Search Results (2,208)

The corrosion behavior and time-dependent mechanism of 22MnB5 steel featuring a thinned Al-Si coating (60 g/m²) were systematically investigated in a chloride ion wet–dry cyclic environment, motivated by the demand for thinning and toughening development of aluminum-silicon coatings. A periodic immersion accelerated corrosion test using 3.5% NaCl solution was conducted, together with macro/microscopic morphology observation (SEM/EDS), phase analysis (XRD, FTIR), and electrochemical measurements (polarization curves, EIS). The Al-Si coated steel was studied over corrosion periods of 1, 8, 10, and 20 days to elucidate its corrosion behavior, interfacial evolution, and failure mechanism. The results indicated that the corrosion process exhibited a three-stage evolution: stable protection, rapid failure, and dynamic equilibrium. At the initial stage (1 day), a dense Al₂O₃ passive film formed on the coating surface, providing excellent substrate protection, with a corrosion current density of only 1.77 µA/cm² and a maximum charge-transfer resistance (R₂) of 652 Ω·cm². In the middle stage (8 days), Cl⁻ permeated through the cracked film, triggering selective dissolution of Al, while Si was enriched in situ to form a porous residual layer; the corrosion current density (I_corr) sharply increased to 13.25 µA/cm², and R₂ dropped to its minimum of 156.6 Ω·cm². Corrosion products at this stage were mainly Al₂O₃ and SiO₂, accompanied by small amounts of iron oxyhydroxides and hydroxides, and local coating failure began to appear. During the later stage (10–20 days), the corrosion products evolved into γ-FeOOH, α-FeOOH, and Fe₂O₃, which, together with an amorphous SiO₂ gel network enriched at the interface, formed a dual-layer composite rust layer. R2 consequently recovered from 156.6 Ω·cm² at 8 days to 424 Ω·cm² at 20 days, indicating a reduced corrosion rate and entry into a stable inhibition stage. The critical failure mechanism is that Cl⁻ preferentially penetrates the surface of the Al₂O₃ passive film, disrupting the metastable state of the coating and thereby creating pathways for corrosive media intrusion. The findings of this study can provide technical support for the safe application of such as-received coatings in non-load-bearing components with heat and corrosion resistance requirements. Full article

Radio frequency identification (RFID) technology has been widely adopted in a variety of practical applications. Usually, the size of a passive tag antenna largely determines the read performance of tag. However, excessively large tag antennas can hinder their practical application and a tag that is too small has poor performance. In this paper, a compact, flexible and corrosion-resistant folding dipole tag antenna is proposed, which has a geometrical dimension of 24 mm × 13 mm (0.074${\mathsf{\lambda }}_0\times 0.040{\mathsf{\lambda }}_0$). It is designed on only one surface of a flexible polyethylene terephthalate (PET) substrate, which can be folded. The paper proposes a single-sided laser-patterned GAF/PET flexible RFID tag that is mechanically folded to form a backside dipole arm without vias, targeting compact and corrosion-resistant UHF RFID operation. Changing the size of the folding arm can effectively adjust the resonant frequency and impedance of the tag antenna. A stepped radiation arm is used to extend the current path and lower the resonance frequency. The capacitance and inductance effects introduced by loading a T match for reducing the resonant frequency of the tag to the useful UHF RFID band. Finally, it can achieve a power transfer coefficient of 99.9% and exhibit high impedance matching between the tag antenna and the chip. The proposed tag antenna uses graphene-assembled film (GAF) as its conductor material. Thanks to the physicochemical properties of GAF, the proposed tag antenna maintains stable radiation performance even after prolonged exposure to acidic (5 wt%), alkaline (5 wt%), and salt (5 wt%) corrosion, as well as more than 1000 mechanical bending cycles. When the EIRP of the reader is 2.2 W, the maximum read range of the tag in the 800–1000 MHz is 1.38 m. Full article

