Search Results (1,259)

Rainfall-induced failures in red clay slopes are common, yet the coupled influence of soil structure degradation and rainfall temporal patterns on slope hydromechanical behavior remains poorly understood. This study advances the understanding by investigating a cut slope failure in Yunnan through integrated field monitoring, laboratory testing, and numerical modeling. Key advancements include: (1) elucidating the coupled effect of structure degradation on both shear strength reduction and hydraulic conductivity alteration; (2) systematically quantifying the impact of rainfall temporal patterns beyond total rainfall; and (3) providing a mechanistic explanation for the critical role of early-peak rainfall. Mechanical and hydrological parameters were obtained from intact and remolded samples, with soil-water retention estimated via pedotransfer functions. A hydro-mechanical finite element model of the slope was constructed and calibrated using recorded rainfall, displacement data and failure surface. Six simulation scenarios were designed by combining three strength conditions (intact at natural water content, intact at saturation, remolded at natural water content) with two hydraulic conductivity values (intact vs. remolded). Additionally, four synthetic rainfall patterns, including uniform, peak-increasing, peak-decaying and bell-shaped rainfall, were simulated to evaluate their influence on pore water pressure development and slope stability. Results show remolding reduced hydraulic conductivity 4.7-fold, slowing wetting front advance and increasing shallow pore water pressure. Intact soil facilitated deeper drainage, elevating pressure near the soil-rock interface. Strength reduction induced by structure degradation (water saturating and remolding) enlarged the slope deformation zone by 1.5 times under same hydraulic conductivity. Simulations using saturated intact strength best matched field observations. The results from this specific slope indicate that strength parameters primarily control stability, while permeability affects deformation depth. Simulations considering different rainfall patterns indicate that slope stability depends more critically on the temporal distribution of rainfall intensity than on the total amount. Overall, peak-decaying rainfall led to the most rapid rise in pore water pressure, earliest instability and lowest failure rainfall threshold, whereas peak-increasing rainfall showed the opposite trends. Our findings outline a practical framework for assessing red clay slope stability during rainfall. This framework recommends using saturated intact strength parameters in stability analysis. It highlights the important influence of rainfall temporal patterns, especially those with an early peak, on failure timing and rainfall threshold. Full article

This review explores the variety of diamond-based sensing applications, emphasizing their material properties, such as high Young’s modulus, thermal conductivity, wide bandgap, chemical stability, and radiation hardness. These diamond properties give excellent performance in mechanical, pressure, thermal, magnetic, optoelectronic, radiation, biosensing, quantum, and other applications. In vibration sensing, nano/poly/single-crystal diamond resonators operate from MHz to GHz frequencies, with high quality factor via CVD growth, diamond-on-insulator techniques, and ICP etching. Pressure sensing uses boron-doped piezoresistive, as well as capacitive and Fabry–Pérot readouts. Thermal sensing merges NV nanothermometry, single-crystal resonant thermometers, and resistive/diode sensors. Magnetic detection offers FeGa/Ti/diamond heterostructures, complementing NV. Optoelectronic applications utilize DUV photodiodes and color centers. Radiation detectors benefit from diamond’s neutron conversion capability. Biosensing leverages boron-doped diamond and hydrogen-terminated SGFETs, as well as gas targets such as NO₂/NH₃/H₂ via surface transfer doping and Pd Schottky/MIS. Imaging uses AFM/NV probes and boron-doped diamond tips. Persistent challenges, such as grain boundary losses in nanocrystalline diamond, limited diamond-on-insulator bonding yield, high temperature interface degradation, humidity-dependent gas transduction, stabilization of hydrogen termination, near-surface nitrogen-vacancy noise, and the cost of high-quality single-crystal diamond, are being addressed through interface and surface chemistry control, catalytic/dielectric stack engineering, photonic integration, and scalable chemical vapor deposition routes. These advances are enabling integrated, high-reliability diamond sensors for extreme and quantum-enhanced applications. Full article

