Search Results (294)

Soil erosion on sloping farmland impairs cultivated land quality, food security, and watershed ecological sustainability across China. Vegetation serves as a core erosion buffer, yet how nitrogen–phosphorus (N-P) stoichiometry shapes coordinated maize growth to regulate multi-stage runoff–sediment coupling remains underexplored. This study reveals the complete mechanistic chain linking N-P ratios, crop growth synchrony, and hillslope erosion dynamics via 60 mm·h⁻¹ simulated rainfall experiments at three key summer maize stages, with six N/P gradients (0–3.75) in an eastern China brown soil zone. An N/P ratio of 2 optimized maize biomass, canopy cover, and root soil-binding capacity, yielding the lowest sediment concentrations. Excess nitrogen (N/P = 3.75) triggered spindly, mechanically weak maize growth, elevating runoff volume and sustaining high-variability sediment transport. High-frequency runoff–sediment signals maintained a consistent positive correlation, while mid/low-frequency components decoupled under imbalanced N-P supply. Moderate balanced N-P fertilization (N/P = 1–2) stabilized hillslope hydrological-erosion processes throughout the growing cycle, whereas surplus nitrogen induced asynchronous erosion responses. This research delivers quantitative evidence for coordinated high-yield and erosion-control nutrient management. Full article

In conventional spaceborne Synthetic Aperture Radar (SAR) systems, raw echo data are usually downlinked to ground stations for image formation, resulting in substantial communication burden and processing delay. Although onboard SAR imaging can alleviate this problem, onboard processors are constrained by power consumption, memory capacity, thermal dissipation, and physical size. Therefore, low-power embedded GPU platforms have become a practical choice for onboard SAR processing. Existing onboard processing is mainly suitable for relatively low-complexity imaging modes and algorithms, while high-resolution sliding spotlight SAR requires more accurate frequency-domain processing due to its extended azimuth bandwidth, strong range–azimuth coupling, and nonlinear range cell migration. The $\omega$-k algorithm is well-suited for such high-resolution imaging scenarios, but its large-scale FFTs, phase compensation, and Stolt interpolation impose significant pressure on the memory capacity, memory bandwidth, and computational resources of embedded GPU platforms. To address these challenges, this paper presents a GPU-oriented $\omega$-k imaging framework for high-resolution sliding spotlight SAR on the Jetson AGX Orin embedded platform. The proposed framework formulates a complete sliding spotlight $\omega$-k processing flow and develops GPU-oriented optimization strategies for efficient execution on the embedded GPU platform. Specifically, hybrid data partitioning is designed to adapt memory access patterns to range- and azimuth-dominant stages, an asynchronous multi-stream pipeline with reusable GPU buffers is introduced to overlap data movement and computation, and customized kernels are developed for Stolt interpolation and FFT-related spectral centering. Experiments on simulated sliding spotlight SAR data demonstrate that the proposed method achieves well-focused imaging results with consistent impulse response characteristics. For a 32,768× 32,768 simulated SAR dataset, the proposed implementation achieves an end-to-end imaging time of 32.17 s on Jetson AGX Orin. These results demonstrate the feasibility of the proposed framework for onboard high-resolution SAR imaging on an embedded GPU platform. Full article

Amid rising global economic uncertainty and frequent external shocks, strengthening marine economic resilience has become a core priority for coastal nations to stabilize industrial supply chains and achieve sustainable marine development. China’s traditional resource-driven marine economy faces persistent structural bottlenecks, including homogeneous industrial structure, low value addition and weak risk resistance. As a landmark national policy for sustainable marine economic growth, the Marine Economic Innovation and Development Policy (MEIDP) has been piloted in 15 coastal cities across two batches, yet its causal impact on marine economic resilience remains under systematic evaluation. Using panel data of 51 Chinese coastal cities from 2008 to 2023, this study employs a multi-period difference-in-differences approach with supporting analyses to systematically evaluate the MEIDP’s impact on marine economic resilience, as well as its moderating mechanisms and heterogeneous patterns. The key findings are threefold. First, the MEIDP significantly improves coastal cities’ marine economic resilience, and this positive effect remains stable after multiple robustness tests. Second, public health emergencies exert a significant positive moderating effect, where the industrial support capacity and risk-resilience foundations established through policy implementation function more effectively under shock conditions, thereby amplifying the enhancement of resilience. Third, the policy effect shows prominent heterogeneity, being more pronounced in high-tourism cities and the Northern Marine Economic Circle, while statistically insignificant in low-tourism cities and the Southern Marine Economic Circle. This study enriches the theoretical framework of marine economic policy evaluation and provides empirical evidence from a major developing country for global marine governance, confirming that marine policies that promote innovation are an effective path to strengthen economic risk resistance. In light of these findings, we propose targeted policy recommendations to steadily enhance overall marine economic resilience. Coastal regions should deepen marine policies that promote innovation to bolster industrial upgrading and technological empowerment, adopt differentiated schemes aligned with local industrial foundations and resource endowments, promote marine industrial diversification and chain extension to reduce structural vulnerability, and improve public risk response mechanisms to strengthen the counter-cyclical buffering capacity of the marine economy. Full article

