Search Results (659)

Fuzz buttons are formed by interweaving and compacting fine metallic wires, resulting in a highly porous architecture with complex internal contact interactions. Their compressive behavior is governed by the evolution of wire–wire contacts, frictional sliding, local bending, and plastic deformation, which cannot be adequately captured by conventional homogenized models. To address this limitation, a process-informed finite element modeling approach based on virtual fabrication is proposed. First, the spatial trajectories of 24 beryllium copper wires are generated using a parametric three-dimensional weaving algorithm and smoothed by cubic spline interpolation to obtain continuous wire centerlines. The resulting preform is then virtually compacted to reconstruct the densified wire network and its contact topology. The model employs a globally controlled solid-element mesh, a penalty-based general contact algorithm, a Coulomb friction model, and an explicit quasi-static solution scheme. The size-dependent plastic response of the fine wires is further incorporated through a Nix–Gao-based correction to the constitutive relation. The model is validated against quasi-static compression experiments at compressive strains of 15%, 20%, and 25%. The relative errors in the predicted peak forces are 2.12%, 5.65%, and 6.81%, respectively, while the corresponding coefficients of determination for the force–displacement curves are 0.984, 0.970, and 0.973. The model successfully reproduces the nonlinear loading–unloading response and hysteretic energy dissipation over the investigated strain range. The proposed approach provides a physically grounded numerical framework for predicting the compressive behavior of fuzz buttons and investigating the mesoscopic mechanics of complex interwoven wire networks. Full article

Early engagement with psychotherapy is a public mental health issue because potential patients’ first appraisals of psychological care may shape treatment expectations, willingness to continue, and openness to receiving effective support. In first-contact therapeutic encounters, people respond not only to the content of a therapist’s intervention but also to the interpersonal meaning conveyed by the therapist’s response style. Guided by a recognition–resistance framework and models of narcissistic self-regulation, we examined how therapist response style and trait narcissistic admiration and rivalry shape early appraisals of psychological care in a vignette-based psychotherapeutic encounter. In a between-subjects vignette experiment, Hebrew-speaking adults in Israel (N = 972) were randomly assigned to read a validation-based, recognition-supportive, autonomy-supportive therapist response or a more directive and challenging response to the same clinical scenario. Participants then reported perceived recognition, autonomy-related resistance, anticipated alliance, therapist credibility, expected benefit, and willingness to continue. The validation-based response elicited higher perceived recognition, lower autonomy-related resistance, and greater willingness to continue. Perceived recognition and autonomy-related resistance mediated the effects of response style on all therapy-related outcomes. Narcissistic admiration predicted more favorable appraisals, and narcissistic rivalry predicted lower recognition and greater resistance, but neither moderated style effects nor indirect pathways. Recognition and autonomy-related resistance emerged as proximal appraisal pathways linking therapist response style to anticipated engagement with psychological care in this analogue vignette context. However, the predicted moderation and moderated-mediation effects involving narcissistic admiration and rivalry were not supported. This pattern suggests that, in the present design, admiration and rivalry functioned more as general appraisal orientations than as differential-susceptibility moderators of therapist response style. The moderated-mediation component of the recognition–resistance framework should therefore be regarded as unsupported pending independent replication and more ecologically valid tests. These findings position first-contact therapist communication as a candidate modifiable feature of public mental health engagement, with implications for future research on treatment uptake, early retention, trust in services, and access to effective psychological care. Full article

