Search Results (5,643)

Aeolian sand is the primary geological material for construction in desert regions, and its stabilization with industrial solid wastes-based geopolymer (ISWG) provides an eco-friendly treatment replacing cement. This study comparatively investigated the enhancement effects of chemical activators and expansive agents on compressive strength of aeolian sand stabilized by ISWG (ASIG). Three chemical activators—NaOH, Ca(OH)₂, and CaCl₂—along with two expansive agents—desulfurized gypsum and bentonite—were considered. Through X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, mercury intrusion porosimetry and pH values tests, the enhancement mechanisms of the additives on ASIG were elucidated. Results demonstrate that the expansive agent exhibits significantly superior strengthening effects on ASIG compared to the widely applied chemical activators. Chemical activators promoted ISWs dissolution and hydration product synthesis, thereby densifying the hydration product matrix but concurrently enlarged interparticle pores. Desulfurized gypsum incorporation induced morphological changes in ettringite, and excessive desulfurized gypsum generated substantial ettringite that disrupted gel matrix. In contrast, bentonite demonstrated superior pore-filling efficacy while densifying gel matrix through a compaction effect. These findings highlight bentonite superior compatibility with the unique microstructure of aeolian sand compared to conventional alkaline activators or expansive agents, and better effectiveness in enhancing the strength of ASIG. Full article

Large-scene space-borne SAR images with a high resolution are particularly effective for monitoring vast oceanic areas globally. However, ships are easily overlooked in such large scenes due to their small size and cluttered backgrounds, making SAR ship detection challenging for the existing methods. To address this challenge, we propose a progressive saliency-guided (PSG) method, which uses saliency-derived positional priors to guide the model in focusing on small targets and extracting their features. Specifically, a dual-guided perception enhancement (DGPE) module is developed, which introduces additional target saliency maps as prior information to cross-guide and highlight key regions in SAR images at the feature level, enhancing small object feature representation. Additionally, a saliency confidence aware assessment (SCAA) mechanism is designed to strengthen small object proposal learning at the proposal level, guided by classification and localization scores at key locations. The DGPE and SCAA modules jointly enhance small object learning across different network levels. Extensive experiments demonstrate that the PSG method significantly improves the detection performance (+4.38% AP on LS-SSDD and +4.35% on HRSID) for small ships in large-scene SAR images compared to that of the baseline, providing an effective solution for small ship detection in large scenes. Full article

With the rising urgency of global environmental challenges, understanding the mechanisms behind green consumption has become increasingly vital. This study investigates how green product information disclosure influences consumers’ green consumption intention, focusing on new energy vehicle (NEV) consumers in China. Grounded in the Theory of Planned Behavior (TPB), the study introduces environmental concern as a mediator and brand reputation as a moderator to enhance the explanatory power of the model. A total of 527 valid questionnaires were collected on-site from NEV exhibitions in Beijing. Structural equation modeling and PROCESS macro analysis were employed to test the research hypotheses. The results indicate that environmental information disclosure significantly promotes green consumption intention, both directly and indirectly, through the mediating effects of green consumption attitude, subjective norms, and environmental concern. However, the direct effect of information communication channels was not statistically significant. Moreover, brand reputation positively moderates the relationship between environmental information disclosure and green consumption intention. These findings provide new theoretical insights by extending TPB with contextual and psychological variables and offer practical implications for NEV manufacturers and marketers. Specifically, companies are encouraged to prioritize transparent and credible environmental information disclosure, strengthen brand reputation, and consider consumers’ attitudes and social norms when designing green marketing strategies. Full article

