Новые публикации
Two-layer radio-frequency shielding sandwich structures based on irregular microgrids
https://doi.org/10.1364/JOT.92.000082
This study investigated the spectral properties of silver irregular microgrids (AgIMGs) and sandwich structures in the visible and radio frequency (RF) ranges. AgIMGs were fabricated using a self-assembled template formed by cracking a thin film of egg white. Aim of study. The aim of this study was to develop a method for producing AgIMGs with a thickness exceeding 500 nm, low surface resistance, and high optical transmittance in the visible range. Additionally, sandwich structures based on such microgrids that demonstrate a shielding effectiveness (SE) of at least 60 dB in the RF range were fabricated. Main results. A method for locally peeling off the perimeter (CPP) of self-organized template cells has been developed. It allows for an increase in the thickness of the deposited silver to more than 500 nm. Increasing the thickness of the deposited metal is a critical factor for improving the optoelectric characteristics of AgIMG. Two-layer sandwich structures were obtained based on our AgIMG. Sandwich structures consisting of irregular silver microgrids based on a template with a partially peeled off perimeter of the cells show an SE of 71.01 dB in the range of 1–7 GHz with a transmission value of 80.02% in the visible range. Practical significance. Sandwich structures based on AgIMGs formed on a template with a partially detached cell perimeter are a promising solution for shielding optically transparent objects and information display devices. The sandwich structures developed in this study outperform existing optically transparent RF-shielding screens in terms of the combined parameters of SE, optical transmittance, and production cost.
Effect of external factors on the optical and structural characteristics of higher plants
https://doi.org/10.1364/JOT.92.000138
The rate of electron transfer between plant photosystems based on fluorescence measurements and calculated density graphs of photon processes is studied. Aim of study. The purpose of this paper is to determine how the structural and optical parameters of plants are affected by their growth conditions. Method. The morphology of chloroplasts was examined by electron microscopy of tissue samples of barley flag leaves grown under the same intensity of illumination in a growing chamber and in the field. The samples underwent full preparation for electron microscopy, including staining with heavy metals to increase the contrast, and were analyzed using a Hitachi HT 7700 transmission electron microscope. Chlorophyll fluorescence parameters of the flag leaves were measured in vivo using the LI-6800 photosynthesis system in a closed leaf chamber that included a built-in fluorimeter. Main results. The role of structural coloration caused by interference and diffraction of light on structural elements of a green leaf having a period comparable with the wavelength of light has only been described in recent years. The study also identified a significantly denser and better-ordered grana structure in the chloroplasts of barley leaf cells grown under artificial conditions. Despite this difference, the maximum quantum yield of Photosystem II in both samples lay in the range of values typical for plants in their normal physiological state. Since electron transport is highly dependent on the spatial organization of the photosynthetic apparatus in the chloroplast thylakoid membranes, the denser “packing” of grana will clearly support more efficient electron transport because the molecular complexes involved in the process are closely arranged. We found that the electron transport rate was different for the plants grown in the field and those grown in the chamber. The electron transport rate for the plants grown in the growth chamber was 1.7 times faster than that for plants grown in the field. Thus, numerical calculations and the spectroscopy/electron microscopy results showed a connection between the photon state density, electron transport rate, and the occurrence of chemical reactions during photosynthesis. Practical significance. Comparing the photosynthetic parameters of the same plants grown in different environments provides useful information on the mechanism behind the photosynthesis process. Identification of the main factors (quantity and quality of water, external environment, amount of nutrients, etc.) affecting the structure and optical properties of plants will increase agricultural yields and reduce costs by optimizing resources and technological processes.
Drift of non-spherical optical particles driven by counter-propagating beams in a viscous medium
https://doi.org/10.1016/j.photonics.2025.101489
We consider spheroidal dielectric microparticles subject to radiation forces and torques induced by two linearly polarized weakly-focused counter-propagating Gaussian beams. Since the symmetry is lifted by the spheroidal shape of the particles the effects of both net radiation force and torque are taken into account. It is found that in the case of oblate spheroids there is a specific ratio of the semi-axes leading to anomalous drift of particles both in the lateral and the longitudinal direction. Such an effect results in displacement from the initial condition by distance up to 70μm.
