Search Results (903)

Optical ground wire (OPGW) cables are subjected to extreme electromagnetic stresses from lightning and short circuits. Existing models have three main limitations: (i) they assume uniform current distribution, (ii) they use constant material properties, and (iii) they do not couple the electromagnetic, thermal, and mechanical domains. This paper proposes a coupled multiphysics model that incorporates non-uniform current distribution with ${\mu }_r$ dependent on the magnetic field, temperature-dependent properties, and differentiated failure criteria. The model was implemented in COMSOL Multiphysics and was validated against experimental short-circuit tests (15–30 kA) conducted at the HPT-Laboratory (FEC). For the lightning scenario (10/350 μs impulse), the model predictions were compared with experimental results reported in the literature, showing good agreement in temperature rise and damage patterns. Results show that including a non-uniform current distribution modifies the predicted maximum temperature by 15.8% and shifts its location from the center to the outer aluminum layers. The model reproduces the experimental temperature with an RMSE of <7 °C and a relative error of <8%. A combined failure criterion (thermal + mechanical) predicts strand breakage with 89.2% accuracy, outperforming the purely thermal (72.5%) and mechanical (78.3%) criteria. Specific $I-t$ and $I^{2}t$ curves were generated for two commercial OPGW cable configurations (Manufacturer A and Manufacturer B), with $I^{2}t$ capacities at 500 ms of 128 kA²s and 98 kA²s, respectively. The proposed model provides a useful tool for protection selection and coordination in transmission lines with OPGW cables. Full article

This paper presents a two-dimensional magneto-photo-thermoelastic model for a fiber-reinforced anisotropic semiconductor half-space subjected to optical excitation and a variable gravity field. The formulation is developed within the framework of generalized photo-thermoelasticity by considering the coupled interactions among thermal, elastic, carrier-density, electromagnetic, and gravity-induced effects. The constitutive equations of a fiber-reinforced anisotropic medium are employed, while the influences of the magnetic field and gravity are incorporated into the governing equations. A suitable nondimensionalization procedure is introduced, and the resulting coupled system is solved analytically using the normal mode technique and eigenvalue approach. Numerical results are obtained for the temperature, carrier density, displacement components, and stress distributions. The influence of the gravity parameter on the physical fields is investigated in detail. The results indicate that gravity significantly affects the mechanical and stress responses, whereas its effect on the thermal and carrier-density fields is comparatively less pronounced. A comparative study between silicon and germanium semiconductors is also carried out, revealing noticeable differences in the amplitudes and attenuation behavior of the coupled fields due to variations in material properties. The present study provides useful insights into coupled multiphysical interactions in semiconductor structures and may be relevant to applications in optoelectronic devices, photonic systems, smart composite materials, and aerospace technologies. Full article

Rapid room-temperature identification of gases and volatile organic compounds remains challenging for compact sensing platforms, particularly when chemically related analytes must be discriminated using accessible sensing materials. In this work, we evaluate whether magneto-optical surface plasmon resonance (MOSPR), combined with multi-spot sensing and conventional SPR readout from the same chip, can provide complementary response features for improved gas/VOC discrimination. The sensing spots are made from accessible chemicals and nanoparticles with plasmonic and magnetic properties. The sensor chip consists of a multilayer structure of metallic materials with both plasmonic and magnetic properties featuring enhanced sensitivity and stability. Measurements are made using a custom-built MOSPR instrument at relevant analyte concentrations. Analyte-specific sensor channels were selected for concentration-dependent calibration while the complete multivariate data were first explored using principal component analysis for supervised analyte classification. The combined 16-feature MOSPR/SPR model achieved an overall accuracy of 88.3% and a balanced accuracy of 87.6% under leave-one-concentration-block-out cross-validation compared with 66.2% and 65.7%, respectively, for the SPR measurement alone. These results show that MOSPR provides response information that encompasses and extends that obtained from conventional SPR measurements, thereby improving analyte discrimination. The proposed approach may provide a basis for future environmental monitoring and industrial process control, including real-time monitoring of harmful gaseous emissions pending further validation under application-specific conditions. Full article

