., Astakhov O. V., Postnov D. E.

We suggest functional model that qualitatively describes oscillatory processes in renal autoregulation. Our model consists of ensemble of two-mode oscillators that are coupled by means of two different pathways. The above coupling pathways count both the geometry of ensemble (tree-like structure or local interaction) and the specific action of individual oscillator (energy distribution netrwork or diffusive coupling). We study the typical operating regimes of suggested model as well as transitions between them.

Signal Propagation in Nerve Fiber

Authors: Zayko Y. N.

In this article a problem of signal propagation in nerve fiber is considered. Ohm’s losses and heat processes are taken into account. These permit to join two stages (metabolic and non-metabolic) of propagation and Na+ and K+ ions transmission through cell membrane connected with propagation. Electrodynamics of nerve fiber is described by telegraph equations with losses. Heat processes in fiber are described by an equation of entropy transfer. Ion motion at metabolic stage against the electro-chemical potential is described by negative conductance, responsible for the escape flow.

The Resonant Mechanism of Excitation Exchange Spin Waves in Layered Monolithic Ferrite-Ferrite Structures

Authors: Tikhonov V. V.

It is found out high (up to 80% and more) efficiency of pulse transformation of exchange spin waves (ESW) and a sound in implanted YIG films. Impulses ESW extended deep into YIG film and were reflected from its opposite surface. Resonant effects colinear and noncolinear transformations ESW are investigated. It is shown, that these effects have long character that allows to reach high efficiency of transformation of energy of fast and slow types of waves even at weak intensity of radiation ESW.

On Conservation Lows for Energy and Momentum in Electromagnetic Field in Media and Under Plane Wave Diffraction on Conducting Plate

Authors: Davidovich M. V.

The general nonstationary balance equations for energy and momentum densities of field-matter system based on rigorous nonstationary approach for their definitions with dependence from the field creation prehistory have been obtained. Also the transport velocities of these densities have been derived. The concrete examination and detailed consideration have been performed for simplest dispersion low which is defined by the conductivity connected with the dissipation.

Identification of Action Potentials of Small Neuron Ensembles Using Wavelet-Analysis and Neural Networks Method

Authors: Tupitsyn A. N., Nazlmov A. I., Alexyi A. N.

A possibility to solve the problem of automatic identification of neuronal spikes in the extracellularly recorded electrical potentials is discussed that is based on a combined approach assuming application of neural networks and the discrete wavelet-transform. Efficiency of the combined approach is illustrated in the analysis of experimental data.

About Conditionality of Nonlinear Responce of Miogenic Response of Afferent Arteriola for Irregular Self-Sustained Oscillations of Nephron Proximal Pressure

Authors: Pavlova O. N., Postnov D. E.

By means of nonlinear dynamics and time series analysis we investigate the possible mechanisms for the onset of chaotic selfsustained dynamics in nephron tubular pressure that is observed experimentally. Our results suggests that the miogenic constriction mechanism of afferent arteriola plays the key role providing the nonlinear response on temporal variation of filtration rate.

Cryptography from the Physicist's Point of View

Authors: Zayko Y. N.

The results of treating of crypto algorithms such as DES (USA) and GOST 28147-89 (Russia) with the help of nonlinear dynamics methods are presented. Point maps which are generated by the blocks of substitutions (S-blocks) are investigated. The phenomenon of return is demonstrated. The ergodicity of these maps are treated. An estimation of quality of S-block could be made by maps of first return. The results of statistical treating of S-biocks are presented.

Structure-Dinamic Modeles of Cyclopropane and Cyclopentene

Authors: El’kin M. D., Dzhalmukhambetova E. A.

Fashionable calculations of geometric and vibrational spectra of cyciopentane and cyclopentene are carried out. Nonplanar conformation for five-member cycle of molecule is cofirmed.

The Vibrationai Spectra of 2-Biphenylmethanol and their Interpretation by Using of Molecul Structural-Dynamical Model Taking into Account Mechanical Anharmonicity

Authors: Babkov L. M., Uspenskiy K. E., Davydova N. A.

Using hybrid density functional (B3LYP/6-31 (d)) the calculation of the geometry, electro-optical parameters, quartic force field and vibrational spectra of the 2-biphenylmethanol molecule were performed. The vibrational analysis was implemented and the full interpretation of its IR (400-3800 cm^(-1)) and Raman (50-3600 cm^(-1)) spectra was given.

IR Spectrum of the Methyl-β-D-Glucopyranoside and its Interpretation on Basis Structural-Dynamic Model Construction

Authors: Babkov L. M., Korolevich M. V., Moisejkina E. A.

Structural-dynamic models of the methyl-β-D-glucopyranoside molecule are constructed by density functional method in bases 6-31 G(d), 6-31+G (d, p). Energies, structures, dipole moments, polarizabilities, frequencies of normal modes in harmonic approximation and IR intensities have been calculated. Interpretation of IR absorption spectrum is presented in range 400-3700 cm^(-1). Advantages of model, which was constructed, compared with model, which bases on using valence-force field method and valency-optical theory, are discussed.

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