Competition of anisotropies in antiferromagnetic Ni3–xCoxB2O6 solid solutions
https://doi.org/10.1016/j.jpcs.2025.113452
In Ni3–xCoxB2O6 the direction of the easy axis of magnetization changes from the crystallographic direction c to the crystallographic direction b with an increasing concentration of cobalt ions due to the competition of anisotropies and exchange interactions. The theoretical calculations of the orientation of magnetic moments in the Ni3–xCoxB2O6 solid solutions are in good qualitative agreement with the experimental data. The orientation of magnetic moments is significantly influenced by the spin-orbit interaction of nickel and cobalt ions. In the Ni2.81Co0.19B2O6 compound two magnetic phase transitions are observed. Moreover, an oblique phase is observed in the concentration range 0.6 < x < 0.93.
Highly Selective Bandpass Filter for the Input Multiplexer of C-Band Satellite Communication
https://doi.org/10.1134/S1063784225700409
A channel bandpass filter of the satellite communication multiplexer has been developed around a design consisting of 12 coaxial resonators. To cut the group delay time and considerably improve the selectivity of the device, two additional inductive and two additional capacitive couplings between nonadjacent resonators have been applied. This makes it possible to provide two zero poles near the right and left edges of the passband. To reduce the spread of the passband’s transmission factor, a special method was applied that allows one to somewhat decrease reflection losses near the edges of the bandpass of the filter. This, in combination with the electrodynamic analysis of a 3D model developed for the given design, makes it possible to synthesize a small-size filter with the center frequency of the bandpass f0 = 4 GHz and its width Δf = 45 MHz measured at a level of 0.8 dB from minimal losses. The measured characteristics of the filter prototype are in good agreement with calculation data.
Thermopower in lutetium-substituted manganese sulfides
Thermoelectric effects in the solid solution Mn1-xLuxS (x ≤ 0.2) in a wide temperature range without a field and in a magnetic field of 12 kOe are studied. The temperatures at wich a change in the sign of the thermoelectric power and the maxima of the Seebeck coefficient below Neel temperature in a magnetic field are found. The thermal expansion coefficients are measured to establish a correlation with the thermoelectric power. The thermoelectric power anomalies are explained within the framework of the orbital glass model and a change in the type of magnetic order in a magnetic field in a magnetically ordered region.
Electrically Controlled Structures in Cholesteric Droplets with Planar Anchoring
https://doi.org/10.3390/molecules30224482
Structure transformations in cholesteric droplets with planar anchoring induced by an electric field are studied experimentally. The radial spherical structure is formed initially, then it transforms into the quasi-nematic untwisting state under the action of an electric field 𝐸 =1.75 V/μm. The dependence of structure transformations on the voltage switching-off mode is examined. At the one-step voltage-off mode, the Lyre structure is realized in cholesteric droplets at the relative chiral parameter in the range 4.3 ≤𝑁 ≤8.5. The axis-symmetric bipolar structure and the low-symmetric planar bipolar structure are obtained at the multi-step voltage-off mode. The possibility of forming such structures and their stability are determined by the type of voltage switching-off mode, the N value, the surface anchoring strength (the value of cholesteric helix pitch), and the presence of the surface point defects.
Mechanical Enhancement of Polychloroprene Adhesives via Reinforcement with Aluminum Oxide Nanofibers
https://doi.org/10.3390/polym17223064
In this study, we demonstrated chloroprene rubber (CR)-based composites with the addition of synthesized alumina nanofibers (AONF) with a high aspect ratio (>1000). AONF were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). AONF were introduced by pre-dispersion. The resulting chloroprene rubber/aluminum oxide nanofiber (CR/AONF) composites were subjected to tensile and shear adhesive bonding tests. The tensile test results for the CR/AONF composites are 81% greater than those of the original CR composite (0.85 MPa and 1.54 MPa, respectively). Shear adhesive bonding tests were conducted for glass and steel. CR/AONF demonstrates a 213% (for steel) and 262% (for glass) increase in shear strength. The main strengthening mechanisms are reinforcement, CR adsorption on the AONF surface, and crack arrest. These results may expand our understanding of the potential of sealant strengthening using AONF.
