Search Results (86,243)

In padel, an emerging racket sport, evidence regarding competition demands in adolescent players remains limited. Therefore, this study aimed to analyze absolute external load during official competition in male and female U18 padel players. A total of 18 official matches from the Spanish Championship of Regional Teams were analyzed. Eighteen U18 players (9 females: age 15.1 ± 1.5 years, height 162.9 ± 8.2 cm, body mass 54.6 ± 9.1 kg; 9 males: age 15.4 ± 1.8 years, height 175.1 ± 9.4 cm, body mass 67.2 ± 11.0 kg), competing at the regional and national levels, were monitored using OLIVER™ inertial devices. External load variables included playing time, total distance, high-intensity accelerations and decelerations, changes of direction, time spent at high metabolic power, session volume, session intensity, and maximum speed. Statistical analysis was performed using linear mixed models to compare differences between sexes. Male players showed significantly higher values than female players in playing time (82.34 ± 23.95 vs. 51.03 ± 12.39 min; p < 0.001) and total distance (3958.50 ± 242.57 vs. 2225.54 ± 257.29 m; p < 0.001). They also presented significantly greater values in high-intensity external load variables, including accelerations, decelerations, changes of direction, time spent at high metabolic power, session volume, and session intensity (all p ≤ 0.009). No significant differences were found for maximum speed (p = 0.074). These findings suggest that official competition demands differ according to sex in U18 padel and may help inform more specific training prescriptions and load-monitoring strategies. Full article

Viticulture is a globally significant economic activity; however, the scientific literature lacks in-depth, long-term studies integrating historical trends with future market concentration projections. This study fills this gap by analyzing global grape production dynamics and market structure over a 63-year period (1961–2023). The detection of structural breaks and the forecasting of yield trajectories using AutoRegressive Integrated Moving Average with Exogenous Variables (ARIMAX) models are crucial for the strategic planning of agricultural resources and enhancing viticultural resilience. Results indicate that while the global population increased 2.58-fold (1961–2023), grape production rose only 1.69-fold, leading to a decline in per capita availability. Although traditional leaders remain dominant, the combined share of the top five producers fell from 60% to 51.8%. The market concentration analysis Herfindahl-Hirschman Index (HHI) = 0.092; the Concentration Ratio (CR₅) = 53.65%) for 2024–2030 suggests a monopolistic competition structure. The arithmetic mean of annual global production for the 2024–2030 period is projected to reach 79.42 million tons. China is expected to lead (23.11%), followed by Italy, the United States, France, and Spain. These findings highlight the necessity of precision viticulture and modern technology to stabilize yields and enhance competitiveness in high-value horticultural markets. Full article

Coalbed methane (CBM) is an important unconventional natural gas resource, and coal seam gas content is a key parameter for CBM resource evaluation and favorable-zone prediction. Taking the Jiulongchuan exploration area in Gansu Province as the study area, this study integrated drilling, well-logging, and measured gas content data to establish a multivariate regression model for coal seam gas content prediction. On this basis, three-dimensional geological modeling and variogram analysis were applied to characterize the spatial distribution of gas content in the main mineable coal seams (Nos. 5, 6, and 8). The results indicate that the regression model constructed using acoustic transit time, natural gamma-ray values, density logging parameters, and burial depth shows generally reasonable predictive capability for coal seam gas content. Cross-validation results suggest that the predicted gas contents are generally consistent with measured values. Spatial modeling results show that gas content in Seam No. 8 is generally higher than that in Seams No. 5 and No. 6, and gas content tends to increase with burial depth and coal seam thickness. In addition, relatively high gas contents are commonly observed along synclinal zones, whereas lower values occur near anticlinal areas. The integrated application of well-log interpretation and three-dimensional geological modeling provides a reasonable characterization of the spatial variation in coal seam gas content in the study area. The results may provide useful references for CBM resource evaluation and favorable-zone prediction in the Jiulongchuan exploration area. Full article

