Technical Physics Letters最新文献

{"title":"Discharge in a Supersonic Gas Flow in the Expanding Region of a Laval Nozzle","authors":"B. A. Timerkaev,&nbsp;O. A. Petrova,&nbsp;I. G. Galeev,&nbsp;B. R. Shakirov,&nbsp;A. A. Saifutdinova,&nbsp;O. E. Zilyaneva","doi":"10.1134/S1063785025700130","DOIUrl":"10.1134/S1063785025700130","url":null,"abstract":"<p>A theoretical study of a glow discharge in a supersonic gas flow between the central body (cathode) and the nozzle (anode) is carried out. It is a feature of such discharges that the gas-dynamic characteristics change significantly along the gas flow. This refers to the gas pressure, density, and temperature. In such a situation, the discharge location occurs at а place in accordance with the principle of least action. In a supersonic gas flow inside a nozzle, the gas density increases upstream along the central body. Therefore, in accordance with Hehl’s law, the current density increases along the central body. The theoretical model takes these features of the glow discharge into account and calculates the distribution of the internal characteristics of the discharge both along the electric field strength lines and along the stream. Тhe discharge performances in terms of spatial localization, radiation intensity, and formation of near-electrode zones have been established to depend on the magnitude of the current and the geometric parameters of the nozzle and the central body.</p>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":"51 1","pages":"37 - 41"},"PeriodicalIF":0.9,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145167617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomic Force Microscopy Study of the Physical Properties of Aluminum Nitride Thin Films","authors":"V. I. Strunin,&nbsp;L. V. Baranova,&nbsp;N. A. Davletkil’deev,&nbsp;A. Yu. Kuklev,&nbsp;N. A. Chirikov","doi":"10.1134/S1063785025700129","DOIUrl":"10.1134/S1063785025700129","url":null,"abstract":"<p>The results of the measurements of the roughness and longitudinal piezoelectric modulus <i>d</i>₃₃ of aluminum nitride films of different thicknesses obtained by vacuum magnetron sputtering are reported. The characteristics of the synthesized films are described and atomic force microscopy images of the film surface morphology are presented. It is shown that the roughness of the obtained films decreases when a nucleation layer is formed from molybdenum and the piezoelectric moduli <i>d</i>₃₃ of the two materials are similar.</p>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":"51 1","pages":"34 - 36"},"PeriodicalIF":0.9,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145167619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconstructing Object Inhomogeneity Parameters from Near-Field Measurements Using Neural Networks","authors":"A. V. Medvedev,&nbsp;M. Yu. Medvedik","doi":"10.1134/S1063785025700099","DOIUrl":"10.1134/S1063785025700099","url":null,"abstract":"<p>The paper investigates the near field-interaction with a scatterer located in space <i>R</i>². This area is a priority in problems of medical diagnostics and defectoscopy. The process of wave propagation inside various objects is described using the Helmholtz equation. The field is induced by a point source located outside the body. The problem is reduced to the Lippmann–Schwinger integral equation. A two-step algorithm is used to search for inhomogeneities. A neural network approach has been used to filter the values obtained after a two-step algorithm. This problem arises in acoustics, electrodynamics, and flaw detection, as well as in medical diagnostics. When solving the problem numerically, the order of the matrix obtained in the calculation is about 25 thousand elements. Graphic illustrations of the restoration of the function of inhomogeneities within an object are presented. An experiment has been performed demonstrating the features of restoring object parameters using neural networks. The results show the effectiveness of the calculated data autoencoder filtering. A software package for determining the parameters of inhomogeneities within an object has been proposed and pursued.</p>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":"51 1","pages":"13 - 20"},"PeriodicalIF":0.9,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145167620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solving the Inverse Problem for the Havriliak–Negami Model in the Detection of Breast Tumors by Impedance Spectroscopy","authors":"Y. G. Smirnov,&nbsp;A. V. Kuzmin,&nbsp;V. A. Baranov","doi":"10.1134/S1063785025600206","DOIUrl":"10.1134/S1063785025600206","url":null,"abstract":"<p>The inverse problem of calculating coefficients in the Havriliak–Negami model has been considered in order to determine the structure of an inhomogeneous dielectric object on the basis of determining the parameters and analyzing the frequency characteristics of the relative permittivity. A method for calculating coefficients in the Havriliak–Negami model using three measurements of the complex permittivity at various frequencies has been applied. A numerical method has been developed to determine the coefficients in the Havriliak–Negami model, which is used in dielectric spectroscopy for early detection of tumors in the mammary gland.