Search Results (189)

Improving cropland carbon performance while maintaining food security is central to China’s agricultural transition and climate goals This study examines low-carbon cropland use performance (PCLU) and its model-implied interprovincial association network across 31 Chinese provinces from 2010 to 2023. A global super-efficiency slacks-based measure model estimated PCLU by incorporating agricultural output, carbon emissions, nonpoint-source pollution, and crop sequestration; annual directed networks were constructed with a modified gravity model and analyzed using social network analysis, a temporal exponential random graph model (TERGM), and complementary quadratic-assignment analyses. Mean PCLU increased from 0.524 to 0.861, while the interquartile range widened from 0.146 to 0.310; network density declined before partially recovering as hierarchy increased, indicating improvement without provincial convergence and reconnection within a more differentiated multi-hub structure. Persistence (β = 4.510) and reciprocity (β = 2.376) dominated network evolution, whereas shared partners produced neither additional triadic closure nor expanding open chains; similarities in urbanization and planting structure favored ties, while rural-income differences reflected socioeconomic complementarity. External validation showed moderate overall correspondence with green-technology patent collaboration (mean annual QAP r = 0.335) but limited overlap among the strongest dyads. Overall, China’s low-carbon cropland transition combined rising but increasingly uneven performance with a path-dependent and selective interprovincial structure, providing an empirical basis for differentiated coordination based on provincial performance and network position. Full article

Historic water infrastructure has often been treated primarily as a technical system, while its relationships with urban form, architectural organization, and everyday life have received less attention. Focusing on the old city of Mardin, this study examines historic water infrastructure, including partially accessible underground routes and their above-ground interfaces, as a constitutive component of spatial organization in a settlement shaped by arid climatic conditions and steep topography. A multi-scalar spatial-decoding approach combines Quantum Geographic Information System (QGIS)-based mapping, morphological and sectional analysis, Light Detection and Ranging (LiDAR)-based three-dimensional documentation, archival research, field observation, and oral testimony. The findings reveal a decentralized configuration of largely independent gravity-fed source-to-outlet routes embedded across urban and architectural scales. Water access, maintenance requirements, and architectural integration contributed to the organization of public nodes, institutional buildings, domestic spaces, and everyday practices without independently determining them. The transition to centralized modern supply disrupted these embedded relationships and transformed the visibility, accessibility, use, and situated knowledge of water. Methodologically, the study offers a transferable cross-scalar approach for reconstructing relationships between partially concealed infrastructure and visible urban form. Full article

Background/Objectives: This exploratory, randomized, patient-masked, intra-individual pilot study evaluated the feasibility of intraoperative swept-source optical coherence tomography (SS-OCT) for quantifying capsular-bag dynamics during cataract surgery and explored potential differences between an adaptive fluidics system (AFS) and a gravity-based fluidics system (GFS). Methods: Twenty-seven myopic cataract patients (54 eyes) underwent bilateral phacoemulsification, with one eye randomly assigned to AFS and the fellow eye to GFS using the same phacoemulsification platform (Stellaris/Stellaris Elite, Bausch & Lomb, Rochester, NY, USA). Intraoperative SS-OCT scans were acquired at six predefined surgical stages (M1–M6) to measure anterior and posterior capsule distances relative to the corneal endothelium. Intraoperative discomfort was assessed using a visual analog scale. Results: Of 648 attempted scans, 392 (60.5%) were analyzable, confirming partial feasibility of the prototype system. At the onset of phacoemulsification with irrigation on (M2), the predefined primary endpoint, anterior-capsule distance was greater with GFS than with AFS (4.23 ± 0.58 mm vs. 3.72 ± 0.73 mm), corresponding to greater mean deepening from baseline under GFS (1.19 mm) than under AFS (0.63 mm). However, this difference was not statistically significant after adjustment for multiple comparisons. No significant inter-system differences were found at other timepoints, and overall discomfort scores were similar (p = 0.70). Conclusions: Intraoperative SS-OCT enabled real-time visualization and partial quantitative assessment of capsular-bag dynamics during cataract surgery. The observed difference at the initiation of phacoemulsification may suggest reduced anterior-capsule deepening with adaptive fluidics, but this comparison was not statistically significant after multiplicity adjustment. The 39.5% measurement failure rate underscores the need for technical refinement before routine clinical implementation. Full article