Graphene oxide (GO), a functionalized derivative of graphene, has emerged as one of the most promising nanomaterials for biomedical applications owing to its unique physicochemical properties, including a large specific surface area, abundant oxygen-containing functional groups, excellent dispersibility, and versatile surface chemistry. This review provides a comprehensive overview of the progress made between 2005 and 2025 in the development and application of GO-based nanomaterials across diverse biomedical fields, including drug and gene delivery, cancer therapy, tissue engineering, antimicrobial treatment, bioimaging, and biosensing. Recent studies demonstrate that GO serves as an effective platform for the delivery of therapeutic agents, enabling targeted delivery, controlled release, and enhanced cellular uptake. Functionalized GO systems have also shown considerable potential in gene delivery and cancer treatment, particularly in combined therapeutic approaches involving chemotherapy and photothermal therapy. Furthermore, GO-based composites have been widely explored in tissue engineering due to their ability to support cell growth, proliferation, and tissue regeneration. In antimicrobial applications, GO exhibits promising activity against a broad range of microorganisms through multiple mechanisms, while its optical and magnetic properties have facilitated advancements in multimodal bioimaging and biosensing technologies. Despite these significant advances, challenges remain regarding the clinical translation of GO-based nanomaterials. Variations in synthesis methods, physicochemical properties, and surface modifications contribute to differences in biological responses, including biocompatibility and toxicity. The long-term safety, environmental impact, and lack of standardized evaluation protocols continue to be major concerns. Overall, graphene oxide represents a versatile and multifunctional nanomaterial with substantial potential for next-generation biomedical applications; however, further studies are required to establish standardized fabrication methods, comprehensive safety assessments, and clinically relevant performance evaluations. Full article

Accurate assessment of shale wettability is crucial for optimizing fracturing design and enhancing shale gas recovery. However, conventional evaluation methods are often unreliable due to shale’s complex mineral composition and heterogeneous pore structure. This study investigated marine shale from the Sichuan Basin by establishing a multi-scale research framework that integrates macro-scale spontaneous imbibition evolution, micro-scale dynamic video observation, and interfacial property characterization. Using techniques including X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and deep-field microscopy, we investigated the water distribution patterns and imbibition mechanisms. The results indicate that the mixed-wettability characteristics of shale are governed by the synergistic effects of mineral composition and pore structure. Specifically, hydrophilic surfaces facilitate stable adsorbed water film formation via hydrogen bonding and van der Waals forces, whereas hydrophobic surfaces inhibit water spreading. At the macro-scale, a distinctive “water ring” was observed immediately upon immersion. This phenomenon reveals a physical correlation between the mass per unit length of the water ring and the contact angle at the gas–solid–liquid interface. Based on this correlation, an innovative standard curve method was developed to evaluate rock wettability. This method allows for the inversion of the apparent contact angle by simply measuring the mass per unit length of the water ring, thereby overcoming the limitations of traditional optical methods that are constrained by surface roughness and pore structure. Consequently, a logical chain of “wettability → occurrence characteristics → imbibition patterns” was established. This work provides new insights and theoretical support for understanding fluid dynamics and optimizing fracturing fluids in unconventional reservoirs. Full article

We demonstrate the molecular beam epitaxy growth of two-dimensional van der Waals ferromagnet Fe₃GaTe₂ films with precisely controlled thicknesses down to a single unit cell. Magneto-optical Kerr effect microscopy measurements reveal robust room-temperature ferromagnetism with perpendicular magnetic anisotropy persisting across all thicknesses, including finite coercivity in monolayer films. The magnetic domain structures show strong thickness dependence: ultrathin films exhibit near-single-domain states without resolved domain nucleation or domain wall propagation, while thicker films develop complex multi-domain configurations featuring bubble-like domains. These findings underscore the pivotal role of dimensional confinement in modulating the magnetic properties of Fe₃GaTe₂ and provide critical insights into thickness-dependent phenomena in two-dimensional magnets, advancing their prospects for room-temperature spintronic applications. Full article

