Search Results (1,634)

Expansive clays exhibit shrink–swell behavior driven by microscale physicochemical interactions that are not fully captured by conventional macroscopic descriptors. This study presents a quantitative framework for evaluating microstructural evolution in expansive clays using Environmental Scanning Electron Microscopy (ESEM) combined with fractal dimension and lacunarity analysis under controlled suction paths. ESEM micrographs were collected along primary drying and secondary wetting paths across multiple magnification scales. Fractal dimension quantifies surface complexity, while lacunarity characterizes pore distribution and clustering. Fractal dimension increases with magnification and suction, reflecting greater exposure of particle surfaces as pore water is removed. Lacunarity decreases with magnification and shows soil-dependent trends with suction, indicating changes in pore heterogeneity. Hysteresis in both metrics reveals irreversible microstructural rearrangement associated with particle aggregation and fluid redistribution. These results demonstrate that fractal dimension and lacunarity provide complementary descriptors of soil fabric and establish a quantitative link between microstructure and suction-driven behavior in expansive clays. Full article

With the expansion of ammonia energy applications, long-distance liquid ammonia pipelines are expected to support large-scale cross-regional ammonia transport. In the liquid ammonia pipeline commissioning process, gaseous ammonia purging involves ammonia–nitrogen mixing and possible liquefaction, while liquid ammonia injection may induce flashing and severe local cooling, all of which can affect commissioning safety. To characterize these thermodynamic phenomena, a transient gas–liquid two-phase flow model was established and validated using OLGA 2022.1.0 software for simulating the long-distance liquid ammonia pipeline commissioning. The model adopts the cross-sectionally averaged one-dimensional approach. A volume-corrected Soave–Redlich–Kwong (SRK) equation of state for ammonia was adapted, validated, and used to generate OLGA-compatible thermodynamic property tables. The results show that, during gaseous ammonia purging, a higher flowrate shortens the displacement time by accelerating nitrogen removal, and this effect is more pronounced at higher ambient temperatures due to enhanced molecular diffusion. Along the pipeline, pressure gradually decreases from frictional resistance, with a steeper drop near the outlet caused by gas acceleration, and temperature gradually approaches ambient through heat exchange with the pipe wall and surrounding soil. A high gaseous ammonia flowrate can cause partial liquefaction, regasification, and temperature fluctuations. During liquid ammonia injection, local condensation and slight liquid accumulation occur before the liquid front arrives, and the low-temperature region moves with the liquid front. The liquid ammonia mass flowrate has the strongest influence on the injection process, as it reduces the completion time but increases the outlet temperature, outlet pressure, and the low-temperature risk downstream of the valve. Therefore, it should be controlled within an appropriate range to balance efficiency and low-temperature safety risks. This work provides a rapid and efficient prediction model for key thermo-hydraulic parameters during liquid ammonia pipeline commissioning, and the overall analyses offer insights for on-site process design and safety control. Full article

Accurate assessment of carbon storage dynamics and their driving factors is important for ecological sustainability and land management on the Loess Plateau under China’s dual carbon goals. In this study, the InVEST and PLUS models were integrated to evaluate carbon storage changes from 2000 to 2020 and simulate future carbon storage patterns for 2030 under four development scenarios, including natural development (ND), rapid development (RD), cropland protection (CP), and ecological protection (EP). In addition, the XGBoost-SHAP framework was employed to identify the dominant drivers and nonlinear response relationships controlling spatial variation in carbon storage. During 2000–2020, ecosystem carbon storage across the Loess Plateau generally increased, rising from 5.780 Pg to 5.893 Pg. Spatially, carbon storage displayed a pronounced pattern characterized by higher levels in the southeast and lower levels in the northwest, aligning with forest–grassland restoration belts. Scenario simulations showed that EP produced the largest carbon storage gain, with total carbon storage projected to reach 5.962 Pg in 2030. In contrast, RD reduced carbon storage to 5.858 Pg because of intensive construction land expansion. XGBoost-SHAP results identified net primary productivity (NPP) as the most influential factor controlling spatial variation in carbon storage, accounting for 57.3% of the total explanatory importance, whereas soil erosion (SE) exhibited a strong negative effect on carbon storage. Population density (POPD) also exerted a negative effect, whereas gross domestic product (GDP) showed positive contributions in economically developed counties. These findings enhance understanding of the spatial response characteristics of carbon storage under environmental gradients and human disturbance across the Loess Plateau. They further provide scientific support for differentiated ecological management and regionally adapted carbon mitigation planning. Full article