In this study, In_0.40Mn_0.15Co_3.85Sb₁₂ was synthesized by the ceramic method, using a traditional melting–annealing treatment (MA), followed by grinding and sintering via the hot-pressing (HP) technique. Rietveld refinement of the powder diffraction (PXRD) data confirms that the resulting phase has a cubic crystal structure in space group Im-3, which is isostructural with the pristine Co₄Sb₁₂ phase. The cell parameter a of the filled In_0.40Mn_0.15Co_3.85Sb₁₂ increases after hot pressing compared with the Co₄Sb₁₂ phase. This suggests that the partial substitution of cobalt atoms with manganese (Mn) alters the cell size of the resulting material. The PXRD pattern of the In_0.40Mn_0.15Co_3.85Sb₁₂ phase of the MA sample shows a low-intensity line (~30°), which is related to elemental antimony (~4%, by Rietveld refinement). Rietveld refinements support a second model which implies the pressure-induced self-insertion of remanent antimony from the (MA) phase into the void sites after (HP) treatment, leading to a new phase: In_0.30Sb_0.10Mn_0.15Co_3.85Sb_11.90 (HP). The vibrational Raman modes of the obtained phases, In_0.40Mn_0.15Co_3.85Sb₁₂ (MA and HP), are correlated with those of the pristine phase, Co₄Sb₁₂. A strong primary signal at 185 cm⁻¹ in the Raman spectrum of In_0.40Mn_0.15Co_3.85Sb₁₂ (MA) is associated with antimony impurities, which is confirmed by Rietveld refinement. Raman spectra of the HP sample are well correlated to the (SPS) Co₄Sb₁₂ phase, which reveals structural changes due to self-insertion of antimony into the voids. The band-gap energy values of both the In_0.40Mn_0.15Co_3.85Sb₁₂ (MA) phase and the (HP) phase are 0.750 ± 0.006 eV and 0.650 ± 0.004 eV, respectively. These values are higher than those of the Co₄Sb₁₂ phase, which has a band-gap energy of 0.55 eV. This indicates that the electronic band structure is modified by the partial substitution of cobalt with manganese and the introduction of indium in the icosahedral cages. Electrical transport properties at room temperature show that In_0.40Mn_0.15Co_3.85Sb₁₂ (MA) and In_0.30Sb_0.10Mn_0.15Co_3.85Sb_11.90 (HP) are n-type semiconductors. Full article

Healing agent encapsulated in polymeric microcapsules has proven its ability to seal surface and internal cracks. Focused on mitigating the negative impact of capsules on the properties of fresh cement paste and hardened cementitious matrix, uncertainties in self-healing triggering, and poor control of the released quantity, researchers report technological improvements in predominantly experimental studies. However, practical applications will necessitate lightweight models that capture all the characteristics of practical importance. Analysis of the scientific literature reveals the lack of such models adapted for cementitious composites. In this paper, a model rooted in continuum damage mechanics, tuned based on empirical data, is used in the finite element analysis of concrete specimens containing polymer self-healing microcapsules to quantify self-healing efficiency and local damage-healing behavior. The predicted increase in the self-healing rate is more pronounced for specimens subjected to compression compared to that for elements subjected to four-point bending. Thus, for a 20% increase in healing efficiency, strength recovery in compression increases from 18.5% to 32% for C25 and C30, respectively, whereas the corresponding values for tension in the tension-be-flexure setup are 3.5% and 5.3%. Full article

