Search Results (65,636)

In this study, laser powder bed fusion (PBF-LB) 022Cr17Ni12Mo2 steel plates with dimensions of 50 mm × 50 mm × 2 mm were fabricated using a laser power of 206 W, a scanning speed of 900 mm/s, a hatch spacing of 90 μm, a layer thickness of 30 μm, and an interlayer scanning rotation of 67°. The specimens were then subjected to solution treatment at 900–1100 °C for 30 min and at 950 °C for 30–120 min. Unlike previous ultrasonic studies on additively manufactured metals, which mainly focused on defect detection, elastic-constant characterization, or residual stress evaluation, this work investigates whether solution-treatment-induced changes in grain size and dislocation density can be quantitatively reflected by laser-ultrasonic attenuation and further correlated with yield strength. Laser ultrasonic nondestructive testing using a 1064 nm pulsed laser with a pulse width of 8 ns and a pulse energy of 500 mJ was combined with metallographic observation, EBSD characterization, XRD analysis, tensile testing, and microhardness measurement. The results show that the solution-treated samples retained a single-phase γ-austenitic structure, while microstructural recovery, weakening of PBF-LB-induced cellular substructures, and partial annihilation of cell-wall dislocations led to a reduction in KAM-derived dislocation density from 2.04 × 10¹⁴ m⁻² to 1.45 × 10¹⁴ m⁻² and a decrease in yield strength from 466.9 MPa to 407.4 MPa. Within the present dataset, the EBSD-equivalent grain size showed an apparent positive correlation with ultrasonic attenuation, while the KAM-derived dislocation density showed an empirical negative correlation with ultrasonic attenuation. However, ultrasonic attenuation should be interpreted as a combined microstructure-sensitive response rather than as a response controlled only by EBSD-equivalent grain size or dislocation density. Based on the empirical correlations among ultrasonic attenuation, EBSD-equivalent grain size, KAM-derived dislocation density, and yield strength, a preliminary attenuation-based calibration model was established for the present solution-treated samples. The model should be regarded as an in-sample empirical calibration within the present experimental range rather than a general Hall–Petch-based predictive model. The model showed good in-sample fitting performance, with (R²) values higher than 0.85 and a maximum in-sample fitting error of 3.85%. However, because the model was established and assessed using the same eight solution-treatment conditions, it should be regarded as a preliminary calibration model within the present experimental range rather than a general predictive model. This study demonstrates the potential of laser ultrasonic attenuation for non-contact evaluation of microstructural and mechanical-property variations in solution-treated PBF-LB 022Cr17Ni12Mo2 steel. Full article

Oculomics uses ocular images, ocular biofluids and functional ocular tests to extract diagnostic information on local or systemic biological states. Most current evidence is cross-sectional: one retinal photograph, OCT scan, OCTA examination or tear sample is compared with a reference population, or converted into a diagnostic or prognostic score. This approach is useful for screening and risk enrichment, but it does not show whether the same patient is changing over time. In this review, dynamic oculomics, or oculomic kinetics, is presented as a diagnostic-monitoring approach based on repeated ocular measurements within the same individual. Its object is the personal trajectory: baseline level, short-term variability, long-term drift, response to stimulus, recovery and modification by treatment. We discuss the biological basis of ocular trajectories, the limits imposed by local ocular regulation and disease, and the technical constraints of fundus photography, structural OCT, OCTA, functional challenge tests, tear analysis, aqueous humour analysis, continuous intraocular pressure monitoring and home-based imaging. We also examine artificial intelligence, validation, governance, health-economic considerations and practical implementation. The available evidence does not support a universal ocular surrogate for systemic disease. More realistic applications include detection of unexpectedly rapid tissue change, individualised risk stratification, treatment-response assessment and recognition of discordance between systemic markers and ocular tissue behaviour. Full article