An explicit coupled two-dimensional (2D) hydromechanical model (HMM) that can simulate discontinuous features in the foundation, as well as the effects of grout curtains and drainage systems, is employed to evaluate the influence of key parameters such as dam height, foundation behaviour, joint patterns, joint stiffness and strength, hydraulic apertures, and grout curtain permeability. A parametric sensitive study using four gravity dams, and a real case study of an operating dam are presented. The results presented show that dam height influences the relationship between water level in the reservoir and drain discharges, with higher dams showing more pronounced curved nonlinearity. The strength properties of the concrete–rock interface are also shown to have a meaningful influence on the HM response, especially for an elastic foundation and for higher dams, showing the need to properly characterize this interface through in situ testing. The joint aperture at nominal zero stress is shown to be the parameter with the most significant effect on the HM response. The results also show that a progressive degradation scenario of the concrete–rock interface or of the grout curtain permeability is easier to identify through the hydraulic measurements than in the mechanical displacement field. Full article

Metal–organic frameworks (MOFs) and porous organic frameworks (POFs) have been extensively explored in recent years as lubricant additives for various systems due to their structural designability, pore storage capacity, and tunable surface chemistry. These materials are utilized to construct low-friction, low-wear interfaces and investigate the potential for superlubricity. This paper systematically reviews the tribological behavior and key mechanisms of MOFs/POFs in oil-based, water-based, and solid coating systems. In oil-based systems, MOFs/POFs primarily achieve friction reduction and wear resistance through third-body particles, layer slip, and synergistic friction-induced chemical/physical transfer films. However, limitations in achieving superlubricity stem from the multi-component heterogeneity of boundary films and the dynamic evolution of shear planes. In water-based systems, MOFs/POFs leverage hydrophilic functional groups to induce hydration layers, promote polymer thickening, and soften gels through interfacial anchoring. Under specific conditions, a few cases exhibit superlubricity with coefficients of friction entering the 10⁻³ range. In solid coating systems, two-dimensional MOFs/COFs with controllable orientation leverage interlayer weak interactions and incommensurate interfaces to reduce potential barriers, achieving structural superlubricity at the 10⁻³–10⁻⁴ level on the micro- and nano-scales. However, at the engineering scale, factors such as roughness, contamination, and discontinuities in the lubricating film still constrain performance, leading to amplified energy dissipation and degradation. Finally, this paper discusses key challenges in achieving superlubricity with MOFs/POFs and proposes future research directions, including the design of shear-plane structures. Full article

In this study, a high-performance MoS₂-based strain-gauge pressure was sensor fabricated entirely below 80 °C, enabling direct integration onto flexible polyethylene terephthalate (PET) substrates. The sensor comprised a three-layer MoS₂ channel (~2 nm) patterned via dry transfer and O₂/Ar plasma etching, interfaced with Cr/Au electrodes. This wafer-scale and cost-effective fabrication route preserves the crystallinity of the film and prevents substrate degradation. The sensor achieved a gauge factor of ~104 under compression, representing a fifty-fold improvement over conventional metal foil gauges (~2), with a linear response across both compressive and tensile regimes. Mechanical robustness was confirmed through repeated bending and tape adhesion tests, with no degradation in electrical performance. When configured as a Wheatstone bridge, this device exhibits normalized sensitivity suitable for real-time monitoring, with response and recovery times below 200 ms. These results establish O₂/Ar-plasma-patterned MoS₂ architectures as a scalable, cost-effective platform for next-generation flexible sensors, outperforming metal-foil technology in applications including seat-occupancy detection, wearable physiological monitoring, and tactile interfaces for soft robotics. Full article

