75 research outputs found
Surface acoustic waves
The book describes surface acoustic waves in solids, one of the most interesting and important types of wave motion. Classification of the main currently known types of surface acoustic waves is given. Their physical properties, including the specifics of propagation, scattering, and interaction with electrons, are discussed. Much of attention is paid to surface waves in piezoelectric crystals, which play a particularly important role with regard to a variety of applications in signal processing devices. There are numerous examples illustrating various manifestations of surface acoustic waves in science and engineering
Introduction to physical acoustics
The book gives a concise account of physical acoustics β a branch of physics studying the interaction of acoustic waves with matter at the macro and microscopic levels. It starts with the basics of mechanics of continuum needed to analyse the problems of physical acoustics. This is followed by the description of linear and nonlinear problems of acoustics of gases, liquids and solids. Also considered are the problems of βturbulence and soundβ, acoustics of magnetic media, and acoustics of crystals. Important information is provided also on acousto-electronics and acousto-optics. Some parts of the book are illustrated by description of the methodology of experiments and experimental data. The book would be of interest to undergraduate students of physical, chemical and engineering specialities, postgraduate students, researchers, lecturers, acoustic engineers, and all those engaged in fluid mechanics, elasticity, solid state physics, radio physics, signal processing, underwater acoustics and geophysics. (Abstract translated from the Russian)
Model of the evolution of acoustic emission as the randomization of transient processes in coupled nonlinear oscillators
The behavior of a crack as a resonator radiating acoustic emission (AE) pulses at instants of sudden growth
is investigated theoretically and experimentally. This resonance behavior of a growing crack is determined to
a large extent by surface waves propagating along its edges. The crack can therefore be regarded as an acoustic
resonator excited at the instant of growth of its tip. Transformations in the form of high-frequency harmonic
and combination-frequency subharmonic generation are observed in the spectra of the AE signals. The final
stage in the evolution of AE is characterized by the transition to a wideband noise spectrum. These facts lead
to the hypothesis that bifurcations analogous to those encountered in the onset of dynamic chaos take place
