Search Results (22,329)

High-resolution vertical profile observations of ocean environmental parameters are essential for investigating mesoscale ocean dynamic phenomena, such as internal waves, mesoscale eddies, and oceanic fronts. At present, vertical profile measurement in marine surveys mainly relies on shipborne winches to deploy and recover marine sensors, which entails high labor costs and considerable energy consumption. Unmanned observation platforms integrated with winch systems enable automatic sensor deployment and recovery, offering a viable approach to cutting observation costs. Nevertheless, inadequate energy supply remains a critical bottleneck restricting the large-scale popularization and application of such equipment. Accordingly, the development of high-efficiency winch systems tailored for unmanned autonomous observation platforms is of great engineering significance for facilitating long-term, continuous, and low-energy marine profile observation. This paper proposes a novel energy-saving winch with an embedded three-stage parallel nested energy storage structure for unmanned marine observation platforms. During operation, the coil spring energy storage system is charged during cable payout, and the stored elastic potential energy is released to assist motor driving in the cable retraction process. This auxiliary driving mode reduces motor power demand and improves the overall energy utilization efficiency of the platform. Experimental results demonstrate that, neglecting ocean current resistance, the proposed winch reduces energy consumption by 5% during cable payout and 21% during cable retraction. The overall energy consumption is decreased by 13% throughout a complete vertical profile measurement cycle. Under constrained and fixed energy supply conditions, this technology substantially enhances the sampling capability of unmanned marine platforms for ocean environmental monitoring. It further improves operational efficiency and extends continuous service time, providing key technical support for revealing ocean dynamic evolution and clarifying the formation and driving mechanisms of marine environmental phenomena. Full article

The promising potential of porous metallic materials for railway applications (e.g., conductive materials, materials for braking systems) is due to their unique combination of low density, high specific surface area, and high energy absorption capabilities. Porous multi-phase silicide coatings (FeSi, Si₂CN₄) provide a synergistic effect, doubling surface hardness and establishing a stable diffusion barrier. The article proposes a comprehensive approach to replacing materials for critical railway transport components, involving the development of a base material and a barrier coating. The use of widely available induction-melting components to produce a base material with superior mechanical properties is demonstrated. The material exhibits high static strength and hardness while maintaining acceptable impact toughness and ductility. To enhance wear, corrosion, and scale resistance, technology for forming a barrier layer via silicide coatings is proposed. The coating formation technology enables the regulation of porosity through the formation of nitrogen-containing phases. It is shown that pores can serve as “containers” for fillers that impart functional properties to the coatings (e.g., adjusting the friction coefficient or electrical conductivity). The new base material–barrier coating system can serve as a foundation for the sustainable production of critical rolling stock parts and other devices for railway transportation systems. Full article

Differential enrichment of shale oil hydrocarbon fractions exerts a fundamental control on the spatial distribution of “sweet spots” and the efficiency of unconventional resource recovery. This study investigates the continental shales of the Upper Es4 Member in the Dongying Sag, Bohai Bay Basin, through an integrated analytical framework combining Laser Scanning Confocal Microscopy (LSCM), Scanning Electron Microscopy (SEM), and high-pressure mercury intrusion. By moving beyond qualitative observations, we characterize the micro-scale partitioning of light and heavy fractions and establish a deterministic hierarchy of controlling factors. Our results indicate the following. (1) Mineral composition functions as a “primary geochemical filter,” where carbonate minerals exhibit a preferential adsorption affinity for light fractions (≤ C₁₈), while clay minerals facilitate the selective retention of heavy components (> C₁₈). (2) Pore–throat architecture acts as a “secondary mobility modulator.” A statistically significant linear correlation (R² = 0.72, p < 0.05) was identified between mean pore diameter and the light-to-heavy fluorescence ratio, suggesting that interconnected macropores in carbonate laminae provide low-resistance conduits for light oil accumulation, whereas isolated mesopores in argillaceous matrices promote heavy-component sequestration. (3) Thermal maturity (Ro) drives a progressive shift in the light-to-heavy ratio, enhancing oil fluidity and regulating the transition from adsorption-dominated to migration-dominated enrichment. This study clarifies the lithofacies-dependent coupling mechanisms between mineral diagenesis and pore-scale fractionation, providing a semi-quantitative conceptual model for shale oil sweet-spot prediction in complex lacustrine basins. Full article

