Search Results (252)

Given the pressing need for efficient CO₂ valorization, the precise modulation of metal–support interfaces via strong metal-support interaction (SMSI) have emerged as a pivotal strategy for tuning catalytic activity in CO₂ hydrogenation. However, despite the proliferation of relevant studies, a comprehensive and critical review that systematically evaluates the role of SMSI in this specific reaction remains absent. This work takes oxide-supported metal catalysts as the research object, focusing on the dynamic mechanism of SMSI-induced interface reconstruction and electron transfer. The relevant characterization progress and regulation strategies are systematically reviewed, and the synergistic regulation effect of the two on the reaction pathway is further explored. We analyze the impact of the above factors on the catalytic performance of CO₂ hydrogenation from three aspects: SMSI coverage layer formation, electronic structure optimization, and key intermediate stabilization. At the same time, key descriptors currently used to describe SMSI interface reconstruction and electronic transmission processes are summarized. On this basis, the main challenges faced in existing research are identified, and future directions are discussed, emphasizing the need for breakthroughs in the key issues mentioned above in order to provide a more guiding theoretical basis for the structural design of efficient CO₂ hydrogenation catalysts. Full article

The interfacial reaction between solder and substrate is a critical factor governing joint reliability, making it essential to understand the formation and stability of interfacial reaction layers when developing new high-temperature lead-free solders. This study investigates the interfacial reaction layers formed in Zn-5Al-3Mg solder/Cu substrate joints soldered at 693 K under vacuum. With a binary Zn-Al solder, the Cu substrate is progressively consumed by Zn, and the intermediate phases CuZn₄, Cu₅Zn₈, and CuZn nucleate and grow concurrently at the solder interface. The addition of a minor amount of Mg to the Zn-Al alloy, however, fundamentally alters this reaction sequence. Transmission electron microscopy analyses, including scanning transmission electron microscopy–energy-dispersive X-ray spectroscopy (STEM-EDS), energy-filtered TEM (EF-TEM), and electron diffraction, reveal three distinct interfacial layers: an outer Mg₂Zn₁₁ layer, a middle two-phase mixture of CuZn₄/Mg₂CuZn₃, and an inner Cu₅Zn₈ layer adjacent to the Cu substrate. The biphasic CuZn₄/Mg₂CuZn₃ mixture layer is shown to form via a quasi-peritectic reaction governed by sequential four-phase equilibria in the Zn-Mg-Cu ternary system. These findings demonstrate that minor Mg additions redirect the interfacial reaction pathway between Zn-Al-based solders and Cu substrates, providing new insight for the design of high-temperature Pb-free solder systems. Full article

Pulmonary fibrosis is a progressive interstitial lung disease characterized by persistent alveolar epithelial injury, aberrant repair, and excessive extracellular matrix deposition. Increasing evidence indicates that disease progression is closely associated with alveolar type II (AT2) cell dysfunction, impaired AT2-to-AT1 differentiation, and the persistence of transitional epithelial populations, including KRT8⁺ intermediate populations. Because the formation and resolution of these transitional epithelial populations require dynamic regulation of stress-responsive transcripts and differentiation-associated RNA programs, they provide a biologically relevant context for investigating RNA modification-mediated post-transcriptional regulation. RNA modifications have emerged as post-transcriptional regulatory layers that modulate RNA stability, processing, translation efficiency, and stress-response gene expression, thereby influencing epithelial stress adaptation and repair-related state transitions. Among these modifications, N6-methyladenosine (m6A) is the best-characterized layer, with evidence linking it to epithelial injury responses, senescence-associated transcript remodeling, and differentiation impairment. In contrast, non-m6A modifications, including m5C, m1A, m7G, pseudouridine (Ψ), and A-to-I RNA editing, remain emerging regulatory layers with limited AT2 cell-specific functional validation. This review summarizes current evidence connecting RNA modifications with alveolar epithelial injury, transitional-state persistence, epithelial–mesenchymal communication, and fibrotic remodeling. Rather than interpreting RNA modifications as isolated pathogenic drivers, we highlight their context-dependent roles in RNA fate control, epithelial stress adaptation, and aberrant repair in pulmonary fibrosis. Full article

