Search Results (3,581)

Since the Mesozoic, the Chengdao-Zhuanghai area of the Jiyang Depression in eastern China has undergone multiple tectonic movements, leading to extensive fault development in Mesozoic strata. This study analyzes fault features and evolution using seismic, well logging, and mud logging data to clarify the major characteristics of Mesozoic faults and the impact of their sealing capacity on hydrocarbon migration and accumulation. It quantitatively evaluates sealing capacity using a fuzzy evaluation method based on fault plane effective normal stress, shale gouge ratio, and tightness factor, and discusses hydrocarbon-related impacts using well testing and production data. The results showed that the major faults are secondary and tertiary normal faults, predominantly ramp-flat or listric in cross section, with NW, NNW, NNE (NE), and nearly EW strikes and dips of 50–70°; the Chengbei Fault has the largest throw (2–3.2 km) and the longest extension (45.94 km). These faults transition from reverse to normal during Fangzi Formation deposition. The Chengbei 30 North and 304 Faults exhibit poor sealing capacity (hydrocarbon migration), whereas the Chengbei, Chengbei 20, Chengbei 30 South, and Zhuanghai 104 South Faults exhibit good sealing capacity (trap formation and hydrocarbon entrapment). This study provides guidance for the exploration of hydrocarbon-enriched fault block reservoirs near major faults. Full article

The purpose of the present study was to examine whether countermovement vertical jump (CMJ) force-time metrics differ among teams with three ranking statuses competing within the same professional women’s handball league in Europe (i.e., SuperLeague). Following a standardized dynamic warm-up procedure, twenty-six professional female handball players (top-ranked: n = 8; mid-ranked: n = 8; bottom-ranked: n = 10) performed three CMJs on a uni-axial force plate sampling at 1000 Hz (VALD Performance). Nineteen force-time metrics were derived to characterize neuromuscular performance qualities during both the eccentric (i.e., braking) and concentric (i.e., propulsive) phases of the jumping motion. A one-way ANOVA revealed no statistically significant differences (p < 0.05) between the teams for any CMJ force-time metric of interest (i.e., peak and mean eccentric force and power, jump height, reactive strength index-modified, countermovement depth, eccentric and concentric duration) across ranking status in either phase of the movement, nor for anthropometric characteristics (i.e., height and body mass). Overall, the results indicate that CMJ force-time metrics did not differentiate team ranking status within this sample of professional female handball players. These findings suggest that, within a homogeneous cohort competing at the same level of play, CMJ-derived neuromuscular performance characteristics may have limited sensitivity for distinguishing between teams of different competitive rankings. While CMJ force-time analysis remains a useful tool for monitoring individual neuromuscular status, the present results do not allow conclusions regarding the role of other performance determinants (e.g., tactical or technical factors), which were not directly assessed in this study. Full article

To address the severe snow accumulation within road cuttings triggered by wind-blown snow on mountainous highways, and to elucidate the influence mechanisms of cutting depth and snow fence parameters on the wind–snow flow field, this study presents a systematic investigation based on typical sections of the G577 Grade I mountain highway in the Xinjiang Uygur Autonomous Region, China. First, indoor wind tunnel experiments were conducted to observe the distribution characteristics of the wind– snow field inside and outside the cuttings and around the snow fences under varying cutting depths and fence parameters. Second, numerical simulations were performed using the Analysis System Fluent software with models identical to those used in the wind tunnel tests to analyze the airflow field and snow particle movement patterns. Finally, experimental results were compared with field observations of winter snow accumulation to validate the reliability of both the numerical simulations and wind tunnel experiments. The results indicate that under small intersection angles (15–30°), deep cuttings significantly exacerbate snowdrift accumulation trends, reducing wind speed within the cutting and increasing snow accumulation at the bottom (an increase of 31–81% per 5 m of depth). Furthermore, a nonlinear relationship regarding the impact of different snow fence parameters on flow field distribution. These findings provide theoretical support and valuable engineering references for optimizing road cutting design and snow fence construction in mountainous regions. Full article