Two-dimensional (2D) group-IV materials are promising for spintronics due to their silicon compatibility and tunable properties. In this work, we investigate the structural, electronic, magnetic, and optical properties of semi-hydrogenated 2D SiGe random alloys—where hydrogen atoms saturate only one side of the atomic plane—using density functional theory and many-body perturbation theory ($G{W}_0$). Substitutional disorder is modeled via representative high-symmetry configurations introduced by Baldereschi and co-workers to enable quasiparticle and optical simulations in large supercells. We demonstrate that these semi-hydrogenated alloys possess an intrinsic magnetic semiconducting ground state, arising from the electronic structure of the system, with an integer magnetic moment of $1{\mathsf{\mu }}_{\mathrm{B}}$ per primitive cell. The spin-resolved electronic structure features nearly flat frontier bands and a finite energy gap, which is significantly renormalized by quasiparticle corrections while maintaining robust spin polarization. These properties remain remarkably stable across different realizations of chemical disorder and over a wide range of alloy compositions considered in this work. Optical spectra calculated within the random phase approximation reveal a composition-dependent red-shift of the low-energy onset in the imaginary part of the dielectric function, consistent with the evolution of the quasiparticle electronic structure and the persistence of flat spin-polarized frontier bands. Our findings establish semi-hydrogenated 2D SiGe random alloys as a resilient model platform to explore interaction-driven magnetism in disordered two-dimensional systems, while simultaneously offering realistic prospects for spintronic and magneto-optoelectronic applications in the presence of chemical disorder. Full article

Ionogels combining ionic liquids with polymer networks show promise for flexible electronics, but their mechanical and functional performance often needs enhancement. Here, we report a series of magnetic nanocomposite ionogels fabricated by doping triiron tetraoxid (Fe₃O₄) nanoparticles into a [C₂mim]⁺[EtSO₄]⁻-dispersed cross-linked PAA matrix. The effect of PAA content (10–20 wt%) on the optical, mechanical, and dielectric properties of pure imidazolium ionogels was first investigated. Increasing PAA concentration enhanced tensile strength (up to ~0.7 MPa) and compressive modulus (~0.65 MPa) while reducing optical transmittance; dielectric relaxation peaks around 6–8 GHz were observed, with the 15 wt% sample showing the highest permittivity. Subsequently, Fe₃O₄ nanoparticles (0–20 wt%) were incorporated into the 10 wt% PAA ionogel. The resulting magnetic ionogels exhibited reduced tensile strength, but significantly increased elongation (up to ~12 strain), indicating network softening. Magnetic hysteresis measurements confirmed superparamagnetic behavior with saturation magnetization reaching ~2.5 emu/g at 20 wt% Fe₃O₄ loading. This work demonstrates a facile strategy to simultaneously tune mechanical, dielectric, and magnetic properties in imidazolium ionogels, providing guidelines for designing soft multifunctional materials for microwave absorption, magnetic actuation, and flexible sensor applications. Full article

Perovskite manganites (AMnO₃) and perovskite-like manganites (A′_1−xA_xMnO₃) are complex oxide materials that have attracted significant attention from the scientific community in recent years due to their structural flexibility, mixed-valence state, tunable electronic configuration, and multifunctional properties. This review systematically analyzes the synthesis methods, structural classification, and physicochemical characterization of perovskite manganites, as well as their magnetic, optical, electrical, dielectric, and catalytic properties. The influence of solid-state reactions, sol–gel, Pechini, hydrothermal, co-precipitation, microwave, and other mild chemical approaches on phase purity, morphology, particle size, and oxygen stoichiometry was examined. The structural diversity of perovskite and perovskite-like manganites, including simple ABO₃, double perovskites, multilayer, and low-dimensional systems, was characterized in relation to their functional properties. The review discussed the capabilities of methods for synthesizing and analyzing morphological properties, demonstrating the role of doping, cation substitution, oxygen vacancies, and Jahn–Teller distortions in controlling material properties. Prospects for the application of perovskite manganites in spintronics, magnetocaloric cooling, photocatalysis, gas-sensing devices, and energy conversion and storage systems were analyzed. This review highlights the structure–property–application relationship in perovskite manganites. Full article

