Search Results (1,253)

In southern Tibet, tectonic extension has created north–south rift systems that host hydrothermal zones with episodic silica sinter and travertine deposition. Earlier researchers usually attributed these deposits to hydrothermal activity driven by regional tectonics. However, the timing of deposition and its possible climatic controls remain poorly constrained. In this study, we dated six samples from the Targejia geothermal field and the Xiakangjian hot spring area using electron spin resonance (ESR), and evaluated ESR signal stability, dose response, and irradiation effects to assess age reliability. The new ages range from 209 to 49 kyr. When combined with 108 published ages, they indicate repeated sinter and travertine formation over the past 720 kyr. The dated deposits are concentrated in several intervals, especially during the last 100 kyr, and some age clusters occur near warm and humid stages. These patterns suggest that tectonics controlled where hydrothermal systems developed, whereas climate-related changes in recharge, meltwater supply, permafrost thaw, and water–rock interaction may have affected when deposition was more active. Because the compiled ages come from different methods and have uneven uncertainties, this climate link remains provisional and needs testing with additional samples dated by consistent protocols. Full article

The application of unmanned aerial spraying systems (UASS) in hilly orchards is challenged by terrain-induced airflow variability, which affects droplet transport and deposition. This study investigated the effects of terrain slope and flight patterns on rotor downwash airflow and droplet deposition using airflow measurements, computational fluid dynamics (CFD) simulations, and field experiments. Adjustable slope platforms (0°, 10°, 20°, and 30°) were used to characterize airflow behavior, while droplet deposition was evaluated under flat, uphill, downhill, and contour-parallel flight conditions, both outside and within citrus canopies. Results showed that increasing slope transformed the downwash airflow from an axisymmetric structure to a downslope-biased asymmetric pattern. Flight patterns significantly influenced deposition distribution. Uphill flight enhanced deposition in upslope and upper-canopy regions, whereas downhill flight increased deposition in rear and lower-canopy regions due to stronger recirculation. During contour-parallel flight, airflow shifted downslope, resulting in higher deposition on the downslope side of the canopy. Under the experimental conditions investigated in this study, the effective spray swath width during single-flight-line operations perpendicular to the contour lines (uphill and downhill flights) was approximately equivalent to the width of one individual tree canopy, whereas contour-parallel flight resulted in a narrower effective spray swath width due to terrain-induced airflow redistribution. An upslope route offset of 0.3–0.5 m improved droplet deposition uniformity between the upslope and downslope canopy regions. These findings provide guidance for optimizing UASS spraying strategies by adjusting flight trajectories, route offsets, and operational parameters according to terrain slope and canopy position. Full article

Accurate recognition of snow avalanches from aerial imagery is crucial for cryosphere hazard monitoring and assessment. However, avalanche traces in snow-covered mountain scenes often exhibit weak texture, low contrast, blurred boundaries and large-scale variation, which degrade the reliability of existing visual recognition models. This paper proposes AVANET, a multiscale weak-texture-aware network for aerial snow-avalanche recognition. Specifically, AVANET combines a Multi-branch Weak-Texture Response Fusion (MWTRF) mechanism and a lightweight Multiscale Contextual Enhancement (MCE) module. The MWTRF mechanism is introduced during training to strengthen subtle discriminative cues using high-frequency residual, Sobel gradient, and multi-orientation Gabor responses. The MCE module aggregates cross-scale contextual information while preserving fine-grained texture details. Smooth Gradient-weighted Class Activation Mapping++ (SmoothGrad-CAM++) is further adopted to visualize model attention and support interpretability analysis. Experimental results show that AVANET achieves 86.13% overall accuracy (OA) and 90.67% F1-score, outperforming the YOLOv11s baseline by 3.06% in OA and 2.21% in F1. Interpretability analysis indicates that the model focuses on plausible avalanche-related regions, including release zones, track areas, and debris deposits. These results demonstrate the effectiveness of AVANET for avalanche recognition in aerial remote sensing imagery. Full article

