Search Results (657)

With the large-scale integration of high-penetration distributed photovoltaic (DPV) into distribution networks, its output volatility and reverse power flow characteristics are prone to causing voltage violations, necessitating the accurate identification of weak nodes to enhance operational reliability. This paper investigates the definition, quantification criteria, and multi-indicator comprehensive determination methods for weak nodes in distribution networks. A multi-criteria assessment method integrating voltage deviation rate, sensitivity analysis, and power margin has been proposed. This method quantifies the node disturbance resistance and comprehensively evaluates the vulnerability of voltage stability. Simulation validation based on the IEEE 33-node system demonstrates that the proposed method can effectively identify the distribution patterns of weak nodes under different penetration levels (20~80%) and varying numbers of DPV access points (single-point to multi-point distributed access scenarios). The study reveals the impact of increased penetration and dispersed access locations on the migration characteristics of weak nodes. The research findings provide a theoretical basis for the planning of distribution networks with high-penetration DPV, offering valuable insights for optimizing the siting of volatile loads such as electric vehicle (EV) charging stations while considering both grid safety and the demand for distributed energy accommodation. Full article

Arid regions, while providing essential ecosystem services, are among the most ecologically vulnerable worldwide. Understanding and monitoring their long-term vegetation dynamics is essential for accurate environmental assessment and climate adaptation strategies. This study examined the spatiotemporal variations and driving forces of the vegetation dynamics in arid Northwestern China during 2000 to 2020, using the annual peak fractional vegetation cover (FVC) as the primary indicator. The Sen’s slope estimator with the Mann–Kendall test and the coefficient of variation were employed to assess the spatiotemporal variations in FVC, while the Pearson correlation, geographic detector model and random forest model were applied to identify the dominant driving factors for FVC. The results indicated that (1) overall vegetation cover was low (averaged peak FVC = 0.191), showing a spatial pattern of higher values in the northwest and lower values in the southeast; high FVC values were primarily observed in mountainous areas and river corridors; (2) the annual peak FVC increased significantly at a rate of 0.0508 yr⁻¹, with 33.72% of the region showing significant improvements and 5.49% degradation; (3) the spatial pattern of FVC was shaped by the distribution of land use types (59.46%), while the temporal dynamics of FVC were driven by land use changes (16.37%) and the land use intensity (37.56%); (4) both the spatial pattern and the temporal dynamics were limited by the environmental conditions. These findings highlight the critical role of anthropogenic activities in shaping the spatiotemporal variations in FVC, particularly emphasizing the distinct contributions of changes in land use types and land use intensity. This study could provide a scientific basis for sustainable land management and restoration strategies in arid regions facing global changes. Full article

To improve the mobility of mobile robots in complex terrain environments, a novel 2-UPS&PRPU parallel mechanism is proposed, for which the parallel mechanism branched-chain decomposition and synthesis method is adopted. Based on the structural characteristics of the Hooke joint kinematic substructure, an inverse solution calculation for the mechanism is carried out, and the parameters of the simulation model are formulated to determine the workspace of the parallel mechanism. The linear velocity dexterity and minimum output carrying capacity of the parallel mechanism are analyzed, allowing the optimal parameters of the mechanism to be selected through dimension optimization, thus greatly improving the mechanism’s linear velocity dexterity and carrying capacity. The results show that the proposed parallel mechanism can satisfy the mobility requirements of mobile robots. Full article

Meloidogyne enterolobii, a highly virulent and broad-host-range plant-parasitic nematode, poses an increasing threat to global agricultural production. By inducing the formation of nutrient-rich giant cells in host roots and deploying a diverse array of effector proteins to modulate plant immune responses, this nematode achieves efficient colonization and invasion, resulting in impaired crop growth and significant economic losses. In recent years, global climate warming combined with the rapid development of protected agriculture has broken the traditional geographical limits of tropical and subtropical regions, thereby increasing the risk of M. enterolobii occurrence in temperate and high-latitude areas. Concurrently, conventional chemical control methods are increasingly limited by environmental pollution and the development of resistance, steering research toward green control strategies. This review systematically summarizes the latest research progress of M. enterolobii in terms of ecological diffusion trends, pathogenic mechanisms, and green control, and explored the feasibility of integrating multidisciplinary technologies to construct an efficient and precise control system. The ultimate aim is to provide theoretical support and technical supports for green and sustainable development of global agriculture. Full article