Lactic acid fermentation (LAF) is a promising low-tech approach for the stabilization and hygienization of human feces from dry toilets. However, practical implementation remains limited due to a lack of application-relevant knowledge. This study systematically evaluated the influence of a series of practical process parameters on the performance of LAF under standardized laboratory conditions. Feces obtained from different types of dry toilets were physicochemically characterized and subsequently fermented under varying process conditions, using pH and lactic acid production as key indicators of fermentation performance. The results indicate that LAF is feasible across a broad range of process conditions, including temperatures between 8 and 30 °C, and is largely independent of carbon source type, air intrusion, and extended storage periods (>1 year), provided that a sufficient carbon supply is ensured. The investigated parameters exhibited varying degrees of influence on process performance, with carbon source dosage (≥10 w/w-% sugar beet molasses equivalent) and feces type emerging as the most influential factors. While ferrous iron addition (≤5 w/w-%) enhanced pH reduction, biochar, bentonite, and rock flour (≤10 w/w-%) showed negligible effects. Maximum lactic acid production was limited to ≤4.5 w/w-%, irrespective of carbon source dosage, resulting in minimum pH values ranging from 4.1 to 5.2. These values varied primarily with fecal type, suggesting a strong influence of intrinsic buffering capacity. Under conditions supporting stable LAF, i.e., rapid acidification followed by sustained low pH, E. coli was consistently reduced below the detection limit in the investigated samples. Overall, the findings suggest that LAF is a comparatively robust treatment approach and highlight operational parameters that are likely to be important for its practical implementation as a sanitation technology. Full article

Silicon suboxide (SiO_x) has been extensively investigated as an anode material for lithium-ion batteries. However, its low electrical conductivity and significant volume expansion during cycling have hindered its practical application. Although compounding SiO_x with carbon can effectively alleviate these issues, practical challenges such as complex preparation processes and high production costs still remain. In this study, porous SiO_x/C anode materials were synthesized in a single step using residue after acid-extraction aluminum from coal fly ash (high silica slag) as the silicon source and calcium carbide as both the reducing agent and carbon source, in a NaCl-CaCl₂ molten salt medium. The intimate interface between SiO_x and carbon not only enhances the electrical conductivity of the electrode but also buffers volume expansion, while the porous structure inside the SiO_x/C particles facilitates rapid ion transport. The SiO_x/C anode fabricated from this material exhibits excellent electrochemical performance and cycling stability: the anode material synthesized at 700 °C for 3 h (denoted as SiO_x/C-700-3) retains a reversible specific capacity of 1093.58 mAh g⁻¹ after 1000 cycles at a current density of 0.4 A g⁻¹. Moreover, the optimized SiO_x/C-700-3 electrode achieves robust long-cycle stability under a high current density of 2 A g⁻¹, sustaining a reversible capacity of 486.22 mAh g⁻¹ after 800 cycles with an average Coulombic efficiency approaching 99.6%. The method proposed in this work provides a new strategy for the preparation of SiO_x/C anode materials and holds great significance for the high-value comprehensive utilization of coal fly ash and the protection of the ecological environment. Full article

Nanostructured Co₃O₄ was synthesized via a sol–gel approach employing the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethylsulfonate ([EMIm]TfO) and subsequently evaluated as a high-performance anode material for lithium-ion batteries. Ionic liquids, distinguished by their low volatility, high thermal stability, and tunable chemical properties, represent a greener alternative to conventional organic solvents for the synthesis of functional nanomaterials. The electrochemical performance of the as-prepared material was systematically assessed through galvanostatic charge–discharge cycling, cyclic voltammetry, and rate capability tests. The Co₃O₄ electrode exhibited a high reversible capacity of approximately 1100 mAh g⁻¹ after 50 cycles at a current density of 200 mA g⁻¹, along with excellent coulombic efficiency approaching ~100% after the initial cycles. Furthermore, the material demonstrated strong rate capability, delivering about 600 mAh g⁻¹ at 1 C, and recovering its capacity upon returning to lower current densities. The improved electrochemical performance is primarily attributed to the nanoscale architecture induced by the ionic liquid-assisted synthesis, which facilitates rapid lithium-ion transport and effectively buffers volume variations during repeated cycling. Notably, the ionic liquid serves a dual function as both a green reaction medium and a structure-directing agent, enabling precise control over the material’s morphology and properties. This study demonstrates a versatile strategy for the rational design of potential transition-metal oxide anodes, paving the way for high-performance electrode materials. The findings contribute to the development of next-generation lithium-ion batteries tailored for clean and sustainable energy storage applications. Full article