Urban economic development together with the concentration of population acts as a major stimulus for changes in land-use configurations, thereby reshaping local ecosystems and influencing habitat quality. Conducting a rigorous evaluation of the temporal–spatial dynamics and the mechanisms underlying these changes is crucial for refining spatial management strategies, improving urban livability, and steering cities toward sustainable pathways. In this research, we established a comprehensive analytical framework that integrates the PLUS model, the InVEST model, and the GeoDetector model to examine shifts in land-use patterns and habitat quality in Busan Metropolitan City during 1988–2019 to pinpoint the principal influencing factors and to project possible trajectories for 2029–2049 under multiple climate change scenarios. The key findings can be summarized as follows: (1) during the last thirty years, the city’s land-use structure underwent substantial transformation, with forested areas and built-up zones becoming the primary categories, indicating continuous urban encroachment and the reduction in ecological land; (2) the average habitat quality dropped by 18.23%, displaying a distinct spatial gradient from low values in plains and coastal areas to higher values in mountainous and inland zones; (3) results from the GeoDetector revealed that variations in land-use type and NDVI exerted the greatest influence on habitat quality differences, reflecting the combined impacts of environmental conditions and socio-economic pressures; (4) scenario projections show that the SSP1-2.6 pathway supports ecological land growth and leads to a notable improvement in habitat quality, while SSP5-8.5 causes ongoing deterioration driven by the expansion of construction land. The SSP2-4.5 pathway demonstrates a relatively moderate pattern, balancing urban development needs with ecological preservation and thus is more consistent with the long-term sustainability objectives of Busan. This study provides a robust scientific basis for understanding historical and projected changes in land cover and habitat quality in Busan and offers theoretical guidance for optimizing land-use structures, strengthening ecological protection, and fostering sustainable development in Busan and other coastal mountainous cities. Full article

The continuous discharge voltage waveform and phenomena between the electrode and substrate were explored in this paper to study the ultrasonic electro-spark deposition process. Additionally, the impact of ultrasonics on the ultrasonic electro-spark deposition process and the properties of the deposition layer were examined. The results show that the charge–discharge frequency of the ultrasonic electro-spark deposition process was commensurate with the discharge frequency of the ultrasonic electro-spark deposition power source, and the voltage waveform was stable. When ultrasonics is introduced, the molten droplet spray trajectory is efficiently guided, resulting in the spark spray trajectory displaying notable directional concentration characteristics. During a single charging and discharging phase, the electrode and substrate made roughly 15 mechanical contacts, 1 of which was discharging, and the remaining 14 were mechanically contacted reinforcement. The surface of the ultrasonic electro-spark deposition layer exhibited a sputtering morphology with no surface cracks. Phase structures such as Co₃W₃C, Fe₃W₃C, Fe₆W₆C, WC, and W₂C constituted the majority of the ultrasonic electro-spark deposition layer’s microstructure and showed strong metallurgical bonds with the substrate. The ultrasonic electro-spark deposition layer has a surface roughness of 2.554 μm, a cross-section porosity of 1.3%, and a maximum microhardness of 1038.8 HV_0.025. Comparative analysis demonstrates that the addition of ultrasonics can significantly enhance the deposition layer’s quality and performance. When compared to the electro-spark deposition layer, the surface roughness of the ultrasonic electro-spark deposition layer decreases by roughly 61.4%, the cross-sectional porosity decreases by around 57.5%, and the maximum microhardness increases by about 15.5%. Many cracks and much high surface roughness in the conventional electro-spark deposition layer are resolved by the ultrasonic electro-spark deposition technique, which is crucial for cold drawing mold surface strengthening. Full article

Broken or loose strands in high-voltage transmission conductors constitute critical defects that jeopardize grid reliability. Unmanned aerial vehicle (UAV) inspection has become indispensable for their timely discovery; however, conventional detectors falter in the face of cluttered backgrounds and the conductors’ diminutive pixel footprint, yielding sub-optimal accuracy and throughput. To overcome these limitations, we present PowerStrand-YOLO—an enhanced YOLOv8 derivative tailored for UAV imagery. The method is trained on a purpose-built dataset and integrates three technical contributions. (1) A C2f_DCNv4 module is introduced to strengthen multi-scale feature extraction. (2) An EMA attention mechanism is embedded to suppress background interference and emphasize defect-relevant cues. (3) The original loss function is superseded by Shape-IoU, compelling the network to attend closely to the geometric contours and spatial layout of strand anomalies. Extensive experiments demonstrate 95.4% precision, 96.2% recall, and 250 FPS. Relative to the baseline YOLOv8, PowerStrand-YOLO improves precision by 3% and recall by 6.8% while accelerating inference. Moreover, it also demonstrates competitive performance on the VisDrone2019 dataset. These results establish the improved framework as a more accurate and efficient solution for UAV-based inspection of power transmission lines. Full article