This study systematically investigated flow boiling characteristics within a novel three-layer microchannel heat sink with 3/4 open-ring pin fin arrays, designed for high-heat-flux thermal management of low-carbon metallurgical reactors. Two-phase flow regimes, pressure drop, and wall temperature responses were analyzed. To evaluate the impact of functional surface material properties on thermo-hydraulic behavior, a hydrophilic nano-coating modification was applied to the inner copper channel walls for comparison. Increasing the flow rate triggered a transition from a vapor-dominated confined slug flow to a liquid-dominated dispersed bubble flow, which effectively improved the thermo-hydraulic stability. Hydrophilic surface modification resulted in an average pressure drop reduction of 33% and significantly diminished the sensitivity of flow resistance to velocity variations. Through hydrophilic treatment, the localized vapor film effect at high velocities was suppressed, and temperature field homogenization was promoted, yielding a maximum convective heat transfer coefficient of 7760 W/(m²·°C), i.e., 72.9% enhancement over the baseline heat sink. The underlying mechanism is attributed to the formation of a stable near-wall thin liquid film and the promotion of high-frequency nucleate boiling. These results will be of high relevance for developing efficient cooling solutions for power electronics, thereby supporting the advancement of low-carbon metallurgical reactors. Full article

To accelerate the transition to sustainable energy, efficient methods for CO₂-free hydrogen production and carbon utilization are needed. This study presents a new, sustainable approach for the simultaneous production of hydrogen, valuable hydrocarbons, and functional carbon materials by converting methane in low-pressure microwave plasma. Compared to traditional methane reforming methods (such as steam reforming), our plasma-based process operates at low temperatures, eliminates direct CO₂ emissions, and enables the conversion of methane into three valuable products: (1) environmentally friendly hydrogen for fuel cells and energy storage systems, (2) a range of valuable organic products (C₂H₂, C₂H₄, C₂H₆), and (3) functional carbon films with self-improving catalytic properties. Optical emission spectroscopy (OES) and the Langmuir double probe method were used for plasma diagnostics, revealing an increase in the concentration of active species (CH, Hα, C₂) and electron temperature upon argon addition. The structure, morphology, and impurity composition of the deposited films were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and inductively coupled plasma mass spectrometry (ICP-MS), respectively. Gas-phase byproducts were analyzed using gas chromatography–mass spectrometry (GC-MS). Argon addition at an Ar/CH₄ ratio of 1 leads to the formation of carbon films with a more ordered structure, as confirmed by XRD data, and improved surface morphology. It was established that argon, by effectively participating in the excitation and dissociation processes of methane molecules through energy transfer from metastable states and increased electron temperature, optimizes plasma–chemical reactions, promoting the deposition of higher-quality carbon coatings. Full article

This work investigates the design, simulation, and characterization of thin-film platinum resistive heaters fabricated by magnetron sputtering. Finite element simulations were performed in COMSOL Multiphysics to analyze heat generation and temperature distribution as a function of heater geometry under steady-state conditions. The influence of convective heat transfer on temperature uniformity and thermal efficiency was systematically examined. Platinum thin films deposited by magnetron sputtering were characterized in terms of their structural, morphological, and electrical properties. The crystallographic structure was analyzed using X-ray diffraction, while the surface morphology and microstructure were examined by atomic force microscopy and scanning electron microscopy. Electrical conductivity measurements were carried out to evaluate resistive behavior relevant to heater performance. All characterizations were conducted for as-deposited samples and after post-deposition annealing at 500 °C to assess the effect of thermal treatment on film stability and properties. The simulation results were experimentally validated by infrared thermography, allowing a direct comparison between calculated and measured temperature distributions. The combined numerical and experimental approach enables the correlation among the deposition conditions, microstructural evolution, geometry, and electrical heating performance, providing guidelines for the optimization of thin-film platinum resistive heaters. Full article

Few-layer hexagonal boron nitride (hBN) is a promising two-dimensional dielectric for electronic and neuromorphic devices. However, its practical deployment is often hindered by the thickness nonuniformity of as-grown samples and by defects introduced during the transfer-stacking process of assembled samples. In particular, the influence of the initial hBN quality on the final stacked-film quality remains insufficiently understood. Here, we report a wafer-scale strategy for fabricating high-quality few-layer hBN based on ultraflat single-crystal hBN (USC-hBN) monolayers. Compared with transfer-stacked hBN grown on Cu foil (rough hBN), stacked few-layer USC-hBN shows a much lower surface roughness and a drastically reduced wrinkle density, indicating superior flatness and interfacial cleanliness. Furthermore, memristors fabricated from six-layer USC-hBN exhibit clearer resistive-switching behavior and a higher ON/OFF ratio than those based on rough hBN, owing to the more uniform surface/interface. These results demonstrate that source-material flatness is a critical determinant of transfer-stacked hBN quality and device performance. This work provides an effective route toward reliable integration of high-quality two-dimensional dielectric films. Full article