To elucidate the mechanisms by which the rhizosphere microbial community influences cold tolerance in maize, this study employed the metagenomic technology to systematically analyze the community composition, functional characteristics, and their association with host cold tolerance in the rhizosphere of maize genotypes with different cold tolerance (cold-tolerant material B144 and cold-sensitive material Q319, among others) (n = 3 biological replicates per genotype). The results revealed that the rhizosphere microbial community of the cold-tolerant genotype B144 exhibited higher species diversity and more complex genomic features. LEfSe analysis indicated that the rhizosphere soil microbiota of B144 was significantly enriched in two major phyla, Firmicutes and Actinobacteria, as well as microbial taxa with stress tolerance potential, such as the Bacillus and Streptomyces. Further functional analysis revealed that the microbial community was specifically enriched in metabolic pathways related to glycan biosynthesis and metabolism, as well as coenzyme and vitamin metabolism. We hypothesize that the physiological stability of maize under low temperatures can be enhanced through mechanisms such as the synthesis of extracellular polysaccharides to reduce the freezing point and the provision of vitamins and antioxidant substances. In contrast, the rhizosphere microorganisms of the cold-sensitive material Q319 were more enriched in basic metabolic functions. The present study elucidates the pivotal mechanisms by which rhizosphere microorganisms facilitate maize resistance to low-temperature stress from a functional perspective. This provides theoretical support and new strategies for enhancing crop stress resistance by regulating the rhizosphere microbiome. Full article

To promote circular economy in construction, this study evaluates the mechanical surface integrity and long-term water durability of sustainable low-density particleboards utilizing agro-forestry residues, such as corn cob, corn stalk, hemp shive and wood fibres. These are bonded using an ecological mimosa tannin adhesive in comparison to a conventional urea–formaldehyde-based adhesive. Performance was assessed through apparent density, surface cohesion, Shore A hardness and impact resistance. Furthermore, the water sensitivity was assessed through total water absorption (WA), thickness swelling (TS), and a customized cyclic immersion-drying protocol. Results showed a significant correlation between density and Shore A hardness (R² = 0.77). While hemp- and corn-based boards showed surface performance competitive with commercial standards, the wood fibre series exhibited extreme water susceptibility, with mass variations exceeding 400% during cycling. Additionally, tannin-based boards showed evidence of leaching, with an 11% mass loss after three emersion cycles. These findings conclude that while tannin adhesives are viable renewable alternatives, these bio-boards are primarily suited for interior lining in dry environments, as lightweight formulations require additional protection to ensure durability in practical building applications. Full article

Deploying post-quantum cryptography on highly constrained devices remains challenging due to the large key sizes and substantial storage and memory-traffic demands of leading lattice-based schemes. Although constructions such as Kyber, Dilithium, and NTRU offer strong resistance against quantum adversaries, their multi-kilobyte public keys and intensive memory access patterns limit practical adoption in microcontrollers, smart cards, and low-power edge environments. This work proposes a hybrid key-encapsulation mechanism that integrates a compact, seed-generated Module-LWE structure with a quantum-secure hash-based authentication layer. The design employs a small public seed to instantiate lattice matrices on demand via a lightweight pseudorandom generator and incorporates a Merkle-tree commitment to represent compressed auxiliary error information. Additional design considerations—including sparsity-aware secret keys, SIMD-friendly polynomial operations, and cache-efficient decryption paths—are intended to reduce runtime memory usage and computational overhead. The security of the proposed construction is analysed under both Module-LWE and hash-based one-way assumptions, with further consideration of constant-time execution and cache-line alignment to mitigate side-channel risks. This hybrid approach outlines a design pathway toward post-quantum key-encapsulation mechanisms suitable for deployment on memory-limited and energy-constrained platforms. Full article

