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Article
High-Intensity Acoustic Beams
We present a brief overview of the theory of high-intensity nonlinear diffracting beams. Characteristic distortions of the profiles of acoustic waves, which are observed during the wave propagation, are descri...
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Article
First Data on the Paleogeographical Settings and Chronology of the Last Interglacial on the Zimnii Coast of the White Sea
Based on field lithostratigraphic studies, microfaunistic and palynological analyses, and optically stimulated luminescence (OSL) dating of sediments exposed in the lower part of Quaternary sections along the ...
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Article
Open AccessInteraction of Finite Perturbations with the Front and Singularity of the Profile of a Nonlinear Wave in a Dissipative Medium
The interaction of a short pulse with three types of wave profiles in a nonlinear dissipative medium are described: a stationary shock front of finite width, a nonstationary forming front, and a “stationary” w...
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Article
Nonlinear Acoustics in Medicine: A Review
Unique instrument engineering is known to be based on new physical concepts, among which suggestions on the use of nonlinear acoustic effects can be selected. The emphasis of this review is on the developments...
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Article
Nonlinear Acoustic Waves in Liquids with Gas Bubbles: A Review
This brief abstract historical review consists of two parts. Linear and weakly nonlinear oscillations of bubbles in acoustic field are considered in the first part. Basic data are presented on the following un...
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Article
Sonic Boom: From the Physics of Nonlinear Waves to Acoustic Ecology (a Review)
A history of the topic is presented. First, information is given about the development of supersonic aviation. Then, the history of studying the phenomenon of sonic boom generated by flying bullets and project...
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Article
Moving Object: Spectra of Signals of Passive, Active Location and Transient Radiation
The paper presents an analysis of basic problems of signal formation by a moving object as problems of wave radiation and reflection with allowance for moving boundaries. The inverse problem is considered: rec...
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Article
Time–Frequency Analysis of The Second Heart Sound to Assess Pulmonary Artery Pressure
A method is proposed for noninvasive assessment of the pulmonary artery pressure based on separation of the aortic and pulmonary components of the second heart sound S2 and determining the delay time between them...
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Article
Reconstruction of Natural and Climatic Conditions in the Western Caspian Region during the Bronze Age and Humans’ Adaptation to Them
In order to identify the evolutionary stages of the natural environment of the Western Caspian Sea region in the second half of the Holocene, buried submound soils and bone remains in the Bogomolnye Peski 1 mo...
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Article
Modular “Solitons”: Mutual Absorption and Annihilation in Dissipative Media
Collisions of two pulsed signals in a medium with modular (M) nonlinearity and a special relaxation law are investigated. The processes are described by an integro-differential equation, the kernel of which is...
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Article
A Relaxing Medium with “Linearly Weakening Memory”: Evolution of Intense Pulses
The evolution of pulsed signals in a quadratically nonlinear medium with a special relaxation law is studied. It is believed that the “memory of the medium” weakens according to a linear law and becomes zero w...
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Article
Vibrations of the Semilunar Valve Modeled by an Elastic Stretched Membrane in a Fluid
A modified model for the operation of the semilunar valve is proposed, which makes it possible to estimate the spectrum of acoustic oscillations that occur as it closes. The authors have analyzed closing of th...
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Article
Oscillation and Wave Excitation in Quadratically Nonlinear Systems with Selective Second Harmonic Suppression
Oscillation and wave excitation processes are investigated in systems with quadratic nonlinearity in the presence of selective absorption at second harmonic frequency. Specific examples are considered: wave ex...
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Article
Intense Pulses in Relaxing Media with Limited “Memory Time,” Power-Law and Nonanalytic Nonlinearities
Processes that accompany propagation of time-limited pulsed signals in a relaxing medium are investigated for the case of a nonlinear medium with power-law (quadratic or cubic) nonlinearity or nonanalytic nonl...
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Chapter
Exact Solutions of Nonlinear Micropolar Elastic Theory for Compressible Solids
In this article we obtain exact solutions of finite inhomogeneous deformations of three-dimensional micropolar elastic bodies. We consider a model of the physically linear isotropic compressible material with ...
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Article
Transformation of High-Frequency Noise in the Field of a Shockwave
We study the interaction of noise and regular signals with a front whose steepness increases or decreases owing to nonlinear distortion of the profile of an intense pum** wave. Projective transformation is u...
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Article
An Intense Wave in Defective Media Containing Both Quadratic and Modular Nonlinearities: Shock Waves, Harmonics, and Nondestructive Testing
The observed nonclassical power-law dependence of the amplitude of the second harmonic wave on the amplitude of a harmonic pump wave is explained as a phenomenon associated with two types of nonlinearity in a ...
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Article
Wave Resonance in Media with Modular, Quadratic and Quadratically-Cubic Nonlinearities Described by Inhomogeneous Burgers-Type Equations
The phenomenon of “wave resonance” which occurs at excitation of traveling waves in dissipative media possessing modular, quadratic and quadratically-cubic nonlinearities is studied. The mathematical model of ...
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Article
Wave Excitation in a Dissipative Medium with a Double Quadratically-Modular Nonlinearity: a Generalization of the Inhomogeneous Burgers Equation
Solutions of a forced (inhomogeneous) partial differential equation of the second order with two types of nonlinearity: power (quadratic) and nonanalytic (modular) are found. Equations containing each of these...
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Article
A Simple Bimodular Nonlinear Element
We have studied the dynamics of an artificial nonlinear element representing a flexible membrane with oscillation limiters and a static pressing force. Such an element has the property of “bimodularity” and de...