Objectives: To determine whether acute oral hydration alters thoracolumbar fascia stiffness in healthy adults and to characterize concurrent changes in urine-specific gravity and bioimpedance-derived fluid compartments. Methods: In this prospective single-arm repeated-measures study, 50 healthy adults were assessed at baseline (T0), 60 min after ingestion of 2 L of water (T1), and 6 h later (T2). Thoracolumbar fascia stiffness was measured by shear wave elastography at four standardized points (P1–P4). Hydration was assessed using urine specific gravity and bioimpedance-derived intracellular water, extracellular water, and the extracellular-to-intracellular water ratio. Repeated-measures analyses of variance and Holm-adjusted pairwise comparisons were used. Results: Urine specific gravity changed markedly over time (F(2,98) = 290.175, p < 0.001, ηp² = 0.856), decreasing from 1.016 ± 0.002 at T0 to 1.006 ± 0.002 at T1, with partial return at T2 (1.014 ± 0.002). Mean thoracolumbar fascia stiffness remained unchanged (45.88 ± 2.01, 45.87 ± 2.01, and 45.89 ± 2.02 kPa at T0, T1, and T2, respectively; F(2,98) = 0.671, p = 0.514, ηp² = 0.013). The two-factor shear wave elastography model showed no effect of point (F(3,147) = 2.147, p = 0.097) and no time-by-point interaction (F(6,294) = 0.195, p = 0.978). Bioimpedance parameters also showed no significant change (all p ≥ 0.381). An exploratory correlation between change in urine specific gravity and change in mean stiffness was observed from T0 to T1 (r = −0.346, p = 0.028). Conclusions: In this single-arm repeated-measures study, acute oral water ingestion was followed by a clear urinary hydration response but by no detectable short-term within-participant change in thoracolumbar fascia stiffness or bioimpedance-derived fluid distribution in healthy adults. Because no non-hydration or placebo control condition was included, these findings should be interpreted as evidence of temporal stability under the tested protocol rather than as a definitive controlled estimate of the causal effect of hydration. Clinical Registration: ISRCTN96046168 (31 March 2026). Full article

Biological thin-sheet systems, including leaves, insect wings, and flowering organs, achieve adaptive deformation through distributed compliance, segmentation, curvature, and controlled opening. Kirigami offers a bio-inspired route for translating such deformation logics into programmable thin-sheet surfaces; however, the geometric parameters that most strongly influence elastic displacement remain insufficiently quantified, especially across different loading regimes. This study investigates Bio-Inspired Regime-Dependent Parameter Selection in Parametric Kirigami through twenty-five laser-cut specimens spanning five boundary shapes and three thermoplastic substrates. Specimens were tested under two contrasting regimes: quasi-static tensile loading and gravity-drape loading. Elastic displacement was measured under eight-point boundary fixation and analyzed using regime-separated Pearson correlations, Bonferroni-corrected significance testing (α/18 = 0.0028), and shape-controlled partial correlations. Under tensile loading, the Number of Offsets (r = 0.807), Segments per Offset (r = −0.603), and outer-boundary void perimeter (r = 0.621) showed the strongest Bonferroni-robust associations with displacement. Under gravity-drape loading, effects were weaker and more curvature-sensitive, indicating that parameter relevance is not universal but regime-dependent. Within the tested parametric design space, the study provides an experimentally grounded basis for selecting Kirigami geometric parameters in thin-sheet structures whose adaptive deformation logic is analogous to compliant systems found in nature. Full article

This study investigates the use of sugarcane bagasse ash (SCBA) and steel slag (SS) as partial replacements for cement and natural river sand in concrete, with the objective of identifying replacement levels that maintain structural performance while reducing the consumption of conventional materials. An experimental program was conducted to evaluate the unit weight, compressive strength, and splitting tensile strength of concrete containing SCBA and SS in individual and combined replacement systems. The results showed that the incorporation of SCBA reduced concrete density, whereas SS increased unit weight due to its higher specific gravity. At 28 days, compressive strength ranged from 13.09 to 38.10 MPa, while splitting tensile strength varied between 1.81 and 4.74 MPa, depending on the replacement level and combination of materials. Among the investigated mixtures, the concrete containing 15% SCBA and 50% SS exhibited the most favourable overall performance, achieving the target compressive strength of 25 MPa required for structural applications while maintaining acceptable tensile strength. In contrast, higher replacement levels resulted in strength reductions attributed to cement dilution, increased porosity, and the delayed pozzolanic reactivity of SCBA. Overall, the findings demonstrate that appropriately proportioned SCBA and SS can be successfully incorporated into concrete without compromising structural performance. The optimal mixture provides an effective balance between mechanical performance and the utilization of alternative raw materials, highlighting the potential of these industrial by-products to support more sustainable concrete production. Full article

