Search Results (994)

The “three rights separation” system plays a vital role in enhancing the economic efficiency of rural residential land use, thereby contributing to land revitalization and rural-urban integration. Using survey data from 456 farmers in Yujiang District and Deqing County, this study employs DEA, Tobit, and threshold regression models to analyze the system’s effects. The results show that the system improves economic efficiency by approximately 8.9%, primarily by incentivizing investment and promoting land transfers. A nonlinear threshold effect exists: investment incentives become significant only when idle land exceeds 35 m², consistent with farmers’ economic decision-making. Land transfers enhance efficiency via marginal return equalization, however, economies of scale are not evident, being constrained by legal and coordination factors. The findings highlight the importance of deepening reform implementation, enhancing farmers’ understanding of property rights, adopting differentiated incentives tailored to land size and farmer capacity, and regulating the land transfer market to ensure transparency and fairness. Furthermore, promoting collective or service-based management models can help overcome natural scale limitations, thereby unlocking the system’s full institutional dividends. Full article

Dissimilar steel welding is a necessary means for engineering structures to meet complex service conditions. However, residual stress becomes a challenge for the service properties of dissimilar welded joints (DWJs), as it can reduce fatigue strength and trigger cracking in welded components. Therefore, accurately estimating the distribution of residual stress and efficiently eliminating it is of great importance. This study investigated the evolution of residual stress during the welding process of two commonly used ferritic steels through experimental and numerical analyses. The results show that different thermal cycle behaviors between DWJs have a significant impact on the formation of residual stress. Longitudinal tensile residual stress is predominant in the weld and heat-affected zone (HAZ), with higher longitudinal tensile and compressive stresses in the Q390 side than in the Q690 side, while the maximum transverse tensile stress occurs in the HAZ of the Q690 side. Hammer peening shows excellent ability to eliminate residual stress after welding, with a maximum elimination rate of approximately 62%, and converts the stress state from tensile to compressive at a certain welding depth. The analysis of process parameters reveals that peening velocity is the most influential factor. Under the present experimental configuration, the peening velocity should be set between 4.5 m/s and 5.5 m/s. Full article

Background: Chronic obstructive pulmonary disease (COPD) is a progressive condition leading to declining lung function, dyspnea, and reduced quality of life. Pulmonary rehabilitation (PR) remains a cornerstone in COPD management; however, access remains limited, with less than 3% of eligible patients participating. Inspiratory muscle training (IMT), especially through novel methods like the Test of Incremental Respiratory Endurance (TIRE), offers a potential home-based alternative to traditional rehabilitation services. Despite growing interest, a key knowledge gap persists: few randomized trials have directly compared TIRE with threshold loading IMT over extended, largely unsupervised home-based periods while concurrently evaluating inspiratory muscle endurance and adherence. This randomized controlled trial aimed to evaluate the long-term efficacy of TIRE IMT compared to traditional threshold IMT and sham training in COPD patients. The study also assessed adherence to these home-based interventions, focusing on unsupervised periods without additional motivational support. Methods: A total of 52 COPD patients were randomly assigned to one of three groups: TIRE IMT, Threshold IMT, or Sham IMT. The study consisted of an 8-week supervised Phase I followed by a 24-week unsupervised Phase II. Training details: TIRE—session template set to 50% of the day’s maximal sustained effort; 6 levels × 6 inspirations (total 36) with preset inter-breath recoveries decreasing from 60 s to 10 s. Threshold IMT—spring-loaded valve set to 50% MIP (re-set at week 4); 36 inspirations completed within ≤30 min. Sham—valve set to minimal resistance (9 cmH₂O); 36 inspirations within ≤30 min. Primary outcomes included changes in maximal inspiratory pressure (MIP) and sustained maximal inspiratory pressure. Secondary outcomes focused on adherence rates and correlations with functional capacity. Results: Of the 52 participants, 36 completed the study. Participant details: TIRE n = 12 (mean age 60.9 ± 12.9 years), Threshold n = 12 (67.4 ± 6.9 years), Sham n = 12 (67.3 ± 8.7 years); overall 21/36 (58%) men; mean BMI 30.0 ± 7.5 kg/m². The TIRE IMT group demonstrated significantly greater improvements in MIP (31.7%) and SMIP compared to both the Threshold and Sham groups at 24 weeks (p < 0.05). Despite a decline in adherence during the unsupervised phase, the TIRE group maintained superior outcomes. No adverse events were reported during the intervention period. Conclusions: In this randomized trial, TIRE IMT was associated with greater improvements in inspiratory muscle performance than threshold and sham IMT. While adherence was higher in the TIRE group, it declined during the unsupervised phase. The clinical interpretation of these findings should consider the relatively wide confidence intervals and modest sample size. Nevertheless, the mean change in MIP in the TIRE arm exceeded a recently proposed minimal important difference for COPD, suggesting potential clinical relevance; however, no universally accepted minimal important difference exists yet for SMIP. Further adequately powered trials are warranted. Full article

