Low Temperature Physics最新文献

{"title":"Superradiance and solids: Reduced description method","authors":"S. Lyagushyn, A. Sokolovsky","doi":"10.1063/10.0023899","DOIUrl":"https://doi.org/10.1063/10.0023899","url":null,"abstract":"Spontaneous ordering in a system of excited emitters with a powerful short radiation pulse predicted by Dicke attracted the great attention of scientists for decades as a bright example of the nontrivial behavior of a nonequilibrium system. The Bogolyubov reduced description method has some advantages and provides new possibilities in the theoretical investigation of the Dicke process. The paper presents the authors’ results of modeling such processes concerning both optical ones in the presence of crystal lattice influence and acoustic superradiance, which is possible in solids. The right choice of reduced description parameters allows the account of atom motions (phonons), cavity influence, and excitations in the emitter system (excitons) in the electromagnetic radiation process. The mathematical analogy between the Dicke system and a spin system in a magnetic field opens the way to applying the reduced description technique to acoustic phenomena previously investigated with the boson variable elimination method. Such a new approach to superradiance in crystals with paramagnetic impurities and with competing mechanisms of relaxation (Wagner model) is outlined. Acoustic superradiance is discussed in connection with the problem of structural phase transitions.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459428","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":"Model study of the protein-ligand binding in the development of hypersensitivity to folic acid and its analogs","authors":"N. V. Khmil, V. G. Kolesnikov","doi":"10.1063/10.0023884","DOIUrl":"https://doi.org/10.1063/10.0023884","url":null,"abstract":"Folic acid (FA) plays a vital role in various metabolic processes, including synthesis and repair of DNA, cell division, the production of red blood cells, and fetal development. However, hypersensitivity to FA and its analogs can occur, leading to various symptomatic manifestations, including shortness of breath, skin rashes, itching, hives, swelling, gastrointestinal disturbances, tachycardia, and anaphylaxis. The mechanism of hypersensitivity to FA and its analogs is not well understood. However, it is known that human serum albumin (HSA) serves as a major pharmacokinetic effector for many substances and drugs, including FA and its analogs such as 5-methyltetrahydrofolic acid (5-MTHF), tetrahydrofolic acid (THFA), and methotrexate (MTX). HSA can interact with these compounds, affecting their distribution and metabolism. The study aimed to study the energetic and topological characteristics of the non-covalent complexes formed between HSA and FA and its analogs in order to obtain more complete information about the potential mechanisms involved in hypersensitivity reactions. Molecular docking was applied to search for the most energetically favorable conformations of the protein-ligand complexes and score the geometries based on their lowest binding energy. The 3D structure of HSA (PDB ID: 1AO6) was used as the docking target, which was obtained from the protein database. The structures of the ligands (FA, 5-MTHF, THFA, and MTX) were downloaded from PubChem, an open chemistry database at the National Institutes of Health. The surface area, volume, and depth of the binding pocket were determined using Proteins Plus. The identification of non-covalent interactions between HSA and the ligands was carried out using the PoseView and DoGSiteScorer web tools. It has been demonstrated that hydrophobic interactions and hydrogen bonds predominantly stabilize all the studied HSA-ligand complexes. Molecular docking analysis revealed that HSA binds the ligands within subdomains IB, IIA, and IIIA, with a binding energy of less than –10.0 kcal/mol. Identifying specific binding sites within the new antigen structures (the complex of HSA with the ligands) can be valuable in determining the energetically favorable binding of epitopes from these antigens to the active sites of IgE antibodies or immune cell receptors.