The manufacturing of personalized implants from Ti–6Al–4V alloy using additive manufacturing technologies is a promising direction in modern medicine. However, components produced by these methods are characterized by a non-equilibrium microstructure, high residual stresses, and anisotropy of mechanical properties, which necessitates subsequent heat treatment. The aim of the present work was a systematic comparative study of the effect of three heat treatment regimes—stress relief annealing (600 °C, 3 h), subtransus annealing in the (α + β) region (950 °C, 1 h, furnace cooling), and solution treatment followed by aging (STA: 950 °C, 0.5 h, water quenching + aging at 675 °C, 3 h)—on the microstructure and mechanical properties of Ti–6Al–4V alloy manufactured by laser powder bed fusion (L-PBF) and plasma arc directed energy deposition (PA-DED). The microstructure was examined using scanning electron microscopy, transmission electron microscopy, and electron backscatter diffraction (EBSD). Tensile mechanical properties were determined in two directions: parallel and perpendicular to the build direction. Stress-relief annealing led to an increase in the ductility of the alloy without a noticeable decrease in strength and without significant changes in the microstructure. Subtransus annealing resulted in the formation of an equilibrium lamellar (α + β) structure, which provided a substantial increase in ductility with a moderate decrease in strength. Solution treatment and aging resulted in formation of a bimodal microstructure. Subtransus annealing (both alloys), STA (L-PBF) and stress relief annealing (PA-DED) provided properties comparable to those of wrought material. The obtained results form the basis for a scientifically informed selection of both the manufacturing route and the heat treatment regime for biomedical implants made of Ti–6Al–4V alloy. Full article

To address the problems of disordered flow patterns, wall-separated recirculation, and sediment deposition that commonly occur in the forebay of forward-facing pumping stations on sediment-laden rivers, the first-stage Xin Zhuangji Pumping Station in Ningxia was selected as the study case. A three-dimensional numerical simulation was conducted using the Realizable k–ε turbulence model coupled with the Mixture two-phase flow model for water–sediment flow. The regulation effects of splayed guide walls with different guide-wall deflection angles on the velocity distribution, vortex structures, and sediment deposition in the forebay were investigated. The results show that large-scale recirculation zones exist on both sides of the prototype forebay, accompanied by uneven velocity distribution and severe sediment deposition within the recirculation regions. The installation of splayed guide walls can effectively suppress lateral recirculation, expand the mainstream flow region, and reduce the deposition area. However, the regulation effect of the diffusion-type guide wall varied significantly with the guide-wall deflection angle. Since the main objective of this study was to control sediment deposition rather than to maximize a single hydraulic indicator, a multi-criteria screening method oriented toward sediment-reduction control was adopted. Under the (θ = 25°) scheme, the reduction ratio of the overall potential deposition area based on the primary threshold criterion reached the maximum value of 53.67%, the recirculation area on plane Z1 decreased by 23.23%, the global recirculation coefficient increased to 68.69%, and the sediment deposition efficiency decreased to 0.033. The axial velocity uniformities at the suction-pipe sections of pumps B# and C# were 71.23% and 80.61%, respectively. Although the (θ = 30°) scheme produced the highest velocity uniformity for pump B# and showed a slightly better reduction effect on local high-concentration sediment-enrichment regions, the (θ = 25°) scheme exhibited a more balanced improvement in overall sediment-deposition control and flow-pattern regulation. Therefore, under the investigated operating condition, the (θ = 25°) scheme is recommended as the guide-wall deflection angle oriented toward sediment-reduction control. Full article

Long-term success of root canal therapy depends not only on effective disinfection but also on durable sealing of the obturated canal system. However, currently available sealers still face persistent challenges in balancing handling, interfacial stability, bioactivity, and antibacterial performance. Here, we developed an injectable calcium silicate-based root canal sealer reinforced with mesoporous bioactive glass nanoparticles (MBGN) to improve sealing-related performance. The formulation integrated a hydration-active calcium silicate matrix with a mesoporous bioactive component while maintaining practical handling characteristics. MBGN incorporation enhanced dentin-associated mineralization, promoted intratubular crystal deposition, reduced apical microleakage, and decreased internal porosity after obturation. The 5% MBG formulation showed the most favorable sealing profile, reducing the dye penetration depth from 2.68 ± 0.41 mm in the 0% MBG group to 1.87 ± 0.32 mm, together with decreased open and closed pore parameters in the apical region. In parallel, the MBGN-reinforced sealer preserved acceptable cytocompatibility and exhibited stronger antibacterial activity against Streptococcus mutans than the reference formulations. The improved performance may be associated with effective initial adaptation and bioactive interfacial densification. Together, these findings suggest that MBGN incorporation may be a promising route for engineering more bioactive calcium silicate sealers with improved sealing stability and antibacterial function for endodontic applications. Full article