In China, most of the ancient wooden structure mortise and tenon buildings, under the long-term upper load, have columns with surface surfaces that have varying degrees of damage, which need to be repaired and strengthened urgently, but the theory related to CFRP, mortise size, and pre-damage simulation still needs to be deeply studied. To investigate the effects of CFRP reinforcement layers, cross-sectional area of concealed tenons as the projected area after installation, and tenon engagement length as the axial length after installation on the axial compressive mechanical properties of pre-damaged quad-segment spliced Pinus sylvestris var. mongolia composited wooden columns, axial compression failure tests were conducted on 10 specimens following pre-damage simulation and CFRP strengthening. The experimental program yielded comprehensive data, including observations, mechanical analyses, load-displacement curves, load-strain curves, ultimate load-bearing capacities, ductility coefficients, and stiffness values. The results demonstrate that with consistent tenon cross-sectional area and engagement length, increasing CFRP layers from 1 to 3 raises the ultimate bearing capacity from 472.3 kN to 620.3 kN and improves the ductility coefficient from 4.67 to 7.95, clearly indicating that CFRP reinforcement significantly enhances axial compressive performance while effectively mitigating brittle failure. When maintaining constant CFRP layers and tenon cross-sectional area, extending the tenon engagement length from 30 mm to 90 mm elevates the bearing capacity from 494.95 kN to 546.3 kN and boosts the ductility coefficient from 5.58 to 7.95. In contrast, with fixed CFRP layers and engagement length, expanding the tenon cross-sectional area from 360 mm² to 810 mm² produces only marginal bearing capacity improvement from 548.2 kN to 556.2 kN with ductility coefficients ranging between 4.67 and 5.56, conclusively revealing that tenon engagement length has substantially greater influence on mechanical properties than cross-sectional area. The optimal axial compressive performance configuration combines 3 CFRP layers, an 810 mm² tenon cross-section, and a 90 mm engagement length. Full article

Resveratrol (RES), a natural polyphenol with lipid metabolism-regulating properties, also demonstrates remarkable efficacy in strengthening intestinal barrier integrity. In order to elucidate the mechanism by which RES ameliorates intestinal damage and lipid metabolism disturbances in Megalobrama amblycephala under a high-fat (HF) diet, a conventional diet (CON), an HF diet (HF), or an HF diet supplemented with 0.6, 3, or 6 g/kg RES (HF + 0.06%, 0.3%, or 0.6% RES) was fed to fish. After 8 weeks, RES supplementation in the HF diet significantly improved the growth performance and alleviated hepatic lipid deposition. Microbiota profiling revealed RES improved intestinal barrier function by reducing α-diversity, Actinobacteria and Bosea abundances, and enriching Firmicutes abundance. RES also maintained the integrity of the intestinal physical barrier and inhibited the inflammatory response. MeRIP-seq analysis indicated that RES modulated intestinal mRNA m⁶A methylation by upregulating methyltransferase-like 3 (mettl3) and downregulating fat mass and obesity-associated gene (fto) and Alk B homolog 5 (alkbh5). Combined RNA-seq and MeRIP-seq data revealed that RES alleviated endoplasmic reticulum stress (ERS) by upregulating the m⁶A methylation and gene level of heat shock protein 70 (hsp70). Correlation analyses identified significant associations between intestinal microbiota composition and ERS, tight junction, and inflammation. In summary, RES ameliorates lipid dysregulation via a synergistic mechanism involving intestinal microbiota, m⁶A modification, ERS, barrier function, and inflammatory response. Full article

The Philippines, a country with abundant natural resources, has set a high 35% renewable energy (RE) share target by 2030. However, progress is slow with the implementation of its key policy mechanisms. Through the years, the Department of Energy has slowly increased the goals from 30% to 35% by 2030 and even up to 50% by 2050%. The key legal framework for the Philippine Renewable Energy sector is the Renewable Energy Act of 2008, which outlines key policy mechanisms: Renewable Portfolio Standards (RPSs), Net Metering, the Green Energy Auction Program (GEAP), and the Green Energy Option Program (GEOP). This paper analyzes the implementation and enforcement of the key policy mechanisms along with factors affecting their intended rollout. Along with the policy mechanism issues, this paper highlights key institutional and structural issues for the stakeholders of the RE sector. The main issues can be attributed to the incoherence of government agencies such as the Department of Energy (DOE), the Energy Regulatory Commission (ERC), and the National Grid Corporation of the Philippines (NGCP). Other issues include insufficient transmission infrastructure, resistance from Distribution Utilities (DUs) and Electric Cooperatives (ECs), and weak Local Government Unit (LGU) participation. The paper provides recommendations on the key issues of policy mechanisms and structural and institutional bottlenecks. The main recommendations that will help achieve the intended purpose of the drivers of RE are to strengthen the National Renewable Energy Board (NREB) and other agency capabilities, provide financial incentives to utilities, streamline permitting and other processes, and prioritize grid development for areas with RE development. For the targets of the DOE to be achieved, the main drivers for the RE sector must be revisited and fixed at their core. Achieving the RE targets of the DOE will need strong leadership and sustained focus on renewable energy development led by the government. Full article