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459847","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":"New emission band of solid nitrogen","authors":"E. Savchenko, I. Khyzhniy, S. Uyutnov, M. Bludov","doi":"10.1063/10.0023897","DOIUrl":"https://doi.org/10.1063/10.0023897","url":null,"abstract":"New results on the study of radiation effects in solid nitrogen and N2-doped Ne matrix are presented, with a focus on the so-called γ-line origin. The irradiation was carried out in dc regime with an electron beam of subthreshold energy. The relaxation dynamics was monitored by emission spectroscopy: cathodoluminescence (CL) and nonstationary luminescence (NsL), along with current activation spectroscopy. Thermally stimulated luminescence (TSL) and exoelectron emission (TSEE) of pure nitrogen and N2 in the Ne matrix were measured in a correlated manner. Three emission bands were recorded in the NIR CL spectra of solid N2: 794, 802, and 810 nm. The band at 810 nm was detected for the first time. These three bands are characterized by similar behavior and form molecular series with spacing between adjacent vibrational energy levels of the ground state of 125 and 123 cm−1. These data cast doubt on the recently made assumption that the γ-line is attributed to the emission of the nitrogen anion N− [R. E. Boltnev, I. B. Bykhalo, I. N. Krushinskaya et al. Phys. Chem. Chem. Phys. 18, 16013 (2016)]. The processes of electron attachment and neutralization of positively charged species are discussed. It has been established that the γ-line in the TSL spectra of pure nitrogen and N2-doped Ne matrix correlates with TSEE currents and recombination emission of O+, N2+, and N4+ ions, which indicates its connection with the neutralization reaction. The measurement of NsL supported this conclusion. A new possible assignment of the γ-line and its satellites to the emission of tetranitrogen N4 is discussed.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139456306","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":"III International Advanced Study Conference “Condensed Matter and Low Temperature Physics 2023” (CM&LTP 2023) Kharkiv, Ukraine, June 5–9, 2023","authors":"N. Mysko-Krutik, O. Dolbin","doi":"10.1063/10.0023882","DOIUrl":"https://doi.org/10.1063/10.0023882","url":null,"abstract":"","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139639844","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":"The effect of biologically active substances on BSA and on the textures of films obtained by drying water-salt solutions of BSA","authors":"O. A. Gorobchenko, D. Glibitskiy, O. T. Nikolov, T. A. Cheipesh, T. Dzhimieva, I. Zaitseva, A. D. Roshal, M. A. Semenov, G. Glibitskiy","doi":"10.1063/10.0023892","DOIUrl":"https://doi.org/10.1063/10.0023892","url":null,"abstract":"In the previously published results, we studied the effect of flavin mononucleotide (FMN), sodium halides NaF and NaBr, iron chloride FeCl3 and aluminum chloride AlCl3 on zigzag patterns of films obtained from saline solutions of bovine serum albumin (BSA). Changes in the properties of the biopolymer and its aqueous environment in solutions were monitored by UV absorption and fluorescence spectroscopy, microwave dielectrometry and dynamic light scattering. This work summarizes the obtained results on the influence of components of various nature on BSA and its film textures. Changes in the parameters of zigzag patterns are associated with polydispersity due to the presence of colloidal particles, aggregates and FMN associates, as well as a decrease in the surface potential and BSA hydration. The possibility of predicting the character of the influence of the studied biologically active substances on BSA is analyzed.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139456669","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":"Selective uptake and desorption of carbon dioxide in carbon honeycombs of different sizes","authors":"N. Krainyukova, D. G. Diachenko, E. A. Kotomin","doi":"10.1063/10.0023898","DOIUrl":"https://doi.org/10.1063/10.0023898","url":null,"abstract":"Carbon honeycombs (CHs) are new carbon cellular structures, very promising in many respects, in particular, for high-capacity storage of various materials, especially in gaseous and liquid forms. In this study, we report a strong uptake of carbon dioxide kept inside carbon honeycomb matrices up to temperatures about three times higher as compared with CO2 desorption at ≈ 90 K from flat solid surfaces in vacuum where we conduct our high-energy electron diffraction experiments. Desorption of CO2 from CH matrices upon heating exhibits non-monotone behavior, which is ascribed to carbon dioxide release from CH channels of different sizes. It is shown that modeling of CO2 uptake, storage, and redistribution in the thin CH channels of certain types and orientations upon heating can explain experimental observations.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139458432","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":"Near-field heat transfer between disordered conductors","authors":"Alex Kamenev","doi":"10.1063/10.0022365","DOIUrl":"https://doi.org/10.1063/10.0022365","url":null,"abstract":"Heat transfer mediated by near-field fluctuations of the electromagnetic field was studied. In the case of metals, the latter are dominated by Coulomb interactions between thermal fluctuations of electronic density. It was shown that an elastic scattering of electrons, leading to a diffusive propagation of density fluctuations, results in a qualitative change of the radiation law. While the heat flux between clean metals follows the Stefan–Boltzmann-like T4 dependence, the heat exchange between disordered conductors is significantly enhanced and scales as T3 at low temperatures.