Neuropsychiatric disorders are characterized by complex etiologies, widespread involvement of brain regions, and pronounced clinical heterogeneity, with core pathological mechanisms closely associated with abnormal activity in deep brain structures and their functional networks. Although current pharmacological therapies and conventional neuromodulation techniques have shown therapeutic benefits in certain conditions, they are generally limited by insufficient stimulation depth or the risks associated with invasive procedures. Temporal interference (TI) electrical stimulation has recently emerged as a non-invasive deep neuromodulation technique that generates low-frequency difference-envelope fields through high-frequency carrier signals, thereby enabling relatively precise modulation of deep brain regions while maintaining favorable safety and tolerability. This technique provides a novel technical pathway for precision intervention in neuropsychiatric disorders. In this review, we summarize the principles and technical characteristics of TI stimulation and highlight its recent applications in mood and stress-related disorders, cognitive impairment and neurodegenerative diseases, movement disorders, addiction, and disorders associated with dysregulated neural excitability. We integrate its potential mechanisms across multiple levels, including neural oscillations, deep–cortical network synchronization, reward and motivational circuits, synaptic plasticity and structural remodeling, excitatory-inhibitory balance, and gene and epigenetic regulation. Current evidence suggests that TI stimulation can modulate electrophysiological activity and may engage molecular and network-level processes relevant to functional improvement, although durable clinical benefits remain to be established. Although clinical translation remains challenged by parameter optimization, interindividual variability, and long-term safety evaluation, advances in computational modeling, multimodal neuroimaging, and closed-loop stimulation strategies are expected to facilitate its development. Overall, TI stimulation represents a promising non-invasive deep neuromodulation approach for mechanistic investigation and precision treatment of neuropsychiatric disorders. Full article

To clarify the migration characteristics of overlying strata during backfill mining of close-distance coal seams, the 3306 working face of Chaili Coal Mine was taken as the engineering background, and similar-material simulation, fracture-fractal analysis, and FLAC3D numerical simulation were carried out under an 85% backfill ratio. The study reveals the coordinated inherited and reactivated evolution of fractures, displacement, and stress in the overlying strata during successive extraction of the upper and lower seams. The results indicate that the movement of the overlying strata shows pronounced stage dependence and inheritance. After extraction of the upper No. 3 coal seam, the response of the overlying strata evolves from local disturbance to overall structural readjustment, with continuous bending subsidence and progressive fracture propagation, and ultimately forms a two-belt structure. During extraction of the lower No. 3 coal seam, the response develops on the basis of the structural state formed after upper-seam mining and is manifested mainly by the reactivation and readjustment of the pre-existing fracture network and displacement field. The fractures undergo a dynamic process of generation, development, closure, redevelopment, and reclosure. Compared with upper-seam mining, lower-seam mining produces a larger vertical displacement and a weaker stress response. The maximum vertical displacement in-creases from 478.85 mm to 1019.76 mm, whereas the stress concentration coefficient of the immediate roof decreases from 2.01–2.03 to 1.93–1.99. Under the geological and mining conditions considered in this study, the 85% backfill ratio maintains overall bending subsidence of the overlying strata and alleviates strata pressure manifestations during lower-seam extraction. These findings provide a reference for strata control under similar backfill mining conditions. Full article