Soil salinity is a major constraint on global wheat productivity, yet the genetic and molecular determinants of root system architecture (RSA) adaptation under salt stress remain poorly characterized. We integrated a genome-wide association study (GWAS) of 566 wheat accessions with comparative RNA-seq transcriptomics to identify the genetic and transcriptional determinants of RSA adaptation under 200 mM NaCl. GWAS identified a candidate locus on chromosome 7B harboring TaIAO, which encodes a protein with predicted aldehyde oxidase-like activity consistent with a role in tryptophan-dependent auxin biosynthesis. Accessions carrying the favorable CC allele exhibited significantly greater root volume retention than those carrying the GG genotype (p < 0.001). Comparative RNA-seq revealed that the salt-tolerant Sarajevo 1 exhibited coordinated transcriptional repression of three distinct modules—cell wall expansion (TaExpansin), auxin redistribution (TaPIN-like), and stress-associated ROS defense (TaPOD1)—whereas the sensitive genotype CI 17260 aberrantly induced or incompletely repressed these modules under stress. ELISA-based IAA quantification, ROS imaging, and qRT-PCR analysis provided independent physiological and transcriptional support for these patterns. These findings support a two-tier adaptive model in which constitutive genetic variation at the TaIAO locus may contribute to a developmental baseline, coupled with coordinated stress-responsive transcriptional repression of energy-consuming modules, providing promising targets for marker-assisted breeding of salt-tolerant wheat. Full article

Leptospirosis is a globally distributed zoonotic disease caused by pathogenic bacteria of the Leptospira genus. Currently, 77 genomic species have been described. Leptospira interrogans is the most extensively studied species due to its high prevalence worldwide and the severity of the disease it causes in humans and animals. However, Leptospira santarosai is an important pathogenic species in the Americas, the Caribbean islands, and Taiwan. This species has a high serological diversity: it can infect domestic, wild, and agricultural production animals, causing reproductive problems and substantial economic losses. Additionally, Leptospira santarosai has been detected in water sources and wet soils. In humans, infection with this species can lead to a wide range of clinical manifestations and severe complications. Therefore, this study aimed to synthesize available information on the serological diversity, geographical distribution, natural sources of infection, and human leptospirosis caused by Leptospira santarosai to better understand their role in the leptospirosis transmission cycle. Methods: A systematic review of the literature was conducted, following the criteria established by the PRISMA-2020 guide, the search for scientific articles was conducted in five specialized and multidisciplinary databases (PubMed, Scopus, Web of Science, SciELO, and LILACS), and a search engine (Google Scholar). Two different search strategies (Leptospira santarosai OR L. santarosai) were used. Result: Once the search was carried out in the databases, 2989 scientific articles were identified. These articles underwent a process of identification, screening, eligibility, and inclusion, resulting in 84 articles that met all established inclusion criteria. These articles were included in the qualitative synthesis and elaboration of the systematic review. Conclusions: Leptospira santarosai shows a high serological diversity, with 14 serogroups and 59 serovars. The species has a wide geographic distribution, having been reported on five continents and in 26 countries, and has been described as an infectious agent in at least 24 host animals. It has also been detected in environmental sources such as water and wet soils; 24 serovars have been identified as the causative agents of human leptospirosis, causing clinical manifestations that range from mild to severe forms of the disease and clinical complications such as myocarditis, uveitis, and neuroleptospirosis. Although L. santarosai is considered native to the Americas, it shows an expansion pattern to other continents and countries. Therefore, this pathogenic species of the Leptospira genus represents an important public health problem worldwide. Full article