The establishment of a new green space system based on the green belt has become a new trend in the world. Shanghai’s Outer Ring Ecological Park Belt (formerly the Outer Green Belt) faces challenges of spatial imbalance in recreational service distribution and mismatched supply and demand in functional allocation during its transition from an ecological barrier to a recreational service provider. An approach based on spatial spillover effects serves as a critical solution to address these issues. We integrate RPS and ROS models to build an evaluation framework, map recreational service supply for 2013, 2018, and 2023, delimit core areas via MSPA, and quantify spatial spillovers with models SLM and SEM. The results show that high-value areas of recreational service levels along the ecological park belt have driven the development of neighboring areas through spatial spillovers, with this promoting effect radiating outward from the core zones. As the distance from the core areas increases, the effect weakens, with 400 m as the maximum effect boundary, 1 km as the critical spillover boundary, and unstable effects with decreased significance beyond 2 km. We further conduct localized spatial spillover analysis using representative parks as case studies. The research provides theoretical support and implementation suggestions for the planning and construction of an ecological park belt. Full article

Fine particulate matter (PM_2.5) has been associated with mortality at low concentrations, with higher per-unit risk at lower exposure levels, and no threshold of effect. We examined characteristics of Medicare decedents living in zip codes at the lowest end of the U.S. PM_2.5 exposure distribution to determine whether there is a demographic, health or exposure profile of beneficiaries for whom even low PM_2.5 exposure is associated with increased mortality. The study included 2,773,647 decedent cases and 27,736,470 non-decedent controls, matched on decile of long-term PM_2.5 exposure from among 36 million Medicare fee-for-service beneficiaries enrolled 2015–2016. Outcomes of the study included all-cause and cause-specific mortality, stratified by decile and beneficiary characteristics. Increased PM_2.5-related mortality within the lowest exposure decile was found only among Native American beneficiaries, with odds ratios of 1.11 (95% CI, 1.01–1.21) and 1.21 (95% CI, 1.11–1.32) per 1 µg/m³ increase in PM_2.5, for those eligible and ineligible for Medicaid, respectively, and was driven by significant increases in selected kidney and cardiovascular outcomes, diabetes, and chronic obstructive pulmonary disease. These results may reflect particular sensitivity to PM_2.5; factors varying with PM_2.5 at the zip code level, including constituent exposures or social determinants of health; or inaccuracies in exposure estimates. Full article

Tyre wear is a major contributor to global microplastic pollution, affecting air, soil, water, and wildlife as well as human health. In the European Union (EU), the latest Euro 7 regulation foresees the introduction of tyre abrasion limits covering all tyre categories, referring to two testing methods (convoy on road or laboratory drum) developed by the United Nations (UN) Economic Commission for Europe (UNECE) World Forum for Harmonization of Vehicle Regulations (WP.29). In this study, we applied the convoy method adopted by the UNECE Working Group on Noise and Tyres (GRBP) as part of the UN Regulation 117 on tyre performance parameters. The method has been developed by the Task Force on Tyre Abrasion (TFTA) of the UNECE and involves vehicles driving on public roads for about 8000 km. Candidate and reference tyres are fitted in a convoy of up to four vehicles, and an abrasion index for each candidate tyre is determined as a ratio of the abrasion of the candidate and reference tyres. In our tests, in addition to the abrasion rate, we measured the tread depth reduction and defined a service life index (i.e., total mileage potential) without the need of a different methodology. The results from six summer and nine winter C1 class passenger car tyres of various sizes showed a wide range of abrasion rates and service life values. We also compared our results with values reported in the literature and on websites. The conclusions of this study are expected to support the ongoing discussion on limit setting for C1 tyres and the definition of a service life index. Full article