Solid oxide fuel cells (SOFCs) are a promising near-zero-emission propulsion source for Northern Sea Route (NSR) vessels, but their yttria-stabilized zirconia (YSZ) electrolyte and Ni-cermet anode are susceptible to thermomechanical degradation under repetitive start–stop thermal cycling. We develop a hierarchical Bayesian competing-risk framework built on a dual degradation model that decomposes area-specific resistance (ASR) growth into cycle-induced fatigue and time-dependent electrochemical aging and apply it across six NSR duty-cycle scenarios spanning f = 1–27 cycles/month. Posterior inference via the No-U-Turn Sampler (NUTS) yields 17 estimated parameters meeting standard convergence criteria (R̂ ≤ 1.01, ESS_bulk ≥ 479, zero divergent transitions). The analysis identifies a failure-mode transition at f ≈ 3–6 cycles/month: high-frequency routes are crack-dominated (S1a: 10/15 cells fail by crack within the 600-cycle window with 5/15 right-censored), whereas low-frequency routes are ASR-dominated (S3b: 100% ASR). Global sensitivity analysis indicates the time-dependent rate coefficient k_time as the primary remaining-useful-life driver (S_T = 0.37–0.46). Cycle-based maintenance thresholds span 160 cycles (S3b) to ≥600 cycles (S2b), bracketed by S1a (270 cycles, 10.0 months, crack-dominant) and S3a (480 cycles, 160 months, transition regime); qualitative consistency with published experimental data supports physical plausibility. Full article

The in-service assessment of marine propulsion engines requires more than nominal rating comparison because operating severity is shaped by propeller demand, resistance growth, air-path response, and thermal state. This study develops a quantitative benchmarking method for the regime-dependent performance assessment of a low-speed two-stroke Wärtsilä 6RT-flex58T-D engine installed on a 31,000 DWT multi-purpose container vessel. The method integrates certified sea-trial measurements, endurance-test records, manufacturer load-diagram constraints, and a 15% service-margin projection within one reference framework. Three representative regimes are evaluated: a measured light-running baseline (SR1), a measured thermally stabilised sustained regime (SR2), and a projected heavy-running regime derived from the baseline using a 15% sea-margin assumption (R2). Comparison is performed using indicators of operating-point position, shaft torque, propeller-law consistency, selected air-path and thermal variables, load-diagram proximity, and corrected specific fuel oil consumption where available. The SR1 baseline followed the fitted propeller law with deviations not exceeding 1.18%, confirming a coherent light-running reference. In SR2, corrected SFOC decreased from 174.4 to 172.0 g/kWh, while the exhaust temperature before turbine increased from 359 °C to 435 °C, and the corresponding thermal margin decreased from 156 °C to 80 °C. Under the +15% service-margin projection, the required shaft power at the 100% trial point increased from 12,046.0 to 13,852.9 kW, exceeding the 13,560 kW installation MCR by 2.2%, with corresponding 15% increases in torque and BMEP. These results demonstrate that measured baseline operation, sustained-load severity, and projected heavy-running demand can be distinguished quantitatively within one installation-specific load-diagram-based benchmarking framework. Full article

Hybrid polymeric woven composites (HPWCs) are increasingly important in automotive, aerospace, and renewable energy structures where low weight, impact tolerance, damage containment, and superior mechanical properties are required. By combining dissimilar fibres within woven architectures, HPWCs can achieve a more favourable balance of stiffness, strength, and energy absorption than single-fibre woven systems; however, experimental evidence and predictive modelling remain insufficiently integrated, particularly under dynamic and post-impact loading. This systematically searched critical review provides an HPWC-focused synthesis that links architecture-driven mechanical behaviour, damage development, and multiscale numerical simulation within a single framework. The effects of reinforcement architecture, fibre pairing, and matrix selection on tensile, flexural, compressive, interlaminar, strain rate-dependent, and impact responses are examined, with particular emphasis on barely visible impact damage and post-impact residual strength. Macroscale, mesoscale, and microscale finite element strategies are critically compared in terms of predictive fidelity, computational cost, and suitability for design-orientated assessment. The main contribution of this review lies in integrating experimental characterisation with modelling limitations, validation requirements, and industrial relevance, thereby clarifying where current approaches are effective and where critical gaps remain. Practical implications for lightweight structural design, impact-resistant components, and future validation-driven research are highlighted. Full article

During flood disasters, on-site operations often face the “triple disruption” of network outages, power cuts and blocked roads. This renders terrestrial cellular infrastructure inoperable and disrupts communication links. Satellite internet can partially restore emergency communications thanks to its wide-area coverage and resistance to ground damage. However, limited computing power, memory and unstable bandwidth at the terminal prevent cloud-based flood segmentation from providing near-real-time situational awareness. This paper therefore proposes a lightweight semantic flood segmentation framework for emergency terminals that uses satellite internet. This comprises a parallel dual-branch design with a lightweight U-Net-style convolutional neural network (CNN) branch for local boundary details and a compact Transformer branch for global context. A dynamic gated fusion mechanism (DGFM) balances local texture and global information adaptively. Experiments on the public synthetic aperture radar (SAR) dataset Sen1Floods11 demonstrate that the hybrid architecture strikes a balance between accuracy and inference efficiency. The proposed method combines gated fusion with quality-aware training. Compared to a lightweight CNN baseline and state-of-the-art segmentation models using the same protocol, the proposed configuration (Hybrid-Gated with Quality-Aware Training) achieves the highest mean intersection over union and F1 score among the compared fusion variants, while maintaining competitive false alarm and risk-sensitive performance under deployment constraints. This aligns with the preferences of emergency decision makers. The framework provides a deployable perception module for emergency systems supported by low-orbit satellites and terrestrial networks under triple-disruption conditions. Full article