316LN stainless steel is widely used in critical nuclear fusion structural components due to its excellent mechanical properties and machinability. However, its high thermal expansion coefficient and low thermal conductivity promote welding distortion, while work hardening causes residual stress accumulation. Thermo-elastic–plastic finite element modeling (FEM) is the primary numerical method for predicting these effects. Yet, despite hardware advances, full-scale simulations—especially for thick plates with multi-pass welds—remain computationally expensive, hindering the balance between efficiency and accuracy. To address the inherent trade-off between welding efficiency and dimensional accuracy in multi-pass, multi-layer welding of thick-section components, this study employs MSC. Marc to develop a finite element model of a 15 mm thick butt-welded joint fabricated from 316LN stainless steel. Three distinct heat source models—instantaneous, enhanced moving, and moving element-set—are systematically implemented to simulate transient temperature fields, residual stress distributions, and welding deformation. All numerical predictions are rigorously validated against experimental measurements to comprehensively assess both accuracy and computational efficiency. Results indicate that: (i) the predicted molten pool geometries and characteristic thermal cycle profiles from all three models exhibit strong agreement with experimental observations; (ii) longitudinal residual stress distributions predicted by all models align closely with measured values; (iii) transverse residual stresses predicted by the moving element-set and enhanced moving heat sources agree well with experiments, whereas those from the instantaneous heat source show marked deviation; (iv) angular distortion predictions from the moving element-set heat source achieve over 90% conformity with experimental data, while the instantaneous heat source substantially underestimates angular distortion, and the enhanced moving heat source yields approximately 65% agreement; and (v) in terms of computational efficiency, the instantaneous heat source requires only ~40% of the computation time needed by the moving heat source. Full article

Rapid urbanization has intensified inequalities in the distribution of urban green resources, making green equity a critical concern within the framework of the United Nations Sustainable Development Goals. This study examines Zhangdian District in Zibo City, China, a representative “Whole-Area Park City” pilot area. This study integrates 1 km population density grid data with GIS network analysis, space syntax, population-weighted service pressure assessment, and a location–allocation model. Using these methods, it evaluates four categories of urban parks from the perspectives of spatial distribution, road connectivity, and social equity. The results reveal that vehicle and cycling modes achieved nearly complete 15 min coverage, whereas pedestrian accessibility remained insufficient. Walking accessibility for comprehensive parks reached 77.69%, whereas that of community parks and petty street gardens was below 33%. Population-weighted analysis further suggests that more than 78% of residents, concentrated in dense central–western neighborhoods, are served by only 21% of total park area. The Gini coefficient of per capita park area reached 0.4765, indicating substantial inequality in park green space allocation. After optimization through the addition of 76 new parks, improvements in road connectivity, and construction of a slow-traffic system, the Gini coefficient decreased to 0.4053, representing a 14.9% reduction. Meanwhile, the population below the national standard declined from 78.09% to 40.64%. These findings reflect spatial accessibility and area-based equity, while actual park service value also depends on park quality, facilities, and user behavior. This study provides quantitative evidence for equity-oriented park planning and a replicable framework for sustainable urban green space planning. Full article

China’s inland regions are vital for territorial spatial planning and sustainable development due to their abundant resources. However, the dynamic coordination between natural resource utilization (NRU) and ecological resilience (ER) remains poorly understood. Using panel data from 20 inland provinces in China (2009–2023), this study constructs NRU and ER evaluation systems, with ER assessed through the Pressure–State–Response (PSR) framework. Indicator weights are determined using an AHP–entropy method. Kernel density, panel vector autoregression (P-VAR), and coupling coordination models are applied to examine spatiotemporal evolution patterns, coordination levels, and interaction mechanisms between NRU and ER. The results show that: (1) The NRU index rises overall, peaking around 2020 (0.706), while the intensity of resource development continues to decline. Regional disparities widen, resulting in a spatial pattern of development intensity that was higher in the west and lower in the east. (2) The ER index continues to rise, accelerating at certain stages, and reaches a peak (0.723) between 2018 and 2020. Geographically, the eastern region led the way, with values decreasing in a stepwise manner, and regional disparities showed relatively gradual changes. (3) The degree of coordination between the two continues to improve, evolving from a “low level of dispersion” to a “medium-to-high level of concentration.” This has resulted in a pattern where the eastern region leads, followed by the central and southwestern regions in succession. Specifically, the EC index rose from 0.429 to 0.615, and the CC index rose from 0.384 to 0.533. Eastern and Central China have already reached a medium level of coordination, while Northwest and Southwest China remain primarily at a basic level of coordination. (4) Significant bidirectional dynamic interactions exist between the NRU and ER, with asymmetric pathways. By region, the NE, EC, and NC exhibit greater fluctuations and higher system sensitivity, while the CC experiences more concentrated short-term shocks; the SW and NW exhibit relatively smoother responses and converge more rapidly. Policy implications highlight the need for region-specific coordination strategies, better alignment between resource development and ecological protection, and enhanced cross-regional governance to support sustainable inland development. Full article