Background: In February 2024, a nationwide resignation of resident physicians and fellows in South Korea caused a sudden disruption in the healthcare service delivery system. This study aimed to investigate how the crisis affected hospital admission patterns, treatment timelines, and early outcomes in patients with acute hemorrhagic stroke. Methods: We retrospectively analyzed data from prospective cohorts of patients diagnosed with intracerebral hemorrhage or subarachnoid hemorrhage admitted to a single cerebrovascular-specialty hospital between March 2023 and February 2025. Patients were categorized into two groups: those admitted before (Before crisis group, n = 130) and after (After crisis group, n = 214) the crisis. Clinical characteristics, regional distribution, time delays, and 3-month modified Rankin Scale (mRS) outcomes were compared. Results: Following the crisis, a significant increase was observed in admissions from outside the hospital’s primary coverage area (p < 0.001). Onset-to-arrival (138.0 vs. 92.0 min, p = 0.040) and onset-to-operation times (200.0 vs. 166.0 min, p = 0.046) were significantly delayed, particularly in patients who underwent surgical treatment. However, arrival-to-operation time remained stable (p = 0.694), and initial neurological severity was comparable. Functional outcomes at 3 months did not differ significantly (mRS 0–2: 53.8% vs. 50.5%, p = 0.157), indicating preserved in-hospital care quality, despite external disruption. Conclusions: The medical crisis disrupted the stroke care delivery system and delayed prehospital care in South Korea. Nevertheless, the cerebrovascular-specialty hospital maintained timely intervention and preserved outcomes. These findings support the strategic importance of decentralized specialty hospitals in ensuring the resilience of the healthcare service delivery system during a national healthcare crisis. Full article

The stability of ecosystems in coastal plain cities is fragile, and the interaction between humans and the land is complex, making the region’s natural water cycle capabilities more vulnerable to destruction. Quantitatively assessing the water conservation services in coastal areas and revealing its spatial characteristics and driving factors play a crucial role in the construction of regional ecological barriers and the assurance of ecological security. In this study, based on the water balance model, the spatial dynamics of water in the ecosystems of Yancheng from 2019 to 2021 were assessed in two dimensions: ecosystem and administrative subdivision. The response of the influencing factors to the water conservation was examined using a geographical detection. The results show the following: (1) Yancheng’s water conservation services increased (2019–2021), averaging 1.188 × 10⁹ m³/a. Spatially, it was higher in southeastern/northern sectors and lower in western/central regions, with wetlands and croplands contributing 93.76% collectively while others each accounted for <1%. (2) NDVI was the strongest driver of spatial heterogeneity (q = 0.736), followed by per capita water use, population density (q = 0.642), and DEM (q = 0.638); GDP per capita and annual precipitation exerted the weakest influences. (3) Factor interactions exceeded individual factors in explanatory power, dominated by population density synergies with per capita water use and NDVI, which most strongly controlled spatial patterns. (4) Optimization thresholds were identified: peak water conservation occurred at DEM 5.34–5.47 m and NDVI 0.37–0.42. This study provides a new perspective on water conservation in coastal areas, supplying serves as a reference for crafting specific water preservation strategies in the coming years. Full article

Space-based on-orbit servicing missions impose stringent requirements for precise identification and localization of satellite components, while existing detection algorithms face dual challenges of insufficient accuracy and excessive computational resource consumption. This paper proposes SLD-YOLO, a lightweight satellite component detection model based on improved YOLO11, balancing accuracy and efficiency through structural optimization and lightweight design. First, we design RLNet, a lightweight backbone network that employs reparameterization mechanisms and hierarchical feature fusion strategies to reduce model complexity by 19.72% while maintaining detection accuracy. Second, we propose the CSP-HSF multi-scale feature fusion module, used in conjunction with PSConv downsampling, to effectively improve the model’s perception of multi-scale objects. Finally, we introduce SimAM, a parameter-free attention mechanism in the detection head to further improve feature representation capability. Experiments on the UESD dataset demonstrate that SLD-YOLO achieves measurable improvements compared to the baseline YOLO11s model across five satellite component detection categories: mAP50 increases by 2.22% to 87.44%, mAP50:95 improves by 1.72% to 63.25%, while computational complexity decreases by 19.72%, parameter count reduces by 25.93%, model file size compresses by 24.59%, and inference speed reaches 90.4 FPS. Validation experiments on the UESD_edition2 dataset further confirm the model’s robustness. This research provides an effective solution for target detection tasks in resource-constrained space environments, demonstrating practical engineering application value. Full article