To achieve non-contact and continuous monitoring of body length in Micropterus salmoides and overcome the stress damage and subjective error associated with traditional manual measurement, this paper proposes an improved YOLOv8-based multi-target tracking framework for intensive recirculating aquaculture systems. The system employs a geometric measurement framework based on monocular vision that achieves conversion from pixel coordinates to actual body length through camera calibration, water-surface refraction correction, and pose projection correction. Under a collaborative optimization framework integrating detection and tracking, the model incorporates multi-scale feature enhancement, lightweight re-identification (ReID), and a robust data association mechanism, which improves system stability under conditions of high fish density, variable illumination, and turbid water. A shallow feature fusion path is introduced to enhance small-target perception, and a MobileNetV3_ReID model is adopted to extract highly discriminative appearance features, which improves identity consistency while maintaining model compactness. In the data association stage, a hybrid cost matrix integrating IoU, cosine similarity, and motion consistency is constructed, and optimal matching is realized through the Hungarian algorithm. Dynamic threshold adjustment and an exponential moving-average feature-update strategy are introduced to effectively suppress identity switching. Experiments were conducted on an overhead video dataset of Micropterus salmoides collected at a recirculating aquaculture system facility. The results show that the proposed method achieves 82.7% mAP50 while maintaining a real-time throughput of 88 FPS, with MOTA reaching 76.9% and IDF1 reaching 81.5%—the latter representing an improvement of 3.2 percentage points over BoT-SORT and 5.3 percentage points over the YOLOv8 baseline tracker. The number of identity switches (IDSW) decreased from 89 in the baseline configuration to 39, a reduction of 56.2%. Crucially, these component-level improvements translate into a body length error (BLE) of 5.2 ± 1.8% (MAE = 1.35 cm, Pearson r = 0.972), representing a 38.8% improvement over the baseline BLE of 8.5% and satisfying the 5–10% tolerance required for aquaculture growth monitoring. Ablation analysis confirms that both detection enhancements (contributing −1.3% BLE) and tracking optimizations (contributing −2.0% BLE) are necessary to achieve this application-level accuracy. Full article

To accurately characterize the effects of polydisperse particle sizes, multimineral composition, and angular morphology on the packing structure of lunar regolith, a two-dimensional sequential packing method based on random convex octagons is proposed. The method establishes a particle parameter system using data from Chang’e-5 samples and generates polygonal particle models with controllable angular features through radial perturbation. On this basis, a sequential packing algorithm based on available arc analysis is developed. Non-overlapping particle insertion is achieved via geometric envelope constraints, and progressive filling is realized through effective arc sampling. Meanwhile, a packing control coefficient is introduced to enable continuous regulation of packing density. Results show that the proposed method can generate highly dense particle assemblies, with a maximum packing density of 0.8757 and an average coordination number of approximately 3.18, capturing the structural characteristics of “high compactness–low coordination number” in polydisperse angular particle systems. The algorithm exhibits a computational complexity of O(N^1.628), demonstrating high efficiency. Furthermore, contact area and contact strength are quantitatively characterized through contact contour extraction and an equivalent bow-shaped model. Radial distribution function and contact statistics indicate that the generated structures possess good randomness and physical consistency. The proposed method provides a high-fidelity mesoscopic structure generation approach for discrete element modeling (DEM) of lunar regolith and establishes a reliable foundation for analyzing the mechanical behavior of granular systems. Full article

Petrophysical parameters of rocks and ores, influenced by composition, porosity, temperature, and pressure, are generally distributed uniformly or continuously in space—relatively homogeneous within individual geological units and varying smoothly across stratigraphic transition zones and contact boundaries. Based on this geological characteristic, this paper establishes a three-dimensional (3-D) piecewise linear continuous spectral parameter model to compute forward responses of apparent spectral parameters under low-frequency current excitation. The calculation follows a two-step workflow: finite-element forward simulation of multi-frequency apparent complex resistivity, followed by recursive inversion to obtain apparent spectral parameters. The subsurface medium is discretized with hexahedral meshes, with four Cole–Cole parameters (zero-frequency resistivity, chargeability, time constant, and frequency exponent) assigned to each mesh node. Linear interpolation is adopted for complex resistivity and potential within each element, ensuring piecewise linear continuity of both physical properties and simulated fields. To improve accuracy, the total complex potential is decomposed into a primary field from the source current and a secondary field from complex conductivity variations, and the corresponding boundary value problem and variational form are derived. On this basis, we implement the finite-element algorithm for 3-D piecewise linear continuous media and the recursive inversion algorithm for spectral parameters, and develop an interactive 3-D SIP forward modeling program. Comparison with analytical solutions for a continuous layered model shows good agreement, with relative errors below 1.5% for the real part and 3.8% for the imaginary part of apparent complex resistivity. Two numerical cases—a cubic anomaly in homogeneous half-space and a sandbox model—further verify the performance of the proposed method. Full article