Triple-negative breast cancer (TNBC) remains a major clinical challenge due to its aggressive behavior and lack of targeted therapies. Accurate early prediction of response to neoadjuvant chemotherapy (NACT) is essential for guiding personalized treatment strategies and improving patient outcomes. In this study, we present an attention-based multiple instance learning (MIL) framework designed to predict pathologic complete response (pCR) directly from pre-treatment hematoxylin and eosin (H&E)-stained biopsy slides. The model was trained on a retrospective in-house cohort of 174 TNBC patients and externally validated on an independent cohort (n = 30). It achieved a mean area under the curve (AUC) of 0.85 during five-fold cross-validation and 0.78 on external testing, demonstrating robust predictive performance and generalizability. To enhance model interpretability, attention maps were spatially co-registered with multiplex immunohistochemistry (mIHC) data stained for PD-L1, CD8+ T cells, and CD163+ macrophages. The attention regions exhibited moderate spatial overlap with immune-enriched areas, with mean Intersection over Union (IoU) scores of 0.47 for PD-L1, 0.45 for CD8+ T cells, and 0.46 for CD163+ macrophages. The presence of these biomarkers in high-attention regions supports their biological relevance to NACT response in TNBC. This not only improves model interpretability but may also inform future efforts to identify clinically actionable histological biomarkers directly from H&E-stained biopsy slides, further supporting the utility of this approach for accurate NACT response prediction and advancing precision oncology in TNBC. Full article

Melanin is a complex natural pigment that imparts a variety of colors to the fruiting bodies of edible fungi, influencing both their nutritional quality and commercial value. Stropharia rugosoannulata is an emerging type of edible fungus that has been widely cultivated in recent years. It can be categorized into red and yellow varieties based on cap color, while its pigment characteristics remain unclear. In this study, the melanins from the two varieties were obtained using an alkaline extraction and acid precipitation method, followed by comprehensive characterization of their chemical properties and ultrastructural features. Both melanins displayed distinct absorption maxima at approximately 211 nm. The melanin extracted from the red variety consisted of 55.63% carbon (C), 7.40% hydrogen (H), 30.23% oxygen (O), 5.99% nitrogen (N), and 0.64% sulfur (S), whereas the yellow variety comprised 52.22% C, 6.74% H, 29.70% O, 5.91% N, and 0.99% S. Both types of melanin included eumelanin and phaeomelanin forms, with eumelanin being the predominant type. Variations in the quantities and relative proportions of eumelanin and phaeomelanin contributed to the observed color differences in the mushroom caps. Ultrastructural micrographs revealed the melanins were primarily localized in the cell wall, consistent with findings in other fungal species. These findings contribute valuable insights into fundamental knowledge and potential applications of mushroom pigments. Full article

The interactions of Fusarium graminearum PG-Fg1 and its main trichothecenes with the 28 Trichoderma isolates were studied in vitro. The antagonistic effect assessed by dual-culture tests showed that Trichoderma isolates arrested the growth of PG-Fg1 after contact, overgrew the PG-Fg1 colony and inhibited the production of deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3-ADON), and 15-acetyldeoxynivalenol (15-ADON) by up to 95.3%, 99.4%, and 99.6%, respectively. PG-Fg1 was hard to overgrow Trichoderma for further extension. Additionally, the inhibitory effects on PG-Fg1 by the Trichoderma metabolites, including volatiles and non-volatiles, were also investigated. Most of the Trichoderma isolates produced metabolites which inhibited PG-Fg1 growth and mycotoxins production. Specifically, Trichoderma non-volatiles and volatiles showed Fusarium growth inhibition rates ranging from 7% to 72% and 3% to 32%, respectively. Notably, non-volatile compounds from two isolates and volatiles from one isolate up-regulated the expression of DON biosynthesis genes (tri4 and tri5), leading to increased production of DON, 3-ADON, and 15-ADON. This study highlights the potential risk posed by certain Trichoderma strains as microbial agents, which can stimulate toxigenic fungi to produce higher levels of mycotoxins. Based on our results and previous reports, when selecting Trichoderma species as biocontrol agents against Fusarium graminearum, its effects on mycotoxins production should be carefully assessed, particularly given observed stimulatory impacts. Full article

Thermosensitive hydrogels undergo reversible sol-gel phase transitions in response to changes in temperature. Owing to their excellent biocompatibility, mild reaction conditions, and controllable gelation properties, these hydrogels represent a promising class of biomaterials suitable for minimally invasive treatment systems in diverse biomedical applications. This review systematically summarizes the gelation mechanisms of thermosensitive hydrogels and optimization strategies to enhance their performance for broader application requirements. In particular, we highlight recent advances in injectable thermosensitive hydrogels as a carrier within stem cells, bioactive substances, and drug delivery for treating various tissue defects and diseases involving bone, cartilage, and other tissues. Furthermore, we propose challenges and directions for the future development of thermosensitive hydrogels. These insights provide new ideas for researchers to explore novel thermosensitive hydrogels for tissue repair and disease treatment. Full article

