Search Results (3,958)

Complex nonlinear physical systems can exhibit dynamic responses that provide useful resources for information processing. In this study, an electrical circuit-based multiple-electron model was developed and implemented in a random network to investigate its dynamic electrical properties and information-processing capability. The model represents discrete electron transfer and charge accumulation using tunnel junctions and charge-storage nodes and was constructed as a two-dimensional random network inspired by carbon nanotube/polyoxometalate (CNT/POM) networks. The network exhibited time-varying current responses under a constant voltage and nonlinear and hysteretic current–voltage characteristics. The hysteresis became more pronounced as the number of charge-storage nodes increased. The information-processing capability of the network was further investigated using delayed XOR and sine waveform generation tasks. The delayed XOR task was achieved using the integrated squared current response, whereas a target sine waveform was reconstructed from multiple network responses under a constant voltage input using a linear readout, yielding a coefficient of determination of 0.816. These results demonstrate that the proposed multiple-electron network exhibits nonlinear and history-dependent electrical dynamics and can support information-processing tasks. Full article

This study presents a full-scale steady CFD methodology for evaluating flow quality in a large-scale low-speed wind tunnel (8 m × 6 m test section, 130 m/s). The tunnel geometry is resolved at 1:1 scale, the damping screens and honeycomb are modeled as porous media, and results are validated against wind tunnel test data and the GJB 1179A-2012 acceptance criteria. The baseline configuration reproduces the axial static pressure gradient within the acceptance criterion but substantially overpredicts turbulence intensity, dynamic pressure coefficient, and both velocity direction deviation angles. Damping screens, modeled as porous jumps, provide the dominant correction, bringing all metrics within the acceptance limits. Adding honeycomb yields incremental improvement: porous zone modeling preserves or improves all metrics, whereas a porous jump representation pushes velocity direction deviations beyond the limit. Between RNG k-ε and SST k-ω, only turbulence intensity is closure-dependent, with RNG k-ε closer to experiment. At Ma ≈ 0.38, compressibility does not alter the flow quality assessment, confirming that incompressible assumption is sufficient. By replacing costly physical trials with a validated CFD workflow, these findings provide a practical, resource-efficient reference for the CFD-based evaluation, design, and retrofit of wind tunnel infrastructure that underpins renewable-energy and energy-efficiency research. Full article

In cold and humid regions, icing events often occur on wind turbines. The phenomenon changes the profile of the aerodynamic airfoil and reduces the power generation efficiency of wind turbines. In the present study, icing tests were conducted in an icing wind tunnel based on NACA0018 airfoils made of fiber reinforced plastics (FRP) and aluminum alloy to investigate the effects of material type and wind speed on the characteristics of icing, including the icing area, the thickness of ice and the adhesive strength of ice. The experimental results indicated that the types of ice on the FRP airfoil and aluminum alloy airfoil were mixed ice and rime ice, respectively. The icing area increased linearly with icing time. The aluminum-alloy airfoil exhibited greater ice accretion at 6 and 10 m/s, whereas the FRP airfoil showed greater ice accretion and a broader ice-covered region at 14 m/s. The FRP airfoil also had a higher adhesive strength. The research in the present study provided an experimental foundation for anti- and de-icing technology development of wind turbine blades. Full article

Underground mine object detection is challenged by low illumination, blur, dust scattering, and repetitive tunnel clutter, which jointly corrupt backbone features, entangle DETR queries, and weaken localization for small objects. Existing enhancement-based and detector-internal methods do not explicitly propagate degradation reliability across features, decoder queries, and box refinement. We propose Spectral-DETR, a detector-internal reliability framework built on RF-DETR. Its central design is a cross-stage reliability pathway that connects Degradation-Aware Frequency Decomposition (DAFD), Degradation-Adaptive Query Contrastive Denoising (DQCD), and Salience-Calibrated Uncertainty with Learned Uncertainty Estimation (SCU+LUE). On Mine-Objects (14 classes, 3081 images), Spectral-DETR achieves an average precision of 0.917 at an intersection-over-union threshold of 0.5 and 0.493 when averaged over thresholds from 0.5 to 0.95, exceeding YOLOv9m by 1.6 and 0.8 percentage points, respectively, under the dataset-specific evaluation protocol. In controlled RF-DETR validation, the three reliability stages improve these two measures from 0.883 to 0.913 and from 0.472 to 0.486, respectively. Spectral-DETR obtains corresponding values of 0.848 and 0.571 on ExDark and 0.973 and 0.495 on ScienceDB. DQCD and SCU remain training-only losses with no inference cost. Full article