Organic–inorganic hybrid crystalline materials formed in multicomponent aqueous systems are of interest because their phase behavior and physicochemical properties can be controlled by composition and crystallization conditions. In this study, the phase equilibria and crystallization behavior of the ternary aqueous Ca(ClO₃)₂·2CO(NH₂)₂–CH₂ClCOOH·(C₂H₄OH)₃N–H₂O system were investigated over the temperature range of −24 to 60 °C using the visual-polythermal method. Experimental data obtained for the two boundary binary subsystems and eight internal sections were used to construct the polythermal phase diagram. The diagram revealed distinct crystallization fields corresponding to ice, Ca(ClO₃)₂·2CO(NH₂)₂·2H₂O, CH₂ClCOOH·(C₂H₄OH)₃N, and a separate crystallization region associated with a previously unreported crystalline phase with the proposed composition ClCH₂COOH·Ca(ClO₃)₂·(C₂H₄OH)₃N. The solid phase was isolated from its crystallization region, washed with cold distilled water, dried to constant mass, and characterized by complementary Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS), thermogravimetric analysis, derivative thermogravimetry, and differential scanning calorimetry (TG–DTG–DSC), and powder X-ray diffraction (PXRD). The experimentally determined Ca²⁺ and ClO₃⁻ contents were reasonably consistent with the proposed composition, while FT-IR spectroscopy revealed characteristic chlorate vibrations and changes in the vibrational environment of the organic component. SEM showed predominantly prismatic and plate-like crystalline morphologies, and EDS confirmed the presence of Ca, Cl, O, C, and N. Thermal analysis demonstrated multistage decomposition, with comparatively good thermal stability below approximately 150 °C. PXRD revealed a diffraction fingerprint distinct from those of the starting components and the corresponding physical mixture. Preliminary indexing of 19 principal reflections was consistent with a tetragonal candidate lattice with a = b = 7.7411(5) Å, c = 24.7182(10) Å, V = 1481.2(5) ų, and M₂₀ ≈ 23.0. The crystallographic analysis is considered preliminary because the diffraction profile was reconstructed from the available pattern and was not subjected to complete structure refinement. Overall, the combined phase-equilibrium, compositional, spectroscopic, morphological, thermal, and diffraction data support the isolation of a distinct organic–inorganic crystalline phase with the proposed composition. Full article

Speech deepfake detection (SDD) is commonly formulated as offline utterance-level binary classification, which limits early decisions in streaming communication and provides little mechanism-level evidence for a spoofing prediction. We propose C-MCSS-Mamba, a block-causal SDD framework that processes fixed-duration audio blocks with a partially fine-tuned XLS-R frontend and carries detection states across blocks through Mamba. Its selective scan is replaced by the proposed Counterfactual Mechanism-Contrastive Selective Scan (C-MCSS), which maintains shared, text-to-speech (TTS), and voice conversion (VC) states. Frame-level TTS/VC hypotheses directly modulate state update, retention, and forgetting. A Causal Counterfactual Evidence Reliability Module (C-CERM) further suppresses transient mechanism evidence through a recurrent reliability state that adaptively regulates these dynamics. Model-internal TTS/VC evidence is obtained by counterfactually disabling the corresponding recurrent state and measuring the resulting spoof-logit decrease. The model produces prefix-level spoof decisions and contribution-based state-dependence measures; these measures only characterize the model’s internal decision process, and do not identify the physical speech generation process of an individual sample. A joint objective combines detection, early-prefix, mechanism, contrastive, and intervention supervision. Experiments demonstrate competitive detection performance, achieving $0.47\%$ EER on the ASVspoof 2019 LA evaluation set while maintaining effectiveness across four cross-dataset benchmarks. Full article

Wearable sweat biosensors require electrode materials with high surface area, conductivity and mechanical compliance, yet chemically polymerized polyaniline forms dense, low-surface-area films with limited flexibility. In this work, flexible free-standing nanofiber mats were fabricated by coaxial electrospinning, using a sulfuric-acid-doped polyacrylonitrile/polyaniline (PAN/PANI) core and a shell containing graphene oxide nanoscrolls (GONS) at 1 and 3 wt%, followed by gold nanoparticle and ferrocene incorporation, glucose oxidase (GOx) immobilization and a Nafion coating. Scanning electron microscopy showed uniform bead-free fibers with an interconnected pore network and an apparent image-derived porosity of approximately 40%. Energy-dispersive X-ray spectroscopy confirmed the uniform distribution of carbon, oxygen, nitrogen and sulfur across the matrix. Fourier-transform infrared spectroscopy retained the nitrile band at 2243 cm⁻¹ and the quinoid and benzenoid bands at 1547 and 1476 cm⁻¹, while amide bands at 1730 and 1641 cm⁻¹ confirmed retention of protein from enzymes. X-ray diffraction gave crystallinities of 76.6% for GONS and 60% for the pure PANI. Four-point probe measurements showed conductivity increasing from 0.0481 S/cm to 1 wt% GONS to 0.0595 S/cm for the 3 wt% mat with additives. These material and structural characterizations establish a promising foundation for future electrochemical validation and sensor development. Full article