Electrochemical Performance of Dysprosium-Doped Strontium Cobaltite with Perovskite Structure
https://doi.org/10.3390/molecules30224437
The electrochemical properties of the dysprosium-doped strontium cobaltite SDC (Sr0.8Dy0.2CoO3−δ) were evaluated for possible application as pseudocapacitor electrode materials. Dense perovskite SDC ceramics were prepared using standard solid-state synthesis techniques. The SDC sample was characterized using XRD, structural analysis, SEM/EDS, and simultaneous thermal analysis. The electrochemical performance of the electrode was estimated in 3M KOH in a standard electrochemical cell for corrosion studies using cyclic voltammetry, impedance spectra, galvanostatic charge/discharge, and long-term cycling stability. The study demonstrated that the SDC exhibits high oxygen mobility and has the ability to release or incorporate oxygen from the gas phase. This process leads to the formation of structural anion vacancies without compromising the structural integrity. The SDC electrode demonstrates a specific capacitance of approximately 500 F/m2 and exhibits satisfactory cyclability. Electrochemical treatment in charge–discharge cycles has been shown to result in the formation of a thin strontium-depleted layer on the electrode surface. The observed behavior is believed to be caused by a high concentration of oxygen vacancies, which is consistent with oxygen intercalation into the perovskite structure. The present study suggests that rare earth-doped strontium cobaltite may serve as a prospective precursor for electrode material in supercapacitors.
Kinetics of intermetallic phase formation in multilayer Al/Pt thin films
https://doi.org/10.1016/j.jallcom.2025.185110
Complex investigations of a solid-state reaction process were carried out in bilayer and multilayer thin films of Al/Pt and (Al/Pt)15 by the methods of simultaneous thermal analysis, transmission electron microscopy, in situ electron diffraction, and X-ray diffraction. The solid-state reaction between the aluminum and platinum layers was found to start with the formation of an amorphous a-Al2Pt phase. The sequence of the phase formation in the solid-state reaction was determined to be the following: Al+Pt→a-Al2Pt→Al3Pt2→Al21Pt8→Al4Pt. Thermokinetic modeling of the solid-state reaction was made in the Al/Pt films under study. The “An” type of reaction (n-dimensional formation of grains followed by crystallite growth) was shown to most accurately correspond to the formation of the a-Al2Pt phase. The formation of the Al3Pt2 phase was revealed to occur in two sequential stages: the first stage corresponds to the “Bna” type of reaction (a chain mechanism of grain formation followed by fast crystallite growth), while the second stage belongs to the “R3” type of reaction (three dimensional diffusion along grain boundaries and/or a reaction on grain boundaries which proceeds according to the type of a contracting sphere). With regard to the Al21Pt8 and Al4Pt phases, their formation process can be best described by a kinetic model which consists of two parallel reactions. The “An” type of reaction corresponds to the formation of the Al21Pt8 phase, with the “Cn-Х” type of reaction (a reaction with autocatalysis with grain formation following the chain mechanism) corresponding to the formation of the Al4Pt phase. Kinetic parameters of the phase formation for a-Al2Pt, Al3Pt2, Al21Pt8 and Al4Pt, were determined, with those for Al21Pt8 and Al4Pt found for the first time.
Talbot effect caused by periodic arrangement of fork-shaped dislocations
https://doi.org/10.1016/j.optcom.2025.132681
In the present work, we report the first experimental observation of Talbot effect caused by a linear periodic arrangement of fork-shaped dislocations. The presence of dislocations imposes phase discontinuities to the optical field given rise to forming an array of optical vortices co-propagating behind the structure. Two types of masks have been considered, with the same or alternating signs of topological charges. Unlike the mask with the same signs of topological charges, a multi-fork grating with alternating signs of dislocations exhibits the Talbot effect. The observed Talbot effect proved by correlation analysis is conditioned by the modality of an array of fork-shaped dislocations under consideration. Theoretical and numerical results are found to be in good correspondence with experimental data. By unveiling the intricate dependencies of optical vortex trajectories on configuration of dislocation arrangement and topological charge distribution therein, this work has advanced the state of the understanding of structured singular optics, paving the way for innovative applications in optical manipulation, communications, and complex light field engineering.