</p>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":"51 1","pages":"30 - 33"},"PeriodicalIF":0.9,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145167618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of the Epidemic and Pulsating Biophysical Wave Processes Based on Hybrid Computing Structures","authors":"A. Yu. Perevaryukha","doi":"10.1134/S1063785025700105","DOIUrl":"10.1134/S1063785025700105","url":null,"abstract":"<p>A method for computational modeling of rapidly developing biophysical processes on the basis of physical analogies and the transient damped oscillation theory has been developed. The relevant phenomena, including invasions of aggressive species, have been discussed and epidemics in the form of a series of peaks in the pathogen activity have been compared. The spread of COVID waves in regions turned out to be difficult to predict using conventional systems of equations of the Kermack–McKendrick theory. A new method for forming modeling structures with the included logic that sets the conditions for redefining the system of equations has been developed. It has been proposed to identify key events for changing the right-hand sides of the system of equations on the basis of tracking the changing evolutionary characteristics and transforming parameters of the interaction between the aggressive agent and the environment. Continuous evolution causes the wave-like dynamics; therefore, repeated virus activity outbreaks have been observed. To model the evolving biophysical processes, several wave equations at once should be used, since the properties of oscillations are not preserved. A hybrid model of wave differential equations has been built from a set of redefined activation and damping functions of oscillations selected according to specified conditions, while the oscillation minima remain positive and the wave maxima do not increase indefinitely. Using a new original method, consequences of the event-driven pathogen evolution has been simulated, which is especially reflected on the characteristics of a new series of COVID wave oscillations. Based on the algorithmic implementation of the structure of transitions between behavioral modes in a series of simulation scenarios for the development of epidemic waves in regions depending on immunization factors and estimated efficiency of anti-epidemic measures, scenarios for the development of the epidemic situation with a change in the dominant strains of coronavirus in five regions have been obtained. The method for organizing hybrid models from variable sets of wave equation forms can be applied to the scenario modeling of many stage oscillatory transient modes that arise both during the formation of new neural connections and in electrical circuits with feedback and trigger switching. The physical, biophysical, and social wave processes have a surprisingly large number of common dynamic aspects. Pulse and rapidly damping phenomena similar to epidemic waves are observed, for example, when waves of negative reactions spread in indignant social networks to information with the deliberate dissemination of shocking content. In social networks, there are groups that actively spread the impact and slow down this indignation, as in physics. The main problem in 2005 is the activity of the group of chronic “Long COVID” spreaders.</p>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":"51 1","pages":"21 - 26"},"PeriodicalIF":0.9,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145167621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calculation of the Temperature Field in a Cylindrical Channel by the Spline Collocation Method","authors":"A. V. Sadykov","doi":"10.1134/S1063785025700117","DOIUrl":"10.1134/S1063785025700117","url":null,"abstract":"<p>A computational scheme is proposed for the numerical solution of the energy equation by the spline collocation method. The spline collocation method uses the representation of cubic splines through normalized B-splines. The system of linear equations with respect to the spline coefficients is solved by the method of variable directions with a variable iterative parameter.