To clarify the migration and structural evolution of mining-induced overburden following grouting reconstruction of the Fourth Aquifer, the inner section of Panel 1022-2 in Wugou Coal Mine was taken as the engineering background. The evolution law of overburden movement and the development characteristics of the caving zone were systematically investigated via theoretical analysis, similar-material simulation, and numerical simulation. In addition, the maximum caving-zone height of Panel 1022-2 was calculated based on the measured caving-to-mining ratio of the adjacent Panel 1010-1. The results show that following grouting reconstruction of the Fourth Aquifer, the water inflow and permeability coefficient decreased significantly, the mining-induced water-body grade was classified as Grade III, and the required coal pillar type was converted from a waterproof safety coal (rock) pillar to an anti-collapse safety coal (rock) pillar. The bedrock failure morphology evolved sequentially from a symmetrical trapezoid to a stepped shape and finally to an asymmetrical saddle shape, with a maximum caving-zone height of 19.0 m, whereas the Fourth Aquifer evolved from fracture initiation and bed separation to asymmetrical overall subsidence. Overburden migration is jointly controlled by bedrock thickness and the mechanical properties of the unconsolidated layer, presenting a distinct three-stage evolution pattern. As the size of the reserved safety coal (rock) pillar decreases, the overburden failure mode changes from overall plastic failure under relatively thick bedrock, to semi-block failure with longitudinal fractures penetrating to the base of the Fourth Aquifer and transverse fractures and interlayer separation initiating inside the aquifer, and finally to intensified failure under thin-bedrock conditions. Based on field analogy with Panel 1010-1, the maximum caving-zone height of Panel 1022-2 was calculated to be 19.73 m, which is in good agreement with the numerical and similar-material simulation results, verifying the reliability of the three-stage overburden evolution law and the caving-zone height evaluation. Full article

We analyse pebble RFID tracing observations to investigate sediment transport dynamics in gravel-bed rivers using statistical modelling. This study examines a dataset of nearly 3500 tracer displacement measurements collected during 27 sediment-mobilizing events in a pre-Alpine reach in Italy. Our analysis follows three main steps, addressing tracer mobility patterns, event-scale transport dynamics, and reach-scale bedload inference. First, using Markov Chain analysis of state transitions on typical and high-magnitude transport events, we demonstrate that pebbles tend to maintain their mobility state between events, characterizing the between-event intermittency of bedload transport. A subsequent analysis of flow characteristics reveals that consecutive floods of similar magnitude exhibit increasing movement probability while maintaining similar virtual velocities. Finally, we train Gradient Boosting regression models to estimate distributions of pebble displacements and virtual velocities (defined, following common usage, as the ratio between the distance a tracer travels during a mobilising event and the duration of that event). Together with Monte Carlo propagation, these models are used to derive reach-scale volume estimates. The models identify flow rate and event duration as primary controls, while grain size has minimal influence within the sampled range of tracer dimensions. To strengthen our approach, we implement an extensive multi-stage validation process aimed at both single-tracer predictions and overall basin-scale movement estimates. The results indicate that high-magnitude transport events (12% of observations) contribute similar bedload volumes as typical events (88% of observations), highlighting the significant role of extreme events in total sediment transport. Model predictions yield bedload volume estimates that align well with independent measurements from a downstream sediment retention basin. Full article

Thisarticle develops and analyzes a fractional-order Leslie–Gower prey–predator–parasite system incorporating two discrete delays and nonlocal spatial diffusion. The model’s central novelty lies in the simultaneous integration of three biologically realistic features that have not previously been combined: (i) fractional-order memory effects via a Caputo derivative of order $\alpha \in (0,1]$, (ii) two distinct biological delays—an infection transmission delay ${\tau }_1$ and a predator handling delay ${\tau }_2$—and (iii) nonlocal spatial dispersal modeled through fractional Laplacian operators ${(-\Delta )}^{\gamma /2}$. This triple integration enables the model to capture long-range temporal memory, delayed biological responses, and nonlocal spatial interactions simultaneously, offering insights into dynamics that are challenging to capture with classical integer-order or single-delay formulations. The fractional Laplacian generalizes classical diffusion by allowing long-range dispersal events (Lévy flights), where individuals can occasionally move over large distances with heavy-tailed step-size distributions—a phenomenon observed in many animal movement patterns but absent from standard diffusion models. We provide rigorous proofs of solution existence, uniqueness, non-negativity, and boundedness in both temporal and spatiotemporal settings. Local asymptotic stability conditions are derived for all feasible equilibrium states via characteristic equation analysis. The coexistence equilibrium undergoes a Hopf bifurcation when either delay crosses a critical threshold, with fractional order $\alpha$ modulating the bifurcation point and post-bifurcation oscillation frequency. A Lyapunov functional demonstrates global asymptotic stability of the infection-free equilibrium under biologically interpretable conditions. Turing instability analysis reveals conditions for spontaneous pattern formation, with the fractional exponent $\gamma$ controlling pattern wavelength and correlation length. Numerical simulations validate theoretical predictions, including spatial patterns, traveling waves, and chaos. To bridge theory with potential applications, we outline a statistical framework for parameter estimation and uncertainty quantification, suggesting that $\beta$, $\alpha$, and ${\tau }_1$ may be priority targets for parameter estimation. Full article