Bisphenol A type epoxy resin has the problem of relatively high brittleness after curing. Although traditional polysiloxane toughening methods can improve toughness, they often come at the expense of strength. In this paper, methylphenyl dimethoxysilane (MPS) was used as a monomer to synthesize end-hydroxyl poly(methylphenyl)siloxane (PMPS), which was then used to modify E51 epoxy resin. The structure and reaction degree were characterized by infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry and viscosity tests. The mechanical test results show that when the PMPS content is 20 wt%, the tensile, flexural, compressive and impact strengths of the modified resin increase by 31.26%, 26.16%, 18.53% and 98.66%, respectively, compared with the unmodified resin, and the tensile and flexural elastic moduli increase by 38.36% and 32.25%, respectively. The fracture toughness increases by 60.29%, indicating that the strength, stiffness and toughness of the material have all been improved. Dynamic mechanical analysis shows that the glass transition temperature and crosslinking density of the system gradually decrease with increasing PMPS content. Thermogravimetric analysis shows that the introduction of PMPS increases the char yield and decreases the maximum thermal decomposition rate, thereby enhancing the thermal stability of the system. Microscopic morphology analysis by optical microscopy, scanning electron microscopy and atomic force microscopy shows that the system has good compatibility, and the internal different modulus phases are distributed in a network-like manner, forming a uniform co-continuous or bicontinuous phase structure. This structure effectively promotes stress transfer and energy dissipation, alleviates local stress concentration, and thus comprehensively improves the mechanical properties of the resin system. Full article

In medicine, nanoparticles are used for various purposes, including theranostics, imaging, diagnostics, drug delivery, tissue regeneration and targeted cancer treatments, and to minimize the harmful side effects associated with conventional therapies. Target-specific biomolecules, such as silica nanoparticles (SiNPs) labeled with metallic radionuclides, are becoming increasingly popular. The choice of radionuclide is based on its nuclear properties. Silica has several advantages for nanoparticle synthesis, including high biocompatibility, the capacity for drug encapsulation due to its porous structure, and the potential for extensive surface functionalization, including radiolabeling for imaging and therapeutic applications. A radionuclide can be attached to a silica nanoparticle either directly or through the use of chelators or polymers. Additionally, the capability to encapsulate therapeutic agents within such systems offers significant potential for the development of targeted therapies. This study aims to provide a comprehensive overview of recent developments in the radiolabeling of silica-based nanoparticles, with a focus on their application in nuclear medicine, particularly in diagnostic imaging and targeted radionuclide therapy. Theranostics employs a range of imaging modalities to guide and monitor therapeutic interventions. Principal techniques include positron emission tomography (PET), single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), and Optical Imaging (such as fluorescence and bioluminescence). These imaging methods enable precise visualization of pathological sites, facilitate tracking of therapeutic agent distribution, and permit real-time assessment of treatment efficacy. Full article