Port green spaces are essential protective barriers, enhancing safety and environmental resilience in high-activity port regions. Given the intensity of human activities in these areas, understanding the factors influencing the carbon sequestration capacity and ecological benefits of port green spaces is crucial for developing sustainable green ports. This study integrated field investigations and remote sensing data to estimate carbon density and carbon sequestration capacity in the Dongjiakou Port area, examining their relationship with port green space planning. The results indicated that carbon density in green spaces showed a significant negative correlation with the number of lanes in adjacent roads, where an increase in lane numbers corresponded to lower carbon density. Additionally, carbon density decreased significantly with increasing distance from the shipping center. In contrast, a significant positive correlation was observed between carbon density and distance from large water bodies, indicating that green spaces closer to large water bodies exhibited smaller carbon density. Infrastructure development in Dongjiakou substantially negatively impacted vegetation carbon sequestration capacity, with effects not reversible in the short term. However, green space enhancement efforts provided additional ecological benefits, leading to a 50.9 ha increase in green space area. When assessing carbon density in urbanizing areas, geographical influences should be prioritized. Furthermore, the long-term environmental impacts of urban expansion must be considered at the early planning stages, ensuring the implementation of proactive protective measures to mitigate potential ecological disruptions. Full article

Offshore wind platforms face critical low-frequency vibration challenges requiring advanced isolation solutions. This work develops a quadrilateral-shaped vibration isolation platform (QVIP) with a quasi-zero stiffness property for floating structures, combining negative stiffness elements and optimized damping to achieve high-static-low-dynamic-stiffness. Theoretical modeling establishes the QVIP’s working principle and parametric behavior, while numerical simulations validate its ultra-low frequency (<1 Hz) suppression capabilities with time domain analysis. The design overcomes conventional trade-offs between low-frequency isolation and load-bearing capacity, offering improved stability for offshore applications compared to linear isolators. Results demonstrate effective vibration control through tailored nonlinear stiffness characteristics (e.g., 48.17% isolation efficiency, 39.48% peak amplitude reduction, and 73.14% variance reduction), suggesting practical viability for next-generation floating platforms. Full article

With the development of intelligent transportation systems, platooning can reduce vehicle aerodynamic drag by decreasing spacing between vehicles, improving transportation efficiency and reducing emissions. However, it is difficult for existing models to enable dynamic adjustment and real-time feedback. Therefore, this study proposes a digital twin system for real-time drag coefficient prediction using stacking ensemble learning. First, 2000 datasets of pressure distributions and drag coefficients under varying spacings were obtained through simulations. Then, an online prediction model for the aerodynamic performance of platooning vehicles was then constructed, realizing real-time drag coefficient prediction, and verifying the model performance using computational fluid dynamics data. The results indicate that the model proposed achieves 98.56% prediction accuracy, significantly higher than that of the traditional BP model (75.78%), and effectively captures the nonlinear relationship between vehicle spacing and drag coefficient. The influence mechanism of vehicle spacing on the aerodynamic performance of platooning vehicles revealed in this study enables high-precision real-time prediction under dynamic parameters. Full article

Seamounts are distributed globally across the oceans and are generally considered oases of biomass abundance as well as hotspots of species richness. Diverse microbial communities are essential for biogeochemical cycling, yet their functional partitioning among seamounts with geographic features remains poorly investigated. Through metagenomic sequencing and genome-resolved analysis, we revealed that Proteobacteria (33.18–40.35%) dominated the bacterial communities, while Thaumarchaeota (5.98–10.86%) were the predominant archaea. Metagenome-assembled genomes uncovered 117 medium-quality genomes, 81.91% of which lacked species-level annotation, highlighting uncultured diversity. In the Nazuna seamount, which is located in the Marcus-Wake seamount region, microbiomes exhibited heightened autotrophic potential via the 3-hydroxypropionate cycle and dissimilatory nitrate reduction, whereas in the Magellan seamounts regions, nitrification and organic nitrogen metabolism were prioritized. Sulfur oxidation genes dominated Nazuna seamount microbes, with 33 MAGs coupling denitrification to sulfur redox pathways. Metal resistance genes for tellurium, mercury, and copper were prevalent, alongside habitat-specific iron transport systems. Cross-feeding interactions mediated by manganese, reduced ferredoxin, and sulfur–metal integration suggested adaptive detoxification strategies. This study elucidates how deep-sea microbes partition metabolic roles and evolve metal resilience mechanisms across geographical niches. It also supports the view that microbial community structure and metabolic function across seamount regions are likely influenced by the geomorphological features of the seamounts. Full article