A multimodal interactive system, HortiVQA-PP, is proposed for horticultural scenarios, with the aim of achieving precise identification of pests and their natural predators, modeling ecological co-occurrence relationships, and providing intelligent question-answering services tailored to agricultural users. The system integrates three core modules: semantic segmentation, pest–predator co-occurrence detection, and knowledge-enhanced visual question answering. A multimodal dataset comprising 30 pest categories and 10 predator categories has been constructed, encompassing annotated images and corresponding question–answer pairs. In the semantic segmentation task, HortiVQA-PP outperformed existing models across all five evaluation metrics, achieving a precision of 89.6%, recall of 85.2%, F1-score of 87.3%, $mAP@50$ of 82.4%, and IoU of 75.1%, representing an average improvement of approximately 4.1% over the Segment Anything model. For the pest–predator co-occurrence matching task, the model attained a multi-label accuracy of 83.5%, a reduced Hamming Loss of 0.063, and a macro-F1 score of 79.4%, significantly surpassing methods such as ASL and ML-GCN, thereby demonstrating robust structural modeling capability. In the visual question answering task, the incorporation of a horticulture-specific knowledge graph enhanced the model’s reasoning ability. The system achieved 48.7% in BLEU-4, 54.8% in ROUGE-L, 43.3% in METEOR, 36.9% in exact match (EM), and a GPT expert score of 4.5, outperforming mainstream models including BLIP-2, Flamingo, and MiniGPT-4 across all metrics. Experimental results indicate that HortiVQA-PP exhibits strong recognition and interaction capabilities in complex pest scenarios, offering a high-precision, interpretable, and widely applicable artificial intelligence solution for digital horticulture. Full article

In gas drilling operations, the blooey line is highly susceptible to erosion-induced leakage. This study focuses on the use of field-welded V-shaped elbows in blooey lines, establishing a numerical method for erosion prediction and validating its accuracy through experimental data. The numerical results reveal that, due to the inclined configuration of the V-shaped elbow, particles from the central inlet flow directly impact the outer wall of the outlet pipe opposite the inlet, and then rebound and strike the inner wall. Meanwhile, solid particles near the pipeline wall on both sides of the inclined plane collide with the outer wall and exit in a helical flow pattern along the outlet pipe. The maximum erosion rate (3.6 × 10⁻⁴ kg/(m²·s)) occurs at the intersection of these spiral particle flows. Based on erosion predictions under various operating conditions, an empirical formula was established to correlate the erosion rate with the gas injection rate at a rate of penetration (ROP) of 1 m/h, along with corresponding conversion relationships for different ROPs. The predicted residual thickness of the V-shaped elbow showed a 6.8% relative error compared to field measurements. The proposed method can be programmed to enable real-time monitoring of the residual wall thickness and the remaining service life of the blooey line before leakage occurs, assisting field operators in determining optimal pipeline replacement schedules to ensure operational safety. Full article

(1) Background: It seems that (i) the most frequent and critical physical tasks during police service are fence jump, victim drag, and arrest suspect, and (ii) high fitness attributes are conducive to solving police physical tasks with higher success rates. By this, this study aims (i) to evaluate the reliability for assessing police physical tasks (PPTs) and (ii) to identify the fitness attributes that best explain the performance in carrying out PPT. We hypothesize that performance in PPT presents high reliability and that fitness attributes are significant predictors of performance in PPT. (2) Methods: A total of 76 cadets from the Portuguese Police Academy completed (i) three PPT (fence jump—FJ; victim drag—VD; and arrest suspect—AS) in two distinct sessions (T1 and T2), separated by a one-week interval (test–retest design), and subsequently, separated by a one-week interval, (ii) seven fitness tests (T3; cross-sectional design). (3) Results: It was observed that (i) the mean difference in performance (T2-T1) in FJ was 0.05 s (ICC = 0.88), in VD was −0.06 s (ICC = 0.92), and in the AS was −1.21 s (ICC = 0.81); (ii) male cadets were significantly faster, more agile, stronger, and more resistant than female cadets, and they were significantly faster at FJ and VD; (iii) in females, performance in the 30 m sprint tests, sit-ups, and horizontal jump are predictors of FJ, VD, and AS, respectively; and (iv) in males, performance in the horizontal jump and the 20 m shuttle run are predictors of FJ performance, while handgrip strength is a significant predictor in the VD. (4) Conclusions: This study showed that (i) the PPT evaluation protocol presents high reliability (ICC of 0.87, SE = 0.17), suggesting that it is a reliable protocol, capable of being applied to police officers, and (ii) within the scope of attributes that predict performance in the PPTs under study, it appears that the explosive strength of the lower limbs is a relevant attribute, regardless of gender. Full article