Invasive alien species (IAS) threaten coastal wetland ecosystems, and smooth cordgrass (Spartina alterniflora) is among the most damaging invaders along the coast of China. We compiled occurrence records from the invaded range (China) and native range (United States) and retained 358 and 291 spatially thinned occurrences after quality control and definition of coastal-accessible areas. We assembled climatic, topographic, land use, soil and anthropogenic predictors and fitted species distribution models using the biomod2 ensemble-modeling framework, complemented by an ecospat-based comparison of native and invaded niche spaces. The ensemble model (EM) showed high predictive accuracy (China: AUC = 0.98, TSS = 0.99; USA: AUC = 0.99, TSS = 0.94). Elevation (73.6%) and human influence (6.0%) were the strongest predictors, highlighting the role of intertidal geomorphology and human-mediated propagule pressure. Niche overlap between ranges was low (Schoener’s D = 0.13), and the invaded niche showed substantial unfilling (0.36), indicating additional environmental space at risk of colonization in China. The current suitable habitat forms a continuous coastal belt from the Bohai Rim through the Yellow Sea–East China Sea to the South China Sea. Projections under future climate change suggest predominantly stable suitable areas with localized expansions but potential contractions in some periods. Our results may support the early warning, surveillance prioritization, and adaptive management of S. alterniflora under climate change. Full article

In the context of intensifying global climate change, high-altitude mountain ecosystems play a critical role in climate regulation, biodiversity conservation, and the advancement of sustainable human development. Plateau regions, such as the Qinghai–Tibet Plateau, are particularly sensitive and responsive to global climatic fluctuations and function as essential ecological barriers supporting development across Asia. These areas occupy a strategic position within Asia’s ecological security framework and the broader international community, influencing not only regional ecological stability and social cohesion but also sustainable development pathways. However, owing to their fragile ecosystem structures, limited regenerative capacity, and the ongoing expansion of urbanisation and human activities, these regions frequently suffer from habitat fragmentation and degradation of ecological functions. This issue is especially acute in natural protected areas adjacent to plateau cities. Consequently, there is an urgent need for quantitative assessments of ecological restoration effectiveness within natural protected areas, alongside investigations into development approaches that underpin long-term regional stability and sustainability. Focusing on Chokpori Mountain—the “urban green heart” of Lhasa, a principal city on the Qinghai–Tibet Plateau—this study develops a three-dimensional assessment framework encompassing ecological, economic, and social dimensions. By integrating the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model, remote sensing inversion techniques, field monitoring, and questionnaire surveys, the research systematically evaluates the effectiveness of ecological restoration and proposes insights for sustainable governance. The findings indicate that ecological restoration elicited positive ecological responses, evidenced by a 69.2% increase in soil retention post-renovation, an increase in vegetation coverage, and modeled total nitrogen (TN) and total phosphorus (TP) export loads demonstrating enhanced nutrient retention potential and improved water purification potential; (2) economic stimulation was evident, as demonstrated by an increase in average weekend daily visitor numbers from 876 to 1567 and a 24.2% rise in average monthly revenue of shops within a 1 km radius; and (3) social well-being improved, with ecological satisfaction reaching 89.2% and recognition of cultural communication attaining 67.3%. An integrated analysis indicates a synergistic enhancement of ecological environmental quality, regional vitality, and public perception. Accordingly, the outcomes of this study provide both theoretical insights and practical guidance for the ecological restoration and sustainable management of urban protected areas in high-altitude plateau regions worldwide. Full article