Background: Photothermal therapy (PTT), a highly efficient and controllable method with minimal drug resistance, transforms near-infrared (NIR) radiation into heat. This process exerts antibacterial effects, aids in tissue repair, and promotes healing. Methods: Our study presented a novel kind of composite wound dressing that incorporated adhesive conductive hydrogel combined with piezoelectric film for NIR-responsive applications. The inherent adhesiveness of the hydrogel ensured robust anchoring of the piezoelectric film to both hydrogel matrix and wound site. Its conductivity enabled synergistic endogenous electrical stimulation with the piezoelectric film, while also serving as therapeutic layer to augment hemostasis, analgesia, and antibacterial activity. Results: The hydrogel’s capacity for moisture retention and exudate absorption sustained optimal wound environment, thereby supporting debridement and recovery. Furthermore, the piezoelectric film possessed excellent photothermal properties and transferred heat to the hydrogel through heat conduction to enhance antibacterial activity and promote wound healing. The in vitro and in vivo experiments confirmed that the composite dressing exhibited strong promotion effect on wound healing under NIR irradiation. Conclusions: In summary, our research provided a new strategy for developing advanced piezoelectric biomaterials with great clinical potential for wound healing. Full article

The food-packaging sector is undergoing a major transition driven by the environmental burden associated with petroleum-based plastics and the increasing demand for sustainable alternatives. In this context, biodegradable packaging materials capable of extending food shelf life through active preservation functions have attracted considerable interest. Cellulose is the most abundant natural polymer and an attractive candidate for sustainable packaging; however, it lacks intrinsic antimicrobial activity. In the present study, innovative carboxymethyl cellulose (CMC)-based composite films were developed by incorporating zinc oxide (ZnO) nanoparticles (NPs) and thyme essential oil (TEO) as antibacterial active agents. The obtained films exhibited strong antibacterial activity against both Escherichia coli and Staphylococcus aureus, completely eliminating planktonic cell viability after 3 h of contact and producing inhibition zones of up to 30 mm. In addition to their biological performance, the composite films showed improved mechanical and functional properties. ZnO NPs appear to act as multifunctional junctions within the CMC matrix, while the dispersed TEO droplets contribute, together with the inorganic phase, to reduced water-vapor transfer. The films retained good transparency in the visible range while exhibiting UV-A transmittance below 7%, indicating enhanced light-barrier performance. Preliminary tests on soft cheese indicated shelf-life extension up to 14 days at 4 °C, while in inoculated cheese slices packed in the composite films, S. aureus was not detected from the 3rd day. Overall, these results demonstrate the potential of CMC/ZnO/TEO composite films as biodegradable active packaging materials for perishable food products. Full article

Blade tip leakage flow in gas turbines is associated with aerodynamic loss and local heat transfer variation in the tip region. In this study, the flow structure, total pressure loss coefficient, heat transfer coefficient (HTC), and film cooling effectiveness (FCE) were numerically investigated for a plane tip (PLN) and five squealer tip geometries: a conventional squealer tip (SQR), cutback squealer tip (CBS), multi-cavity squealer tip (MCS), triangular-grooved suction-side squealer tip (GSS), and multi-cavity triangular-grooved suction-side squealer tip (MGS). All configurations were compared under the same cascade geometry, tip-clearance condition, and inlet/outlet boundary conditions to examine the geometry-dependent relationship among aerodynamic loss, heat transfer, and film cooling performance. Film cooling was evaluated at blowing ratios of M = 1 and 2 using a camber-line hole arrangement, and the effect of hole rearrangement was further examined at the same blowing ratio and with the same number of cooling holes. The results indicate that the aerodynamic and thermal characteristics of the tip region vary with the leakage-flow path, cavity recirculation, and reattachment behavior formed by each tip geometry. Under the present conditions, SQR showed the lowest downstream total pressure loss coefficient, with a 7.27% reduction relative to PLN, whereas MGS showed the lowest geometry-normalized heat transfer rate among the tested geometries. Increasing the blowing ratio tended to increase FCE, although local cooling performance was affected by high-pressure or reattachment-dominated regions where coolant ejection, surface attachment, or lateral spreading was limited. Compared with the camber-line arrangement, the rearranged hole configuration increased local FCE by up to 29.6% for CBS and 23.3% for MGS at the same blowing ratio. These results may be used as comparative data for evaluating squealer tip geometries and cooling-hole placement during preliminary blade tip cooling design. Full article