With the increasing diversity of multimedia data types, single-modal steganography is insufficient to meet the demand for the simultaneous covert communication of multiple types of data, and single optical transformation encryption schemes are insufficiently secure against cryptanalytic attacks. To address these challenges, this paper designs and implements a multimodal secret information steganography system based on the optical Gyrator transform. We propose a multimodal steganographic system for the covert transmission of three types of heterogeneous secret data—text, color images, and audio—using a three-level cascaded optical encryption architecture. The system first uniformly encapsulates the multimodal data into a unified bitstream via a Type–Length–Value (TLV) format; it then uses the Ushiki chaotic map to generate a pure phase mask for random phase modulation of the carrier image, followed by spatial-frequency scrambling via a fractional Fourier transform (FrFT, order γ = 1.6). The secret bitstream is embedded into all eight bit planes of the amplitude components in the FrFT domain using binary square representation, achieving an embedding capacity of 2.23 × 10⁶ bits—approximately 8.5 times that of traditional LSB methods; finally, a speckle-noise-like ciphertext is output via a Gyrator transform (angle α = 0.5). Experiments demonstrate that under non-attack conditions, the system achieves lossless recovery with a zero bit-error rate. Under known-plaintext and chosen-plaintext attacks on the Gyrator layer, the PSNR of the recovered images was only 4.89 dB and 4.80 dB, respectively, and the secret information could not be effectively extracted, as the chaotic-FrFT pre-encryption statistically isolates the intermediate image from natural image statistics. This system provides a functionally complete and practically secure solution for multimodal covert communication. Full article

The oxygen evolution reaction (OER) is a key kinetic bottleneck in water electrolysis because it involves multistep proton-coupled electron transfer, the evolution of oxygen-containing intermediates and O–O bond formation. MXenes, as two-dimensional transition-metal carbides, nitrides and carbonitrides, possess high electrical conductivity, hydrophilic surfaces, tunable surface terminations and adjustable layered structures, making them promising platforms for OER catalyst design. However, their limited intrinsic active sites, sheet restacking and oxidative instability under anodic conditions restrict their direct application. This review firstly discusses the fundamental OER pathways based on the adsorbate evolution mechanism (AEM), lattice oxygen mechanism (LOM) and oxide path mechanism (OPM), providing a mechanistic basis for understanding intermediate adsorption, oxygen activation and working-state evolution. Then, a system framework from low-dimensional and micro-level control to high-dimensional and macro-level integration is constructed. The framework covers four levels: atom and local structure, interface, morphology and composite electrode. Drawing on specific examples, this review analyzes the characteristics and mechanisms of modification strategies from four different perspectives, starting with the basic principles of modification. These strategies include micro-scale, low-dimensional approaches such as “Vacancy and other atomic-Level Regulation”, macro-scale, high-dimensional methods like “Composite Engineering”, as well as intermediate approaches involving “Interface engineering” and “morphology engineering”. Special emphasis is placed on distinguishing between beneficial surface reconstruction of catalytically active hydroxyl oxide species and destructive oxidation. Finally, the review identified the unresolved key challenges, including the fuzziness of active sites, the diversity of initial material states and the lack of stability under industrial conditions, and looked forward to the future direction of reasonable design, operational characterization and device-level evaluation. Through this cross-scale analysis, this review aims to clarify the relationship between structure–activity–stability, and provide practical guidance for designing efficient, durable and experimentally verifiable MXene-based OER electrodes. Full article

High-entropy carbide (HEC) coatings have emerged as promising candidates for extreme tribological and high-temperature applications; therefore, the objective of this work is to systematically investigate the correlation between carbon stoichiometry and the microstructural evolution, mechanical response, and thermal stability of (TiAlTaZrNb)Cx high-entropy carbide coatings. Here, HEC coatings were synthesized via reactive unbalanced-field pulsed-bias magnetron sputtering, with methane flow rates precisely tuned to yield carbon concentrations ranging from 24 to 55 at.%. XRD and Raman analyses reveal a transition from a dense, columnar FCC NaCl-type solid solution with a (200) preferential orientation to a (111)-textured matrix containing secondary carbides (TiC, TaC) and sp²-bonded free carbon at elevated carbon levels. Nanohardness and elastic modulus reach an optimal plateau at ~35 at.% C (29 GPa and 350 GPa, respectively), followed by a decline to ~20 GPa and 223 GPa at 55 at.% C due to the percolation of soft carbon-rich phases. Remarkably, increasing carbon content drastically enhances tribological performance: the coefficient of friction decreases from 0.40 to 0.20, and the specific wear rate drops from 35 × 10⁻⁶ to 1.7 × 10⁻⁶ mm³/(N·m), consistent with a solid-lubrication mechanism inferred from as-deposited Raman trends and wear-track compositional analysis, though direct post-wear spectroscopic validation remains a priority for future work. Thermal stability assessments at 600 °C at an intermediate low pressure demonstrate excellent microstructural and mechanical retention for low-to-intermediate carbon compositions, with oxidation confined to a ~200 nm surface layer attributed to the formation of stable titanium and tantalum oxides and oxycarbides, which possibly forms an oxygen diffusion barrier at that temperature. An optimal carbon content of ~35 at.% C delivers a superior synergy of high hardness, exceptional wear resistance, and robust thermal stability, establishing (TiAlTaZrNb)Cx as a highly tunable coating system for next-generation protective applications. This work provides the first systematic composition–performance map for this quinary HEC system across a broad stoichiometric range, demonstrating that carbon stoichiometry serves as a master variable to tailor the balance between mechanical integrity and tribological functionality. Full article