BslA (Biofilm surface layer protein A), a highly hydrophobic lipoprotein from Bacillus spp., self-assembles at fluid interfaces to form a crystalline film that reduces surface tension. In this study, we selected Pichia pastoris as a eukaryotic system for expressing recombinant BslA identified in Bacillus paralicheniformis BL-1. The secretory expression of recombinant BslA in the P. pastoris GS115 strain under the AOX1 promoter was confirmed in shake-flask cultivation. Next, two fed-batch fermentation strategies, constant dissolved oxygen strategy (DO-stat) and oxygen-limited fed-batch (OLFB) strategy, in a 5 L scale, were compared. The DO-stat process led to late-stage cell death and product degradation, limiting yields. Switching to the OLFB process by removing the glycerol feeding phase mitigated this issue, allowing extended fermentation and increasing the final recombinant BslA concentration to 657 mg/L. This study establishes P. pastoris with an OLFB strategy as an effective system for secreting recombinant BslA protein, providing a basis for future industrial-scale production. Full article

Changes in preservation conditions act as an important environmental filter driving shifts in microbial communities. However, the precise identities, functional traits, and ecological mechanisms of the dominant agents driving stage-specific deterioration remain insufficiently characterized. This study investigated microbial communities and dominant fungal degraders in waterlogged versus dried bamboo slips using amplicon sequencing, multivariate statistics, and microbial isolation. Results revealed compositionally distinct communities, with dried slips sharing only a small proportion of operational taxonomic units (OTUs) with waterlogged slips, while indicating the persistence of a subset of taxa across preservation states. A key discovery was the dominance of Fonsecaea minima (92% relative abundance) at the water-solid-air interface of partially submerged slips. Scanning electron microscopy (SEM) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) indicate that this fungus forms melanin-rich, biofilm-like surface structures, suggesting enhanced surface colonization and stress resistance. In contrast, the fungal community isolated from dried slips was characterized by Apiospora saccharicola associated with detectable xylanase activity. Meanwhile, the xerophilic species Xerogeomyces pulvereus dominated (99% relative abundance) the storage box environment. Together, these results demonstrate that preservation niches select for fungi with distinct functional traits, highlighting the importance of stage-specific preservation strategies that consider functional traits rather than taxonomic identity alone. Full article

Silicon carbide (SiC) MOSFETs, as one of the representative power electronic devices, have faced reliability challenges due to threshold voltage (V_th) instability under dynamic gate stress. To explore the underlying mechanisms, this work investigates 4H-SiC MOS structures (P-MOS and N-MOS) under AC bias temperature instability (AC BTI) stress, utilizing a laser to generate minority carriers and simulate realistic switching conditions. Through combined capacitance–voltage (C-V) and gate current–voltage (J_g-V_g) characterizations on P-MOS and N-MOS devices before and after degradation at different temperatures, we reveal a critical temperature dependence in defect interactions. At room temperature, degradation is dominated by electron trapping in shallow interface states and near-interface traps (NITs). In contrast, high-temperature stress activates charge exchange with deep-level, slow states. Notably, a positive V_FB shift is consistently observed in both N-MOS and P-MOS devices under AC stress, confirming that electron trapping is the dominant cause of the commonly observed positive V_th shift in SiC MOSFETs. These findings clarify the distinct defect-mediated mechanisms governing dynamic V_th instability in SiC devices, providing fundamental insights for interface engineering and reliability assessment. Full article

Magnesium hydride (MgH₂) is a promising solid-state hydrogen storage material owing to its high hydrogen capacity and low cost, yet its practical application is limited by sluggish kinetics, high operating temperatures, and poor cycling stability. Among various catalytic approaches, Fe-based catalysts have emerged as attractive candidates due to their abundance, compositional tunability, and effective promotion of hydrogen sorption reactions in MgH₂ systems. This review critically summarizes recent progress in Fe-based catalysts for MgH₂ hydrogen storage, encompassing elemental Fe, iron oxides, Fe-based alloys, and advanced composite catalysts with nanostructured and multicomponent architectures. Mechanistic insights into catalytic enhancement are discussed, with particular emphasis on interfacial electron transfer, catalytic phase evolution, hydrogen diffusion pathways, and synergistic effects between Fe-containing species and MgH₂, supported by experimental and theoretical studies. In addition to catalytic activity, key stability challenges—including catalyst agglomeration, phase segregation, interfacial degradation, and performance decay during cycling—are analyzed in relation to structural evolution and kinetic–thermodynamic trade-offs. Finally, a roadmap for the scalable design of Fe-based catalysts is proposed, highlighting rational catalyst selection, interface engineering, and compatibility with large-scale synthesis. This review aims to bridge fundamental mechanisms with practical design considerations for developing durable and high-performance MgH₂-based hydrogen storage materials. Full article

