JETP Letters最新文献

{"title":"Opening of New Windows to the Early Universe by Means of Multi-Messenger Astronomy (Brief Review)","authors":"E. V. Arbuzova, K. A. Dolgikh, A. D. Dolgov, O. E. Kalashev, A. A. Korochkin, L. A. Panasenko, N. A. Pozdnyakov, G. I. Rubtsov, A. S. Rudenko, I. I. Tkachev","doi":"10.1134/s0021364024600629","DOIUrl":"https://doi.org/10.1134/s0021364024600629","url":null,"abstract":"<p>The current situation in cosmology and particle physics, which are two closely related fields of fundamental physics, is unique. The Standard Model of particle physics excellently reproduces all existing experimental data except for neutrino oscillations. Similarly, the comparison of the standard cosmological model with astronomical observations indicates that we well understand the evolution of the Universe from its “birth” to the present. However, to understand mechanisms of numerous cosmological phenomena, it is certainly necessary to go beyond the Standard Model. These are primarily the problems of dark matter and dark energy, generation of the baryon asymmetry of the Universe, and the mechanism of inflation expansion. The problem of the appearance of cosmic magnetic fields and the recent problem of the existence of massive black holes whose number in the Universe is much larger than the expected values are among less known, but also very important problems in conventional cosmology and astrophysics. To understand and possibly solve these problems, it is very important to provide deep insight into the Universe and to obtain data on physical processes at the early stages of the cosmological evolution. Multi-messenger observations involving all possible messengers (“windows”) provide a powerful tool for this. In addition to conventional detection of electromagnetic radiation in all bands and all types of cosmic rays, the observations of gravitational waves have recently opened a new window. A complex analysis of information obtained from various astronomical data has been performed in our works supported by the Russian Science Foundation (project no. 20-42-09010 “Opening of New Windows to the Early Universe by Means of Multi-Messenger Astronomy”). In particular, the characteristics of cosmic magnetic fields and possible mechanisms of their appearance have been studied and the observed manifestations of primary black holes have been examined using the data on gravitational waves observed at the LIGO/Virgo/KAGRA interferometers.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141064133","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":"Conformational Diversity of Lipids","authors":"I. A. Boldyrev","doi":"10.1134/s0021364023603573","DOIUrl":"https://doi.org/10.1134/s0021364023603573","url":null,"abstract":"<p>The conformational diversity of hydrophobic lipid chains has been studied. The number of possible conformations of a lipid chain, as well as the number of these conformations that can be realized in a real system, has been determined. A set theory approach to the analysis of conformations of lipid molecules has been proposed, and a relation of the sets of conformations realized in a lipid structure to the energy of the system has been introduced. Using the set theory, it has been considered which conformations of hydrophobic lipid chains can be realized in the real system. The notion of the key conformation has been formulated to estimate the correlation between the structural characteristics of lipids and the energy characteristics of membranes.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141058930","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":"Analysis of Skin Neoplasms’ Raman Spectra Using the Lorentz Approximation Method: Pilot Studies","authors":"I. N. Saraeva, E. N. Rimskaya, A. B. Timurzieva, A. V. Gorevoy, S. N. Sheligyna, V. I. Popadyuk, E. V. Perevedentseva, S. I. Kudryashov","doi":"10.1134/s0021364023604153","DOIUrl":"https://doi.org/10.1134/s0021364023604153","url":null,"abstract":"<p>Confocal Raman microspectroscopy provides the ability to diagnose cancer by quantitatively analyzing spectral features and identifying underlying biochemical changes. The differentiation of malignant skin neoplasms (basal cell carcinoma, squamous cell carcinoma), benign skin neoplasms (papilloma) and healthy skin was carried out by obtaining Raman spectra in vitro with excitation wavelengths of 532 and 785 nm. We present a new method for analyzing the parameters of spectral bands, based on the calculation of the second derivative and Lorentz approximation of the spectra. Using this method on a small selection of skin tumors, we have demonstrated that processes in skin tumors can cause deformation of the proteins’ secondary structure, leading to degradation and shift of the corresponding bands (972, 1655 cm^–1) to the lower frequency. Bands corresponding to lipids in skin neoplasms either broaden and increase or split into two peaks (bands 1061, 1127, 1297, 1439, 1745 cm^–1). The disruption of lipid structure, also indicated in several bands as a shift to lower wavenumbers, is possibly due to increased cell membrane fluidity in tumors. The results of the study may be useful for the development of optical biopsy methods for early diagnosis of tumors.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141058960","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":"Anomalous Josephson Effect in a Planar Hybrid Structure with the Spin–Orbit Coupling","authors":"A. V. Samokhvalov","doi":"10.1134/s0021364024600411","DOIUrl":"https://doi.org/10.1134/s0021364024600411","url":null,"abstract":"<p>The way of formation of controlled phase inhomogeneity in a hybrid structure consisting of a short Josephson junction between two superconducting thin films, with one electrode partially coated with a ferromagnetic insulator, has been theoretically studied. The joint action of spin splitting and the Rashba spin–orbit coupling at the superconductor–ferromagnet interface leads to the generation of a spontaneous supercurrent, which changes the transport properties of the junction. The critical current and the current–phase relation of this hybrid structure have been calculated; it has been shown that this structure can be used to form an anomalous φ₀ Josephson junction with the phase shift φ₀ smoothly varying over a wide range.