In this study, warm shot peening was applied to Ti-Al coatings to investigate its effect on high-temperature oxidation behavior at 800–1000 °C. WSP induced severe plastic deformation and thermal effects, resulting in grain refinement, increased lattice distortion, and TiAl-to-Ti₃Al phase transformation, thereby enhancing the structural stability of the coating matrix. Cyclic oxidation kinetics revealed a two-stage process transitioning from reaction-controlled to diffusion-controlled behavior. WSP delivered prominent protective effects at intermediate temperatures, substantially reducing oxidation weight gain and rate constants by promoting the formation of dense, stable Ti₂O₃ and Al₂O₃ protective layers with finer, more uniform oxide-scale morphology. However, this beneficial effect progressively weakened with increasing temperature and sharply diminished at 1000 °C, where massive generation of porous, thermally unstable TiO₂ dominated the oxidation process. The loose TiO₂ structure provided channels for inward oxygen diffusion, offsetting the microstructural optimization advantages of WSP and compromising oxide-scale barrier effectiveness. These findings establish a clear structure–performance correlation for WSP-modified Ti-Al coatings and elucidate the temperature-dependent failure mechanism of surface modification under ultra-high-temperature oxidation conditions. Full article

Tight dolomite gas reservoirs are promising exploration targets, yet their evaluation is complicated by multiscale pore-throat heterogeneity and poor seepage connectivity. Here, high-pressure mercury intrusion (HPMI), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and deep-learning-assisted pore extraction were integrated to characterize the pore-throat structure and fractal features of the Middle Ordovician Majiagou Formation in the Ordos Basin. The reservoir is dominated by diagenetic-origin pores, mainly intercrystalline and intragranular dissolution pores, together with microfractures, and can be classified into three types with progressively poorer connectivity and flow capacity. Type I reservoirs contain more regular pores, larger pore-throat systems, and better storage and seepage capacity; Type II reservoirs are intermediate, whereas Type III reservoirs exhibit complex pore morphology, isolated pore networks, poor petrophysical properties, and limited gas-flow potential. The corresponding fractal dimensions are weakly correlated but complementary: D_SEM captures pore-boundary complexity, D_HPMI reflects pore-throat architecture and capillary-pressure-controlled seepage pathways, and D_NMR reflects multiscale movable-fluid distribution. Clay minerals, especially illite-rich mixed layers, further intensify pore-throat heterogeneity. Increasing fractal dimension is generally associated with higher displacement and median pressures, but poorer connectivity, porosity, permeability, movable-fluid content, and gas deliverability. These results provide a basis for the quantitative evaluation of multiscale pore systems and reservoir quality in tight dolomite gas reservoirs. Full article

Volatile organic compounds (VOCs) emitted during solid-fuel combustion contribute to air pollution, secondary organic aerosol formation, and adverse environmental impacts. Improving the interpretation of VOC emissions is therefore important for developing more sustainable combustion systems and emission-monitoring strategies. Although online flame ionization detector systems enable continuous monitoring of total volatile organic compounds (TVOCs), the resulting measurements remain chemically non-specific and provide limited information about the composition of emitted mixtures. This study investigates whether data-driven approaches can improve the interpretation of TVOC signals generated during controlled solid-fuel combustion and proposes a descriptor-space-based pseudo-speciation framework. Continuous laboratory measurements of TVOCs and combustion parameters demonstrated that the integrated TVOC signal contains meaningful information about combustion dynamics, while preliminary machine-learning models confirmed that a substantial fraction of TVOC variability can be explained using routinely monitored process variables. To address the limited chemical specificity of TVOC measurements, principal component analysis and hierarchical clustering were applied to combustion-related VOCs described by molecular and physicochemical descriptors. The resulting framework organized VOCs into representative physicochemical groups, providing an intermediate interpretation layer between bulk TVOC measurements and compound-specific analysis. The proposed methodology demonstrates how artificial intelligence and chemoinformatics can enhance the interpretation of chemically non-specific TVOC signals and support more sustainable emission monitoring, combustion diagnostics, and environmental management. Full article