Silicon is considered one of the most promising next-generation anode materials for lithium-ion batteries (LIBs) because of its very high theoretical specific capacity (≈3579 mAh·g⁻¹). However, its practical application is limited by severe volume expansion (>300%), an unstable solid electrolyte interphase (SEI), and low electronic conductivity. Recent progress in nanostructuring has significantly improved the electrochemical performance and durability of silicon anodes. In particular, nanosilicon particles, porous structures, and Si–carbon composites enhance structural stability, cycling life, and coulombic efficiency. These improvements arise from better mechanical integrity and more stable electrode–electrolyte interfaces. This review summarizes recent advances in nanostructured silicon anodes, focusing on particle size control, pore design, composite architectures, and interfacial engineering. We discuss how these nanoscale strategies reduce mechanical degradation and improve lithiation kinetics while also addressing the remaining challenges. Finally, future research directions and industrial prospects for the practical use of nanostructured silicon anodes in next-generation LIBs are outlined. Full article

This numerical study demonstrates the existence of a critical injection momentum threshold necessary for stable liquid film formation, highlighting that either excessive or insufficient momentum degrades cooling performance. This optimization is critical for maximizing cooling effectiveness from short injection holes in high-performance propulsion systems. By comparing Smoothed Particle Hydrodynamics (SPH) and Volume of Fluid (VOF) methods, we find that the SPH method predicts a thicker, more continuous coolant film due to its superior mass conservation during interface breakup. A key design insight emerges: cooling performance peaks at a distinct, critical coolant momentum. Insufficient momentum leads to poor coverage, while excess momentum causes film separation and is counter-productive. The identified configuration—defined by a precise combination of flow rate, pressure, and geometry—promotes immediate and stable film formation. The robustness of this finding is confirmed by the agreement between the two numerical methods on film thickness and the captured physical evolution of the film from a pronounced wave to a damped state. Full article

Composite materials are increasingly required to operate in cryogenic environments, including liquid hydrogen and oxygen storage, deep-space structures, and polar infrastructures, where long-term strength, toughness, and reliability are essential. This review provides a unique contribution by systematically integrating recent advances in understanding cryogenic behaviour into a unified multi-scale framework. This framework synthesises four critical and interconnected aspects: constituent response, composite performance, enhancement mechanisms, and modelling strategies. At the constituent level, fibres retain stiffness, polymer matrices stiffen but embrittle, and nanoparticles offer tunable thermal and mechanical functions, which collectively define the system-level performance where thermal expansion mismatch, matrix embrittlement, and interfacial degradation dominate failure. The review further details toughening strategies achieved through nano-addition, hybrid fibre architectures, and thin-ply laminates. Modelling strategies, from molecular dynamics to multiscale finite element analysis, are discussed as predictive tools that link these scales, supported by the critical need for in situ experimental validation. The primary objective of this synthesis is to establish a coherent perspective that bridges fundamental material behaviour to structural reliability. Despite these advances, remaining challenges include consistent property characterisation at low temperature, physics-informed interface and damage models, and standardised testing protocols. Future progress will depend on integrated frameworks linking high-fidelity data, cross-scale modelling, and validation to enable safe deployment of next-generation cryogenic composites. Full article