In oil-rich countries, petroleum contamination of soils frequently occurs during refining, transportation, and exploitation. Such contamination significantly alters soil behavior and properties from a geotechnical perspective. Given that some fine-grained soils exhibit insufficient bearing capacity or excessive settlement, soil improvement is often necessary. The selective use of nanoparticles offers a promising novel approach in this regard. This study investigates the effects of diesel contamination and nanosilica modification on the physical and mechanical properties of clayey sand and aims to interpret the variations in the mechanical properties and the permeability of the treated soil based on microstructural observations. Diesel (0–10% in 2% increments) and nanosilica (0%, 1%, 2%) were added to the soil, preparing a total of 18 mixtures for testing. The microstructural changes directly alter the physical parameters such as specific gravity, optimum moisture content (OMC), and maximum dry unit weight, consequently affecting the permeability and the mechanical behavior. The microstructural analysis via scanning electron microscopy revealed diesel-induced clay flocculation and increasing macroporosity, while the nanosilica at 1% improved the soil fabric through pore filling and interparticle bonding, whereas 2% nanosilica led to partial dispersion and agglomeration. The findings demonstrate that soil behavior is controlled by the interplay between diesel (lubrication, pore blocking, hydrophobicity) and nanosilica (surface activation, micro-bonding, agglomeration). Increasing the diesel content consistently reduces the specific gravity across all the mixtures, due to the replacement of heavier mineral particles by lighter hydrocarbon, diesel adsorption onto the soil grains, the formation of low-density organic films, and increased micro-voids. Diesel addition reduces the OMC but increases the maximum dry unit weight due to its lubrication effect. Mechanically, the unconfined compressive strength (UCS) peaked at approximately 4% diesel contamination, with the addition of 1% nanosilica yielding the highest strength overall. Conversely, the California Bearing Ratio (CBR) increased continuously with diesel due to improved packing and frictional resistance and was further improved by nanosilica. The results show that permeability decreases with increasing diesel content due to hydrophobic diesel molecules coating soil particles, filling micro-voids, and blocking pore channels, while the consolidation parameters exhibit non-monotonic trends, peaking at moderate contamination levels. An optimal nanosilica content effectively mitigated some of the adverse effects of diesel and enhanced the mechanical performance, providing valuable insights for managing hydrocarbon-contaminated soils. Full article

Future long-duration human space missions will expose astronauts to chronically reduced gravitational loading, a condition associated with oxidative stress and epithelial barrier dysfunction. The intestinal epithelial barrier depends on tight junctions (TJs), yet the impact of partial gravity on TJ composition, assembly, and claudin organization remains poorly defined. Here, we show that differentiated intestinal epithelial monolayers exposed to simulated Mars gravity undergo TJ ultrastructural remodeling, characterized by loss of apical membrane “kissing points” and widening of the paracellular space, accompanied by impaired barrier function. Simulated Mars gravity also induces oxidative stress and accumulation of cytoplasmic and nuclear lipid droplets, consistent with altered membrane and lipid homeostasis. At the molecular level, simulated Mars gravity promotes selective TJ changes, with significant downregulation—but not mislocalization—of barrier-forming claudins CLDN1 and CLDN3 and the scaffolding protein ZO-1, while CLDN2, CLDN4, CLDN7, CLDN12, CLDN23, and OCLN remain unchanged. STAT3 activation, but not ERK or NF-κB signaling, may be associated with these alterations and is consistent with a stress-adaptive remodeling response to oxidative stress under simulated Mars gravity. Overall, these findings identify simulated Mars gravity as a disruptor of intestinal barrier homeostasis and highlight TJ remodeling as a target for countermeasures to preserve gut integrity during deep-space missions. Full article