Kinetics of intermetallic phase formation in multilayer Al/Pt thin films
https://doi.org/10.1016/j.jallcom.2025.185110
Complex investigations of a solid-state reaction process were carried out in bilayer and multilayer thin films of Al/Pt and (Al/Pt)15 by the methods of simultaneous thermal analysis, transmission electron microscopy, in situ electron diffraction, and X-ray diffraction. The solid-state reaction between the aluminum and platinum layers was found to start with the formation of an amorphous a-Al2Pt phase. The sequence of the phase formation in the solid-state reaction was determined to be the following: Al+Pt→a-Al2Pt→Al3Pt2→Al21Pt8→Al4Pt. Thermokinetic modeling of the solid-state reaction was made in the Al/Pt films under study. The “An” type of reaction (n-dimensional formation of grains followed by crystallite growth) was shown to most accurately correspond to the formation of the a-Al2Pt phase. The formation of the Al3Pt2 phase was revealed to occur in two sequential stages: the first stage corresponds to the “Bna” type of reaction (a chain mechanism of grain formation followed by fast crystallite growth), while the second stage belongs to the “R3” type of reaction (three dimensional diffusion along grain boundaries and/or a reaction on grain boundaries which proceeds according to the type of a contracting sphere). With regard to the Al21Pt8 and Al4Pt phases, their formation process can be best described by a kinetic model which consists of two parallel reactions. The “An” type of reaction corresponds to the formation of the Al21Pt8 phase, with the “Cn-Х” type of reaction (a reaction with autocatalysis with grain formation following the chain mechanism) corresponding to the formation of the Al4Pt phase. Kinetic parameters of the phase formation for a-Al2Pt, Al3Pt2, Al21Pt8 and Al4Pt, were determined, with those for Al21Pt8 and Al4Pt found for the first time.
Talbot effect caused by periodic arrangement of fork-shaped dislocations
https://doi.org/10.1016/j.optcom.2025.132681
In the present work, we report the first experimental observation of Talbot effect caused by a linear periodic arrangement of fork-shaped dislocations. The presence of dislocations imposes phase discontinuities to the optical field given rise to forming an array of optical vortices co-propagating behind the structure. Two types of masks have been considered, with the same or alternating signs of topological charges. Unlike the mask with the same signs of topological charges, a multi-fork grating with alternating signs of dislocations exhibits the Talbot effect. The observed Talbot effect proved by correlation analysis is conditioned by the modality of an array of fork-shaped dislocations under consideration. Theoretical and numerical results are found to be in good correspondence with experimental data. By unveiling the intricate dependencies of optical vortex trajectories on configuration of dislocation arrangement and topological charge distribution therein, this work has advanced the state of the understanding of structured singular optics, paving the way for innovative applications in optical manipulation, communications, and complex light field engineering.
Quantum noise suppression in non-Hermitian resonators at an exceptional point
DOI: https://doi.org/10.1103/kcm2-2mz4
We investigate the impact of quantum noise on non-Hermitian resonators at an exceptional point. The system's irreversible Markovian dynamics is modeled using the Lindblad master equation, which accounts for the incoherent pump, radiative losses, and external monochromatic field. An exact analytic solution is derived in the form of the characteristic function of the Husimi distribution, enabling the calculation of all quantum mechanical observables associated with the bosonic degrees of freedom. Our analysis reveals that quantum noise strongly influences the system's response when the system exhibits 𝒫𝒯 symmetry. Out of the 𝒫𝒯-symmetric regime, however, the system demonstrates stability within a specific parametric domain, where the effects of quantum noise on the signal-to-noise ratio can be mitigated by increasing the external field.
Evolution of the pseudogap band structure in a system of electron-correlated lattice polarons
DOI: https://doi.org/10.1103/xzzp-w7bd
The evolution of the role of lattice vibrations in the formation of the pseudogap state in strongly correlated electron systems has been investigated concerning changes in the electron-phonon coupling parameters and the concentration of doped charge carriers. We apply the polaronic version of the generalized tight-binding method to analyze the band structure of a realistic multiband two-dimensional model that incorporates the electron-lattice contributions of both Holstein and Peierls types. It has been demonstrated that the emergence of polaronic effects begins with the modulation of spectral function intensity. However, within a specific region of the phase diagram, a significant transformation of the electron band structure and pseudogap state occurs. It results from coherent polaron excitations that create a partially flat band near the Fermi level. This process leads to a change in the topology of the Fermi surface and the emergence of corresponding features in the density of states.