With the growing global population, intensifying resource constraints, and deepening climate change impacts, agriculture faces dual challenges of ensuring food security and advancing sustainable development. Artificial intelligence (AI) has emerged as a transformative technology, penetrating the entire crop production chain and offering innovative solutions to traditional agricultural bottlenecks. This paper systematically reviews AI applications in five core domains: biotic stress monitoring, soil health management, precision operation, supply chain optimization, and climate-resilient agriculture. It further categorizes and analyzes four key technical pathways—deep learning, sensor fusion, data-driven methods, and hybrid modeling—while critically examining major challenges across data, technology, implementation, and ethics/policy dimensions. Future directions are discussed from technological innovation, scenario expansion, implementation guarantees, and sustainability orientation. Research findings show that AI has achieved technical validation in pest/disease detection, soil parameter modeling, and intelligent spraying, with accuracy exceeding 85% in some cases. However, regional data bias, insufficient model generalization, and the digital divide still hinder large-scale deployment. Moving forward, coordinated efforts in technological innovation and policy support are required to promote inclusive, standardized, and sustainable AI applications in crop production. Full article

Curcuma lampangensis Saensouk, Maknoi & Rakarcha is a member of the family Zingiberaceae within the genus Curcuma L. This species is endemic to Thailand and is classified as critically endangered due to its restricted distribution and the ongoing degradation of its natural habitats. The species predominantly occurs in areas that are increasingly impacted by anthropogenic activities, particularly agricultural expansion, which contributes to habitat fragmentation and poses a significant risk to its persistence in the wild. In addition, propagation by rhizomes or seeds shows relatively low propagation efficiency. Therefore, plant tissue culture techniques are considered important for improving propagation efficiency. In this study, shoot and root induction of C. lampangensis were investigated by culturing on solid and liquid MS medium for 8 weeks, supplemented with different plant growth regulators including BA, kinetin, IAA, IBA, NAA, 2,4-D, TDZ, mT and Ads. The results showed that solid MS medium supplemented with 2 and 3 mg/L mT induced the highest mean number of shoots of 7.26 to 7.63 shoots per explant, a mean roots number of 18.57 to 19.88 roots per explant, and 30 to 60% callus formation. Meanwhile, liquid MS medium without plant growth regulators induced the highest mean number of roots of 34.73 roots per explant, with a mean root length of 3.49 cm. Acclimatized rooted plantlets transferred to sandy soil showed 85% survival rate. Full article

Unsustainable land-use transitions in peri-urban watersheds threaten both food security and ecological integrity. While Patch-generating Land Use Simulation (PLUS) and Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) models for ecosystem service (ES) assessment are commonly integrated, limited studies have simultaneously (i) accounted for multiple real-world spatial policies (e.g., ecological redlines) as hard constraints, (ii) targeted a comprehensive suite of ESs, and (iii) explicitly pursued synergies without relying on large-scale land conversion. To address these gaps, we developed a spatially explicit framework that integrates the PLUS and InVEST models to simulate four land-use scenarios and assess six ESs—grain yield, water yield, nitrogen export, phosphorus export, soil conservation, and carbon sequestration—in the Yuqiao Reservoir watershed, China, during 1990–2030. Against a backdrop of historical declines in cropland/grassland and key ESs due to construction expansion (1990–2020), the novel Comprehensive Development scenario—implementing slope-adaptive management and riparian buffers—synergistically increases grain yield (+0.55%) and carbon sequestration (+1.10%) while drastically reducing phosphorus export (−10.86%). It demonstrates that synergistic gains can arise from strategic spatial reconfiguration within a stable land-use area, advancing a paradigm from area-centric to configuration-centric optimization. This provides a quantifiable methodological basis and actionable policy reference for land spatial optimization in similar water-source watersheds. Full article