Engineering schematics, such as electrical, mechanical, piping and instrumentation diagrams, record how industrial plants are built and operated, but most of them survive only as images or scanned sheets that software cannot read. Digitizing them by hand is slow and error-prone: an expert must find and classify hundreds of symbols, read dense technical text, and work out which label belongs to which component. Progress with learning-based methods has been held back on two fronts at once. There are almost no annotations that connect a text label to its symbol, and the drawings themselves are usually confidential, so even unlabeled sheets rarely reach the public domain. We address this with a system that turns a drawing into a structured, queryable graph: it detects and classifies the graphical components with an object detector, recovers the technical text, and then resolves which label belongs to which component. Our contributions are threefold: (i) the first at-scale dataset of manually annotated text-to-symbol links for industrial schematics; (ii) a complete, deployable digitization system combining tiled detection with sliced inference, off-the-shelf OCR, and a text-to-symbol association stage; and (iii) a rigorous, leakage-free benchmark of association methods. Under an observable-only candidate protocol, we find that on logic circuits association is dominated by geometry: a simple pairwise model reaches about 99% top-1 and a graph neural network matches but does not exceed it, whereas the denser P&IDs still benefit from a geometric rule-based chain. Detection reaches an mAP@50 of 0.995 on logic circuits and about 0.91 across the 107-class P&ID taxonomy. The system produces a partial semantic graph; connecting lines and flow direction are not extracted. Full article

Groundwater ingress threatens the serviceability and durability of underground structures, particularly when hydrogeotechnical conditions and waterproofing details are considered separately. This study presents a diagnosis-driven assessment of a reconstructed underground shooting range tunnel where leakage persisted despite reconstruction and previous repairs. The objectives were to identify the cause-and-effect mechanism of water ingress and select a targeted, low-impact remediation strategy. The investigation combined archival analysis, three site inspections, ultrasonic testing at 24 locations, eight tomographic scans, targeted destructive verification, and three geotechnical boreholes extending to 7.5 m. Ultrasonic measurements indicated good concrete homogeneity, with a mean estimated compressive strength of 36.9 MPa and a coefficient of variation of 5.86%. Tomography indicated a 25 cm bottom slab and a 20 cm lean concrete layer, compared with the designed 30 cm and 10 cm, respectively. The original geotechnical investigation was too shallow, and the ground conditions should have been classified as difficult, corresponding to geotechnical category II. Finally, leakage was linked to groundwater underestimation, water accumulation in the backfilled excavation, absence of drainage, waterproofing discontinuities, and ineffective previous injections. Targeted reinjection and joint sealing were selected, demonstrating how integrated diagnostics can support proportionate remediation while limiting excavation, demolition, material use, and operational disruption. Full article

Traditional bone plates provide reliable fracture fixation; however, their high stiffness can cause stress shielding, thereby reducing mechanical stimulation of the bone tissue and slowing its regeneration. The biomechanical performance of a titanium plate with a localized porous structure for osteosynthesis of the radial shaft was investigated in this study. Three designs were considered: a solid plate and two plates with localized porous regions measuring 10 × 10 mm and 10 × 15 mm. The finite element analysis of the bone–plate system was performed using MSC Patran/Nastran, with rigid fixation of the proximal end of the bone and sequential application of an axial compressive load of 100 N, bending, and torsion with a moment of 1 N·m. Biomechanical performance was evaluated based on von Mises equivalent stress, fragment displacement (FD), interfragmentary movement (IFM), interfragmentary strain (IFS), and strain energy density (SED). To confirm the manufacturability of the design, the plate was fabricated from Ti–6Al–4V alloy using laser powder bed fusion (LPBF), and the geometry of the porous structure was verified by scanning electron microscopy. The results showed that the localized porous structure altered the load distribution between the plate and the bone, resulting in an increase in local stresses in the bone under the investigated loading conditions. These changes indicate an alteration in the mechanical environment within the bone, which may potentially affect conditions related to fracture healing. Among the investigated configurations, the plate with a 10 × 10 mm porous insert demonstrated the most balanced mechanical characteristics in terms of stresses in the implant, stress distribution in the bone, and structural stability. Full article