Background/Objectives: Primary care clinics increasingly receive urgent and semi-urgent requests from patients who may otherwise attend emergency departments or urgent care centres when timely appointments are unavailable. This article describes and evaluates the Cranston Ridge Medical Clinic Registered Nurse Prescriber-led Triage–Treatment–Continuity model in Calgary, Alberta, Canada. Methods: The manuscript is reported as a single-clinic practice innovation and service evaluation using aggregate, non-identifying operational data from 1 April 2025 to 31 March 2026. The model combines medical office assistant emergency recognition, RN prescriber-led stability assessment, traffic-light urgency classification, a booking-contingency algorithm, clinical support tools, diagnostic test ordering and prescribing within authorized scope, safety-netting, and communication with the patient’s primary care provider through the electronic medical record. Results: During the evaluation period, 5032 pathway contacts were managed. Of 5030 stable contacts assigned traffic-light categories, 4950 (98.4%) were Code Red same-day contacts, 55 (1.1%) were Code Yellow 24–48-h contacts, and 25 (0.5%) were Code Green non-urgent contacts. Two contacts triggered EMS/911 activation before traffic-light classification. Following RN prescriber assessment, 9 emergency department referrals, 2 urgent care referrals, 85 primary care provider follow-up appointments, and 5 patient refusals were recorded; no safety incidents or complaints were recorded in the aggregate monitoring dataset. A CIHI-informed 15% reference scenario corresponds to approximately 755 potentially avoided ED/UCC visits, but no confirmed diversion or monetary savings are claimed. Conclusions: The model reframes triage as an integrated primary care intervention that combines assessment, treatment, escalation, and continuity. Further ethics-approved research is required to evaluate patient-level outcomes, safety, confirmed health-system utilization effects, stakeholder experience, and cost-effectiveness. Full article

To address the issues of local high temperatures, thermal stress concentration, and the susceptibility to spalling of homogeneous ceramic coatings in disc brakes under high-frequency thermal–mechanical cyclic loading, this paper proposes a surface design scheme incorporating a functionally graded material (FGM) coating along the thickness direction. A three-dimensional thermal frictional contact model of a graded coated brake disc with continuously varying material properties (silicon carbide/gray cast iron) along the thickness direction is established by developing user subroutines on the Abaqus finite element platform. The effects of exponential, power-law, and trigonometric gradient distributions on the transient temperature and stress fields are systematically compared. The results indicate that the high thermal conductivity silicon carbide coating significantly reduces the disc surface temperature; however, a homogeneous coating induces interfacial thermal stress concentration due to a sudden stiffness mismatch. The graded design effectively mitigates the stress concentration through a smooth transition of material properties. Taking the power-law function (n = 1.5) as an example, this design not only significantly reduces the maximum disc surface temperature but also limits the residual equivalent stress at the end of braking to 245 MPa, which is approximately 24.8% lower than that of the homogeneous coating (325.8 MPa). The study demonstrates that the gradient function exerts a stronger regulatory effect on the stress field than on the temperature field, meaning the two cannot be simultaneously optimized. Nevertheless, exponential functions and power-law functions with small exponents can achieve a favorable balance of thermal–mechanical performance. This research reveals the mechanism by which thickness-direction gradient distributions regulate thermal–mechanical coupling behavior, providing a theoretical basis for the gradient design of thermal fatigue-resistant friction components. Full article