Whole-plant soybean (WPS) is a high-protein forage resource, but its natural ensiling is often unsatisfactory due to low water-soluble carbohydrate content and high buffering capacity. This study investigated the effects of exogenous melatonin (ME) at 0 (CK), 5 (ME1), 10 (ME2), and 20 (ME3) mg/kg fresh matter on fermentation quality, chemical composition, in vitro rumen fermentation, and bacterial community structure of WPS silage. ME2 and ME3 had lower pH values and higher lactic acid contents than CK, with both treatments achieving pH values below 4.2. Crude protein concentration increased from 15.42% in CK to 19.96% in ME3, while neutral detergent fiber was lower in all ME treatments, and acid detergent fiber was lower in ME2 and ME3 than in CK. At 36 h, no overall treatment effect was detected for cumulative gas production, whereas in vitro dry matter digestibility differed only between ME2 and ME3. 16S rRNA gene sequencing revealed that ME altered the bacterial community, with community-weighted rrn copy number elevated in ME2 and ME3. Random forest analysis identified Enterococcus as the genus with the highest importance for treatment classification, and functional predictions indicated higher predicted abundances of amino acid biosynthesis pathways in ME treatment groups. These results indicate that ME has potential as an additive for improving WPS silage fermentation, but practical dosage recommendations require further validation through aerobic stability, animal performance, economic, and safety assessments. Full article

This study investigated possibilities to increase the efficiency of anaerobic digestion of sewage sludge using biochar produced by pyrolysis of digested sludge (sludgechar). Experiments were conducted in continuous laboratory bioreactors operated at the same loading rate, gradually increased from 3.2 to 4.5 g/(L·d) (COD) under mesophilic conditions (40 °C). Sludgechar (SCH) was dosed into the experimental bioreactor at a rate of 0.4–1.3 g/(L·d), corresponding to 12–28% of the added COD. Biogas production in the experimental bioreactor increased by 6.9–33% compared with the control bioreactor, while the CH₄ concentration remained comparable, averaging 62.8%. The COD removal efficiency remained high in the sludgechar-supplemented bioreactor as the loading rate increased, whereas it decreased in the control bioreactor, corresponding to lower biogas production. The adsorption capacity, alkalinity, and mineral buffering properties of sludgechar prevented pH decline and the accumulation of volatile fatty acids (VFAs) at higher substrate loading. The pH values were less affected by increasing organic loading in the experimental than in the control bioreactor and remained within 6.9–7.0. Continuous experiments confirmed that sludgechar can facilitate stable operation at loading rates that would otherwise cause process failure. However, the low carbon-to-inorganic ratio of sludgechar is its significant disadvantage. Full article

Silicon anodes hold great promise in high-energy lithium-ion batteries (LIBs) owing to their ultrahigh theoretical specific capacity, appropriate operating voltage, and low costs. However, the drastic volume expansion, inferior electronic conductivity, and unstable solid electrolyte interphase of Si anodes severely restrict their practical application. Herein, a nest-shaped microporous silicon (NMPSi) is rationally designed via acid–base co-etching and then synergistically regulated by surface thin-film carbon coating and ZIF-67-derived hard carbon nanotemplate (NMPSi@THC) by an in situ liquid-phase coating strategy. The constructed unique architecture is capable of buffering the huge volume expansion of inner NMPSi during cycling and constructing an optimized electron/ion transport network, thereby stabilizing the SEI film and preserving the electrode’s structural integrity. When it is evaluated as a LIB anode, the NMPSi@THC exhibits typically improved initial coulombic efficiency (ICE) and outstanding long-life cyclic stability (622.7 mAh g⁻¹ after 300 cycles at 1 A g⁻¹ and 2 mg cm⁻²). Furthermore, the NMPSi@THC//LiFePO₄ full cell delivers an ultrahigh ICE of 94% and a capacity retention rate of 86%, demonstrating its practical application potential. Compared with most recently reported Si anodes, this report delivers better cycling stability and maintains more intact electrode structure under relatively high current density and areal mass loading in half/full cells after long-term cycling. This research offers a convenient and scalable route to fabricate highly stable microporous Si anodes toward high-energy and long-lifespan LIBs. Full article