To address the challenges of severe surface undulation in mountainous mining areas, significant InSAR geometric distortion, and the inability to directly calculate three-dimensional (3D) displacement from single-track Line-of-Sight (LOS) data, this paper proposes a 3D deformation reconstruction method that integrates Distributed Scatterer Interferometric Synthetic Aperture Radar (DS-InSAR) with an improved Probability Integral Model (PIM) considering topographic sliding effects. The traditional Probability Integral Method (PIM) ignores the additional sliding caused by topographic slope, leading to significant deviations when applied in mountainous areas. This study introduces a nonlinear sliding influence function and constructs a topographic correction model incorporating sliding intensity, position offset, and morphological attenuation parameters to quantitatively describe surface movement patterns under the coupling effect of mining and topography. Based on this, a model parameter-driven single-track InSAR observation equation is established, and the Adaptive Genetic Algorithm (AGA) is employed to invert the complete set of model parameters using high-density LOS deformation obtained from DS-InSAR as constraints, thereby resolving the full-basin 3D displacement field. Experimental results from a typical mountainous coal mine in the Taihang Mountain area of China demonstrate that this method effectively overcomes the ill-posedness of 3D displacement inversion from single-track InSAR data. The maximum vertical subsidence is 1050 mm, and the maximum horizontal displacement was 370 mm, consistent with leveling measurements (vertical RMSE: 75.1 mm; horizontal RMSE: 27.2 mm). Compared with traditional PIM methods without topographic correction, the proposed model reduces 3D displacement RMSE by approximately 35%, significantly improving calculation accuracy in mountainous areas with topographic undulation. Validation against leveling measurement points distributed along strike and dip directions confirms the reliability of reconstructed 3D displacement fields. This method not only restores the physical characteristics of topographic sliding but also provides a low-cost, high-precision solution for mining damage monitoring in complex terrain. Full article

Island reef road construction faces a complex marine service environment characterized by high salinity and high humidity. Meanwhile, rapid construction and prompt subgrade repair are urgently required, creating a strong demand for novel calcareous-sand-based stabilization materials that combine excellent mechanical performance with resistance to seawater erosion. To this end, this study developed an early-strength cemented calcareous-sand reinforcement material for road base construction. Sulfoaluminate cement (SAC) and ferrite-aluminate cement (FAC), both featuring rapid setting/early strength development and superior corrosion resistance, were used to cement calcareous sand (CS) and to investigate its mechanical and microstructural characteristics under different water environments. Unconfined compressive strength tests (UCS) showed that SC-CS and FC-CS could meet subgrade requirements at 1 d and 7 d, with SC-CS and FC-CS reaching 3.12 MPa and 3.44 MPa at 1 d, and 3.26 MPa and 3.67 MPa at 7 d, respectively, under seawater SS conditions. Seawater mixing and immersion were found to promote the early strength and stiffness development of both SC-CS and FC-CS, with a more pronounced effect observed for FC-CS. Based on experimental results, a damage model for the stabilized specimens was established with a fitting accuracy of R² > 0.97. This constitutive model accurately describes the stress–strain relationship of the material and quantitatively characterizes its damage evolution. Microscopic XRD and SEM analyses indicated that the main hydration product in freshwater-cured specimens was ettringite, and the interparticle connection of CS was dominated by bridging through rod-like ettringite. In contrast, under seawater conditions, the ettringite content decreased, while hydrotalcite and calcium aluminate hydrate increased, forming massive and lamellar bridging products. Compared with SC-CS, the bridging structure in FC-CS was denser. Moreover, the compactness of the bridging structure not only affected its mechanical properties but also governed the movement mode of CS particles, thereby influencing the damage evolution and failure mode of the specimens. The findings provide theoretical support for the construction needs of island road. Full article