Desert highways have long been subjected to aeolian sand hazards, and sand accumulation on the pavement significantly weakens the surface texture and deteriorates skid resistance, which has become one of the core contributing factors to traffic accidents on desert road sections. Current research predominantly focuses on the attenuation law of the macroscopic friction coefficient of sand-covered pavements; however, the quantitative correlation mechanism between three-dimensional micro-texture characteristics and skid resistance has not been sufficiently revealed, and there is a lack of high-precision skid resistance prediction methods under multi-condition coupling scenarios. To address the above research deficiencies, this paper takes the asphalt pavement in the Tengger Desert region as the research object. A handheld three-dimensional texture scanning system was employed to acquire the three-dimensional pavement morphology parameters under different sand coverages, and the sideway force coefficient (SFC) was synchronously measured under the corresponding conditions. Through Pearson correlation analysis and dual multiple comparison correction using the FDR-BH and Bonferroni methods, the core influencing indicators were identified. Subsequently, a skid resistance prediction model based on a BP neural network optimized by the particle swarm optimization (PSO) algorithm was constructed and horizontally compared and validated with LSTM and PSO-SVM models. The research results show the following: ① under dry conditions, the root mean square height ($S_q$), peak density ($S_{pd}$), arithmetic mean peak curvature ($S_{pc}$), valley void volume ($V_{vv}$), root mean square slope ($S_{dq}$), and developed interfacial area ratio ($S_{dr}$) are significantly linearly correlated with the SFC, among which $S_q$, $S_{pd}$, $S_{pc}$, and $V_{vv}$ are the core controlling indicators, with the absolute values of their correlation coefficients all exceeding 0.73, and ② the constructed PSO-BP prediction model achieved a coefficient of determination $R^2$ of 0.86093 on the test set, and its prediction accuracy and generalization ability are both superior to those of the LSTM and PSO-SVM models, enabling it to effectively characterize the nonlinear mapping relationship between multiple texture parameters and skid resistance. This study can provide theoretical support and a technical basis for skid resistance evaluation, sand accumulation disaster warning, and scientific maintenance decision-making for desert highways. Full article

Implant-associated infections remain a major challenge in bone-related biomedical applications, where bacterial colonization and biofilm formation can compromise tissue integration and clinical performance. This study reports the mechanochemical synthesis, physicochemical characterization, antimicrobial activity, antibiofilm performance, and short-term fibroblast cytocompatibility of a TiO₂-containing bovine-derived biogenic hydroxyapatite ceramic composite (BHAp-TiO₂). The composite was prepared by high-energy mechanical milling using 10 wt% TiO₂ and characterized by X-ray diffraction, Rietveld refinement, Raman spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. XRD/Rietveld analysis identified a multiphase ceramic composite composed of hydroxyapatite, whitlockite, and rutile TiO₂, with no evidence of Ti⁴⁺ substitution into the hydroxyapatite lattice or detectable anatase within the XRD/Rietveld detection limit. SEM-EDS confirmed the granular agglomerated morphology of the powders and the elemental presence of Ti in BHAp-TiO₂. Compared with pristine BHAp, BHAp-TiO₂ produced a concentration-dependent reduction in AlamarBlue^®-derived bacterial metabolic activity against five clinically relevant planktonic strains. At 200 µg/mL, residual metabolic activity decreased to 10.90–32.90%, depending on the bacterial species, with the strongest response observed for Escherichia coli. In crystal violet assays, BHAp-TiO₂ markedly inhibited Pseudomonas aeruginosa biofilm biomass, reaching 91.9 ± 3.4% inhibition at 200 µg/mL. In NIH/3T3 fibroblasts, BHAp-TiO₂ preserved short-term cytocompatibility after 24 h of direct exposure within the 0.1–100 µg/mL range, with MTT- and AlamarBlue^®-derived responses remaining close to or above the 80% cytotoxicity limit. Overall, BHAp-TiO₂ is best interpreted as a rutile TiO₂-containing biogenic calcium phosphate ceramic composite with enhanced antimicrobial and antibiofilm performance while maintaining short-term fibroblast cytocompatibility under the evaluated conditions. Full article