The integration of high-penetration renewable energy creates new requirements for cross-timescale peak shaving and for system robustness under extreme meteorological conditions. This study develops a dual-timescale capacity allocation method for pumped hydro storage (PHS), combining 8760 h chronological production simulation with monthly typical-day retrospective analysis. The model represents the operating limits of conventional units, nuclear power, hydropower, wind power, photovoltaic generation, tie-line exchange, and PHS energy shifting. On this basis, a stepwise capacity-sensitivity framework is established to minimize annualized comprehensive system cost while controlling renewable energy curtailment within a predefined planning threshold, rather than treating zero curtailment as an unconditional monthly hard constraint. Using long-term planning data from a coastal provincial power grid in southeastern China, the study compares the 2035 and 2040 planning scenarios. The results show that isolated typical-day models tend to overestimate PHS requirements because they disconnect chronological continuity and cross-day reservoir buffering. In 2035, the system presents a two-level seasonal capacity structure: 15,000 MW can support normalized operation in stable months, whereas the rigid boundary rises to 19,000 MW under extreme autumn high-wind conditions. In 2040, wind and photovoltaic capacity increase by approximately 20.01 GW compared with 2035, deepening low-net-load valleys and compressing seasonal regulation margins. Under the assumed planning boundary, the recommended PHS capacity converges to 23,000 MW. The proposed framework provides a practical reference for flexible resource planning in coastal power grids with deep renewable energy integration. Full article

Global container liner shipping networks (GCLSNs) underpin world trade, yet their organization is increasingly reshaped by geopolitical fragmentation. Existing studies often model GCLSNs as single-layer networks, overlooking how carriers’ geopolitical affiliations structure both connectivity and disruption risk. This study constructs a weighted carrier–geopolitical multiplex network in which layers are defined by carriers’ geopolitical affiliations and coupled through shared port calls. Structural analysis reveals pronounced asymmetry in layer size, cohesion, and inter-layer dependence, with overlap concentrated in a limited set of shared hubs. Using the Red Sea crisis as an empirical stress-test scenario, we develop a load–capacity propagation model, incorporating intra-layer load redistribution, rerouting to substitute shared hubs, and inter-layer resource squeeze at same-port layer copies. Results show that direct losses concentrate in corridor-exposed layers, while indirect losses propagate selectively through bridge hubs, especially Singapore, Shanghai, Shenzhen, and Port Klang. Sensitivity analysis indicates nonlinear amplification when low tolerance, strong inter-layer squeeze, and elevated rerouting pressure coincide. These findings show that multiplexity does not imply resilience by itself; cross-layer connectivity buffers disruption only when spare capacity is distributed but amplifies vulnerability when it converges on a narrow set of shared hubs. The paper contributes a carrier–geopolitical perspective to shipping network analysis and a dynamic framework for studying disruption propagation in complex logistics systems. Full article

Eutric Regosols are globally important but low-fertility soils with poor nutrient retention, limiting crop productivity and increasing environmental risks. This study evaluated whether combining a moderate reduction in synthetic nitrogen (N) fertilizer with organic manure application could rapidly improve soil fertility, sustain maize yield, enhance nitrogen use efficiency (NUE), and increase yield resilience in these soils. A four-year field experiment was conducted on a purple soil (Eutric Regosol) with five treatments: no N (CK), conventional synthetic N (CN), a 20% synthetic N reduction (OP), and the OP treatment combined with 3000 (OPM1) or 6000 (OPM2) kg ha⁻¹ of organic fertilizer. Maize yield, yield components, NUE indices, soil properties, and net economic benefits (NEB) were measured. OP alone reduced yield by 7.57% compared to CN. OPM2 progressively increased yield, surpassing CN by 12.36% after four years, and indicated greater yield resilience during a high-rainfall year. OPM2 also significantly improved topsoil organic matter (+12.9%), total N (+46.3%), and NUE indices over time. Although initial NEB was lower for organic-amended treatments, OPM2 achieved higher economic returns than CN in the latter two years. Integrating a 20% synthetic N reduction with 6000 kg ha⁻¹ of organic manure is an effective strategy for rapid fertility improvement in Eutric Regosols. This approach compensates for yield reductions from less synthetic N, progressively enhances yield and NUE, improves soil health, increases economic returns, and strengthens buffering capacity against high-rainfall events. Full article