In the present paper, we studied the interaction of microwave radiation with conductive indium tin oxide (ITO) coatings deposited on a borosilicate glass. The experiments were carried out with the ITO films, the thickness of which varied in the range from 85 to 607 nm. The transmittance and reflectivity of the ITO film/K108 glass structures were measured in the frequency region from 3 to 23 GHz. Theoretical modeling of the spectra was performed by means of the transfer matrix method. It was shown that for a given thickness of the glass substrate, the transmission and reflection spectra of the ITO film/K108 glass structures were fully determined by only one parameter of the ITO film, namely, its DC sheet resistivity. The considered model predicts an increase in maximum microwave shielding effectiveness up to 45.6 dB with a decrease in DC sheet resistivity to 1 Ohm/sq. ITO coatings with DC sheet resistivities down to 2.3 Ohm/sq have been experimentally investigated. The model microwave transmittance and reflectivity spectra were in good agreement with the experimental ones. In particular, the coefficient of determination for the transmittance spectra was rather high: R² > 0.93. It was experimentally demonstrated that applying antireflective coatings on both sides of the ITO film/K108 glass microwave shielding filter significantly improved its transparency in the operating optical range. A filter has been created that provides microwave shielding effectiveness of 38.7 dB with an average transmission coefficient of 0.81 in the visible range. Full article

Pb-Zn resources are critical strategic assets for many nations. The Dian-Dongbei (northeastern Yunnan) region in Yunnan Province is a significant production area for these resources in China, boasting considerable prospecting potential. However, conventional exploration methods are increasingly inadequate, as they often fail to rapidly and effectively identify concealed mineralization information. To tackle this challenge, we propose a hybrid GAN-ResNet convolutional neural network methodology. This approach constructs a data-driven prospecting model for Pb-Zn deposits in the Dian-Dongbei region, utilizing multi-source geoscientific data encompassing geology, geophysics, geochemistry, and remote sensing (Geo-Phys-Chem-RS) to conduct quantitative mineral prospectivity mapping. A GAN model was introduced to augment the multi-source geoscientific data based on the concepts of random down-sampling and pseudo-window size. The quality of the generated synthetic samples was evaluated using the Peak Signal-to-Noise Ratio (PSNR) metric. The results show that the synthetic samples achieved an average PSNR value of 33.67 dB, effectively preserving the original features of the geoscientific data. This confirms the feasibility and quality of the data generated by this augmentation method. Furthermore, when applied to train the ResNet model, this augmented data effectively increased the prediction accuracy from 0.765 to 0.842. The results demonstrate that the integrated GAN-ResNet method produces prediction maps with higher accuracy. Moreover, it significantly refines and narrows down the target areas with high mineralization potential. This precision can substantially reduce exploration costs, representing a marked improvement in prediction efficacy. Full article

Regional geotechnical archives contain valuable information for numerical modelling, but they are rarely organised in a form that supports traceable derivation of constitutive input parameters for advanced geotechnical analysis. This study develops a groundwater-corrected workflow for transforming regional borehole and consolidation records into finite element-ready constitutive parameter sets for shallow clayey soils, using Al Qadisiyah Governorate, Iraq, as a case study. The workflow combines data cleaning; treatment of limited missing data; derivation of $\lambda$, $\kappa$, $e_0$; preconsolidation pressure, initial effective vertical stress; overconsolidation ratio; and correction of effective stress using observed groundwater conditions. The derived parameter set captures the compressibility, initial state, and stress history variables commonly required for Modified Cam-Clay-based finite element modelling, providing a practical workflow for parameter derivation from routine regional borehole and consolidation data. The results reveal clear vertical and lateral variability in compressibility, density state, and stress history, indicating that the investigated deposits cannot be represented adequately by a single regional parameter set. Groundwater correction was essential for realistic estimation of effective stress and OCR, particularly given the shallow groundwater table throughout the study area. The processed constitutive input dataset was translated into representative finite element material libraries in both overall and depth-specific forms, while GIS-based maps were developed to support spatial interpretation and location-informed parameter selection. The main contribution is the integrated and traceable conversion of regional borehole records into groundwater-corrected constitutive parameters and practical FE material libraries, rather than the separate application of existing empirical or mapping tools. This study demonstrates that routine borehole archives can be transformed into traceable constitutive resources for finite element modelling of shallow clay deposits, supporting preliminary material assignment, depth depth-specific interpretation, and location-informed parameter selection. Full article