in the AE process. This hypothesis forms the basis of a mathematical model of the AE process as a system of
coupled nonlinear oscillators, each corresponding to an individual crack. The initial displacement in one of the
interacting cracks is adopted as the bifurcation parameter. Spectra calculated by computer simulation exhibit
qualitative agreement with the evolution of the spectra obtained in the processing of data from physical experiments
Features of independent physical training students of the departmental institute of the Federal Penitentiary Service of Russia in the conditions of distance learning
The article discusses issues related to the features and problems of independent physical training of cadets of the departmental educational organization of the Federal Penitentiary Service (FSIN) of Russia in the context of distance learning caused by the coronavirus pandemic. The results of a survey of 100 cadets of the Vologda Institute of Law and Economics of the Federal Penitentiary Service of Russia showed that about 27% of the surveyed students did not have sufficient opportunity to visit sports facilities during the period of self-isolation and distance learning. Also, in addition to objective conditions, the psychological and emotional state of students is of no small importance. The problems of physical training considered in the article that arise among students during the period of distance learning are of a complex nature and require an equally integrated approach for their solution, which involves: legal and organizational support for sports in self-isolation, as well as psychological support of students in distance learning.Π ΡΡΠ°ΡΡΠ΅ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°ΡΡΡΡ Π²ΠΎΠΏΡΠΎΡΡ, ΠΊΠ°ΡΠ°ΡΡΠΈΠ΅ΡΡ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠ΅ΠΉ ΠΈ ΠΏΡΠΎΠ±Π»Π΅ΠΌ ΡΠ°ΠΌΠΎΡΡΠΎΡΡΠ΅Π»ΡΠ½ΠΎΠΉ ΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΠΎΠ΄Π³ΠΎΡΠΎΠ²ΠΊΠΈ ΠΊΡΡΡΠ°Π½ΡΠΎΠ² Π²Π΅Π΄ΠΎΠΌΡΡΠ²Π΅Π½Π½ΠΎΠΉ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°ΡΠ΅Π»ΡΠ½ΠΎΠΉ ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΠΈ Π€Π΅Π΄Π΅ΡΠ°Π»ΡΠ½ΠΎΠΉ ΡΠ»ΡΠΆΠ±Ρ ΠΈΡΠΏΠΎΠ»Π½Π΅Π½ΠΈΡ Π½Π°ΠΊΠ°Π·Π°Π½ΠΈΠΉ (Π€Π‘ΠΠ) Π ΠΎΡΡΠΈΠΈ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
Π΄ΠΈΡΡΠ°Π½ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΎΠ±ΡΡΠ΅Π½ΠΈΡ, ΠΎΠ±ΡΡΠ»ΠΎΠ²Π»Π΅Π½Π½ΡΡ
ΠΏΠ°Π½Π΄Π΅ΠΌΠΈΠ΅ΠΉ ΠΊΠΎΡΠΎΠ½Π°Π²ΠΈΡΡΡΠ½ΠΎΠΉ ΠΈΠ½ΡΠ΅ΠΊΡΠΈΠΈ. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΎΠΏΡΠΎΡΠ° 100 ΠΊΡΡΡΠ°Π½ΡΠΎΠ² ΠΠΎΠ»ΠΎΠ³ΠΎΠ΄ΡΠΊΠΎΠ³ΠΎ ΠΈΠ½ΡΡΠΈΡΡΡΠ° ΠΏΡΠ°Π²Π° ΠΈ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ Π€Π‘ΠΠ Π ΠΎΡΡΠΈΠΈ ΠΏΠΎΠΊΠ°Π·Π»ΠΈ, ΡΡΠΎ ΠΎΠΊΠΎΠ»ΠΎ 27% ΠΎΠΏΡΠΎΡΠ΅Π½Π½ΡΡ