Microbially influenced corrosion (MIC) poses a significant threat to buried metallic infrastructure, yet assessing MIC risks in complex, vertically stratified soil environments remains challenging. Unlike traditional models that focus on single canonical corrosion-related species, localized MIC is increasingly recognized as a community-driven process mediated by biofilm formation and stress adaptation. This study investigated the spatial and vertical distribution (0–2.5 m) of microbiomes and corrosion-associated functional genes along a transmission line in Guangxi, China, using shotgun metagenomic sequencing. Taxonomic profiling revealed pronounced site-specific divergence. Site C was enriched in Sphingomonas and nitrifying taxa that promote biofilm-mediated corrosion, whereas Site E was dominated by the iron-reducing Anaeromyxobacter, suggesting anaerobic corrosion susceptibility. Along all investigated sites, surface horizons were dominated by aerobic biofilm formers. Intermediate depths were enriched in dissimilatory iron reducers and nitrite oxidizers, while the deepest layers were dominated by acid-producing Streptomyces. Similarly, the corrosion-related functional genes exhibited a shared vertical stratification across all sites. Functional annotation identified a persistent baseline of corrosion-relevant functions—including oxidative-stress sigma factors (e.g., K03088), nickel-transport systems for hydrogenase assembly (e.g., K02035/K02033/K02034), biofilm-regulatory kinases (e.g., K12132), and ATP-binding cassette (e.g., K06147). These functional markers exhibited clear vertical stratification, with nickel-transport and stress-response genes peaking at intermediate depths. Correlation analyses suggested that K03088 was associated with high resistivity and oxidation-reduction potential, whereas the nickel-transport cluster K02035/K02033/K02034 was correlated with lower pH and reduced salinity. These findings suggest that MIC risk in soils is potentially driven by complex ecological networks, and provide candidate genetic biomarkers for the early warning and risk assessment of buried infrastructure corrosion. Full article

We report on results referring to the growth and characterization of Sn-oxide-semiconductor thin films (SnO₂, SnO and intermediate Sn₃O₄) on silicon substrates forming Type II heterojunction band alignment. The samples were produced by a two-step procedure: (a) growth of a metallic Sn layer by RF magnetron sputtering deposition followed by (b) post-growth treatment of the Sn films with oxygen plasma etching for the formation of the oxides in various time steps. Various annealing steps were considered. The structural and chemical properties of the prepared thin films were determined by means of X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS). The results demonstrated the presence of SnO₂ and SnO in a tetragonal structure and the intermediate Sn₃O₄ in a triclinic structure. The electric properties of thin films were investigated with four-probe I–V characteristics under various conditions. The evaluation of their photo-sensing properties was performed by means of photocurrent J–t curves using a solar simulator. We found that the sample with equal concentrations of SnO₂ and SnO exhibited superior responsivity and detectivity values as well as a responsivity of 12.5 A/W and detectivity of 1.1 × 10¹⁰ Jones for V = 0 under yellow light illumination and an intensity of 2 mW/cm². These excellent values, in combination with the low-cost manufacturing, indicate that the method is promising for future applications. Full article

Controlling the interfacial behavior is essential for understanding the efficiency of surfactant–nanoparticle systems in practice. In this study, we investigate how silica (SiO₂) nanoparticles alter the surface and interfacial properties of sodium dodecyl sulfate (SDS) solutions at water–air and water–hexane interfaces, as well as their impact on the formation and stabilization of foams. While the negatively charged SiO₂ nanoparticles alone exhibit negligible surface activity, their combination with SDS leads to the formation of composite interfacial layers with enhanced surface pressure and dilational viscoelasticity. The increase in interfacial pressure reflects a high surface concentration and denser packing of SDS–SiO₂ associates. Interfacial rheology measurements show that SDS–SiO₂ nanofluids form more elastic interfacial films compared to pure SDS, with a maximum dilational elasticity at intermediate surfactant concentrations. This indicates the formation of mechanically stronger interfacial layers capable of resisting deformation. Foam experiments demonstrate that silica nanoparticles significantly improve foam formation and foam stability. These improvements correlate with increased surface pressure and interfacial elasticity, demonstrating that foam stability is primarily determined by the formation of robust interfacial layers and not solely by a reduction in surface tension. Overall, this study demonstrates how the presence of silica nanoparticles can affect the adsorption of SDS via hydrophobic interaction, leading to the formation of stronger interfacial films, improved foam stability, and expanded potential for applications in industrial processes, such as foam flooding based on nanoparticle/surfactant solutions to enhance oil–gas recovery. Full article