The Ordovician strata in Northern Tarim host extensively developed carbonate karst reservoirs that contain abundant hydrocarbon resources. However, owing to extreme burial depths, pronounced heterogeneity, and limited seismic resolution within the Tarim Basin, the diagenetic fluid types and their specific influences on reservoir development remain poorly understood. Consequently, this study integrates core observation, thin-section identification (TSI), cathodoluminescence (CL), scanning electron microscopy (SEM), X-ray diffraction (XRD), stable isotopes (C, O, Sr), trace and rare earth elements (REE), fluid inclusion analysis (FIA), and in situ laser U-Pb dating (U-Pb). This multifaceted petrographic and geochemical approach characterizes the macro- and microscopic geological features of these karst reservoirs. By elucidating the types, timing, and phases of diagenetic fluids, this research evaluates fluid-driven impacts on reservoir quality and establishes a comprehensive genetic model for reservoir evolution. Results identify five distinct tectonic fracturing phases. Phases 1, 2, and 4 involved calcite infilling precipitated from seawater and meteoric freshwater, with fluid inclusion homogenization temperatures of 62–87 °C, 57–91 °C, and 94–126 °C, formed during the Caledonian–Hercynian, Early Hercynian, and Indosinian–Yanshanian periods, respectively. Phase 3 featured hydrothermal dolomite infilling during the Hercynian, with fluid inclusion homogenization temperatures ranging from 128 to 163 °C, whereas Phase 5 remained unfilled during the Himalayan. Constrained by the U–Pb age interval of 445.2–436.5 Ma acquired from vug-filling calcite together with cross-cutting petrographic relationships, multi-stage meteoric freshwater dissolution mainly occurred from Middle Caledonian Episode III (447–443.7 Ma) to the Early Hercynian (460–359 Ma). Reservoirs within the Penglaiba–Lower Yingshan Formations underwent a complex evolution comprising syngenetic-to-early diagenetic pore development, Middle Caledonian–Early Hercynian weathering crust karstification and dedolomitization, and Late Hercynian hydrothermal dissolution-infilling, ultimately resulting in the formation of tectonic-karst composite reservoirs. Full article

AZ91D is a lightweight, representative commercial magnesium alloy known for its excellent castability and specific strength. However, the mechanical properties of as-cast AZ91D remain limited by inherent brittleness, relatively low strength, and microstructural inhomogeneity caused by enrichment of secondary phases at grain boundaries. In this study, AZ91D/Csf (short carbon fiber at 0, 2.5, and 5 wt.%) composites were prepared by gravity casting with mechanical stirring, followed by post-casting T4 heat treatment and equal-channel angular pressing (ECAP). Material characterization included optical microscopy (OM), field-emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), uniaxial tensile testing, and microhardness tests. The results demonstrate that T4 treatment reduced intermetallic β-Mg₁₇Al₁₂ segregation and homogenized the microstructure, whereas one-pass ECAP further refined the grains. Mechanically, these two processes enable the (AZ91D/5 wt.% Csf) composite to achieve higher ultimate tensile strength (280.7 MPa by T4/280.2 MPa by T4 + one-pass ECAP), larger maximum strain (12.1% by T4/5.4% by T4 + one-pass ECAP), and higher microhardness (63.9 HV by T4/78.1 HV by T4 + one-pass ECAP). Compared to as-cast AZ91D, these findings demonstrate that T4 treatment provides a better strength–ductility balance via solid solution, whereas one-pass ECAP preferentially enhances surface microhardness by plastic deformation. This study highlights the performance of AZ91D/Csf composites and their potential for lightweight, high-strength-demand applications. Full article