Pseudogap in the lightly hole-doped triangular-lattice moiré Hubbard model
https://doi.org/10.1103/22j6-2p89
The electronic structure of the lightly hole-doped triangular-lattice moiré Hubbard model is studied within cluster perturbation theory (CPT) using 13-site clusters for a fixed doping concentration p=1/13 varying the Coulomb parameter U and the hopping phase parameter \phi related to the spin-orbital interaction. We have also developed a rather simple generalized mean-field approximation (GMFA) containing the amplitude of the spin correlations as a free parameter to fit the CPT this http URL evolution of the Fermi surface and the pseudogap with the parameters \phi and U is explained from the viewpoint of the short-range magnetic order. The geometric frustration and the additional model parameter related to the spin-orbital interaction result in a more rich physics of the pseudogap state compared to the case of a more conventional square lattice.
Influence of Interparticle Interactions on the Frequency–Field Diagrams of the Imaginary Component of Magnetic Susceptibility of Nickel Ferrite Nanoparticles
https://doi.org/10.1134/S1062873825713182
Nickel ferrite powders with a particle size of 4 nm were prepared by chemical coprecipitation. The imaginary part �″ of the magnetic susceptibility was measured at room temperature with a broadband ferromagnetic resonance spectrometer in the frequency range from 100 MHz to 10 GHz. The obtained frequency dependences of �″ are described within the framework of an isotropic superparamagnet model taking into account interparticle interactions.
High efficiency near-infrared emission from Fe3+-doped NaAl11O17 phosphors for plant lighting
https://doi.org/10.1016/j.jallcom.2025.184900
Near-infrared (NIR) emitting phosphor-converted LEDs (pc-LEDs) have garnered significant interest due to their promising applications in diverse fields utilizing NIR spectroscopy. Fe3+ ions, as promising NIR activators, possess the advantages of being nontoxic and cost-effective, making them ideal candidates for NIR emission. In this work, NaAl11-xO17: xFe3+ phosphors were successfully synthesized, exhibiting a broad NIR emission band ranging from 650 to 850 nm, with the peak emission centered at approximately 770 nm. The phosphors demonstrate a high external quantum efficiency (EQE = 54.01 %) and excellent thermal stability. Distinct emission profiles were observed under three different excitation wavelengths, and four luminescent sites were discussed through low-temperature emission spectra. Furthermore, the electroluminescence (EL) spectrum of the fabricated pc-LEDs shows a strong spectral overlap with the absorption band of phytochrome Pfr, highlighting their great potential for plant lighting applications.
Structure, electronic and optical properties of (Cr1-xMnx)2GeC MAX phase: DFT calculations and epitaxial film synthesis
https://doi.org/10.1016/j.mtcomm.2025.114184
The energy and electronic characteristics, as well as crystal parameters of the (Cr1-xMnx)2GeC MAX phase with x = 0.00, 0.25, 0.33, 0.50, 0.67, 0.75, and 1.00 were determined using quantum chemical calculations. As the manganese concentration increases, the stability of the compound is expected to decrease. However, the possibility of experimentally realizing a structure with x > 0.25 has been shown. Epitaxial thin (Cr1-xMnx)2GeC MAX films with x up to 0.33 were synthesized by magnetron co-deposition at an increased technological carbon concentration. The samples were studied using electron spectroscopy, high-energy electron diffraction, X-ray diffraction, atomic force microscopy, high-resolution transmission electron microscopy and reflection spectral ellipsometry. The additional graphitic carbon is identified in the films and is attributed to the peculiarities of the deposition method. An increase in x results in an increase in the parameters of the crystal lattice, a deterioration of the crystalline order, and a decrease in optical conductivity. However, a low manganese concentration (x = 0.25) enhances epitaxy compared to Cr2GeC. A threefold increase in the thickness of the (Cr0.75Mn0.25)2GeC film results in an increase in the fraction of the secondary (013) structure and a weakening of the primary (00L) structure, though the single-phase nature of the film is preserved.
Grand Thermodynamic Potential in A Two-Band Unconventional Superconductor
https://doi.org/10.1007/s10948-025-07074-8
In a two-band system, both conventional sign-preserving �++ and unconventional sign-changing �± superconducting state may appear at low temperatures. Moreover, they may transform from one to another due to the impurity scattering. To study the details of such a transition here we derive the expression for the Grand thermodynamic potential Ω for a two-band model with nonmagnetic impurities considered in a �-matrix approximation. For the iron-based materials within the multiband Eliashberg theory, we show that the �±→�++ transition in the vicinity of the Born limit is a first order phase transition.