Nanoimprint lithography (NIL) is highly dependent on imprinted film as a pattern-transfer medium. This paper systematically reviews the research progress of imprint film materials for NIL. Firstly, polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), polyvinyl alcohol (PVA) and other single-polymer films are discussed, and their respective advantages (such as low surface energy, high optical transparency, water solubility) and inherent limitations (elastic deformation, demolding difficulties, humidity sensitivity)) are summarized. In order to overcome the above contradiction, researchers developed a composite imprint film structure, including an elastomer–rigid bilayer template and sandwich structure film, which achieved high resolution, conformal contact and facile demolding characteristics through mechanical function decoupling. At the same time, the emerging polymer/transparent electrode composite system (such as AgNWs/PVA, AgNWs/PDMS) gives the film active functions such as self-heating and antistatic ones, which effectively solves the key challenges in thermal management and electrostatic control. This paper comprehensively presents the evolution path from single-material to multi-functional composites, and provides guidance for the design of advanced imprint film for high precision, high reliability and large-scale NIL applications. Full article

Thermally activated delayed fluorescence (TADF) emitters doped in host–guest systems are widely utilized for organic light-emitting diodes (OLEDs), where key rate constants and the fluorescence quantum yield (Φ_F) are strongly influenced by the surrounding environment. However, the multifaceted interactions, i.e., dipole–dipole interaction and conformational restraint between the emitter and environment have been rarely investigated systematically, where excited state charge transfer (CT) and structural relaxation (SR) of emitters should be considered equally. In this study, four representative CT–TADF emitters were selected as model systems and studied in PS/PMMA:TADF:CA host–guest doped films with varied dielectric constants and matrix rigidity. Within D–A and D–A–D configurations, donor substitution from PXZ to DMAC varied CT characteristics, whereas TRZ-based D–A and DPS-based D–A–D emitters provided a relative difference in SR owing to their different rigidity. The total reorganization energy (λ_Total) was introduced as a quantitative measure of these multifaceted interactions and correlated with the rate constants. The results indicate that the dielectric dependence of the nonradiative decay rate (k_nr^S) for D–A–D molecules cannot be explained by the simplified energy gap law, where the vibronic effect plays the role of a game changer. This work provides a quantitative framework and highlights vibrational frequency as a key design parameter for optimizing Φ_F in host–guest doped OLED devices. Full article

Chloride-induced corrosion of steel reinforcements is one of the main factors restricting the durability of reinforced concrete structures. Chromium (Cr) alloying is an effective strategy to enhance the corrosion resistance of steel. However, the appropriate Cr content for different environments remains undetermined. In this study, steels with three different Cr contents of 0, 5, and 10 wt.% were prepared. Electrochemical methods and physical characterization techniques were used to investigate the effects of Cr content on the passive film and corrosion behavior of steels in a simulated concrete pore solution under chloride attack. The results show that Cr alloying increases the critical chloride concentration for steel depassivation, passive film resistance, and charge transfer resistance. Specifically, the critical chloride concentrations of 0Cr, 5Cr, and 10Cr are 0.63, 0.81, and 1.56 mol/L, respectively. In a simulated pore solution with 0.6 mol/L chloride, the charge transfer resistances of 0Cr, 5Cr, and 10Cr are 4.1, 5.8, and 63.4 × 10⁵ Ω·cm², respectively, corresponding to corrosion rates that are 1.39- and 15.31-times lower for 5Cr and 10Cr relative to 0Cr. Therefore, in concrete exposed to marine chloride attacks, the use of high Cr alloying is necessary. Although the cost increases and the weldability deteriorates, the improvement in corrosion resistance is far superior to that of medium Cr alloying. The excellent corrosion resistance of high-Cr steel stems from its passive film mainly composed of stable Cr₂O₃ with a lower oxygen vacancy defect density, while that of 5Cr is dominated by less stable Cr(OH)₃, which weakens the corrosion resistance of the passive film. Full article