Heavy metal pollution in water threatens ecosystems and human health, necessitating efficient, low-cost, and sustainable remediation technologies. A manganese-modified bamboo biochar (Mn-BC) was synthesized via impregnation of raw biochar in KMnO₄ followed by pyrolysis at 500 °C, and its adsorption ability was systematically evaluated for Pb(II) and Cr(VI) removal through batch adsorption experiments investigating the effects of solution pH (2–9), adsorbent dosage (0.1–0.9 g in 20 mL), contact time (0–50 min), initial metal concentration (20–100 mg L⁻¹), and temperature (25–50 °C). SEM/TEM-EDS and XRD confirmed successful Mn incorporation as MnO_x phases, while textural analysis showed improved porosity after modification, with the BET surface area and total pore volume increasing from 77.28 m² g⁻¹ to 123.51 m² g⁻¹ and from 0.041 cm³ g⁻¹ to 0.063 cm³ g⁻¹, respectively. Batch adsorption experiments demonstrated strong pH dependence, with optimum removal at pH 8 for Pb(II) (91.87%) and pH 5 for Cr(VI) (88.2%). Adsorption was rapid within the first 30 min and reached equilibrium. A pseudo-second-order (PSO) model provided the best kinetic description (R² = 0.99) with calculated q_e values of 19.98 mg g⁻¹ for Pb(II) and 19.13 mg g⁻¹ for Cr(VI). Isotherm analysis yielded Langmuir monolayer capacities of 37.24 mg g⁻¹ (Pb(II)) and 16.39 mg g⁻¹ (Cr(VI)), with Pb(II) better described by Freundlich behavior and Cr(VI) closely fitting Langmuir assumptions. Thermodynamic results indicated endothermic adsorption (ΔH° = 41.98 and 29.67 kJ mol⁻¹ for Pb(II) and Cr(VI)) and increased interfacial randomness (ΔS°), with adsorption becoming more favorable at higher temperature (maximum removal at 50 °C: 93.21% Pb(II), 87.37% Cr(VI)). Mn-BC maintained >60% efficiency after five regeneration cycles. Mechanistically, Pb(II) removal was primarily governed by ion exchange and surface complexation, whereas Cr(VI) removal involved electrostatic attraction, partial reduction to Cr(III), and subsequent complexation on oxygenated and Mn–O sites. Overall, these findings demonstrate that Mn-BC is a practical, reusable, and competitive adsorbent for the efficient removal of Pb(II) and Cr(VI) from wastewater, supporting sustainable water treatment strategies. Full article