Metal oxide nanomaterials have emerged as transformative materials in the quest to enhance the energy density and overall performance of lithium-ion batteries (LIBs) and solid-state batteries (SSBs). Their unique properties—including their large surface areas and short ion diffusion pathways—make them ideal for next-generation energy storage technologies. In LIBs, the high surface-to-volume ratio of metal oxide nanomaterials significantly enlarges the active interfacial area and shortens the lithium-ion diffusion paths, leading to an improved high-rate performance and enhanced energy density. Transition metal oxides (TMOs) such as nickel oxide (NiO), copper oxide (CuO), and zinc oxide (ZnO) have demonstrated significant theoretical capacities, while binary systems like NiCuO offer further improvements in cycling stability and energy output. Additionally, layered lithium-based TMOs, particularly those incorporating nickel, cobalt, and manganese, have shown remarkable promise in achieving high specific capacities and long-term stability. The synergistic integration of metal oxides with carbon-based nanostructures, such as carbon nanotubes (CNTs), enhances the electrical conductivity and structural durability further, leading to a superior electrochemical performance in LIBs. In SSBs, the use of oxide-based solid electrolytes like garnet-type Li₇La₃Zr₂O₁₂ (LLZO) and sulfide-based electrolytes has facilitated the development of high-energy-density systems with excellent ionic conductivity and chemical stability. However, challenges such as high interfacial resistance at the electrode–electrolyte interface persist. Strategies like the application of lithium niobate (LiNbO₃) coatings have been employed to enhance interfacial stability and maintain electrochemical integrity. Furthermore, two-dimensional (2D) metal oxide nanomaterials, owing to their high active surface areas and rapid ion transport, have demonstrated considerable potential to boost the performance of SSBs. Despite these advancements, several challenges remain. Morphological optimization of nanomaterials, improved interface engineering to reduce the interfacial resistance, and solutions to address dendrite formation and mechanical degradation are critical to achieving the full potential of these materials. Full article

Waterproofing systems frequently experience performance degradation during long-term service due to material aging and structural deformation, thereby necessitating localized repair interventions. The bonding interface between newly applied and existing membrane materials is a critical determinant of repair effectiveness. In this study, the aging-dependent repair performance of three representative waterproof membrane systems was systematically investigated using peel strength testing, low-temperature flexibility assessment, and interfacial morphology analysis under thermal–oxidative aging for 2, 5, 14, and 28 days. The results demonstrate that the homogeneous repair system based on ultra-thin reinforced self-adhesive polymer-modified bituminous membranes exhibits superior overall performance, maintaining the highest peel strength with only minor degradation even after 28 days of accelerated aging. In contrast, the polymeric butyl self-adhesive membrane subjected to homogeneous repair exhibited rapid adhesion degradation after 14 days, whereas the heterogeneous repair system showed improved stability during intermediate aging stages. Low-temperature flexibility testing further revealed that root-resistant bituminous membranes exhibited a slower aging rate, with a cracking temperature increase of 7 °C after 28 days, compared to a 10 °C increase observed for ultra-thin self-adhesive membranes. These quantitative findings provide clear guidance for the selection of appropriate repair membrane systems under varying aging conditions in waterproofing engineering, particularly for maintenance and rehabilitation applications. Full article

The coexistence of plastics and metal-based materials in aquatic systems introduces complex interfacial processes that influence pollutant speciation and mobility. This study investigates the role of polystyrene (PS) in promoting UV-induced dissolution of ZnO and Cu₂O in aqueous media, revealing a plastic-mediated pathway for metal ion mobilization. Post-use expanded PS fragments were co-dispersed with the oxides and irradiated at 254 nm for 24 h. Ion concentrations were quantified by ICP-MS, while PS morphology and chemistry were characterized by SEM, EDX, FTIR, Raman, and DSC. The presence of PS markedly enhanced metal release, bringing Zn²⁺ from 29.9 to 50.6 ppm and Cu²⁺ from 1.1 to 26.5 ppm under irradiation, compared to minimal dissolution in the dark. Spectroscopic analyses indicated negligible polymer degradation, suggesting that enhanced dissolution arises from interfacial photooxidation and associated redox/pH microgradients at the polymer–oxide boundary. These findings demonstrate that PS may serve as a catalytic interface that accelerates UV-driven dissolution of otherwise poorly soluble metal oxides. This mechanism expands current understanding of plastic–pollutant interactions and has implications for predicting metal bioavailability and designing strategies to mitigate pollutant release in sunlit marine and coastal environments. Full article