The tunnel portal section is one of the most seismically vulnerable parts of a tunnel, where strong earthquakes may trigger slope instability and induce plastic damage in the tunnel lining. Based on viscous-spring artificial boundary theory, a seismic oblique-incidence method applicable to tunnel portal sections is developed by incorporating the effects of slope topography. A three-dimensional finite element model is then established to investigate the seismic response and damage mechanisms of the tunnel portal section subjected to obliquely incident SV waves. The numerical calculation results in this study indicate that fully connected plastic deformation zones eventually develop in both the original slope site and the slope site with a tunnel structure, leading to slope instability characterized by downward sliding of the rock mass along a slip surface. However, in the presence of a tunnel structure, plastic deformation initiates simultaneously at the slope toe and near the tunnel portal. The maximum plastic strain is concentrated near the tunnel portal. Both topographic amplification and the accumulation of sliding debris markedly aggravate lining damage. The seismic-wave incidence angle, ground conditions and seismic-wave spectral characteristics all have pronounced effects on plastic deformation in both the slope site and tunnel lining at the tunnel portal section. In addition, tensile damage is more pronounced and extends over a wider area than compressive damage. At shear-wave velocities of 450–550 m/s in the upper soft-rock site, the damage zone is approximately two to three times the horizontal projection length of the slope, which is identified as the primary damage zone and should be regarded as a key seismic fortification area in tunnel design. Full article

Mobile networks have become targets of sophisticated cyber attacks. Critical vulnerabilities persist in the General Packet Radio Service Tunneling Protocol (GTP). Signature-based Intrusion Detection Systems (IDS) are inadequate against zero day exploits and novel attack patterns, necessitating more adaptive approaches. We propose GTP-AEGIS (Adaptive Ensemble with Gated Input Selection), a hybrid IDS that integrates signature-based detection with a CatBoost gradient boosting classifier via a Selective Heterogeneous Ensemble (SHE) framework. An Input-Dependent Confidence Gate (IDCG) applies a per-sample priority rule over CatBoost, a NearestCentroid Rule Engine (NCRE), and a signature pathway. A real Suricata engine detects attacks with 100% precision but only 69.2% binary recall when run standalone; within the ensemble, the signature role is played by an idealized Signature-Detection Surrogate (SDS), so the reported ensemble gains are upper bounds. On the evaluated GTP-U dataset, GTP-AEGIS reaches accuracy above 90% with 10% of the training data and raises recall for the rare invalid-TEID class from 48.9% to 64.4%; this improvement comes from the signature pathway rather than the NCRE, and the aggregate accuracy gain is not statistically significant after correction for multiple comparisons. All accuracies are obtained under a packet-level split, which a group-aware comparison shows to be optimistic by approximately 19 percentage points. The model flags 81 to 100% of packets from unseen attack families as non-normal, although this does not constitute unknown-class recognition. We report the limits of signature-only detection and of packet-level evaluation alongside the gains. Full article

Intercellular communication across cancer cells and the tumor microenvironment (TME) is essential for tumor growth, invasion, metastasis, and therapeutic resistance. Traditionally, these interactions have been viewed through the lens of diffusible signaling molecules and extracellular vesicles. However, growing evidence supports an additional paradigm in which specialized cytoskeleton-based membrane extensions, like tunneling nanotubes (TNTs), tumor microtubes (TMs), and cytonemes, mediate direct, contact-dependent communication between cells. This review examines the emerging roles of these cellular extensions in cancer biology, with a particular emphasis on cytonemes, long specialized signaling filopodia that facilitate transport and reception of signaling ligands and receptors. Cytonemes are interwoven with developmental signaling pathways, which are frequently reactivated in cancer, promoting tumor progression. We discuss cytoneme pathology in cancer, with specific examples in growth, stemness, invasion, and microenvironmental remodeling. These extensions represent an unexplored facet of tumor biology and a promising avenue for therapeutic intervention. Full article

Purpose: In a relatively new concept of individualised ACL reconstruction, the restoration or matching of the native ACL footprints at both the tibial and femoral insertions might be sufficient as a surgical objective. This study aimed to determine whether ACL graft size relative to the native ACL tibial footprint influences the rate of graft failure in a Singaporean Asian population. Methods: A retrospective study of all consecutive patients who underwent primary hamstring autograft ACL reconstruction over a 3-year period at a tertiary referral centre was performed. Baseline anthropometric data and native ACL tibial footprint area from pre-operative MRI scans were collected. Graft area was calculated based on the graft tunnel diameter. ACL graft failures were diagnosed clinically and confirmed radiologically. Multivariable analyses were performed using pre-specified variables based on the literature. Results: This cohort comprised 240 patients with a mean age of 24.4 years. There were a total of seven graft failures (2.92%), with two patients undergoing revision surgeries. There was no association between graft-to-footprint ratios and failure rates (71.9 vs. 80.2%, p = 0.386). There were no other significant predictors of graft failure. There was no statistically significant difference in graft failure rate between grafts <8 mm and ≥8 mm (p = 1.00). Gender, but not the graft-to-footprint ratio, was a significant predictor of graft size. Conclusions: No statistically significant association was identified between graft-to-footprint ratio and early graft failure. However, the low event rate and short-term follow-up limit definitive conclusions. Full article