Traditional dynamic community detection methods often struggle to simultaneously preserve local structural consistency, capture global topological relationships, and efficiently adapt to continuous graph updates in large-scale environments. To solve these limitations, this paper proposes a novel dynamic community detection framework called Embedded Clustering Boundary Refinement (ECBR). The proposed method integrates unsupervised GraphSAGE and Node2Vec embeddings to jointly capture local neighborhood aggregation patterns and global structural equivalence among nodes. The generated embeddings are fused through feature concatenation and z-score normalization to construct a unified latent representation space. Subsequently, Mini-Batch KMeans clustering is employed to efficiently generate the initial community structure while maintaining scalability for large-scale graphs. To further improve partition quality, ECBR introduces a boundary-aware refinement mechanism that identifies structurally ambiguous nodes using neighborhood consistency analysis and reassigns them according to embedding-space similarity. In addition, the framework incorporates an adaptive dynamic update strategy capable of distinguishing between major topological shifts and localized structural changes. Significant graph perturbations trigger complete model retraining, whereas minor modifications are handled through computationally efficient incremental updates on local subgraphs. Experimental evaluations were conducted on synthetic LFR benchmark networks and several real-world dynamic interaction datasets, including high school, workplace, and hospital contact networks. The results demonstrate that ECBR consistently outperforms several state-of-the-art methods, including QCA, DyPerm, DCDID, IncNSA, and DCDBFE, achieving better NMI and ARI scores across diverse network conditions. The experimental findings confirm that ECBR provides a scalable, robust, and highly effective solution for dynamic community detection in evolving large-scale social networks. Full article

Localized stress concentration and defect accumulation are prone to occurring during metal spinning because of the coupled effects of complex loading and interfacial friction. In this study, a molecular dynamics model of metal spinning was established to investigate the effects of process parameters and temperature on the mechanical response, material flow, contact loading, and dislocation evolution behavior within the contact zone. The results indicate that the optimal deformation coordination is achieved with an arc radius of 25 Å, an indentation depth of 8 Å, and a tangential velocity of 1.5 Å/ps. Analysis of the normal and tangential forces shows that the normal load is rapidly established during the indentation stage, whereas the tangential load continuously increases with material shear transport. Both loads decrease significantly with increasing temperature. Elevated temperature effectively suppresses dislocation accumulation and simplifies the dislocation structure, causing the plastic deformation behavior to gradually transition toward a dominant primary slip-system mode. This study reveals the local deformation and dislocation evolution mechanisms during spinning and provides theoretical guidance for the process optimization of thin-walled spinning components. Full article

This study presents a systematic terahertz time-domain spectroscopy (THz-TDS) investigation of hardened cement paste, framed as a complex-optical measurement in which the real and imaginary parts of the response probe distinct microstructural attributes. Transmission-mode measurements were made on pastes with water-to-cement (w/c) ratios of 0.3, 0.4, and 0.5 at curing ages of 7, 14, 28, and 56 days. The effective refractive index, obtained from the time-domain pulse delay (7, 28, and 56 days, paired with mercury intrusion porosimetry), correlates strongly and linearly with porosity over nine porosity-paired conditions spanning 15.1–30.4% (pooled R² = 0.94, p < 0.001). In a quasi-static effective-medium framework—where the pores a re far smaller than the THz wavelength—this reflects the dependence of the effective permittivity on the solid volume fraction: the Bruggeman model outperforms the Maxwell–Garnett model, and all data fall within the Wiener bounds, lying close to the upper bound, indicating a continuously connected solid matrix with isolated pores. Cross-validated porosity estimation is reliable to within about ±2 percentage points (refractive-index uncertainty ±0.02–0.04). The absorption follows a power law (β ≈ 1.0–1.3) characteristic of disorder-activated vibrational absorption, in which the loss of long-range order in the amorphous C–S–H relaxes the crystalline selection rules and couples the THz field to the full vibrational density of states. The refractive index (structure-sensitive, governed by volume fraction) and the absorption (material-sensitive, governed by solid disorder; estimated loss tangent of order 0.1) thus form two complementary channels. Combining the THz-derived porosity with the Powers hydration model gives a degree of hydration consistent with literature ranges—an indirect comparison rather than direct validation. These results establish THz-TDS as a non-contact, non-ionizing technique for rapid porosity estimation and hydration assessment of cementitious materials. Full article