Background/Goals: Traumatic brain injury (TBI) is increasingly recognised as an important risk factor for delayed neurodegeneration and has been implicated in the modulation of Alzheimer’s disease (AD)-related amyloid pathology. However, experimental evidence remains equivocal, suggesting that the effects of TBI on amyloidogenesis are context-dependent and influenced by factors including disease stage, injury severity, and the pre-existing neurodegenerative background. This study aimed to comprehensively assess the effects of TBI on cognitive function, synuclein-family gene expression, neuroinflammatory gene expression and amyloid plaque morphology in APPswe/PS1dE9/Blg mice. Methods: Wild-type and APP/PS1 mice were assigned to four experimental groups: WT, WT-TBI, APP/PS1 and APP/PS1-TBI. TBI was induced at 6 months of age using a controlled cortical impact device (precision impactor). Behavioural assessments were conducted at two post-injury time points to evaluate locomotor activity, object recognition memory, short-term spatial memory and spatial learning. Cortex and hippocampus samples were analysed by qRT-PCR to evaluate synuclein-family gene expression and neuroinflammation-related markers. Amyloid plaque pathology was evaluated in Congo red-stained brain sections using QuPath-based image analysis. Results: TBI did not induce a consistent increase in amyloid plaque burden in APP/PS1 mice. Instead, TBI was associated with changes in plaque-size distribution, particularly at the later post-injury time point. Behavioural assessments revealed early trauma-associated cognitive impairmen; whereas, impairments observed at later stages appeared to be driven predominantly by progression of the APP/PS1 phenotype. Gene expression analysis revealed region- and genotype-dependent alterations in synuclein-family transcripts and inflammatory markers with the most pronounced changes observed in the cortex. Conclusions: These findings indicate that TBI does not uniformly accelerate β-amyloid deposition in APP/PS1 mice with established amyloid pathology. Rather, TBI appears to modify the temporal progression and morphological characteristics of amyloid pathology while interacting with genotype-dependent transcriptional responses involving synuclein-family genes and neuroinflammatory pathways. These results highlight the complex interplay between traumatic injury and pre-existing neurodegenerative processes and warrant further studies at the protein-level and over extended follow-up periods to elucidate the underlying mechanisms. Full article

Mining of sulfide-rich deposits enhances the oxidation of sulfide minerals, generating acid mine drainage (AMD) characterized by high sulphate and dissolved metal concentrations and the formation of secondary iron minerals (hematite, goethite, and jarosite). As these minerals display diagnostic features in the visible–near-infrared (VNIR) region, multispectral satellite data provide a cost-effective means of monitoring. Here, the performances of Sentinel-2 and the VNIR bands from WorldView-3 are assessed and compared for the mapping and discrimination of secondary iron minerals in Sierra Minera de Cartagena–La Unión (SE Spain). Both datasets were analyzed using a band ratio and a parabola fitting technique focused on reflectance maxima. Band ratio results were interpreted as broad spectral patterns rather than definitive mineral identifications. Mineral maps were validated by applying X-ray diffraction on 74 surface soil samples. Although both sensors were able to reproduce the main spatial patterns of iron mineral distribution, Sentinel-2 data better discriminated hematite, goethite, and jarosite, especially when using the parabola fitting approach, whereas WorldView-3 VNIR data distinguished mainly hematite from the combined goethite–jarosite group. The better performance of Sentinel-2 is attributed to its red-edge and near-infrared band configuration. These findings indicate that freely available Sentinel-2 imagery can support systematic monitoring of oxidation processes in mining environments and contribute to environmental risk assessment in degraded landscapes. Full article

Fused deposition modeling (FDM) is a material-extrusion additive manufacturing technology that is widely used in rapid prototyping, complex product modeling, and functional part fabrication. However, process-parameter drift and environmental disturbances may induce underfilling, overfilling, warping, delamination, and other defects, thereby reducing part quality or interrupting the manufacturing process. Since FDM is characterized by point-wise extrusion and layer-by-layer deposition, layer-surface images naturally contain both spatial morphology and temporal evolution information. Existing image-based diagnostic methods often treat layer images as independent samples, and the selection of the image-stream length is still insufficiently supported by experimental evidence. Moreover, spatial compression in spatiotemporal neural networks may remove local defect information that is important for distinguishing similar process-parameter drifts. This study provides a deployment-oriented analysis of FDM image-stream diagnosis by systematically examining how layer-window length, spatial feature preservation, and strict data partitioning influence process-parameter drift recognition. To address these issues, this paper studies ConvLSTM-based FDM image-stream process-parameter drift diagnosis. Continuous region-of-interest image streams are constructed for one nominal condition and six process-parameter drift conditions. In this paper, the time step T denotes the number of consecutive layer-surface images, or, equivalently, the number of consecutive printed layers, contained in one diagnostic image stream. A ConvLSTM-Flatten baseline is first developed to preserve complete spatial feature maps and to evaluate the effect of different time-step lengths. Then, a ConvLSTM model with adaptive spatial pooling and temporal attention (ASP-TA) is constructed to analyze the influence of spatial pooling granularity and temporal feature fusion. The experiments show that the ConvLSTM-Flatten model achieves the highest average test accuracy of 0.7288 at $T=9$, whereas $T=3$ is identified as a practical optimal time step when test accuracy, image-frame computation, diagnosis latency, and convergence behavior are considered together. The paired trial-wise accuracy difference between $T=9$ and $T=3$ is small and not statistically significant over ten repeated trials. Thus, the diagnostic window corresponding to $T=3$ covers three consecutive deposited layers; after the initial window is available, stride-one stream construction allows the diagnosis to be updated with each newly acquired layer image. ASP-TA with a pooling size of eight consistently outperforms ASP-TA with a pooling size of four, but both are lower than the Flatten baseline, indicating that preserving sufficient spatial information is essential for distinguishing FDM process-parameter drift states. The results reveal the non-monotonic influence of time-step length and clarify the tradeoff between spatial feature preservation and model compactness in FDM image-stream process-parameter drift diagnosis. Full article