The loss of sand foundation often induces differential settlement in immersed tunnel segments, potentially causing structural damage and reducing structural resilience. Accurately assessing the damage characteristics and their effects on resilience during sand foundation loss is essential for ensuring tunnel safety. This study adopts a typical immersed tunnel project as a case study. Long-term structural deformation data acquired by distributed optical fiber sensing technology and sand foundation detection data are adopted to analyze the response characteristics and damage state of the tunnel. A refined three-dimensional tunnel–stratum interaction model is established and validated against monitoring data to investigate mechanical response characteristics, including deformation and bending moment distributions. A redundancy factor is proposed as a quantitative index for tunnel resilience under foundation loss, and a multi-level resilience grading framework is established accordingly. Furthermore, the evolution of tunnel resilience under various displacement recovery ratios, which represent the extent of differential settlement remediation, is investigated using the refined numerical model. Field detection results show that over 50% of the foundation area is affected by loosening or voids. These defects are highly consistent with regions of abnormal structural deformation, leading to a bending–torsional deformation mode, with a maximum joint differential settlement of 106.7 mm. Stress concentration occurs in the tunnel floor above denser sand zones, with a maximum crack width of 0.43 mm. The tunnel is classified as severely damaged (low resilience) based on the proposed standard, with a redundancy factor of 1.59. Bending-torsional deformation and stress concentration are gradually mitigated as the displacement recovery ratio increases. The redundancy factor exhibits a parabolic relationship with the recovery ratio, indicating that tunnel resilience can be restored to a relatively high level when the displacement recovery ratio exceeds 70%. The proposed redundancy factor and grading framework provide quantitative guidance for designing and optimizing resilience improvement strategies following sand foundation loss. Full article

The exchange bias (EB) effect is widely used for stabilizing reference magnetic layers in traditional spintronic devices, yet the EB strength strongly depends on the interfacial quality. Van der Waals antiferromagnets provide an ideal physical platform to study the interfacial magnetic properties for device design in the 2D limit. Herein, we construct CrSBr/Fe₃GeTe₂ heterostructures and investigate the interfacial coupling via first-principles calculations. The results reveal that robust EB coupling in the heterostructure breaks the intrinsic in-plane magnetic limitation of CrSBr, inducing a stable tilted magnetic structure with magnetic moments tilting toward the out-of-plane direction. Such EB-driven magnetic reconstruction dramatically boosts the perpendicular magnetic anisotropy energy to ~6.5 meV/Cr and increases the AFM-FM energy difference to 1.97 meV/f.u. from 0.32 meV/f.u., achieving simultaneous enhancement of magnetic anisotropy and thermodynamic stability. The transport simulations of the CrSBr/Fe₃GeTe₂-based magnetic tunnel junction demonstrate that ~65% TMR can be achieved with the use of such an EB-pinned reference layer. This work clarifies the EB modulation mechanism in 2D CrSBr/Fe₃GeTe₂ heterostructures and provides a reliable theoretical basis for the design of high-performance CrSBr-based reference layers in spintronic devices. Full article

Tunnel excavation in ground comprising a soft upper stratum and a hard lower stratum posed significant challenges, particularly during invert construction using drilling-and-blasting methods, which could disturb the surrounding rock and the installed support system. To address these issues, this study evaluates the feasibility of an alternative support scheme that eliminates the invert by employing expanded arch feet, thereby utilizing the self-bearing capacity of the underlying hard stratum. Both physical model tests and numerical simulations were conducted to compare the structural performance of a conventional lining with an invert against the proposed expanded arch foot lining. Based on the strain measurements and earth pressure cell readings from the physical model tests, together with the internal force and contact pressure results obtained from the numerical simulations, the axial force, bending moment, and contact pressure between the lining and surrounding rock were compared for the two lining schemes. The safety factors were further calculated using the axial force and bending moment at representative sections. The results showed qualitatively consistent trends between the tests and simulations. Compared with the conventional invert lining, the expanded arch foot lining increased the axial force and bending moment at the arch foot and sidewall by 7.95% and 29.60%, respectively, while slightly reducing those at the crown by 4.44% and 3.09%. This indicates that part of the structural demand is transferred from the crown to the arch foot and sidewall, where the enlarged sections provide greater bearing capacity. The contact pressure distributions of the two lining schemes were different. Owing to its closed structural form, the conventional invert lining produced a more favorable contact pressure condition at the sidewall. In contrast, the expanded arch foot lining showed higher safety factors at the arch foot and sidewall, with increases of 89.80% and 36.00% in the model tests and more than 140% in the numerical simulations. Meanwhile, the internal force distributions of the two lining schemes remained generally comparable. These findings indicated that the lining with expanded arch feet provided sufficient structural capacity at critical sections and could serve as a feasible alternative to the conventional lining with an invert, while avoiding the construction-related disadvantages associated with invert excavation. Full article