Small and medium-sized enterprises (SMEs) often face severe resource constraints and operational fragility during crises. However, little is known about how managerial resilience (MR) translates into performance through time-related psychological resources and innovation—two capabilities that are both scarce and critical under such conditions. Drawing on Temporal Motivation Theory (TMT), this study develops and tests a dual-mediation model in which employee temporal psychological capital (TPC) and employee innovative behavior (EIB) transmit the effects of MR on performance. As a core methodological innovation, we adopt a multi-method analytical strategy to provide robust and complementary evidence rather than a hierarchy of results: Partial Least Squares Structural Equation Modeling (PLS-SEM) is used to examine sufficiency-based causal pathways and quantify the mediating mechanisms; Support Vector Machine (SVM) classification offers a non-parametric predictive validation of how MR and its mediators distinguish high- and low-performance cases; and Necessary Condition Analysis (NCA) identifies non-compensatory conditions that must be present for high performance to occur. These three methods address different research questions—sufficiency, classification robustness, and necessity—therefore serving as parallel, equally important components of the analysis. A total of 455 SME managers and employees were surveyed, and results show that MR significantly enhances all three dimensions of TPC (temporal control, temporal fit, time pressure resilience) and EIB (idea generation, idea promotion, idea realization), which in turn improve employee performance. SVM classification confirms that high MR, strong TPC, and active innovation align with high performance, while NCA reveals temporal control, idea generation, and idea realization as necessary bottleneck conditions. By integrating sufficiency–necessity logic with predictive classification, our findings suggest that SMEs should prioritize leadership resilience training to strengthen managers’ adaptive capacity, while simultaneously implementing time management interventions—such as temporal control workshops, workload balancing, and innovation pipeline support—to enhance employees’ ability to align tasks with organizational timelines, execute ideas effectively, and sustain performance during crises. Full article

Old communities are the weak link in urban security resilience, and smart governance could be a useful tool to address this issue. However, the existing research does not provide a definitive explanation of the mechanisms through which smart governance affects resilience. Based on the Accident Causation Theory and the ABC Theory of Emotion, a mixed-methods approach utilizing NCA and SEM is used to analyze the impact of smart digital technology on the security resilience of old urban communities and to explore the mediating roles of residents’ sense of safety and safety behaviors. The findings from on old urban communities in China reveal that smart digital technology and residents’ safety compliance behaviors are essential for community security resilience. Smart digital technology significantly and positively influences the security resilience of old urban communities. Residents’ sense of safety and safety participation behaviors mediate the relationship between smart digital technology and security resilience of old urban communities; residents’ sense of safety, safety compliance behaviors, and safety participation behaviors also exhibit a chain mediating role in the relationship between smart digital technology and security resilience of old urban communities. Therefore, old urban communities need to strengthen the application of smart digital technologies, while considering the human factor and emphasizing the facilitating role of residents’ sense of safety and safety behaviors. Full article

The rapid evolution of information and communication technologies (ICTs) has made after-hours work-related ICTs (W_ICTs) use commonplace. The double-edged sword effects of W_ICTs have been widely concerned by researchers, but the role of cognitive appraisal has not been fully investigated. Based on the Transactional Model of Stress, this study explores the underlying mechanism and boundary condition of W_ICTs on work goal progress and fatigue. The hypotheses were tested using 200 two-wave employees’ data. The results showed the following: W_ICTs could improve work goal progress through challenge appraisal; Family Supportive Supervisor Behaviors (FSSB) could strengthen the positive relationship between W_ICTs and challenge appraisal while indirectly strengthening the positive relationship between W_ICTs and work goal progress and the negative relationship between W_ICTs and fatigue. This study revealed the positive impact of W_ICTs and the strengthening effect of FSSB on the W_ICTs–challenge appraisal relationship. Full article