Diagonal superexchange in a simple square CuO2 lattice
https://doi.org/10.48550/arXiv.2501.17432
Many microscopic models with the interaction between the next-nearest neighbours as a key parameter for cuprate physics have inspired us to study the diagonal superexchange interaction in a CuO
layer. Our investigation shows that models with extended hopping provide a correct representation of magnetic interactions only in a hypothetical square CuO
layer, where the diagonal superexchange interaction with the next-nearest neighbors always has the AFM nature. The conclusions are based on the symmetry prohibition on FM contribution to the diagonal superexchange between the next-nearest neighbors for a simple square CuO
layer rather than for a real CuO
layer, where diagonal AFM superexchange may be overestimated. We also discuss the reasons for magnetic frustration effects and high sensitivity of spin nanoinhomogeneity to square symmetry breaking.
Competing Magnetic States in the Possible Altermagnet Candidate GdAlGe
Hyperfine interactions and magnetic order in oxyborate Co3BO5 according to 10,11B and 59Co NMR data
Effects of Isomorphous Substitution on Photophysical and Magnetic Properties of Complexes [Ln1-xDyx(MeDPQ)2Cl3] (Ln = Y3+, Ho3+, and Er3+)
https://doi.org/10.1002/chem.202502070
Thermo-optic bistability in two-dimensional all-dielectric resonators
https://arxiv.org/abs/2504.02452
DOI: https://doi.org/10.1103/PhysRevB.85.125307
DOI: https://doi.org/10.1103/1z7s-wcw6
We consider thermo-optic bistability in resonant excitation of high-quality modes in two-dimensional dielectric resonators. We develop a coupled-mode theory approach which account for the frequency shift due to a temperature dependent dielectric permittivity. The model is applied to rectangular and hexagonal resonators supporting an isolated high-quality resonant mode. The results are verified in comparison with straightforward finite-element simulations. It is shown that the model accurately describes the effect bistabily which occurs under variation of the angle of incidence or the intensity of the incident wave. In particular, it is demonstrated that variation of the incident angle can optimize the coupling between the resonator and the incident waves leading to bistabily with low intensity incident waves ![]()
![]()

![]()

![]()
![]()
![]()
![]()
![]()
![]()
![]()
. The bistability threshold is shown to be extremely sensitive to the imaginary part of the dielectric permittivity ![]()
![]()
.
Simulation of an Asymmetric Photonic Structure Integrating Tamm Plasmon Polariton Modes and a Cavity Mode for Potential Urinary Glucose Sensing via Refractive Index Shifts
https://doi.org/10.3390/bios15100644
Diabetes has become a global health challenge, driving the demand for innovative, non-invasive diagnostic technologies to improve glucose monitoring. Urinary glucose concentration, a reliable indicator of metabolic changes, provides a practical alternative for frequent monitoring without the discomfort of invasive methods. In this simulation-based study, we propose a novel asymmetric photonic structure that integrates Tamm plasmon polariton (TPP) modes and a cavity mode for high-precision refractive index sensing, with a conceptual focus on the potential detection of urinary glucose. The structure supports three distinct resonance modes, each with unique field localization. Both the TPP modes, confined at the metallic–dielectric interfaces, serve as stable references whose wavelengths are unaffected by refractive-index variations in human urine, whereas the cavity mode exhibits a redshift with increasing refractive index, enabling high responsiveness to analyte changes. The evaluation of sensing performance employs a sensitivity formulation that leverages either TPP mode as a reference and the cavity mode as a probe, thereby achieving dependable measurement and spectral stability. The optimized design achieves a sensitivity of 693 nm·RIU−1 and a maximum figure of merit of 935 RIU−1, indicating high detection resolution and spectral sharpness. The device allows both reflectance and transmittance measurements to ensure enhanced versatility. Moreover, the coupling between TPP and cavity modes demonstrates hybrid resonance, empowering applications such as polarization-sensitive or angle-dependent filtering. The figure of merit is analyzed further, considering resonance wavelength shifts and spectral sharpness, thus manifesting the structure’s robustness. Although this study does not provide experimental data such as calibration curves, recovery rates, or specificity validation, the proposed structure offers a promising conceptual framework for refractive index-based biosensing in human urine. The findings position the structure as a versatile platform for advanced photonic systems, offering precision, tunability, and multifunctionality beyond the demonstrated optical sensing capabilities.