ΠΎΠ±ΡΡΠ°ΡΡΠΈΡ
ΡΡ Π½Π΅ ΠΈΠΌΠ΅Π»ΠΈ Π΄ΠΎΡΡΠ°ΡΠΎΡΠ½ΠΎΠΉ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΠΈ ΠΏΠΎΡΠ΅ΡΠ°ΡΡ ΡΠΏΠΎΡΡΠΈΠ²Π½ΡΠ΅ ΠΎΠ±ΡΠ΅ΠΊΡΡ Π² ΠΏΠ΅ΡΠΈΠΎΠ΄ ΡΠ°ΠΌΠΎΠΈΠ·ΠΎΠ»ΡΡΠΈΠΈ ΠΈ Π΄ΠΈΡΡΠ°Π½ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΎΠ±ΡΡΠ΅Π½ΠΈΡ. Π’Π°ΠΊΠΆΠ΅, ΠΏΠΎΠΌΠΈΠΌΠΎ ΠΎΠ±ΡΠ΅ΠΊΡΠΈΠ²Π½ΡΡ
ΡΡΠ»ΠΎΠ²ΠΈΠΉ, Π½Π΅ΠΌΠ°Π»ΠΎΠ²Π°ΠΆΠ½ΠΎΠ΅ Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅ ΠΈΠΌΠ΅Π΅Ρ ΠΏΡΠΈΡ
ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΠΈ ΡΠΌΠΎΡΠΈΠΎΠ½Π°Π»ΡΠ½ΠΎΠ΅ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ ΠΎΠ±ΡΡΠ°ΡΡΠΈΡ
ΡΡ. Π°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°Π΅ΠΌΡΠ΅ Π² ΡΡΠ°ΡΡΠ΅ ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ ΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΠΎΠ΄Π³ΠΎΡΠΎΠ²ΠΊΠΈ, Π²ΠΎΠ·Π½ΠΈΠΊΠ°ΡΡΠΈΠ΅ Ρ ΠΎΠ±ΡΡΠ°ΡΡΠΈΡ
ΡΡ Π² ΠΏΠ΅ΡΠΈΠΎΠ΄ Π΄ΠΈΡΡΠ°Π½ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΎΠ±ΡΡΠ΅Π½ΠΈΡ, ΠΈΠΌΠ΅ΡΡ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ½ΡΠΉ Ρ
Π°ΡΠ°ΠΊΡΠ΅Ρ ΠΈ ΡΡΠ΅Π±ΡΡΡ ΡΡΠΎΠ»Ρ ΠΆΠ΅ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ΄Ρ
ΠΎΠ΄Π° Π΄Π»Ρ ΠΈΡ
ΡΠ΅ΡΠ΅Π½ΠΈΡ, ΠΏΡΠ΅Π΄ΠΏΠΎΠ»Π°Π³Π°ΡΡΠ΅Π³ΠΎ: ΠΏΡΠ°Π²ΠΎΠ²ΠΎΠ΅ ΠΈ ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΠΎΠ½Π½ΠΎΠ΅ ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠ΅Π½ΠΈΠ΅ Π·Π°Π½ΡΡΠΈΡ ΡΠΏΠΎΡΡΠΎΠΌ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
ΡΠ°ΠΌΠΎΠΈΠ·ΠΎΠ»ΡΡΠΈΠΈ, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΏΡΠΈΡ
ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΠΎΠΏΡΠΎΠ²ΠΎΠΆΠ΄Π΅Π½ΠΈΠ΅ ΠΎΠ±ΡΡΠ°ΡΡΠΈΡ
ΡΡ ΠΏΡΠΈ Π΄ΠΈΡΡΠ°Π½ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΡΠΎΡΠΌΠ΅ ΠΎΠ±ΡΡΠ΅Π½ΠΈΡ
Unsupervised Classification of SAR Images using Hierarchical Agglomeration and EM
We implement an unsupervised classification algorithm for high resolution Synthetic Aperture Radar (SAR) images. The foundation of algorithm is based on Classification Expectation-Maximization (CEM). To get rid of two drawbacks of EM type algorithms, namely the initialization and the model order selection, we combine the CEM algorithm with the hierarchical agglomeration strategy and a model order selection criterion called Integrated Completed Likelihood (ICL). We exploit amplitude statistics in a Finite Mixture Model (FMM), and a Multinomial Logistic (MnL) latent class label model for a mixture density to obtain spatially smooth class segments. We test our algorithm on TerraSAR-X data
Comissioning of the linear accelerator-injector at the TNK facility
The industrial storage facility has been developed and manufactured at the Budker INP SB RAS. It contains an
80 MeV electron linear accelerator-injector and two electron storage rings: the lesser 450 MeV booster ring and the