A primary challenge in successfully manufacturing reactive materials for laser metal deposition (LMD) is to prevent oxidization. To address the oxidation susceptibility of titanium alloys in open environments, a local atmosphere protection model was developed. Using Ansys Fluent 2023R1 software, the effective protective atmosphere range provided by the local shielding device under varying shielding gas flow rates was investigated in detail, and a mathematical model for the effective protection area was obtained through quadratic polynomial fitting. A quadratic regression model linking process parameters with the length of high-temperature zones was established using central composite design (CCD). By integrating these two models, a local shielding gas model for LMD titanium alloys in an open environment was formulated. Validation experiments demonstrated excellent morphology of the single layers with shiny silver. The local shielding atmosphere can effectively protect the high-temperature region. These findings provide a basis for the deposition of active materials in an open environment and the selection of appropriate shielding gas flow rates. Full article

The Ulungu Depression, located in the northeastern Junggar Basin, adjacent to the Altai Orogenic Belt, exhibits distinctive tectonic relationships and evolutionary mechanisms. Through integrated interpretation of seismic and electromagnetic data, a composite transect was established to characterize the deep-to-shallow geological architecture of the Altai Orogenic Belt–Ulungu Depression system. The tectonic evolution since the Late Paleozoic was reconstructed, revealing three distinct phases: (1) Late Paleozoic peripheral foreland basin development, (2) Mesozoic intracontinental foreland basin formation, and (3) Cenozoic intracontinental foreland basin reactivation. The Late Paleozoic phase records the formation of a peripheral foreland basin in the northeastern Junggar Basin, driven by the Altai-Junggar collision orogeny. During the Mesozoic, intracontinental orogeny along the Altai Belt controlled the development of an intracontinental foreland basin in this region. Paleogene tectonic quiescence facilitated regional subsidence and stable sedimentary deposition. From the Neogene to Quaternary, the Ulungu Depression experienced weak compressional deformation dominated by minor thrust faults, with intermittent regional extensional structures, attributable to the far-field effects of the India-Eurasia collision. This distant tectonic stress primarily localized intracontinental orogeny in the North Tianshan, while the Ulungu Depression, situated farther north, exhibited attenuated strain partitioning. Reconstruction of this multi-phase tectonic evolution provides critical insights into the accretionary orogenic processes of Central Asia. Furthermore, it offers practical implications for hydrocarbon exploration in the Ulungu Depression, particularly regarding structural traps and reservoir distribution patterns. Full article

Cynoscion jamaicensis is an important demersal species in the Southeastern Brazilian Bight (SEBB), yet information on its population dynamics in this region is limited and out of date. This study provides the first assessment of the species’ age, growth, and mortality in the SEBB, based on sectioned otoliths. The annual deposition of annuli was validated through relative marginal increment and edge analyses, and a refined age-assignment approach that incorporated birth date and capture month was employed. Growth was described using the von Bertalanffy growth model, yielding a maximum theoretical length (${TL}_{\infty }$) of 278.49 mm and a growth coefficient ($k$) of 0.545 year⁻¹. Total mortality was estimated at $Z$ = 0.74 year⁻¹, with natural mortality ($M$ = 0.60 year⁻¹) and fishing mortality ($F$ = 0.14 year⁻¹) indicating low-to-moderate exploitation ($F/M$ < 1). The results suggest truncation of the size structure and a shift in growth parameters, which are consistent with the effects of long-term fishing, although current levels of exploitation do not indicate overfishing. These findings provide an updated biological baseline and emphasize the importance of incorporating population parameters into ecosystem-based fisheries management. Full article