Influence of the Interface on Magnetic Resonance in Films in the Fe–Bi System
https://doi.org/10.1134/S1062873825712942
Two-layer films in the Fe–Bi system were experimentally studied, which differed in the order of deposition of the magnetic and nonmagnetic layers. Electron magnetic resonance showed that additional magnetic anisotropy of the easy-plane type arises in Fe–Bi films. The observed changes are explained by the formation of a granular iron layer with strong magnetic anisotropy at the interface with bismuth.
Synthesis, structural characterization, and conductive properties of new Tl5A0.5Hf1.5(MoO4)6 (A = Ca, Cd) molybdates
https://doi.org/10.1016/j.jssc.2025.125716
Ionic conductivity of triple molybdates Tl5A0.5Hf1.5(MoO4)6 (A = Ca, Cd) is studied by the method of impedance spectroscopy in the frequency range from 1 Hz to 1 MHz and in the temperature range of 300–830 K. The molybdates Tl5A0.5Hf1.5(MoO4)6 (A = Ca, Cd) are prepared in the form of fine crystalline powder by solid state synthesis from Tl2MoO4, CaMoO4 (or CdMoO4), and Hf(MoO4)2 at 723–823 K. The conductivity of Tl5Ca0.5Hf1.5(MoO4)6 ceramic samples σ = 2.69‧10−4 S/cm (at 830 K); Tl5Cd0.5Hf1.5(MoO4)6 ‒ 8.5‧10−5 S/cm (at 830 K). The σ vs. T curve demonstrates an anomaly which corresponds to thermal effects in this temperature range. The ionic conductivity of Tl5A0.5Hf1.5(MoO4)6 (A = Ca, Cd) is due to Tl + ions localized in channels of the framework structure. The crystal structures of Tl5A0.5Hf1.5(MoO4)6 (A = Ca, Cd) are obtained by Rietveld method. The following unit cell parameters are calculated for Tl5Ca0.5Hf1.5(MoO4)6: a = 10.68493(26), c = 38.3943(11) Å, V = 3796.13(22) Å3, Z = 6 and for Tl5Cd0.5Hf1.5(MoO4)6: a = 10.66890(17), c = 38.25443(73) Å, V = 3770.96(14) Å3, Z = 6.
Silica-Iron Oxide Magnetic Composite Particles for In Vitro Cell Separation: Synthesis, Possibilities, and Effects on Cell Metabolism
https://doi.org/10.1021/acsabm.5c00587
The development of magnetic particles for cell separation is a promising and actively developing direction. An important requirement for this method of isolation is the preservation of cell viability for the possibility of further study. The aim of the work was to develop magnetic composites based on iron oxide for single-stage cell separation and to evaluate the possibilities of further study of these cells using molecular and cellular biology methods. The particles were synthesized by the precipitation method; the magnetic cores were embedded in silica using TEOS and APTES reagents. Anti-EpCAM antibodies were immobilized on the surfaces of the obtained composites. T24 cells containing this antigen on the surface of some cells were used as a model suspension. It was shown that incubation of particles with the cells led to a decrease in the proportion of EpCAM-positive cells in the suspension and their binding to the magnetic composites. During the first hour of incubation with the particles, a decrease in the proportion of living cells in the suspension and a change in the mRNA level of the BCL2 gene were noted. However, after 2 h of incubation, cell adaptation and restoration of viability were noted. The separation procedure resulted in a stable decrease in the expression of the BIRC5 gene. The cells that were immobilized were subsequently successfully cultured. Thus, the proposed particles do not have high requirements for synthesis but allow for the isolation of living cells that can be used for further studies
Specifics of ice cover measurements using global navigation satellite system reflectometry
https://doi.org/10.1007/s11182-025-03583-0
This work focuses on the improvement of the global navigation satellite system reflectometry (GNSS-R) methods of the underlying terrestrial surfaces. An integrated approach based on a multipath GNSS‑R is applied to determine the parameters of near-surface layered structures, including ice and snow and continuous forest covers. At the same time, experimental measurements of amplitude-time dependencies of signals from navigation satellites are processed by fast Fourier transform and then analyzed using a mathematical apparatus based on the multipath reflection model within geometric optics. In combination with the GNSS‑R technique, numerical modeling of near-surface layers, is based on local meteorological data. This allows assessing not only the current state of layered near-surface structures, but also predicting their dynamics.
Операции с документом