Earth-based materials are promising candidates for balancing thermal performance, hygrothermal regulation, and environmental sustainability. The objective of this study is to evaluate and compare the hygrothermal behavior of two earthen materials, structural cob and lightweight insulating earth, against conventional reference concrete, taking into account not only their insulating properties but also their ability to regulate coupled heat and moisture transfers. Experimental tests show a significantly higher hygroscopic buffering capacity for earth-based materials, with an MBV of 2.23 g/(m²∙%RH) for the structural material and 1.21 g/(m²∙%RH) for the insulation material, compared to less than 0.5 g/(m²∙%RH) for concrete. The sorption isotherms confirm distinct water storage behaviors, with an average sensitivity to relative humidity of 10.47% for the insulation material, compared to 3.8% for concrete and 2.25% for the structural material, in addition to an average reduction of 26% in the adsorption capacity between 23 °C and 45 °C for both earthen materials. Coupled heat–moisture simulations in COMSOL quantitatively demonstrate the hygrothermal superiority of bio-based materials over conventional concrete, as concrete promotes interstitial moisture accumulation due to its low vapor permeability. The parametric sensitivity analysis highlights the effect of hygrothermal properties, where diffusivity controls transport kinetics and sorption governs water storage, while thermal conductivity modulates the spatial redistribution of thermo-hygric fields. The next and final step made it possible to link the phenomena observed at the material scale to the actual energy performance of the building, confirming the potential of the double-wall cob + lightweight earth system to reduce heating and cooling requirements and maintain stable indoor comfort, where the annual heating demand is reduced by approximately 24% compared to the conventional prototype. Full article

Background: This study analyzed the association between caries increment and clinical, salivary, bacteriological, and behavioral risk markers in a two-year follow-up study of schoolchildren in Mexico City. Methods: A two-year follow-up study was conducted in elementary schoolchildren, where 118 schoolchildren aged 7–10 years at baseline (50% boys) participated in the follow-up. Toothbrushing frequency, sugar consumption, and dental caries indices were recorded according to WHO criteria. Salivary secretion rates, buffering capacity (Dentobuff^®), and cariogenic bacterial counts (Dentocult SM and LB^®) were also measured. Logistic regression was applied to analyze associations between caries increment and risk markers. Results: The mean baseline caries indices were dmft 4.8 (SD 4.0) and DMFT 0.6 (SD 0.9). Children were classified into three caries experience groups: caries-free, filled-teeth, and caries-active. After two years, baseline caries-free children had a lower caries increment in permanent teeth (0.2, SD 0.7) than other groups (p < 0.0001). However, the caries increment was similar between groups (p = 0.0827). Logistic regression revealed associations with toothbrushing frequency [OR = 2.77, p = 0.026], S. mutans counts [OR = 3.38, p = 0.050], and Lactobacillus counts [OR = 2.91, p = 0.029]. Conclusions: Children with low toothbrushing frequency and high cariogenic bacterial counts developed more caries lesions than those with better oral hygiene and lower bacterial levels. Greater emphasis should be placed on promoting oral hygiene and reducing bacterial load in the oral cavity. Full article

Aqueous zinc–manganese dioxide (Zn–MnO₂) batteries are undergoing a paradigm shift from traditional ion-insertion mechanisms to a reversible deposition/dissolution process. By leveraging a two-electron transfer (Mn²⁺/MnO₂), this electrolytic system achieves a high theoretical capacity of 616 mAh g⁻¹ and a theoretical operating voltage of 1.99 V. However, the accumulation of dead Mn, electrically isolated inactive phases, and dynamic interfacial pH fluctuations remain critical barriers to cycle life and practical energy density. This review systematizes a trinitarian strategy to overcome these bottlenecks, focusing on interfacial engineering, redox mediator-assisted recovery, and advanced electrode architectures. We evaluate how anion engineering and pH-buffering stabilize reaction pathways, and how diverse mediators (e.g., halogens, metal ions, and organic molecules) chemically rescue inactive manganese. Furthermore, we examine the integration of 3D carbon networks and low-cost hybrid electrodes to sustain high-areal-capacity deposition. To elucidate these complex mechanisms, we highlight multiscale analytical approaches combining synchrotron X-ray techniques and density functional theory (DFT). Finally, we outline a roadmap for applications ranging from grid-scale flow batteries to flexible wearable electronics. This work provides a comprehensive perspective on realizing sustainable, safe, and high-performance zinc-based energy storage. Full article