D. L. Surmanidze, T. E. Lobzhanidze, I. R. Metskhvarishvili, G. N. Dgebuadze, V. M. Gabunia, B. G. Bendeliani, M. R. Metskhvarishvili, D. A. Jishiashvili
Thallium-based high-temperature superconductors exhibit excellent superconductivity performance (Tc, Jc). Formation of the Tl-based superconducting materials critically depends on the used precursor and synthesis conditions. In the present investigation, we used the in situ polymerization method for synthesizing high-purity and reaction-ability precursors. We find the critical dependence of Tl-based superconductor phase formation on the quantity of applied oxygen pressure. The experimental results showed that the Tl-1223 phase formed at an oxygen gas pressure at 1 to 2 atm, Tl-2223 phase at 3 atm, and Tl-2212 phase at 4 to 8 atm.
{"title":"The effect of O2 pressure on phase formation and superconductivity properties of Tl-based HTS","authors":"D. L. Surmanidze, T. E. Lobzhanidze, I. R. Metskhvarishvili, G. N. Dgebuadze, V. M. Gabunia, B. G. Bendeliani, M. R. Metskhvarishvili, D. A. Jishiashvili","doi":"10.1063/10.0023889","DOIUrl":"https://doi.org/10.1063/10.0023889","url":null,"abstract":"Thallium-based high-temperature superconductors exhibit excellent superconductivity performance (Tc, Jc). Formation of the Tl-based superconducting materials critically depends on the used precursor and synthesis conditions. In the present investigation, we used the in situ polymerization method for synthesizing high-purity and reaction-ability precursors. We find the critical dependence of Tl-based superconductor phase formation on the quantity of applied oxygen pressure. The experimental results showed that the Tl-1223 phase formed at an oxygen gas pressure at 1 to 2 atm, Tl-2223 phase at 3 atm, and Tl-2212 phase at 4 to 8 atm.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459351","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}
This paper reports the results of numerical modeling of wave reflection coefficient behavior of the metal-dielectric metasurface at microwaves that can be used for biomedical applications. The study includes optimization of the working parameters of the metasurface-based structure as a sensitive element of a microwave sensoring systems for determination of proteins concentration in different solutions. In the current research a unit with the geometry, which is similar to the geometry of one well of the standard 96-multiwell laboratory microplate, is used as a resonant metasurface unit cell and liquid-holding structure. Human serum albumin (HSA) is used as a protein specimen in our model study. The present numerical modeling is based on the results of our previous experimental measurements of complex permittivity values of HSA water solutions and its biochemical reaction mixtures using microwave dielectrometry method and the developed setup. The unit cell approach calculations are performed by COMSOL Multiphysics software. The optimization of working parameters of the metal-dielectric metasurface structure with tested solutions allow us to observe the resonance effects of the wave reflection coefficient in the microwave range. We can determine the HSA concentration changes in water solutions and enzymatic reaction mixtures by the resonance frequency shift of the wave reflection coefficient of the metal-dielectric metasurface. Developed metal-dielectric metasurface-based structure demonstrates prospects to be used as a sensitive element of microwave sensors for proteins concentration determination with biomedical purposes.
{"title":"Numerical modeling of metal-dielectric metasurface as an element of microwave sensors for biomedical applications","authors":"K. S. Kuznetsova, V. A. Pashynska, Z. E. Eremenko","doi":"10.1063/10.0023885","DOIUrl":"https://doi.org/10.1063/10.0023885","url":null,"abstract":"This paper reports the results of numerical modeling of wave reflection coefficient behavior of the metal-dielectric metasurface at microwaves that can be used for biomedical applications. The study includes optimization of the working parameters of the metasurface-based structure as a sensitive element of a microwave sensoring systems for determination of proteins concentration in different solutions. In the current research a unit with the geometry, which is similar to the geometry of one well of the standard 96-multiwell laboratory microplate, is used as a resonant metasurface unit cell and liquid-holding structure. Human serum albumin (HSA) is used as a protein specimen in our model study. The present numerical modeling is based on the results of our previous experimental measurements of complex permittivity values of HSA water solutions and its biochemical reaction mixtures using microwave dielectrometry method and the developed setup. The unit cell approach calculations are performed by COMSOL Multiphysics software. The optimization of working parameters of the metal-dielectric metasurface structure with tested solutions allow us to observe the resonance effects of the wave reflection coefficient in the microwave range. We can determine the HSA concentration changes in water solutions and enzymatic reaction mixtures by the resonance frequency shift of the wave reflection coefficient of the metal-dielectric metasurface. Developed metal-dielectric metasurface-based structure demonstrates prospects to be used as a sensitive element of microwave sensors for proteins concentration determination with biomedical purposes.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"103 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459386","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}
The contribution of copper and indium cationic sublattices on polarization hysteresis loops in CuInP2S6 van der Waals ferrielectrics has been studied within the quantum anharmonic oscillator model that considers the ordering dynamics of Cu+ cations in the double-well local potential and displacive dynamics of In3+ cations in the three-well shaped potential. The multiple polarization states are manifested as single, double, and triple P(E) hysteresis loops. The triple loops originate from a field-induced ferrielectric to ferroelectric phase transition within a certain range of the phase diagram with continuous increase in the spontaneous polarization below the second-order transition from the paraelectric phase to the ferrielectric state.