main 2.5 GeV storage ring. In 2002, the work on the accelerator assembling was begun. On December, 25 this year
the accelerator was started up, and the current at the linear accelerator output was obtained. The linear accelerator
schematic together with a description of the 6 meter long accelerating DAW structure which operates at 2.8 GHz,
are presented in the paper. The first results of the accelerator start-up are as follows: the accelerated electron current
of ~50 mA with the energy of ~55...60 MeV.Π’Π΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΡΡΠ½ΠΈΠΉ Π½Π°ΠΊΠΎΠΏΠΈΡΡΠ²Π°Π»ΡΠ½ΠΈΠΉ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡ Π±ΡΠ² ΡΠΏΡΠΎΠ΅ΠΊΡΠΎΠ²Π°Π½ΠΈΠΉ Ρ Π²ΠΈΠ³ΠΎΡΠΎΠ²Π»Π΅Π½ΠΈΠΉ Ρ ΠΠ―Π€ ΡΠΌ. Π.Π. ΠΡΠ΄ΠΊΠ΅ΡΠ° Π‘Π
Π ΠΠ. ΠΡΠ½ ΠΌΡΡΡΠΈΡΡ Ρ ΡΠΎΠ±Ρ ΡΠ½ΠΆΠ΅ΠΊΡΠΎΡβΠ»ΡΠ½ΡΠΉΠ½ΠΈΠΉ ΠΏΡΠΈΡΠΊΠΎΡΡΠ²Π°Ρ Π΅Π»Π΅ΠΊΡΡΠΎΠ½ΡΠ² Π· Π΅Π½Π΅ΡΠ³ΡΡΡ Π΄ΠΎ 80 ΠΠ΅Π Ρ Π΄Π²Π°
Π½Π°ΠΊΠΎΠΏΠΈΡΡΠ²Π°ΡΡ Π΅Π»Π΅ΠΊΡΡΠΎΠ½ΡΠ²: ΠΌΠ°Π»ΠΈΠΉ Π½Π°ΠΊΠΎΠΏΠΈΡΡΠ²Π°ΡβΠ±ΡΡΡΠ΅Ρ Π½Π° Π΅Π½Π΅ΡΠ³ΡΡ 450 ΠΠ΅Π Ρ ΠΎΡΠ½ΠΎΠ²Π½ΠΈΠΉ Π½Π°ΠΊΠΎΠΏΠΈΡΡΠ²Π°Ρ Π½Π°
Π΅Π½Π΅ΡΠ³ΡΡ 2.5 ΠΠ΅Π. ΠΡΠΈΠ²ΠΎΠ΄ΡΡΡΡΡ ΡΡΠ½ΠΊΡΡΠΎΠ½Π°Π»ΡΠ½Π° ΡΡ
Π΅ΠΌΠ° Π»ΡΠ½ΡΠΉΠ½ΠΎΠ³ΠΎ ΠΏΡΠΈΡΠΊΠΎΡΡΠ²Π°ΡΠ° ΠΉ ΠΎΠΏΠΈΡ ΠΊΠΎΠ½ΡΡΡΡΠΊΡΡΡ
ΠΏΡΠΈΡΠΊΠΎΡΡΡΡΠΎΡ ΡΡΡΡΠΊΡΡΡΠΈ ΡΠ· ΡΠ°ΠΉΠ±Π°ΠΌΠΈ Ρ Π΄ΡΠ°ΡΡΠ°Π³ΠΌΠ°ΠΌΠΈ Π΄ΠΎΠ²ΠΆΠΈΠ½ΠΎΡ 6 ΠΌ, ΡΠΎ ΠΏΡΠ°ΡΡΡ Π½Π° ΡΠ°ΡΡΠΎΡΡ 2.8 ΠΠΡ.ΠΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½ΠΎ ΠΏΠ΅ΡΡΡ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΈ Π·Π°ΠΏΡΡΠΊΡ ΠΏΡΠΈΡΠΊΠΎΡΡΠ²Π°ΡΠ°: ΠΎΡΡΠΈΠΌΠ°Π½ΠΈΠΉ ΠΏΡΠΈΡΠΊΠΎΡΠ΅Π½ΠΈΠΉ ΡΡΡΡΠΌ Π΅Π»Π΅ΠΊΡΡΠΎΠ½ΡΠ² ~50 ΠΌΠ Π·
Π΅Π½Π΅ΡΠ³ΡΡΡ ~(55...60) ΠΠ΅Π.Π’Π΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠΉ Π½Π°ΠΊΠΎΠΏΠΈΡΠ΅Π»ΡΠ½ΡΠΉ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡ Π±ΡΠ» ΡΠΏΡΠΎΠ΅ΠΊΡΠΈΡΠΎΠ²Π°Π½ ΠΈ ΠΈΠ·Π³ΠΎΡΠΎΠ²Π»Π΅Π½ Π² ΠΠ―Π€ ΠΈΠΌ. Π.Π. ΠΡΠ΄ΠΊΠ΅ΡΠ° Π‘Π
Π ΠΠ. ΠΠ½ Π²ΠΊΠ»ΡΡΠ°Π΅Ρ Π² ΡΠ΅Π±Ρ ΠΈΠ½ΠΆΠ΅ΠΊΡΠΎΡβΠ»ΠΈΠ½Π΅ΠΉΠ½ΡΠΉ ΡΡΠΊΠΎΡΠΈΡΠ΅Π»Ρ ΡΠ»Π΅ΠΊΡΡΠΎΠ½ΠΎΠ² Ρ ΡΠ½Π΅ΡΠ³ΠΈΠ΅ΠΉ Π΄ΠΎ 80 ΠΡΠ ΠΈ Π΄Π²Π° Π½Π°ΠΊΠΎΠΏΠΈΡΠ΅Π»Ρ
ΡΠ»Π΅ΠΊΡΡΠΎΠ½ΠΎΠ²: ΠΌΠ°Π»ΡΠΉ Π½Π°ΠΊΠΎΠΏΠΈΡΠ΅Π»ΡβΠ±ΡΡΡΠ΅Ρ Π½Π° ΡΠ½Π΅ΡΠ³ΠΈΡ 450 ΠΡΠ ΠΈ ΠΎΡΠ½ΠΎΠ²Π½ΠΎΠΉ Π½Π°ΠΊΠΎΠΏΠΈΡΠ΅Π»Ρ Π½Π° ΡΠ½Π΅ΡΠ³ΠΈΡ 2.5 ΠΡΠ. ΠΡΠΈΠ²ΠΎΠ΄ΡΡΡΡ ΡΡΠ½ΠΊΡΠΈΠΎΠ½Π°Π»ΡΠ½Π°Ρ ΡΡ
Π΅ΠΌΠ° Π»ΠΈΠ½Π΅ΠΉΠ½ΠΎΠ³ΠΎ ΡΡΠΊΠΎΡΠΈΡΠ΅Π»Ρ ΠΈ ΠΎΠΏΠΈΡΠ°Π½ΠΈΠ΅ ΠΊΠΎΠ½ΡΡΡΡΠΊΡΠΈΠΈ ΡΡΠΊΠΎΡΡΡΡΠ΅ΠΉ ΡΡΡΡΠΊΡΡΡΡ Ρ
ΡΠ°ΠΉΠ±Π°ΠΌΠΈ ΠΈ Π΄ΠΈΠ°ΡΡΠ°Π³ΠΌΠ°ΠΌΠΈ Π΄Π»ΠΈΠ½ΠΎΠΉ 6 ΠΌΠ΅ΡΡΠΎΠ², ΡΠ°Π±ΠΎΡΠ°ΡΡΠ΅ΠΉ Π½Π° ΡΠ°ΡΡΠΎΡΠ΅ 2.8 ΠΠΡ. ΠΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Ρ ΠΏΠ΅ΡΠ²ΡΠ΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ
Π·Π°ΠΏΡΡΠΊΠ° ΡΡΠΊΠΎΡΠΈΡΠ΅Π»Ρ: ΠΏΠΎΠ»ΡΡΠ΅Π½ ΡΡΠΊΠΎΡΠ΅Π½Π½ΡΠΉ ΡΠΎΠΊ ΡΠ»Π΅ΠΊΡΡΠΎΠ½ΠΎΠ² ~50 ΠΌA Ρ ΡΠ½Π΅ΡΠ³ΠΈΠ΅ΠΉ ~(55...60) ΠΡΠ
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