The current methodologies for assessing divergent thinking in children are predominantly based on verbal response, which limits their applicability for evaluating the creative potential of preschoolers and toddlers. This study introduces the Box Interaction Game (BIG), which is an adaptation of the Unusual Box Test (UBT) to make it more suitable for Chinese children. By simplifying, reorganizing, and expanding the actions in the UBT, the BIG employs action-based assessments that are relevant to the Chinese context and evaluate validity and test-retest reliability in preschoolers. The results revealed statistically significant but modest correlations between the verbal Unusual Uses Task (UUT) and the BIG test. Specifically, total scores (τ = 0.24, p = 0.02), fluency scores (τ = 0.23, p = 0.029), and originality scores (τ = 0.21, p = 0.04) showed low-to-moderate associations, indicating preliminary support for convergent validity, although further refinement is needed to strengthen these relationships. Additionally, the BIG demonstrates strong internal consistency (Cronbach’s alpha = 0.83 for both fluency and originality) and moderate test-retest reliability (ICC for fluency = 0.67, for originality = 0.74). These findings suggest that BIG is a promising and developmentally appropriate tool for assessing divergent thinking in Chinese preschoolers, offering a foundation for future work on early creative thinking in China. Full article

Agricultural production in the saline–alkaline soils of the Yellow River Delta faces persistent challenges in waste recycling and soil improvement. We developed a three-stage circular agriculture model integrating “crop straw–edible mushrooms–vegetables,” enabling simultaneous waste utilization and soil remediation within one year (two mushroom and two vegetable cycles annually). Crop straw was first used to cultivate Pleurotus eryngii, achieving 80% biological efficiency and reducing substrate costs by ~36.3%. The spent mushroom substrate (SMS) was then reused for Ganoderma lucidum and vegetable cultivation, maximizing the resource efficiency. SMS application significantly improved soil properties: organic matter increased 11-fold (from 14.8 to 162.78 g/kg) and pH decreased from 8.34 to ~6.75. The available phosphorus and potassium contents increased several-fold compared to untreated soil. Metagenomic analysis showed the enrichment of beneficial decomposer bacteria (Hyphomicrobiales, Burkholderiales, and Streptomyces) and functional genes involved in glyoxylate metabolism, nitrogen cycling, and lignocellulose degradation. These changes shifted the microbial community from a stress-tolerant to a nutrient-cycling profile. The vegetable yield and quality improved markedly: cabbage and cauliflower yields increased by 34–38%, and the tomato lycopene content rose by 179%. Economically, the system generated 1,695,000–1,962,881.4 CNY per hectare annually and reduced fertilizer costs by ~450,000 CNY per hectare. This mushroom–vegetable rotation addresses ecological bottlenecks in saline–alkaline lands through lignin-driven carbon release, organic acid-mediated pH reduction, and actinomycete-dominated decomposition, offering a sustainable agricultural strategy for coastal regions. Full article

Diluted magnetic semiconductors (DMSs) represent a significant area of interest for research and applications in spintronics. Recently, DMSs derived from BaZn₂As₂ have garnered significant interest due to the record Curie temperature (T_C) of 260 K. However, the influence of doping on their magnetic evolution and transport characteristics has not been thoroughly investigated. This study aims to fill this gap through susceptibility and magnetization measurements, electric transport analysis, and muon spin relaxation and rotation (µSR) measurements on (Ba_1−xRb_x)(Zn_1−yMn_y)₂As₂ (0.1 ≤ x, y ≤ 0.25, BRZMA). Key findings include the following: (1) BRZMA showed a maximum T_C of 138 K, much lower than (Ba,K)(Zn,Mn)₂As, because of a reduced carrier concentration. (2) A substantial electromagnetic coupling is evidenced by a negative magnetoresistance of up to 34% observed in optimally doped BRZMA. (3) A 100% static magnetic ordered volume fraction is achieved in the low-temperature region, indicating a homogeneous magnet. (4) Furthermore, a systematic and innovative methodology has been initially proposed, characterized by clear step-by-step instructions aimed at enhancing T_C, grounded in robust experimental findings. The findings presented provide valuable insights into the spin–charge interplay concerning magnetic and electronic transport properties. Furthermore, they offer clear direction for the investigation of higher T_C DMSs. Full article