{"title":"Involvement of cationic sublattices in multiple polarization states in CuInP2S6 ferrielectrics","authors":"R. Yevych, V. Liubachko, Yu. Vysochanskii","doi":"10.1063/10.0023895","DOIUrl":"https://doi.org/10.1063/10.0023895","url":null,"abstract":"The contribution of copper and indium cationic sublattices on polarization hysteresis loops in CuInP2S6 van der Waals ferrielectrics has been studied within the quantum anharmonic oscillator model that considers the ordering dynamics of Cu+ cations in the double-well local potential and displacive dynamics of In3+ cations in the three-well shaped potential. The multiple polarization states are manifested as single, double, and triple P(E) hysteresis loops. The triple loops originate from a field-induced ferrielectric to ferroelectric phase transition within a certain range of the phase diagram with continuous increase in the spontaneous polarization below the second-order transition from the paraelectric phase to the ferrielectric state.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459356","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}
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.
{"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":"103 1","pages":""},"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}
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.
叶酸（FA）在各种新陈代谢过程中发挥着重要作用，包括 DNA 的合成和修复、细胞分裂、红细胞的生成和胎儿发育。然而，对叶酸及其类似物过敏会导致各种症状表现，包括呼吸急促、皮疹、瘙痒、荨麻疹、肿胀、胃肠功能紊乱、心动过速和过敏性休克。对 FA 及其类似物过敏的机制尚不十分清楚。不过，众所周知，人血清白蛋白（HSA）是许多物质和药物的主要药代动力学效应器，其中包括 FA 及其类似物，如 5-甲基四氢叶酸（5-MTHF）、四氢叶酸（THFA）和甲氨蝶呤（MTX）。HSA 可与这些化合物相互作用，影响它们的分布和代谢。本研究旨在研究 HSA 与四氢叶酸及其类似物之间形成的非共价复合物的能量和拓扑特征，以便更全面地了解超敏反应的潜在机制。分子对接法用于寻找蛋白质-配体复合物中能量最有利的构象，并根据其最低结合能对几何结构进行评分。HSA 的三维结构（PDB ID：1AO6）是从蛋白质数据库中获取的，被用作对接目标。配体（FA、5-MTHF、THFA 和 MTX）的结构是从美国国立卫生研究院的开放式化学数据库 PubChem 中下载的。使用 Proteins Plus 测定了结合口袋的表面积、体积和深度。使用 PoseView 和 DoGSiteScorer 网络工具鉴定了 HSA 与配体之间的非共价相互作用。结果表明，疏水相互作用和氢键主要稳定了所有研究的 HSA 配体复合物。分子对接分析表明，HSA 与亚域 IB、IIA 和 IIIA 中的配体结合，结合能小于 -10.0 kcal/mol。确定新抗原结构（HSA 与配体的复合物）中的特定结合位点对确定这些抗原的表位与 IgE 抗体或免疫细胞受体的活性位点的能量结合非常有价值。
{"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":"270 1","pages":""},"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}
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.
本文介绍了固体氮和掺杂 N2 的 Ne 基体中辐射效应研究的新成果，重点是所谓的 γ 线起源。辐照是在直流状态下用阈下能量的电子束进行的。通过发射光谱监测弛豫动态：阴极发光（CL）和非稳态发光（NsL）以及电流活化光谱。以相关方式测量了纯氮和 Ne 基质中 N2 的热激发发光 (TSL) 和外电子发射 (TSEE)。在固体 N2 的近红外 CL 光谱中记录到三个发射带：794、802 和 810 纳米。810 纳米波段是首次检测到。这三个波段具有相似的行为特征，并形成分子系列，基态相邻振动能级之间的间隔为 125 和 123 cm-1。这些数据使人们对最近提出的关于 γ 线是氮阴离子 N- 发射的假设产生了怀疑 [R. E. Boltnev, I. R. Boltnev, I. R. Boltnev, I. R. Boltnev, I. R. R.E. Boltnev, I. B. Bykhalo, I. N. Krushinskaya et al.Chem.18, 16013 (2016)]。讨论了正电荷物种的电子附着和中和过程。研究发现，纯氮和掺杂 N2 的 Ne 基质 TSL 光谱中的γ 线与 O+、N2+ 和 N4+ 离子的 TSEE 电流和重组发射相关，这表明它与中和反应有关。对 NsL 的测量也支持这一结论。讨论了 γ 线及其卫星线对四氮 N4 发射的新的可能归属。
{"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":"53 8","pages":""},"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}
O. A. Gorobchenko, D. Glibitskiy, O. T. Nikolov, T. A. Cheipesh, T. Dzhimieva, I. Zaitseva, A. D. Roshal, M. A. Semenov, G. Glibitskiy
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.
{"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":"25 16","pages":""},"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}
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.
{"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":"85 20","pages":""},"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}
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.
{"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":"68 1","pages":""},"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}
Graham Baker, Davide Valentinis, Andrew P. Mackenzie
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.
{"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":"4 1","pages":""},"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}
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