Background/Objectives: First-generation CDK4/6 inhibitors (palbociclib, ribociclib, abemaciclib) target the conserved ATP-binding pocket of CDK4 and, despite clinical success, are limited by acquired resistance and insufficient exploration of alternative regulatory sites. This study aimed to identify a putative allosteric small-molecule candidate at the CDK4 αE-helix–Cyclin D1 α1-helix protein–protein interaction (PPI) interface within the CDK4/Cyclin D1/p21 ternary complex using RapidFunnel-AI, a decision-interpretable virtual-screening pipeline. Methods: Starting from 50,000 ChEMBL 33 molecules, the pipeline sequentially applied a Q-Fold/RapidFunnel topological Tanimoto scan based on clinical CDK4/6 inhibitor motifs, fragment-level electronic-property enrichment, ADMET/PAINS filtering, dry Vina-GPU docking, hydration-mediated AutoDock-GPU (Version 1.6) docking, explicit-solvent molecular dynamics, contact-retention analysis, and MM-GBSA energy decomposition. The Q-Fold Thermo-Core surrogate model provided fragment-level enrichment, predicting the HOMO–LUMO gap (R² = 0.93) and isotropic polarizability (R² = 0.98) on QM9. Candidate selection did not rely on the lowest docking or MM-GBSA score alone, but on pose persistence, contact continuity, and energy-component consistency. Results: The workflow reduced the initial library to 43 topologically prioritized candidates, 25 ADMET/PAINS-filtered ligands, and 9 docking-derived complexes for MD validation. Ligand_020 emerged as the only candidate that preserved a persistent binding mode at Site 2 during a 500 ns simulation—an interface engagement reproduced across three independent 500 ns replicates with no full dissociation in any replicate—with a protein Cα RMSD of 2.88 ± 0.32 Å, a ligand heavy-atom RMSD of 3.56 ± 0.28 Å, and a van der Waals-dominated MM-GBSA profile (ΔGbind = −28.23 ± 3.57 kcal/mol). In contrast, palbociclib and ribociclib, forcibly placed at Site 2 as negative controls, lost most initial contacts within 5 ns and tended to detach despite more favorable MM-GBSA values. Conclusions: These results suggest that single-score docking or MM-GBSA ranking can generate false positives at shallow PPI interfaces. By integrating AI-assisted prioritization, multipocket docking, explicit-solvent MD, contact-retention analysis, and energy-component consistency, RapidFunnel-AI nominated Ligand_020 as an experimentally testable putative allosteric hit targeting the CDK4/Cyclin D1 interface, offering a reusable platform for PPI-focused oncological drug discovery. Full article

Robotic belt grinding is an effective and widely adopted finishing method for superalloys, offering notable advantages such as high material removal capability, low heat input, and reduced workpiece damage. In addition, robots can readily integrate multiple sensors—such as infrared radiation cameras, force sensors, and high-speed cameras—which facilitate real-time monitoring of the grinding process and thereby enhance grinding quality control. With the establishment and continuous advancement of large-scale artificial intelligence (AI) data models, new breakthroughs have emerged in the optimization of robotic grinding processes. Owing to its dexterous workspace and advantages in high flexibility and cost-effectiveness, robotic belt grinding has become a critical process for the precision forming of complex curved components such as aero-engine blades and blisks. However, factors such as the limited absolute accuracy of industrial robots, time-varying grinding contact states, and significant transient boundary effects make it difficult for the current constant-parameter open-loop machining mode to simultaneously meet the demands for high material removal efficiency and high surface integrity on complex profiles. This paper systematically reviews the technologies for precision control and process optimization of robotic belt grinding aimed at pointwise precise material removal. First, the structural composition of the robotic belt grinding system and the material removal mechanism are analyzed. Then, centered on the compensation concept, a hierarchical progressive technical framework is outlined, covering geometric calibration compensation, force/position hybrid online compensation, transient entry boundary compensation, and system-level comprehensive compensation of multi-source errors, with a comparison of the applicable scenarios and the effects on shape and property control at each level. Furthermore, under the support of effective compensation, the collaborative optimization methods of material removal modeling, multi-objective optimization of process parameters, force-constrained trajectory planning, and intelligent adaptive processes are elaborated. Finally, current technical bottlenecks are summarized, and future trends in next-generation adaptive grinding technology driven by digital twins and embodied intelligence are envisioned. This review aims to provide a systematic theoretical reference for the high-precision and intelligent upgrading of robotic precision grinding systems. Full article