Thermally conductive epoxy potting compounds require high filler loadings for effective heat dissipation. However, high filler loadings can increase viscosity and brittleness, thereby impairing processability and service reliability. In this study, a mesogen-containing reactive liquid–crystalline epoxy monomer (LCE) was designed, synthesized, and incorporated into a commercial thermally conductive epoxy potting compound to investigate its effects on thermal behavior, rheological and mechanical properties, thermal conductivity, and fracture-surface morphology. The chemical structure and thermotropic liquid–crystalline behavior of LCE were characterized via Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and polarized optical microscopy. Increasing LCE loading elevated the DSC-derived glass transition temperature (T_g) from 59 °C to 96 °C and markedly increased the room-temperature complex viscosity. Single-point measurements at 25 °C showed a monotonic decrease in thermal conductivity from 0.95 to 0.52 W/(m·K) with increasing LCE content. Mechanical testing revealed that the nominal 10% LCE formulation provided the best balance between load-bearing capacity and ductility among the tested formulations, whereas higher LCE loadings were associated with greater local microstructural variation and reduced mechanical properties. This study clarifies the modulation effect of LCE on the performance balance of highly filled epoxy potting compounds, providing valuable insights for future formulation optimization. Full article

Organic–inorganic hybrid perovskites (OIHPs) have been widely used in fields such as solar cells, photodetectors, and light-emitting diodes due to their simple preparation by solution methods and excellent optoelectronic properties. In recent years, numerous scholars have delved deeply into the magneto-optical properties of perovskites and explored their potential applications in the magneto-optical field. Herein, we present the Faraday rotation characteristics of formamidinium lead bromide (Fabri₃) single crystals within the visible spectrum range. Firstly, FAPbBr₃ single crystals with high transparency and a size of 5.5 × 5.6 × 2 mm³ were prepared using the modified inverse temperature crystallization (MITC) method. The experimental results showed that the Verdet constant of FAPbBr₃ single crystal at 565 nm was up to 531.6 rad/(T·m). Furthermore, the FAPbBr₃ single crystal showed similar or an even higher Verdet constant when compared with the mature magneto-optical material TGG single crystal commonly used in the industry. The thermal simulation results of the FAPbBr₃ single crystal show low temperature dependence which achieves about 90% isolation transparency with a magnetic field of 0.35 T for 625 nm. This study demonstrates the outstanding Faraday rotation properties of FAPbBr₃ single crystals, thereby offering promising prospects for the development of perovskite materials in non-reciprocal devices such as optical isolators and optical circulators. Full article

Flat and profile-modulated permalloy films have been studied by the electron magnetic resonance (EMR) method. In addition to ferromagnetic and spin-wave resonances, the structures demonstrate low-field EMR signals of an unusual shape, which form a hysteresis loop in sweeping fields. The low-field signals are attributed to a fast reorientation of magnetic domains. The low-field EMR behavior is comparable to the behavior in magneto-dependent photovoltage previously observed in the optical experiments. The shapes of the loops and typical values of the switching fields depend on the profile modulation parameters confirming the possibility of controlling magnetic properties and the coupling of magnetic and optical effects with nanoscale geometry. Full article

This review systematizes the principal methods for imaging and morphological analysis of burn wounds, ranging from light, electron, and fluorescence microscopy to tomographic techniques and mass spectrometry imaging. Light microscopy with histological staining and immunohistochemistry remains the morphological gold standard, enabling visualization of the zones of coagulation, stasis, and hyperemia, as well as molecular characterization of inflammation, angiogenesis, and fibrosis. Electron microscopy allows the study of the ultrastructure of cells and the extracellular matrix at nanometer resolution. Among optical methods, wide-field indocyanine green angiography demonstrates high accuracy in burn depth stratification, whereas fluorescence lifetime imaging microscopy assesses cellular metabolism without exogenous labels. Among tomographic techniques, high-frequency ultrasound is the most accessible bedside modality with submillimeter resolution, permitting evaluation of tissue anatomy, perfusion, and biomechanical properties. magnetic resonance imaging is limited by its high cost and long examination time, while mass spectrometry imaging is used solely for research purposes. For clinical practice, the optimal combination is high-frequency ultrasound and wide-field fluorescence imaging. All methods retain high relevance for experimental research, enabling the validation of novel therapeutic strategies. Full article