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141064148","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":"Direct Observation of Pinning of Abrikosov Vortices in a Specially Inhomogenious Crystal EuRbFe4As4","authors":"M. S. Sidelnikov, A. V. Palnichenko, K. S. Pervakov, V. A. Vlasenko, I. I. Zverkova, L. S. Uspenskaya, V. M. Pudalov, L. Ya. Vinnikov","doi":"10.1134/s0021364024600514","DOIUrl":"https://doi.org/10.1134/s0021364024600514","url":null,"abstract":"<p>In the two-phase crystal EuRbFe₄As₄/EuFe₂As₂ (1144/122), a linear ordering of Abrikosov vortices, uncharacteristic for superconducting pnictides, has been found using the method of decorating with magnetic nanoparticles. The observed chains of vortices directed along crystallographic 〈110〉 axes of the orthorhombic EuFe₂As₂ phase are explained by pinning of vortices in the superconducting phase 1144 on linear defects associated with the twin boundaries of the non-superconducting 122 phase.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141058961","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":"Suppression of Nucleation in a Turbulent Gas Flow","authors":"S. A. Novopashin, V. V. Kalyada","doi":"10.1134/s0021364024600113","DOIUrl":"https://doi.org/10.1134/s0021364024600113","url":null,"abstract":"<p>The initial stage of argon condensation at discharge to vacuum has been studied experimentally. Mass-spectrometry measurements of the spectrum of clusters at outflow from a long pipe with laminar and turbulent flow regimes in it have been carried out. It has been found experimentally that the turbulent flow regime in the pipe suppresses the nucleation of a condensed phase.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141058919","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":"“Anomalous” Photoelectric Effect in the Ultrafast Electron Diffraction Method","authors":"S. A. Aseyev, B. N. Mironov, D. G. Poydashev, A. A. Ischenko, E. A. Ryabov","doi":"10.1134/s0021364024600745","DOIUrl":"https://doi.org/10.1134/s0021364024600745","url":null,"abstract":"<p>Electron-pulse probing of fast laser-induced processes has allowed the direct observation of the structural dynamics in matter with a high spatiotemporal resolution. A thin gold film has appeared to be a convenient photocathode, and photoelectron emission has been induced by femtosecond ultraviolet radiation with a photon energy of about 4.65–4.75 eV (in particular, <span>(hbar )</span>ω <span>( cong )</span> 4.65 eV for the third harmonic of the Ti:sapphire laser). For the linear photoelectric effect, this energy contradicts the reference work function <i>W</i>_Au <span>( cong )</span> 5.1–5.3 eV of pure metal. Reasons for such contradiction have been analyzed and good agreement with experimental data has been reached with a model proposed for the generation of photoelectron pulses.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141058965","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":"On the Saturation of the Instability of Induced Ordinary Microwave Scattering in the Edge Transport Barrier of a Tokamak during Electron Cyclotron Resonance Heating of a Plasma","authors":"E. Z. Gusakov, A. Yu. Popov","doi":"10.1134/s0021364024600617","DOIUrl":"https://doi.org/10.1134/s0021364024600617","url":null,"abstract":"<p>The saturation of the low-threshold parametric decay instability of an ordinary wave during electron cyclotron resonance heating in the edge transport barrier of a tokamak due to the stochastic damping of a daughter two-dimensionally localized oblique Langmuir wave has been considered. It has been found that the saturation of instability in modern devices occurs at a relatively low level and does not affect the energy balance during plasma heating. It has been shown that the efficiency of nonlinear pump under expected conditions of microwave power injection in the International Thermonuclear Experimental Reactor will exceed the maximum efficiency of stochastic damping, which will result in the breaking of amplitude-dependent saturation and can significantly modify the power deposition profile.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141064134","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":"Implementation of a Quantum Generator of Random Numbers: Extraction of Provably Random Bit Sequences from Correlated Markov Chains","authors":"K. A. Balygin, S. P. Kulik, S. N. Molotkov","doi":"10.1134/s0021364024600575","DOIUrl":"https://doi.org/10.1134/s0021364024600575","url":null,"abstract":"<p>An experimental implementation of a quantum random number generator has been proposed. A new method for the extraction of <i>provably random bit sequences</i> from correlated sequences of photocounts, which are Markov chains, has been implemented experimentally for the first time. The reached generation rate of bits 0 and 1 is 154.5 Mbit/s<i>.</i> Fundamental natural constraints on the achievement of perfect true randomness are also discussed.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141058878","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":"Low-Temperature Crystallization of Structural Defects in LuB12 According to 175Lu NMR Data","authors":"O. M. Vyaselev, A. A. Gippius, N. E. Sluchanko, N. Yu. Shitsevalova","doi":"10.1134/s0021364024600587","DOIUrl":"https://doi.org/10.1134/s0021364024600587","url":null,"abstract":"<p>Studies of dodecaboride LuB₁₂ in the temperature range of 10–300 K show that the ¹⁷⁵Lu spectrum is broadened due to the scatter of quadrupole frequency shifts caused by the defects in the Lu sublattice. To explain the discovered hysteresis in the temperature dependence of the ¹⁷⁵Lu linewidth, a scenario of “crystallization of structural defects” is proposed, in which the defects of the Lu sublattice, disordered at room temperature, are transformed into a more symmetrical and stable configuration with decreasing temperature, apparently due to static distortions of the boron frame caused by the cooperative Jahn–Teller effect.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141058891","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}