Objectives: This study aimed to examine the structure of anthropometric characteristics, motor skills and specific motor skills in young football players. Methods: Study participants (427 male football players) were divided into pre-pioneers (11–13 y), n = 133; pioneers (13–15 y), n = 160; and cadets (15–17 y), n = 134. The entire sample of subjects was evaluated using 13 anthropometric and seven motor variables. The factor structure for each chronological age group was determined using Hotelling’s method. Results: Anthropometric characteristics showed three extracted factors in the pre-pioneers group, four factors in the pioneer group and two factors in the cadet group. Motor skills displayed three factors for the youngest group, two factors for the pioneers and three factors for the cadet group. Four factors were determined for specific motor skills in pre-pioneers, four in pioneers and three in cadet age. Conclusions: This study revealed structural variability and non-uniformity in the latent dimensions across age groups, with the total number of factors fluctuating between two and four. This study revealed two consistent latent dimensions in anthropometric data across all age groups: general morphological parameters and subcutaneous fat tissue. In motor skills, an initial universal factor is separated into central and energetic regulation of movements. Finally, specific motor skills demonstrated a transition from a highly differentiated four-factor structure in younger players toward a more integrated functional system in the oldest cohort, comprising intermuscular coordination, running speed with and without a ball; segmental speed of the lower extremities with a ball; and explosive force in hitting a ball with the foot and head. Full article

Leakage flow interferes with the main flow movement and has a close relationship with the rotational stall phenomenon. To study the rotational stall characteristics of mixed-flow pumps under different tip clearances (rim clearances), numerical simulations of the internal flow field of the mixed-flow pump were carried out based on the SST k-ω turbulence model and hexahedral structured meshes, with the tip clearances set to 0.2 mm, 0.5 mm, and 0.8 mm respectively. The external characteristics, internal flow field under stall conditions, impeller surface pressure, and internal vorticity distribution of the mixed-flow pump were compared among the three different tip clearances. The research results show that when the tip clearance is 0.5 mm, the numerical simulation results are in good agreement with the experimental results, indicating the high reliability of the simulation. Under the three different tip clearances, the near-stall and deep-stall operating points on the external characteristic curves are consistent. When the tip clearance is 0.8 mm, the positive slope characteristic of the flow rate–head curve of the mixed-flow pump is the most obvious. From the small flow rate condition to the large flow rate condition, the influence of the tip clearance on the efficiency of the mixed-flow pump gradually increases. Under deep-stall conditions, with increasing tip clearance, the stall vortex at the flow passage outlet causes more intense disturbances to the inlet of the downstream flow passage and induces the formation of new stall vortices at the downstream passage inlet, thereby increasing internal flow losses. The increase in the tip clearance leads to changes in the morphology of the leakage vortex, a decrease in the impeller surface pressure, intensification of flow disorder, and enhancement of the leakage vortex intensity. Moreover, compared with the rated condition, the leakage vortex of the mixed-flow pump under stall conditions is more affected by the tip clearance. Full article