Molybdenum disulfide (MoS₂) is a compelling candidate for visible-light detection due to its strong optical absorption and tunable bandgap, yet the development of high-performance MoS₂ photodetectors remains limited by challenges in scalable integration, low-voltage operation, and efficient photoresponse. Here, we report an ion-gel-assisted transfer strategy that enables the fabrication of large-area MoS₂/ion gel films that are suitable for low-power phototransistor applications. The transferred MoS₂/ion gel stack is laminated onto an indium-tin-zinc-oxide (ITZO) layer on a glass substrate to fabricate a MoS₂/ITZO heterojunction phototransistor, with the ion gel serving as an ultrathin, high-capacitance gate dielectric. The resulting phototransistor exhibits a field-effect mobility of 4.12 cm²/Vs, an on/off current ratio of 4.9 × 10⁵, and a subthreshold swing of 0.17 V/dec. Under 635, 520, and 405 nm illumination with a power density of 4.5 mW/cm², it achieves responsivities of 0.58, 1.82, and 5.56 A W⁻¹ and detectivities of 5.90 × 10⁹, 1.86 × 10¹⁰, and 5.68 × 10¹⁰ Jones, respectively. These findings demonstrate that the ion-gel-assisted transfer process offers a robust route to high-performance, low-voltage photodetection and provides a promising platform for next-generation optoelectronic technologies. Full article

Event cameras capture sparse, high-temporal-resolution visual information, making them attractive for challenging scenarios with fast motion and severe illumination changes. However, event-based depth models trained on one real-world benchmark often degrade substantially when transferred to another, revealing a practical cross-dataset domain shift between real sensor datasets. In this work, we study parameter-efficient adaptation from MVSEC to DSEC using a frozen VFM-based recurrent depth backbone. We systematically compare several parameter-efficient fine-tuning (PEFT) strategies, including Bias-only, Adapter, Decoder Weight Tuning, ConvLSTM-only, and FiLM-based modulation, under labeled few-shot adaptation. Across three random seeds, Bias-only achieves the best few-shot accuracy, reaching 0.189 AbsRel with 150 calibration samples. Decoder-side FiLM provides the best accuracy–efficiency trade-off, maintaining stable performance while updating only 2048 parameters, and reaches 0.176 AbsRel when trained with the full DSEC training set under our protocol. Our study shows that tuning native pretrained parameters is a strong baseline in this specific MVSEC → DSEC event-depth adaptation setting, whereas higher-capacity auxiliary modules are less effective under limited target-domain supervision. These results establish a controlled MVSEC → DSEC benchmark and provide practical guidance for adapting event-based monocular depth models under cross-dataset transfer. Full article

High-entropy oxide (HEO) thin films hold significant potential for applications in spintronics and catalysis; however, their widespread utilization is hindered by weak room-temperature ferromagnetism (RTFM). Herein, we demonstrate a facile vacuum annealing strategy to enhance the RTFM of HEO thin films. (FeNiAlCrMn)O films exhibit a saturation magnetization (M_S) of 5.9 emu/cm³ and a Curie temperature (T_C) of 350 K after vacuum annealing at 1173 K. Mechanistic investigations reveal that the enhanced RTFM originates from an annealing-induced phase transition from rocksalt-to-spinel. Structurally, annealing facilitates cation diffusion from octahedral to tetrahedral sites, forming a highly crystalline, long-range magnetic lattice of spinel ferrite. Electronically, tetrahedral occupation shortens M–O bonds, drives electron transfer toward metal cations, and enhances orbital hybridization, thereby strengthening magnetic exchange coupling. This study provides a simple and effective strategy for tailoring the RTFM of HEO thin films. Full article