Self-drilling hollow bar micropiles (HBMPs), which integrate drilling, grouting, and reinforcement into a single process, have broad application prospects in mountainous transmission lines and offshore wind power projects. However, existing research has focused mainly on friction piles in soil layers, and there is a lack of systematic understanding of the load-transfer mechanism and bearing capacity calculation method for rock-socketed HBMPs. Based on field static load tests of rock-socketed HBMPs, this study systematically investigates the vertical bearing behavior and capacity calculation method of single rock-socketed HBMPs through a combination of test data analysis, finite element numerical simulation, and theoretical analysis. The field test results show that the load-settlement curves of rock-socketed HBMPs are of a slowly varying type, exhibiting mixed friction-end-bearing characteristics. After data screening, the average Q-s curve of Pile No. 1 and Pile No. 5 was taken as the benchmark, and the representative ultimate bearing capacity of a single pile determined by the 40 mm settlement criterion is 5860 kN. The test data of Pile No. 3 and Pile No. 4 were retained as independent validation data. A three-dimensional finite element model considering the cohesive contact behavior at the pile–rock/soil interface was established using ABAQUS. After calibration with the test results, the error between the simulated and measured bearing capacity is −3.4%, demonstrating good model reliability. Parametric analysis indicates that the bearing capacity increases linearly with the grouting volume increase rate $V_{\mathrm{inc}}$, with the expansion effect being the main enhancement mechanism; the improvement amplitude under hard rock conditions is significantly smaller than that in cohesive soils. The effect of uniaxial compressive strength $q_u$ of hard rock on bearing capacity is negligible because the capacity is controlled by the pile–rock interface shear strength. The bearing capacity increases approximately linearly with the rock-socketed depth $L_r$, and a minimum rock-socketed depth of 1.0 m is recommended. Analysis of the load-transfer mechanism shows that rock-socketed HBMPs rely mainly on shaft resistance (accounting for 90.6%), and the axial force decays significantly along the pile length. Elastic compression of the pile accounts for 78% of the pile head settlement, and the limited displacement at the pile tip leads to insufficient mobilization of end bearing. A modified bearing capacity formula considering the grouting expansion effect is established with shaft resistance as the core. A hierarchical validation strategy is adopted to test its predictive ability: for the finite element cases not participating in parameter calibration, the prediction error is within ±2%; for the field test piles, the prediction error is +7.9%; and for Pile No. 3 and Pile No. 4, the errors are +1.7% and −2.1%, respectively. These values are significantly better than those of existing methods (errors ranging from −72.1% to +54.5%). The research results can provide a theoretical basis for the design of single HBMP bearing capacity under rock-socketed conditions. Full article

To enhance the strength and water stability of stabilized expansive soil, this study investigates the use of cement, montmorillonite adsorption modifier (MAM), and their composite system. Laboratory tests evaluated compaction characteristics, swell–shrink behavior, and mechanical performance. The results show that MAM more effectively regulates compaction by reducing optimum water content and increasing maximum dry density; 6% MAM increases maximum dry density by ≈0.04 g/cm³ and reduces optimum water content by ≈2%. In terms of swell–shrink behavior, MAM reduces both swelling and linear shrinkage more effectively than cement. The incorporation of 5% MAM reduces the free swelling ratio by 40% and the equilibrium moisture absorption by 2.7%, lowering the swelling classification to non-expansive. Furthermore, 5% MAM decreases the unloaded and loaded swelling ratio by 14.7% and 5%, respectively, while increasing MAM from 2% to 6% further reduces linear shrinkage by 1.12%. Cement significantly enhances compressive strength, with 7–28 d values reaching 2.2–2.7 times those of untreated soil at 9% content; however, its water stability under wet–dry cycles is limited. In contrast, the cement–MAM composite system achieves balanced improvement by simultaneously suppressing swelling and enhancing both strength and water stability. These findings provide a reference for the treatment and engineering application of expansive soils. Full article