The documentation and reconstruction of fragile underwater organic artifacts remain among the most challenging tasks in digital heritage practice. This study presents a conservation-first, contact-minimizing protocol applied to a rare Byzantine leather bag recovered from the commercial port of Rhodes, Greece. Due to its incomplete preservation and structural instability, exclusively non-invasive methodologies were employed. High-resolution close-range photogrammetry and structured-light 3D scanning were integrated to capture both micro-topographic detail and metrically stable geometry. Quantitative deviation analysis (nearest-neighbor cloud-to-mesh distances) indicated that most geometric differences remain below 0.5 mm. The resulting models were processed through controlled mesh optimization, UV remapping, and conservation-oriented digital completion workflows. In addition, radiance field visualization techniques such as Gaussian Splatting were explored as complementary visualization approaches for incomplete geometries. These methods were evaluated primarily in terms of visual continuity and interpretative support rather than as reconstruction tools. The study demonstrates that the integration of photogrammetry, structured-light scanning, and Gaussian Splatting can significantly enhance the documentation and visualization of fragile underwater organic heritage. At the same time, it highlights the necessity of methodological transparency and ethical framing when incorporating probabilistic reconstructions into conservation workflows. Full article

To address the significant differences in the structure and mechanical properties of various components of the Shanghai bok choy plug seedling, and the lack of an accurate and reliable discrete element model of the whole plant and key bonding parameters in the simulation of the automatic transplanting process, a 128-cell Shanghai bok choy plug seedling was selected as the research object. Morphological, physical, mechanical, and contact property tests were systematically conducted to obtain the basic parameters of the seedling pot, leaf, petiole, and stem. A whole-plant discrete element model of Shanghai bok choy plug seedling, consisting of the seedling pot, leaf, petiole, and stem, was established using a combined method of component-wise modeling and overall reconstruction. The Hertz–Mindlin (no slip) and Bonding V2 contact models were jointly adopted to characterize interparticle contact, continuous structural behavior, and failure characteristics. Taking the ultimate compressive failure load of the seedling pot, leaf compression density, ultimate bending failure load of the petiole, and ultimate bending failure load of the stem as response indices, significant parameters were screened using the Plackett–Burman test, the optimization ranges were determined through the steepest ascent test, and the key bonding parameters were optimized and calibrated using the Box–Behnken response surface test. The results showed that the relative errors between the simulated and experimental values of the ultimate compressive failure load of the seedling pot, leaf compression density, ultimate bending failure load of the petiole, and ultimate bending failure load of the stem after optimization were 1.19%, 1.13%, 0.99%, and 0.72%, respectively, indicating that the established model can accurately characterize the mechanical response of the constituent parts of Shanghai bok choy plug seedling. The results provide a basis for discrete element simulation of the interaction between Shanghai bok choy plug seedling and key components of automatic transplanting equipment, as well as for the design optimization of automatic transplanting equipment. Full article

Journal bearings are prone to failure due to lubrication state degradation under extreme operating conditions. To address the unclear transition mechanism and undefined state boundaries under insufficient lubrication, a coupled tribological model of engine journal bearings was established. Through parameter analysis and dynamic failure mechanism study, the effects of radial clearance, temperature, rotational speed, load, and surface roughness on the lubrication state transition were revealed. The results indicate that radial clearance, oil temperature, rotational speed, applied load and surface roughness are all decisive factors for lubrication transition, and every parameter has its unique critical threshold; once exceeding the limit, the oil film integrity is damaged and the lubrication rapidly shifts from mixed lubrication toward boundary lubrication. After crossing critical thresholds, aggravated asperity contact further triggers continuous temperature rise and viscosity reduction, which may induce closed-loop thermal deterioration and eventually accelerate bearing failure. The research findings provide a theoretical basis for robust design and operational safety monitoring of journal bearings. Full article