Bridge cranes generally have a significant disparity between their actual service life and design life. If they are scrapped according to the design life, it is likely to result in resource wastage or pose potential safety hazards due to extended service. Existing studies have not thoroughly examined the coupling relationship among actual working conditions, structural damage, and load-matching strategies. It is difficult to achieve real-time and accurate adaptation between loads and the carrying capacity of equipment, and thus cannot effectively narrow this life gap. To this end, this paper defines a digital twin system framework for crane load adaptive matching, constructs a load adaptive matching optimization model, proposes a method for developing a digital twin system for bridge crane load adaptive matching, and builds a digital twin system platform centered on virtual-real mapping, IoT connectivity, and data interaction. Detailed experimental verification was conducted using the DQ40 kg-1.8 m-1.3 m light-duty bridge crane. The results demonstrate that this method and system can effectively achieve dynamic matching between the load and real-time carrying capacity. While ensuring the service life exceeds the design life, the difference between the two is controlled at around 3467 cycles, accounting for approximately 0.000462% of the design life. This significantly improves the equipment’s operational safety and resource utilization efficiency, breaks through the limitations of load reduction schemes formulated based on human experience under the traditional regular inspection mode, and provides a scientific load-matching decision-making basis and technical support for special equipment inspection institutions and users. Full article

Mission-critical services (MCX) comprise a standardized suite of capabilities including Mission-Critical Push-to-Talk (MCPTT), MCVideo, and MCData, designed to meet stringent requirements for availability, reliability, latency, security, and Quality of Service (QoS). These services are essential for public safety, emergency response, and other critical infrastructure domains, where communication performance directly affects operational effectiveness. Integration into 4G and 5G mobile networks, supported by targeted standardization efforts, has extended broadband capabilities to mission-critical environments. 5G networks provide the technical foundations for MCX through ultra-low latency (below 1 ms), high availability (99.999%), broadband throughput over 100 Mbps per user, deterministic QoS via network slicing, massive device connectivity (over one million devices per square kilometer), and seamless Non-Terrestrial Network (NTN) integration. Technical enablers such as Proximity Services (ProSe), network slicing, and Ultra-Reliable Low-Latency Communications (URLLC) are fundamental to delivering these capabilities. This paper reviews MCX architectures, service frameworks, and protocols, relating MCPTT, MCData, and MCVideo to the key performance requirements defined in ITU-T M.2377-2. It also examines the frozen features of 3GPP Release 19, including enhancements to MC services, NTN integration, Reduced Capability device support, sub-meter positioning, extended network slicing for Public Protection and Disaster Relief (PPDR), and strengthened security mechanisms. Finally, the study addresses challenges such as standard maturity, interoperability, and deterministic QoS, identifying research priorities toward 6G readiness. By consolidating advances from standards bodies, research initiatives, and deployments, this work serves as a technical reference for scalable, secure, and standards-compliant MCX solutions in current and future networks. Full article

Hydraulic concrete is prone to cracking and interactive propagation under complex stress, threatening its structural integrity and service life. To address limitations of traditional numerical methods (e.g., mesh dependency in FEM) and imprecision of existing meshless methods for characterizing multi-fissure interactions, this study improved SPH to model double-crack interactions in hydraulic concrete under three-point bending and clarify the underlying mechanisms. A modified SPH framework was developed by introducing a failure parameter (ξ) to refine the kernel function, enabling simulation of particle progressive failure via the Mohr–Coulomb criterion; a three-point bending numerical model of concrete beams containing double precast fissures (induced and obstacle) was established, with simulations under varying obstacle fissure angles (α = 0–75°) and distances (d = 0.02–0.06 m). The results show that the obstacle fissure angles significantly regulate the crack paths: as the α increases, the tensile stress concentration shifts from the obstacle fissure’s middle to its ends, causing cracks to deflect toward the lower end, with a reduced propagation length and lapping time; at an α = 75°, the obstacle fissure’s lower tip dominates failure, forming an “induced fissure–lower end of obstacle fissure–top” penetration mode. The fissure distances affect the stress superposition: a smaller d (e.g., 0.02 m) induces vertical propagation and rapid lapping with the obstacle fissure’s lower end, while a larger d (e.g., 0.06 m) weakens the stress at the induced fissure tip, promoting horizontal deflection toward the obstacle fissure’s upper end and transforming the failure into “upper-end dominated.” This confirms that the improved SPH method effectively simulates crack behaviors, providing insights into multi-fissure failure mechanisms and theoretical support for hydraulic structure crack control and safety evaluation. Full article