Sloshing in partially filled tanks generates significant impact pressures that threaten the structural integrity of LNG cargo containment systems, and accurate scaling of these impacts remains a critical issue. Although Froude-based scaling has been widely applied, its validity may be limited under conditions where multiple impact mechanisms coexist. In this study, sloshing impact pressures measured across different scales were analyzed based on individual impact events. Distribution-based representative metrics, including mean and upper-percentile values, were introduced, and scale dependency was quantified using a power-law relationship. The results show that under low filling conditions, impact responses exhibit relatively consistent distributions, and gravity-based scaling yields nearly scale-independent results. In contrast, high filling conditions lead to increased variability and a pronounced expansion of the upper tail, resulting in stronger scale dependency, particularly for high-intensity events. The increase in the power-law exponent indicates that extreme impacts are more sensitive to scale variation. These findings demonstrate that sloshing impact scaling is governed not by a uniform change in pressure magnitude, but by a redistribution of impact intensity across events. Consequently, reliable scaling requires consideration of both distribution characteristics and underlying impact mechanisms. Full article

Understanding how staple-crop geography aligns with climate resources is important for food-security planning under climate change. Focusing on rice, winter wheat and maize in China from 2001 to 2020, this study constructed 1 km crop-abundance grids from annual 30 m crop-distribution data and integrated weighted centres of gravity (COGs), Standard Deviational Ellipses (SDEs), effective accumulated temperature and a Climate Resource Matching Index (CRMI) to evaluate crop migration, spatial-form change and matching with thermal, pluvial and radiant resource centres. Results show that rice exhibited the strongest northeastward migration, with a cumulative COG path of 448.9 km, but its CRMI declined markedly, indicating that thermal relaxation did not translate into coordinated multi-resource improvement. Winter wheat remained anchored in the Huang-Huai-Hai Plain, with adjustment mainly occurring through internal concentration and persistent moisture constraints. Maize showed expansion before 2015 followed by partial correction, and its CRMI trough in 2015 was robust under alternative weighting schemes. Overall, China’s staple-crop change represents a differentiated spatial reconfiguration rather than a uniform northward shift. Because these metrics are national-scale, the findings should inform crop zoning as broad spatial signals rather than direct local yield responses. Full article

As a crucial national ecological barrier, China’s Southern Collective Forest Region (SCFR) plays an essential role in maintaining regional ecological security and promoting sustainable development. Understanding the mechanisms driving the evolution of its ecosystem service value (ESV) is of great significance. Based on county-level data from 2000 to 2023, this study integrated the equivalent factor method, spatial autocorrelation analysis, the XGBoost-SHAP model, geographically and temporally weighted regression (GTWR), and partial least squares structural equation modeling (PLS-SEM) to examine the spatio-temporal evolution patterns and driving mechanisms of ESV in the SCFR. The results showed that ESV in the SCFR exhibited an overall downward trend, with a cumulative loss of 1973.77 × 10⁸ CNY. This was primarily due to marked reductions in hydrological and climate regulation services. The spatial distribution of ESV exhibited a significant heterogeneity—higher in the southwestern and southeastern mountainous regions, and lower in the northern plains and coastal zones, with the center of gravity shifting first to the northeast and then to the southwest. Local spatial autocorrelation revealed relatively stable “High–High” and “Low–Low” clustering characteristics, where high-value clusters were consistently distributed in core forest zones, while low-value clusters overlapped highly with urban agglomerations. Socio-economic factors exerted a significantly stronger influence on ESV than natural factors. Population density (POP), land use intensity (LUI), and gross domestic product (GDP) were identified as the dominant drivers, exhibiting distinct non-linear threshold effects and significant spatio-temporal heterogeneity. PLS-SEM analysis further quantified LUI as the dominant direct inhibitory pathway on ESV, highlighting urbanization’s indirect negative effect mediated through intensified LUI. Meanwhile, terrain effects were confirmed to positively influence ESV indirectly by constraining LUI and modulating local climate. The analytical framework of “threshold identification–spatio-temporal heterogeneity–causal pathway analysis” proposed in this study elucidated the complex driving mechanisms of ESV evolution, providing valuable guidance for ecological restoration evaluation and differentiated environmental governance. Full article