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138632495","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 non-local electrical transport in anisotropic metals","authors":"Graham Baker, Davide Valentinis, Andrew P. Mackenzie","doi":"10.1063/10.0022360","DOIUrl":"https://doi.org/10.1063/10.0022360","url":null,"abstract":"We discuss various aspects of nonlocal electrical transport in anisotropic metals. For a metal with circular Fermi surface, the scattering rates entering the local conductivity and viscosity tensors are well-defined, corresponding to eigenfrequencies of the linearized collision operator. For anisotropic metals, we provide generalized formulas for these scattering rates and use a variational approximation to show how they relate to microscopic transition probabilities. We develop a simple model of a collision operator for a metal of arbitrary Fermi surface with finite number of quasi-conserved quantities, and derive expressions for the wavevector-dependent conductivity σ(q) and the spatially-varying conductivity σ(x) for a long, narrow channel. We apply this to the case of different rates for momentum-conserving and momentum-relaxing scattering, deriving closed-form expressions for σ(q) and σ(x) — beyond generalizing from circular to arbitrary Fermi surface geometry, this represents an improvement over existing methods which solve the relevant differential equation numerically rather than in closed form. For the specific case of a diamond Fermi surface, we show that, if transport signatures were interpreted via a model for a circular Fermi surface, the diagnosis of the underlying transport regime would differ based on experimental orientation and based on whether σ(q) or σ(x) was considered. Finally, we discuss the bulk conductivity. While the common lore is that “momentum”-conserving scattering does not affect bulk resistivity, we show that crystal momentum-conserving scattering — such as normal electron-electron scattering — can affect the bulk resistivity for an anisotropic Fermi surface. We derive a simple formula for this contribution.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138632801","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":"The exotic ground state of the decorated honeycomb lattice","authors":"O. O. Kryvchikov, D. V. Laptiev","doi":"10.1063/10.0022369","DOIUrl":"https://doi.org/10.1063/10.0022369","url":null,"abstract":"The study is focusing on the exploration of the magnetic properties of the frustrated decorated honeycomb lattices. The presence of geometrical frustration and C3 symmetry leads to an exotic ground state. Monte Carlo simulations and analytical calculations are used to analyze the system’s behavior. The dependence of the magnetization on the external field of the Ising model exhibits a step-like behavior, while the magnetization of the classical Heisenberg model has no plateau in the isotropic case. An efficient Hamiltonian is proposed to describe the properties of this system on the unfrustrated hexagonal lattice within the framework of the chiral Potts model. Within a specific range of fields, the state of the effective Hamiltonian aligns with that of the original Hamiltonian. The ground state configurations and degeneracy of the system are explored, revealing fractured stripe patterns separated by spins with opposite orientations. These findings contribute to the knowledge of the properties of decorated lattices, offering valuable insights for potential experimental and practical applications.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138632643","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":"Two-dimensional electron gases as non-Newtonian fluids","authors":"Serhii Kryhin, Leonid Levitov","doi":"10.1063/10.0022366","DOIUrl":"https://doi.org/10.1063/10.0022366","url":null,"abstract":"Two-dimensional electron systems offer an appealing platform to explore long-lived excitations arising due to collinear carrier scattering enabled by phase-space constraints at the Fermi surface. Recently it was found that these effects can boost excitation lifetimes over the fundamental bound set by Landau’s Fermi-liquid theory by a factor as large as (TF/T)α with α≈2. Long-lived degrees of freedom possess the capability to amplify the response to weak perturbations, producing lasting collective memory effects. This leads to non-Newtonian hydrodynamics in 2D electron fluids driven by multiple viscous modes with scale-dependent viscosity. We describe these modes as Fermi surface modulations of odd parity evolving in space and time, and discuss their implications for experimental studies of electron hydrodynamics.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138627871","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}