Selenium (Se) and silicon (Si) have been demonstrated to mitigate the adverse effects of cadmium (Cd) stress on the growth of various higher plants. However, the distinct mechanisms by which Se and Si, when applied to soil, alleviate the toxicity of Artemisia argyi under Cd stress remain unclear. This study employed A. argyi as the experimental material and simulated a Cd stress environment in soil pot experiments by adding CdCl₂·2.5H₂O at concentrations of 4 mg kg⁻¹ and 10 mg kg⁻¹. Exogenous Se in the form of Na₂SeO₃ (2 mg kg⁻¹) or Si in the form of Na₂SiO₃ (20 mg kg⁻¹) was applied simultaneously. After 90 days of combined exposure, the study investigated the differential mechanisms by which Se and Si application influenced Cd uptake by roots, its translocation within aboveground and underground tissues, and the antioxidant system of A. argyi under two levels of Cd stress. The results indicate that under Cd stress conditions, the application of Se significantly promotes the growth of A. argyi. Under both Cd concentration treatments, the application of Se or Si alone markedly reduces the Cd content in the aboveground parts of A. argyi. This reduction may be attributed to alterations in the subcellular distribution of Cd, decreased Cd content in organelles, and increased Cd sequestration in cell walls and soluble components. Furthermore, the application of Se or Si in soil can enhance the content of osmoregulatory substances, chlorophyll, and plant chelating agents in A. argyi leaves while reducing the levels of malondialdehyde (MDA) and reactive oxygen species (ROS), particularly at high Cd concentrations. The findings suggest that the alleviation of Cd toxicity by exogenous Se is primarily due to its role in inhibiting Cd uptake and translocation to shoots, as well as strengthening Cd compartmentalization in root cell walls and enhancing the antioxidant defense system. In contrast, exogenous Si primarily mitigates Cd toxicity by restricting Cd translocation from underground to aboveground plant tissues. Full article

The effect of dislocation pile-ups responsible for the generation or annihilation of dislocations during friction of Ag and Ni was considered. The steady-state friction was accompanied by the formation of twin bundles, intersecting twins, dislocations, adiabatic elongated shear bands, and intense dynamic recrystallization. The mechanisms of microstructural stability and friction instability were analyzed. The theoretical models of dislocation generation and annihilation in nanocrystalline FCC metals in the context of plastic deformation and failure development under friction were proposed. The transition to unstable friction was estimated. The damage of Ag was exhibited in the formation of pores, reducing the contact area and significantly increasing the shear stress. The brittle fracture of Ni represents a catastrophic failure associated with the formation of super-hard nickel oxide. Deformation resistance of the dislocation structures in the mesoscale and macroscale was compared. The coefficient of similitude (K) has been introduced in this work to compare plastic deformation at different scales. The model of the strength–ductility trade-off and microstructural instability is considered. The interaction between the migration of dislocation pile-ups and the driving forces applied to the grain boundaries was estimated. Nanostructure stabilization through the addition of a polycrystalline element (solute) to the crystal interiors in order to reduce the free energy of grain boundary interfaces was investigated. The thermodynamic driving force and kinetic energy barrier involved in strengthening, brittleness, or annealing under plastic deformation and phase formation in alloys and composite materials were examined. Full article

The reduced ductility caused by the brittle needle-like α′ martensite limits the application of TC4 alloys produced by selective laser melting (SLM). Appropriate heat treatment can improve the microstructures and properties of SLM-fabricated TC4 alloys. In this work, SLM-fabricated TC4 alloys underwent stress relief annealing at 600 °C and high-temperature annealing at 800 °C. The effects of heat treatment temperature on phase composition, microstructural morphology, grain orientation, and mechanical properties were investigated. Meanwhile, the microstructural evolution and fracture mechanisms during the heat treatment process were analyzed. The results indicate that after annealing at 600 °C, the needle-like α′ phase transforms into elongated α, and nano-β phase increases. When annealed at 800 °C, the α′ phase completely transforms into a more stable lath-shaped α phase and a short rod-shaped β phase, with the nano-β phase disappearing. The texture orientation gradually shifts from <0001> towards <01-10>, where slip systems are more active. Additionally, heat treatment promotes the transition of grain boundaries to high-angle grain boundaries, thereby alleviating stress concentration and enhancing solid-solution strengthening. After heat treatment, the ultimate tensile strength of the material slightly decreases, but the elongation significantly increases. As the annealing temperature increased, the elongation (EL) improved from 5.22% to 11.43%. Following high-temperature annealing at 800 °C, necking and larger dimples appear on the fracture surface, and the fracture mechanism shifts from a mixed brittle–ductile fracture to a ductile fracture. This work provides a theoretical basis for improving the microstructures and properties of SLM-fabricated TC4 alloys through heat treatment. Full article