Subsoiling can break the plough pan and improve the root growth environment. The effect of the traditional subsoiler is poor, as it relies only on the chisel tine, but pneumatic subsoiling can improve the soil structure more efficiently through the negative pressure generated by the jet hole. This research used computational fluid dynamics and the discrete element method to optimize the biomimetic structure of the jet hole, model the pneumatic subsoiling process at a depth of 330 mm, and observe the movement of soil particles as airflow passes through. The effect of the jet hole at different positions and sizes on the plough pan soil was analyzed, and fluid domains and measurement areas were set up to observe the upward movement, diffusion, stabilization, and settling of soil particles under the action of airflow. The results of the soil bin experiment validated the accuracy of the simulation model through draft force and vertical force, and the average error between the simulation and experimental data was 2.8%. The study revealed that the increase in the rate of soil porosity reached a maximum of 3.65% when the jet hole was positioned above the chisel tine with a radius of 4 mm. The biomimetic jet hole pneumatic subsoiler designed in this study, along with the established CFD-DEM coupled simulation model capable of predicting pneumatic subsoiling performance, can provide references for the design and application of a pneumatic subsoiler. Furthermore, it also provides a theoretical basis for understanding the mechanism of airflow on soil during pneumatic subsoiling operations. Full article

Background/Objectives: Nutritional vulnerability (NV) describes the interaction of diet quality, access to food, health status and socioeconomic factors and may differ between neighborhoods. Nevertheless, there is still a limited amount of evidence regarding local NV variations in contrasting resource landscapes. The purpose of this study was to operationalize NV in Windham, Connecticut and conduct an analysis of its spatial distribution and the differences between neighborhoods for NV and specifically diet quality. Methods: NV was measured with four indicators, including two diet quality measures (liking-based DQI and short food frequency-based sHEI), food security, obesity, and SNAP participation. Areas of vulnerable concentration were determined through spatial mapping. Indicators related to each other were measured by Spearman correlation. To compare the contrasting neighborhoods (resource-dense vs. resource-limited), contextual differences were studied and differences in NV indicators, sociodemographic and movement factors were compared with the help of chi-square tests. Diet quality measures were jointly examined for concordance (both measures low or high) and discordance. Results: Area-level comparisons showed significant differences in mobility-related and sociodemographic characteristics, including vehicle access and education level (p < 0.05). High diet quality (measure concordance) was reported by individuals living in high-resourced regions; low diet quality (measure concordance) by individuals in low-resourced regions. Conclusions: The NV Map illustrated focal patterns of vulnerability determined by the interplay of sociodemographic disadvantage and mobility-related limitations and not by distance to food resources. These results give practical spatial data to promote specific nutrition and resource intervention. Full article

The rapid growth of hiking tourism presents a critical challenge for balancing visitor safety with the sustainable management of ecologically fragile mountain environments. Traditional models developed in urban settings struggle to capture the highly non-linear, heterogeneous, and zero-inflated characteristics of wilderness trekking behavior. In order to quantify the nonlinear and threshold-based effects of environmental variables on hikers’ spatial decisions in unstructured wilderness and to identify distinct behavioral regimes for segmented management, this study introduces an explainable machine learning framework to reconstruct hikers’ spatial decision-making in a complex mountainous system in Inner Mongolia, China. Random Forest (RF), XGBoost, and LightGBM were compared in predicting trail density and the Euclidean distance to the nearest trail. Results show that transforming behavioral traces into continuous proximity surfaces dramatically improves model performance, with XGBoost achieving the highest predictive accuracy for Trail_Dist. By integrating the SHapley Additive exPlanations framework, this study moves beyond black-box prediction to reveal the nonlinear mechanisms driving hiker behavior. Key findings include: (1) Nighttime light range exhibits a U-shaped threshold effect as the primary anthropogenic attractor. (2) Elevation shows an exponential inhibitory trend above 1238 m. (3) Strong spatial coupling exists between elevation and slope, alongside a landscape compensation effect where high Normalized Difference Vegetation Index (NDVI) areas attract off-trail movements. This research provides a robust methodological pathway for predicting behavior in unstructured outdoor environments. It offers a scientific foundation for smart scenic area management, including optimized route planning, precise ecological protection zoning, and targeted emergency rescue preparedness. Full article