</p>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":"51 1","pages":"27 - 29"},"PeriodicalIF":0.9,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A High-Order Scheme for a Hemodynamic Model","authors":"I. V. Anisimova","doi":"10.1134/S1063785025700087","DOIUrl":"10.1134/S1063785025700087","url":null,"abstract":"<p>In the paper, the application of a high-order approximation scheme in numerical modeling of hemodynamic problems that allows adequate numerical modeling of the change in the volume of the cardiac chamber has been considered. A numerical experiment with the developed software module evaluating the efficiency of the high-order approximation scheme in hemodynamic problems with allowance for their specificity has been performed.</p>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":"51 1","pages":"1 - 5"},"PeriodicalIF":0.9,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145166888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compatibility of Molybdenum with Liquid Tin at 1050°C: Comparison of Theoretical Estimates with Experimental Observations","authors":"V. P. Krasin,&nbsp;A. V. Vertkov,&nbsp;S. I. Soyustova","doi":"10.1134/S1063785025700142","DOIUrl":"10.1134/S1063785025700142","url":null,"abstract":"<p>Liquid tin is considered to be a promising plasma-facing material used in intra-chamber components of a stationary fusion reactor. Since corrosion in liquid tin is largely due to dissolution of solid metals in liquid tin, the solubility and thermodynamic activity of the main components of the structural material are key parameters for understanding corrosion processes. The solubility of the transition metals Fe, Cr, Nb, Mo, and W in liquid tin has been theoretically calculated and the results obtained have been compared with the experimental data from the literature. The results of experiments on the compatibility of molybdenum with liquid tin at 1050°C are reported. The results obtained agree well with the computational estimate and provide an optimistic basis for continuing the investigations on a wider time basis under the conditions similar to those for in-chamber tokamak components.</p>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":"51 1","pages":"6 - 12"},"PeriodicalIF":0.9,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145166889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glow Discharge in an Axially Symmetric Supersonic Gas Flow","authors":"R. S. Shamsutdinov,&nbsp;O. A. Petrova,&nbsp;A. I. Saifutdinov,&nbsp;B. A. Timerkaev","doi":"10.1134/S1063785025700063","DOIUrl":"10.1134/S1063785025700063","url":null,"abstract":"<p>A glow discharge in a supersonic gas flow between the central body (cathode) and nozzle (anode) has been theoretically investigated. Features of a glow discharge in a supersonic gas flow have been taken into account in the theoretical model and distributions of the internal characteristics of the discharge along the electric field lines and along the flow have been calculated. It has been found that the characteristics of the discharge in the spatial localization, radiation intensity, and formation of near-electrode zones depend on the current and geometric parameters of the nozzle and central body. The distribution of the main parameters of the discharge is affected by features of the discharge region geometry. Near the cathode, the field is strong and electrons intensively multiply. Then, the field is almost zero and electrons and ions accumulate in a cloud of electrons and ions. The electrodes absorb this electron and ion cloud. In the distributions, the Faraday dark space can be clearly seen. It extends almost to the anode. The discharge of this type can be used to produce hydrogen by direct pumping of methane through the supersonic nozzle with the central body. Each hydrocarbon molecule will be bombarded by electrons, which will result in decomposition of methane into hydrogen and carbon. The high flow rates and low temperatures will facilitate the long-term operation of the device.</p>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":"50 4-12","pages":"455 - 458"},"PeriodicalIF":0.9,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145169363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study of the Effect of Termodynamic Parameters on Synthesis of Nanostructured Aluminum Oxide-Based Composite Particles by Sub- and Supercritical Water Oxidation","authors":"I. I. Gil’mutdinov,&nbsp;A. N. Sabirzyanov","doi":"10.1134/S1063785025700038","DOIUrl":"10.1134/S1063785025700038","url":null,"abstract":"<p>The synthesis of a catalyst carrier precursor by sub- and supercritical water oxidation of metallic aluminum followed by iron oxide deposition has been investigated. The dependences of the physicochemical properties of the samples on temperature, reaction time, and supercritical fluid density have been examined. Conclusions have been drawn about the optimum reaction parameters ensuring the maximum specific surface of the samples.</p>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":"50 4-12","pages":"419 - 422"},"PeriodicalIF":0.9,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145169916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}