This paper develops foamed mixture lightweight soil (FMLS) using dredged soil for ecological floating landscapes applications, focusing on key performance indices including dry density, compressive strength, splitting tensile strength, water absorption, and fluidity. Orthogonal experiments determined the optimal mix ratio, while CaO expansion agent, MgO expansion agent, polypropylene fiber (PPF), and basalt fiber (BF) were employed to modify material properties. The microstructural mechanisms of FMLS before and after modification were characterized by scanning electron microscopy (SEM). The results show that FMLS achieves optimal comprehensive performance at a cement-to-sand ratio of 0.4, foam content of 10%, and water-to-sand ratio of 0.35, with all parameters conforming to technical specifications. The optimal dosage for both CaO and MgO expansion agents is 5%, PPF is 0.3% and BF is 0.5%, respectively. MgO expansion agent and PPF demonstrate superior suitability for floating landscapes due to enhanced pore-filling efficiency and crack-bridging effects by SEM. Finally, correlation analysis further indicates that the water–binder ratio critically governs the strength characteristics of FMLS. This paper not only provides a new direction to promote the effective use of dredged soil resources, but also provides new ideas for carrier materials for ecological floating landscapes. Full article

Tunnel seepage in heterogeneous ground can trigger hydrogeological hazards such as concentrated water inflow, groundwater depletion, deformation of surrounding structures, and subsequent eco-environmental degradation. However, these processes are still commonly evaluated using deterministic models that neglect the spatial variability of hydrogeological parameters. To address this limitation, this study develops a stochastic hydro–geo–mechanical–ecological framework that integrates random field theory with physics-informed neural networks (PINNs) for hazard evaluation and rapid prediction of tunnel seepage responses. The spatial variability of key parameters, including permeability and porosity, is characterized using the Karhunen–Loeve expansion and embedded into coupled governing equations for unsaturated–saturated seepage, seepage–stress interaction, and groundwater–soil–vegetation responses. A PINN surrogate model with random-field inputs is then constructed to predict hydraulic head, tunnel inflow, displacement, groundwater depth, vegetation coverage, and soil physicochemical indices, while simultaneously quantifying uncertainty. A karst tunnel case in Chongqing, China, is used to demonstrate the proposed framework. The results show that spatial heterogeneity promotes preferential flow paths and intensifies seepage-induced hazards compared with deterministic mean simulations, leading to larger groundwater drawdown, stronger ecological degradation, and greater overall response variability. The proposed PINN achieves high predictive accuracy (R² > 0.97) and reduces single-case computational time from hours to seconds, enabling efficient multi-scenario evaluation and uncertainty-aware risk assessment. This framework provides a physically consistent and computationally efficient tool for evaluating water-related hazards and long-term environmental impacts in underground engineering. Full article

Deltas are highly susceptible to biological invasions because of strong hydrological connectivity, frequent disturbance, and intense human use. Here, we synthesise coordinated monitoring observations and literature evidence on invasive alien plant species (IAS) recorded in four Black Sea riparian protected areas located across five countries, surveyed under the IASON/IASON+ initiatives (Danube Delta, Nestos Delta and Lake Vistonida, Kızılırmak Delta, Chorokhi Delta and Kolkheti National Park). Across the study sites, 17 IAS were documented, mainly represented by taxa native to North America and characterised by high propagule production and/or strong vegetative regeneration. Woody riparian invaders (e.g., Amorpha fruticosa, Robinia pseudoacacia, Acer negundo, Gleditsia triacanthos and Ailanthus altissima) exploited nutrient-rich floodplain soils and disturbances. In contrast, annual weeds (e.g., Ambrosia artemisiifolia, Sicyos angulatus and Xanthium orientale) remained associated with disturbed habitat edges. Aquatic dominance was confined to the Danube Delta, where Elodea nuttallii and Elodea canadensis formed dense submerged stands. Species were assigned to broad range expansion categories (slowly, moderately and rapidly spreading species) based on project observations and supporting records. We discuss shared invasion syndromes linked to reproductive and dispersal traits and outline management implications for Black Sea deltas, emphasising pathway prevention, early detection and rapid response for localised taxa, and sustained control combined with restoration for dominant invaders. Full article