The rapid and nondestructive classification of maize kernels is of great significance for seed screening and quality evaluation. Existing hyperspectral image classification methods based on the Mamba architecture can effectively represent spectral and spatial features; however, they still face limitations in time–frequency analysis and multimodal feature fusion. In addition, traditional approaches often rely heavily on spectral preprocessing, which may introduce additional errors and compromise the model’s robustness and generalization ability. To address these challenges, this paper proposes a novel cross-modal classification framework named CD-TriMamba, which jointly leverages hyperspectral data and visible-light images for comprehensive feature extraction and deep fusion. Specifically, an innovative feature extraction module is designed, consisting of a Spectral Curvelet Convolution (SCC) module for hyperspectral data and a Curvelet-Decomposed Convolution (CDC) module for spatial modeling. A feature rearrangement mechanism is further introduced to mine critical information from both spectral and spatial modalities. Finally, a ConvNeXt-guided tri-branch cross-fusion structure (TriMamba) is constructed to achieve deep collaboration and efficient integration between spectral and spatial features. Experimental results demonstrate that the proposed model achieves outstanding performance in seed classification, with an accuracy (Acc) of 99.2% and a Kappa value of 99.1%. These results strongly confirm the effectiveness and broad application potential of cross-modal feature fusion in maize kernel classification. Full article

Array Gm-APD LiDAR is highly vulnerable to strong backscattering caused by dynamic smoke. Conventional depth imaging methods cannot rapidly identify the smoke occlusion state, which greatly reduces the target recovery quality of the reconstructed depth image. To solve this problem, this paper presents a non-parametric algorithm for rapid smoke detection and depth imaging for array Gm-APD LiDAR. The proposed method does not rely on parameter estimation of the echo model. Instead, it determines the presence of smoke occlusion by calculating the Pearson correlation coefficient between the echo signal obtained from the superposition of all array pixels and the instrument response function. In this way, the method rapidly identifies smoke interference in a single depth image, performs fast denoising, and reconstructs the depth image. In a dynamic smoke environment with an average attenuation length of no more than 5.1, the proposed algorithm achieves 100% accuracy in occlusion discrimination based on 250 frames of array data. When the smoke occlusion rate reaches 96% and the average attenuation length is 2.29, the method obtains a target recovery of 0.71, which is 86.8% higher than that of the conventional algorithm. These results indicate that the proposed method has strong practical value for array Gm-APD LiDAR, especially for high-speed depth imaging in harsh atmospheric environments with severe obscuration. Full article

The spectral features in hyperspectral images are easily affected by the spatial position changes in objects. In this study, a Multi-Scale Spectral Spatial Discriminative model (MS²D) is proposed for the spectral feature changes caused by different positions. This model decomposes the original image into multi-scale low-rank components through multi-scale low-rank decomposition (MSLRD), which decouples the complex correlation between spatial structure and spectral variability. Considering the time complexity of MSLRD, we propose three optimization points: (1) using superpixel segmentation to gather pixels to form superpixels, so as to reduce the calculation of the number of pixels; (2) selecting the band with a large amount of information on the representative band of the input to reduce the cost of redundant bands; (3) replacing standard singular value decomposition (SVD) with random SVD to reduce computational complexity. After classification, the majority voting strategy is used to vote on the results to alleviate the discrimination conflict between features. The experimental results on three public datasets show that the performance of MS²D is better than that of the other models, which verifies that this model can control computational complexity and improve classification accuracy. Full article