The formation of phosphate conversion coatings on St20 low-carbon steel was studied in order to evaluate the effect of organic accelerators on coating formation and protective performance. The influence of pH, temperature, treatment time, and stirring rate on coating formation was studied by gravimetry and SEM-EDS, the influence of accelerators was studied by Raman spectroscopy, salt spray testing, polarization measurements, EIS, and dynamic LPR monitoring. Efficient coating formation was achieved at an initial pH of 3.0, elevated temperature, and intensive stirring; the process showed diffusion-controlled behavior with an apparent activation energy of 28 kJ/mol. Sodium nitrite accelerated coating formation but did not increase the limiting coating mass. Among the organic additives, catechol provided the most pronounced improvement in corrosion resistance, which was attributed to lower effective porosity and possible incorporation of catechol-derived oxidized fragments into the phosphate layer. The catechol-modified coating also improved electrochemical resistance and did not impair the adhesion of subsequent acrylic paint. These results indicate that catechol is a promising organic modifier for zinc phosphate intermediate pretreatment layers. Full article

In this study, we report the results of the structural characterization and electrochemical evaluation of novel cobalt-free layered Ruddlesden–Popper (RP) oxides, La₂SrFe₂O_7−δ and La₂SrFe_1.8Ga_0.2O_7−δ, as electrode materials for intermediate-temperature solid oxide cells. X-ray diffraction confirmed the formation of RP phases and phase stability after reducing treatment. The materials showed compatible thermal expansion behavior, with slightly lower thermal expansion coefficients for the Ga-doped composition. Oxygen pressure relaxation measurements demonstrated that the oxygen surface exchange coefficient increases with temperature and pO₂, while Ga substitution slightly reduces the O₂/oxide exchange rate, which may be associated with a lower concentration of oxygen vacancies. The electrical conductivity in air was higher for La₂SrFe₂O_7−δ than for the Ga-doped sample, while both compositions showed much lower conductivity under reducing conditions. Symmetrical cell impedance spectroscopy showed high polarization resistance for the electrodes, which was substantially reduced by applying a Ag current collector (0.43 Ω cm² for La₂SrFe₂O_7−δ and 0.73 Ω cm² for La₂SrFe_1.8Ga_0.2O_7−δ at 800 °C), consistent with the limited electronic conductivity of the oxide layers. Overall, both oxides exhibit structural stability, acceptable thermomechanical compatibility, and measurable oxygen exchange activity, making them promising candidates for further development as cobalt-free electrodes in solid oxide cells. Full article

An administrator-assisted CLP-SEIRS-T⁺ framework is developed to model malware propagation and urban cyber-resilience in clustered temporal communication networks. The model extends CLP-SEIRS-T by integrating community structure, predicted links, asynchronous node activation, and an endogenous defense layer in which administrator nodes remain infectable, recover faster than ordinary nodes, and trigger local patch diffusion when community-level prevalence exceeds a risk threshold. Unlike formulations that treat defense as an external or perfectly reliable safeguard, the proposed framework embeds administrator intervention directly within the epidemic state space and couples propagation dynamics with resilience-oriented performance measures, including safe functionality, absorptive capacity, spillover attenuation, recovery time, and service continuity. To keep experimental evidence scale-explicit, the validation is organized as a tiered protocol: a 48-node isolated virtual-machine cyber-range verifies safe mechanism realization; emulation-calibrated logical traces and pilot repeated comparisons examine trajectory behavior, pathway composition, and defense-component effects; and expanded numerical sweeps assess scalability, threshold sensitivity, alternative link-prediction scores, and adaptive-stress assumptions. The results show that direct links dominate local amplification, whereas predicted links contribute disproportionately to cross-community spillover. In the pilot comparison, the full CLP-SEIRS-T⁺ configuration achieves the best observed balance, reducing mean peak burden by 56.9%, shortening mean recovery time by 86.7%, increasing absorptive capacity by 37.1%, and improving service continuity by 12.0% relative to the no-intervention baseline. Larger-network sweeps over $N=48,100,150,200,$ and 500 logical hosts preserve the same qualitative mechanism ordering while keeping functionality error below 0.02. Threshold analysis indicates that intermediate trigger values provide a better burden–cost balance than either overly aggressive or delayed patching. Link-score comparisons show that local-neighborhood predictors yield consistent spillover interpretations, whereas degree-driven prediction can increase bridge exposure. Parameterized adaptive-stress tests further indicate that the mechanism remains beneficial under moderate stress but degrades under severe patch suppression, false telemetry, or intensified bridge seeking. These findings suggest that urban cyber-resilience depends jointly on network modularity, temporal availability, structurally likely bridge formation, state-dependent local defense, and the integrity of administrative response. Full article