Asymptotic solutions are derived to model the development of atmospheric internal gravity waves generated by latent heating in a two-dimensional configuration involving a vertically-sheared background flow. The mathematical model comprises nonlinear partial differential equations derived from the conservation laws of fluid dynamics under the anelastic approximation where the background density and temperature vary with altitude. The latent heating is represented by a horizontally-periodic but vertically-localized nonhomogeneous forcing term in the energy conservation equation. This generates gravity waves that are considered as perturbations to the background flow and are expressed as perturbation series, with the leading-order contributions being the solutions of linearized equations. Taking into account the nonlinear terms at the next order gives expressions for the effects of the waves on the background mean flow. Due to the vertical shear, there is a critical level where momentum and energy are transferred from the wave modes to the mean flow. The asymptotic solutions show that the wave–mean-flow interaction is nonlocal and occurs over the range of altitudes from the thermal forcing level up the critical level. This is in contrast to what occurs in the case of waves forced by an oscillatory lower boundary, where the interaction is typically localized around the critical level. It is found that the wave drag is negative above the thermal forcing level, making the mean flow velocity more negative, but it becomes positive as the waves approach the critical level, indicating wave absorption in this region. There is wave transmission through the critical level, as well as absorption, and the extent of transmission depends on the depth of the latent heating profile. The mean potential temperature is reduced above the thermal forcing level and enhanced at the critical level, a situation that could ultimately lead to the development of convective instabilities. Full article

Sustainable materials are increasingly being incorporated into high-strength concrete (HSC) to reduce environmental impact while maintaining structural performance. This study experimentally investigates the combined use of steel scale waste (SSW) as a replacement for natural fine aggregates and graphite nano/micro platelets (GNMPs) as a nano-modifying additive in HSC. Natural sand was replaced with SSW at levels of 0%, 50%, and 100%, while GNMPs were incorporated at dosages of 0%, 0.1%, 0.3%, and 0.5% by weight of cement. The results indicate that partial replacement of sand with SSW significantly improves concrete density and mechanical performance due to enhanced particle packing and the high specific gravity of steel scale particles. At the nanoscale, GNMPs contribute to pore refinement, improved nucleation of hydration products, and crack-bridging within the cement matrix, thereby strengthening the interfacial transition zone and delaying crack propagation. The combined effect of these mechanisms produces a synergistic enhancement in concrete performance. The optimum mixture containing 50% SSW and 0.3% GNMPs achieved a compressive strength of 68.2 MPa and splitting tensile strength of 7.6 MPa, representing improvements of approximately 54% and 52%, respectively, compared with the control mix. Durability-related properties such as water absorption and sorptivity were also significantly improved due to matrix densification and pore structure refinement. Although the incorporation of SSW and GNMPs reduced workability, all mixtures remained within a practical range for casting. The developed concrete is particularly suitable for structural applications requiring high strength and durability, such as high-rise building components, bridge elements, and precast structural members. The findings demonstrate that the combined use of industrial steel waste and nano-reinforcement offers a promising pathway toward sustainable and high-performance concrete. Full article

NASA intends to return humans to the Moon, where partial gravity will put them at risk of musculoskeletal deconditioning. Resveratrol (RSV) is a promising nutritional countermeasure that may protect muscle health during disuse; however, its efficacy and mechanism in simulated lunar gravity are unknown. Forty adult male Wistar rats underwent 14 days of normal loading or partial weight-bearing at 20% of normal loading (PWB20). Unloaded animals received daily RSV supplementation with or without an ERα antagonist to test whether ERα was required to mediate RSV benefits. Muscle function was longitudinally assessed, and a Western blot was used to quantify key signaling proteins in the soleus muscle. PWB20 led to a significant reduction in grip strength (−14.2%) associated with marked changes in electrophysiological muscle properties. RSV-supplemented animals performed better throughout the study, but not when Erα was inhibited. RSV supplementation resulted in a greater ERα phosphorylation ratio compared to PWB20 alone (3.5 vs. 1.91). These results suggest that RSV can mitigate muscle deconditioning in a lunar gravity analog and that ERα signaling is required. Full article

A new version of the linear integral representation method is developed for solving inverse problems in geophysics. This approach is applied to the interpretation of anomalous time-dependent field data. The reconstruction of field elements is reduced to solving a system of linear algebraic equations (SLAE) with an approximately given right-hand side. Since the matrix elements of this system are derived analytically, the modeling process is significantly simplified. The article also analyzes how the approximation quality of a non-stationary field element depends on the observation network geometry, enabling its optimization for more accurate detection of geological properties. The proposed method for solving inverse problems for hyperbolic partial differential equations with constant coefficients can also be applied to data described by systems of nonlinear PDEs, provided the target field is represented as a composition of components differing in magnitude. Finally, the results of non-stationary gravity field modeling are presented. Full article