Background/Objectives: Although creatine monohydrate is widely recognized as an effective ergogenic aid in strength and power sports, its role in endurance and mixed-sport disciplines remains less clearly established. This scoping review aimed to map the current evidence regarding the effects of creatine supplementation on performance, recovery-related outcomes, and body composition in endurance and mixed-sport contexts. Methods: A scoping review of randomized controlled trials published between 1996 and 2025 was conducted. Eligible studies evaluated creatine supplementation in endurance and mixed-sport contexts, including both sport-specific and broader exercise populations when the exercise protocol, testing model, or outcomes were relevant to endurance or mixed-sport performance, recovery, or body composition. A total of 38 studies met the inclusion criteria. Outcomes were categorized into exercise performance, biochemical markers related to recovery and exercise stress, and body composition parameters. Results: Creatine supplementation was most often associated with reported favorable changes in repeated-sprint performance and high-intensity power output, particularly during intermittent, sprint-based, or power-endurance tasks. Several studies reported favorable changes in sprint performance, peak power, or total work output relative to placebo or baseline values in cycling, swimming, rowing, and canoeing/kayaking protocols, although findings were not uniform across studies and not all favorable within-group changes were placebo-superior. Some studies also reported favorable changes in end-phase sprint capacity during prolonged exercise. Findings related to recovery were less consistent. Selected studies reported reductions in inflammatory markers, including C-reactive protein (CRP) and tumor necrosis factor α (TNF-α), whereas markers of muscle damage showed mixed responses. Most supplementation protocols involved a 5–7-day loading phase of 20 g/day, occasionally followed by a maintenance dose of 2–5 g/day. Small increases in total body mass were commonly observed, while evidence regarding fat-free mass and aerobic outcomes remained limited or inconsistent. Conclusions: Current evidence suggests that creatine supplementation may be most relevant in selected endurance and mixed-sport contexts involving repeated high-intensity efforts, sprint finishes, or power-endurance demands, rather than for endurance performance broadly. In contrast, evidence for recovery-related biochemical responses, body composition changes, and aerobic adaptations remains equivocal. Further well-controlled, sport- or context-specific, and field-based studies are needed to better clarify the role of creatine in endurance and mixed-sport exercise. Full article

Cathinone and its synthetic derivatives are among the most popular drugs worldwide. However, the literature provides data on the medicinal and cytotoxic potential of some of these compounds. These data are extremely limited due to the need to obtain additional permits for laboratory studies. Consequently, the therapeutic potential of cathinones may not have been fully explored. Furthermore, the literature provides data on the reduction or reversal of undesirable biological properties of drugs encapsulated in a bio-compatible carrier and administered through targeted therapy. The current study presents preliminary theoretical and experimental tests for further research on target cathinone–graphene–oxide complexes. A non-psychotropic cathinone model—o-fluorophenylacetic acid—was used. The NMR properties (chemical shifts, spin–spin coupling constants, and T₁ relaxation times) of graphene oxide–F-derivative complexes were measured at an acidic and neutral pH. To analyze the structure and stability of the possible complexes in different environments, molecular modelling was performed with simplified graphene oxide models using density functional theory. Experimental data were compared with theoretical values, and the most stable structures that may account for the observed spectral properties of the studied complexes were presented. The obtained data indicate a stronger tendency towards the formation and stabilization of GO-2-fluorophenylacetic acid complexes in a neutral environment. Full article

Background and Objectives: Endothelial dysfunction is essential in the development and progression of coronary artery disease (CAD) and its complications. Galectin-3 mediates inflammation and organ fibrosis and promotes endothelial dysfunction. Meanwhile, the vascular reactivity index (VRI) reflects endothelial function. The purpose of this research was to evaluate the association between serum galectin-3 levels and VRI in patients diagnosed with CAD. Materials and Methods: One hundred and eighteen patients with CAD were enrolled. Endothelial function was noninvasively evaluated using digital thermal monitoring, and VRIs were obtained. According to VRI values, patients were classified into good (≥2.0), intermediate (1.0–1.9), and poor (<1.0) subgroups. Galectin-3 levels were quantified using an enzyme-linked immunosorbent assay. Results: Patients with poor vascular reactivity were older in age (p = 0.028) and had higher serum total cholesterol (p = 0.003), low-density lipoprotein cholesterol (p = 0.005), and galectin-3 (p < 0.001) levels. Multivariable stepwise linear regression analysis revealed galectin-3 as an independently associated factor of lower VRIs (β = −0.488; p < 0.001). Logistic regression model confirmed that galectin-3 independently was associated with higher odds of vascular reactivity dysfunction (odds ratio, 1.120; 95% confidence interval, 1.016–1.235; p = 0.023) or poor vascular reactivity (odds ratio, 1.445; 95% confidence interval, 1.179–1.772; p < 0.001). Conclusions: Serum galectin-3 is independently associated with reduced VRIs and endothelial dysfunction in patients with CAD. Full article