Российский фонд
фундаментальных
исследований

Физический факультет
МГУ им. М.В.Ломоносова
 

M

Makarov S.

 

Makarov S., Osipov D.S. «Voice Identity Recognition Based on the Parameters of the Spectral Voice Source Model» Acoustical Physics, 70, № 1, с. 182-188 (2024)

The information content of the parameters of a spectral voice source model in an automatic voice identity recognition problem is studied. For the voice parameters, the identity recognition error was 20.8%; using these parameters together with the pitch period reduced the error to 13.8%. Lastly, the combined use of the spectral model parameters with the pitch period and mel-frequency cepstral coefficients provided the highest accuracy (the recognition error was 1.2%).

Acoustical Physics, 70, № 1, с. 182-188 (2024) | Рубрики: 13.05 13.06

Makarova D.N.

 

Dembelova T.S., Makarova D.N., Badmaev B.B. «Low-Frequency Shear Elasticity of the Homological Series of Normal Hydrocarbons» Acoustical Physics, 70, № 1, с. 35-38 (2024)

The low-frequency (74 kHz) shear elasticity of the homologous series of normal hydrocarbons (alkanes) is studied using acoustic resonance. The shear modulus and mechanical loss tangent are measured, and the relaxation frequency and effective viscosity are calculated. The dependences of these parameters on homologue viscosity are established. It is shown that the mechanical loss tangent of all studied liquids is less than 1, demonstrating that the relaxation frequency is below the experimental frequency.

Acoustical Physics, 70, № 1, с. 35-38 (2024) | Рубрики: 06.01 06.10

Maksimov O.

 

Maksimov O. «Features of Rayleigh Scattering by a Particle Near an Interface» Acoustical Physics, 70, № 1, с. 1-8 (2024)

Features of Rayleigh scattering by a solid particle at a small distance compared to the wavelength from an impenetrable plane boundary are revealed. The choice of the Green’s function in the integral representation of the Helmholtz equation makes it possible to reduce integration only over the particle surface and eliminate the contribution of the interface surface. When expanding over a small wave parameter, a well-known approach is used, making it possible to represent the solution of a given order as the sum of a potential function and a component expressed in terms of lower-order approximations. The potential component is found, expressed in terms of solid irregular harmonics centered on the particle and its mirror image. The vibrational velocity of the center of a particle and the scattering amplitude are determined. In the lowest order of the wavenumber, the scattering amplitude is expressed in terms of the monopole and dipole components.

Acoustical Physics, 70, № 1, с. 1-8 (2024) | Рубрики: 04.04 04.12 07.06

Mansfeld A.D.

 

Anosov A., Granovsky N.V., Belyaev R.V., Erofeev A.V., Sanin A.G., Mansfeld A.D. «Correlation Measurements of Thermal Acoustic Radiation Using a Sensor Array» Acoustical Physics, 70, № 1, с. 21-28 (2024)

An array consisting of three sensors was used for correlation measurements of thermal acoustic radiation. For the first time, all cross-correlation functions were obtained for each pair of sensors. The measurements were carried out at two positions of the source (a heated narrow Teflon cylinder), the distance between which was equal to half the spatial period of the cross-correlation function of adjacent sensors. The measured correlation functions were in antiphase, which corresponds to the calculated correlation functions of thermal acoustic radiation. To pass from correlation functions to temperature distribution, spatial cross-correlation functions for adjacent and the outermost sensors in the array are summed. The correlation methodology makes it possible to significantly increase the spatial resolution of the method.

Acoustical Physics, 70, № 1, с. 21-28 (2024) | Рубрики: 06.18 12.01 13.02

Mansfeld D.

 

Mansfeld D., Belyaev R.V., Volkov G.P., Kuzmin A.A., Sanin A.G., Shaikin A.A. «Monitoring the Internal Temperature of Active Elements of High-Power Lasers Using Ultrasonic Probing» Acoustical Physics, 70, № 1, с. 68-75 (2024)

Monitoring the internal temperature of active elements (AE) of high-power lasers is necessary for their safe operation. The article describes a method and device for monitoring the internal temperature of the AE of lasers. The measurements utilize pulsed ultrasonic (US) probing and the temperature dependence of the sound speed in the AE material. A change in the sound speed leads to a change in the phase of the ultrasonic signal passing through the object, which is recorded by the described device. The results of monitoring the AE temperature using ultrasonic probing during operation of a laser device are presented.

Acoustical Physics, 70, № 1, с. 68-75 (2024) | Рубрика: 06.23