High-speed steel (HSS) substrates were coated with layers of CrC, NbC, TiC, and VC using thermo-reactive diffusion (TRD) at 900 and 1100 °C for 2 and 4 h. The experimental design was implemented according to the Taguchi L8 orthogonal array. Coating morphology was investigated using scanning electron microscopy (SEM) combined with energy-dispersive spectroscopy (EDS), while phase composition was determined by X-ray diffraction (XRD). The contributions of coating type, temperature, and time to coating thickness, microhardness, coefficient of friction, and specific wear rate were evaluated using analysis of variance (ANOVA). SEM and EDS analyses showed that coatings produced at lower temperatures and shorter times exhibited irregular layer thickness, localized porosity, and irregular carbide formation, while coatings applied at higher temperatures and longer times were associated with smoother layers, more homogeneous element distribution, and improved surface morphology. XRD analyses confirmed that the coatings consisted of dense carbide phases and that the chemical composition of the substrate affected the resulting coating phases. Phase composition analysis revealed the presence of phases such as Cr₇C₃ and Cr₂₃C₆ in the coatings. It was observed that coating thickness and hardness generally increased with increasing temperature and coating time. Variance analysis showed that the highest additive ratios in terms of coating thickness belonged to coating type (45.13%) and temperature (42.34%), while in terms of microhardness, temperature (39.92%) and coating type (37.77%) had higher additive ratios. The highest additive ratio in terms of friction coefficient was obtained with coating type (87.98%), while temperature (34.99%) and coating type (33.37%) were determined as the parameters with the highest additive ratios in terms of specific wear rate. NbC coatings generally showed lower performance values compared to other coating types under the examined experimental conditions. Full article

Population immune pressure from vaccination and prior infection continues to drive the evolution of SARS-CoV-2. Systematic characterization of RBD mutations under complex immune backgrounds is essential for understanding viral adaptation and evolutionary trajectories. Here, we applied a deep mutational scanning (DMS) to comprehensively map the neutralization escape landscape of the Omicron variant JN.1 and its descendant lineage XEC, under immune pressure from individuals who experienced Omicron breakthrough infections following three doses of inactivated vaccines. A neutralization escape map for the single amino acid substitutions in the RBD of JN.1 or XEC was generated, and the escape efficiency of each mutation was determined. The results show that RBD escape mutations are hierarchically organized: low-intensity signals are widespread, whereas high-intensity escape is confined to a few key sites. These escape mutations are not confined solely to the receptor-binding motif (RBM) but are broadly distributed across the entire RBD. Many escape sites could accommodate multiple amino acid substitutions. Integration of DMS data with genomic surveillance of circulating variants from 2024 to 2025 revealed significant overlap between experimentally identified escape sites and mutations observed in natural isolates. This overlap increased substantially in 2025, with site concordance rising from 27.17% and 26.81% to 45.09% and 47.10% for JN.1 and XEC, respectively. The natural prevalence of these escape mutations is further shaped by factors such as receptor-binding affinity, protein stability, and epistatic interactions. Overall, our findings suggest that SARS-CoV-2 antigenic evolution follows the pattern of multiple pathways within a constrained space, providing new insights into the adaptive mechanisms of Omicron-derived variants under hybrid immune pressure. Full article

Random communication delay, delay jitter, and packet loss cause remote bearing measurements in dual-UAV bearing-only cooperative passive localization to arrive after their generation times. Direct fusion of these historical measurements with current local measurements misaligns the observation rays, platform geometry, and target state. Within the Cubature Kalman filter (CKF) framework, this article constructs a timestamped cache that preserves historical states, measurements, and platform geometry, and investigates two processing strategies. The Predictive Compensation Strategy (PCS) migrates a historical angular innovation to the current geometry and inflates its covariance. Timestamp-Aligned Replay (TSA) activates the historical record at the measurement generation time, restores the corresponding dual-platform observation geometry, and propagates the corrected state to the current time. The evaluation jointly considers the baseline terminal-window error B, average-delay sensitivity S, delay-jitter sensitivity J, and packet-loss response intensity L. Monte Carlo communication scans show that, under the tested conditions, TSA achieves lower terminal-window localization error and a more favorable overall communication-disturbance response than CDS and PCS, while incurring higher average computational cost. Full article