In this article, general operating principles for modern photocatalytic solar water-splitting systems are reviewed from a physics perspective, and their fundamental limitations are identified. Several potential approaches to overcome the identified limitations are proposed, and a new solar water-splitting system unifying those approaches based on plasmonic metal nanoparticles linked by a metal-insulator junction is described. Based on already existing scientific knowledge, some probable features of the proposed system are briefly discussed, and an initial theoretical analysis of electromagnetic wave-propagation modeling was performed with COMSOL Multiphysics software. In addition, some rectification capabilities for the metal insulator–metal junction embedded in the system are calculated using a simplified Simmons model for tunneling currents. A probable approach for initial system synthesis with existing nanotechnology techniques is proposed, and its limitations and probable bottlenecks are marked. Full article

Reliable perception in smoke-filled tunnels is essential for rescue robots, yet the temporal evolution of LiDAR degradation under realistic smoke conditions is not well quantified. This paper investigates the degradation of LiDAR data induced by environmental factors in a full-scale tunnel experiment involving three smoke scenarios, with real combustion smoke and theatrical smoke. To enable consistent comparison across experiments with different smoke dynamics, an RGB-based visibility reference is first used for temporal alignment across measurements. Based on this alignment, physically interpretable LiDAR indicators, such as intensity attenuation and range-dependent point density loss, are used to characterize smoke-induced changes in the LiDAR data. In addition, an established Deep semi-supervised anomaly detection (DeepSAD) model is employed to derive a continuous data-driven degradation score that indicates deviations from nominal LiDAR range image patterns. The learned score remains stable under clear-air conditions, despite geometric variations caused by object and sensor movement. During smoke exposure, the score increases in all smoke scenarios, although the temporal evolution differs between scenarios. The results show that the degradation score derived from DeepSAD provides a continuous data-driven description of changes in LiDAR range images under smoke exposure. Overall, the study presents an experimental analysis of LiDAR degradation using full-scale tunnel experiments with smoke, reporting physically interpretable LiDAR indicators and a continuous data-driven degradation score. Full article

This paper presents an analytical compact DC current model and a numerical gate capacitance model for p-type cylindrical gate-all-around (GAA) nanowire metal–oxide–semiconductor field-effect transistors (MOSFETs). The models are formulated within the Landauer transport framework, incorporating source-to-drain tunneling (SDT) and quantum statistical charge analysis. The proposed current model is validated against non-equilibrium Green’s function (NEGF) simulations for different channel lengths, nanowire radii, and bias conditions, showing good agreement with the NEGF results in the ballistic limit. The model parameters are separated into physical parameters obtained or calibrated from the NEGF simulations and a single set of global empirical fitting parameters. The latter is extracted once and remains unchanged across the investigated device geometries and bias conditions, allowing its transferability to be evaluated. The compact model is implemented in Verilog-A, and its SPICE compatibility is verified through DC simulations of PMOS inverter circuits. All NEGF comparisons in this work are performed with a zero channel backscattering coefficient corresponding to the ballistic transport limit; validation of the quasi-ballistic regime is left for future work. Full article

Low-carbon construction of highway projects constitutes a critical pathway toward achieving the carbon peaking target in the transportation sector. Existing studies have been unable to simultaneously address the identification of carbon emission sources across different engineering types and the delineation of responsible entities for implementing management strategies. This study employs the emission factor method to conduct construction-phase carbon emission accounting for a mountainous expressway in Guangdong Province, China, and reveals significant clustering characteristics of highway construction carbon emissions along two dimensions: the proportion of total emissions and the proportion of material-derived carbon emission sources. Based on K-Means cluster analysis, nine engineering categories—temporary works, subgrade works, pavement works, bridge/culvert works, tunnel works, intersection works, traffic engineering works, greening works, and other works—are classified into four types. Accordingly, a dual-factor classification framework is established, comprising “Core–Material Dominant (CMD)”, “Core–Mixed Balanced (CMB)”, “Peripheral–Material Dominant (PMD)”, and “Peripheral–Mixed Balanced (PMB)”. Differentiated carbon abatement strategies are proposed for each engineering type, with explicit definition of implementation stages and primary responsible entities. Application of the proposed framework to the case project achieved a total carbon abatement of 5.2% during the construction phase. This research provides systematic methodological support for differentiated carbon emission mitigation in highway construction. Full article