Gravelly soil is widely used in western China but suffers from poor gradation, low water stability, and weak freeze–thaw resistance. Traditional cementitious stabilizers involve high energy and carbon emissions. To address these issues, a novel, eco-friendly gravelly soil stabilizer was prepared from waste foamed concrete (WFC) via crushing, ball milling, and high-temperature calcination. This study systematically evaluated stabilization performance and mechanisms. Results indicate that the WFC stabilizer significantly enhances soil properties. At the optimal 30% dosage, the 28-day unconfined compressive strength (UCS) reached 6.5 MPa (a 333% increase), and water stability was significantly improved. Under freeze–thaw conditions, the 30% dosage yielded a mere 2% mass loss after five cycles, with the UCS reaching 9.56 MPa (a 437% increase). Microstructural analyses (XRD, SEM) revealed that hydration generates calcium silicate hydrate (C-S-H) gel and katoite (Ca₃Al₂(SiO₄)_3−x(OH)_4x). These products effectively fill soil pores and the spaces of the particles, optimizing the microstructure. This study provides a sustainable pathway for WFC recycling and offers a relatively lower energy consumption, low-carbon and high-performance stabilizer for reinforcing gravelly soil subgrades in cold regions. Full article

The management of red mud (bauxite residue, RM) is critical for environmental protection due to its high alkalinity (pH 12.5–13.0). The study investigates the valorization of RM from the ALUM Tulcea unit (Romania) through accelerated wet carbonation processes (L/S ratio 4:1) and its integration into sustainable construction materials (paving stones). The results indicate a reduction the pH to a stable level of 8.6 in 240 min, a process validated by the formation of new mineral phases (calcite and dawsonite) that stabilize the residual sodium. For the optimized recipe S2 (20% RM, 12% cement, 48% fly ash), an average compressive strength of 33.8 MPa (class T5 according to SR EN 1338:2004) and a low water absorption of 4.12% (Class B) were obtained. Durability tests confirmed superior freeze–thaw resistance (mass loss 0.58 kg/m²) and sodium (Na⁺) leaching below 2.1 mg/L, well below EU limits. In the case of alkaline activated geopolymers (NaOH 8 M), the strength reached 38.5 MPa. The study demonstrates that carbonated RM can reduce the carbon footprint by 20–56% and production costs by up to 43%, providing a viable circular economy solution in line with EU 2030 targets. Full article

To improve the low-temperature crack resistance of asphalt pavement, this paper investigates the effects of fiber length, content, and type on the flexural and tensile properties of asphalt mastic. Firstly, a numerical program was developed in MATLAB to establish a three-dimensional finite element model of asphalt mastic with an uneven fiber distribution in ABAQUS. Then, the Burgers model selected for simulation was obtained through the asphalt low-temperature bending beam rheological test (BBR). Constructing a three-point bending virtual test of asphalt mastic using a three-dimensional fiber model and systematically analyzing the influence of fiber parameters on bending and tensile properties. The accuracy of the three-dimensional fiber model was verified through BBR experiments. The finite element simulation results show that the addition of fibers can significantly improve the tensile performance of asphalt mastic; increasing the fiber content or length can reduce the peak stress at the bottom of the mid-span and delay cracking. The higher the fiber elastic modulus, the smaller the vertical displacement of the specimen. The model established in this article can effectively elucidate the mechanism of fiber reinforcement, providing a theoretical basis for optimizing fiber parameters and improving the crack-resistance performance of asphalt pavement. Full article

Aging has a significant influence on the rheological behavior and service performance of asphalt binders. In this study, base asphalt binder (BAB) and rubberized asphalt binder (RAB) with different aging levels were investigated to clarify their aging evolution and performance correlations. Rheological tests were conducted to evaluate high-temperature rutting resistance, intermediate-temperature fatigue performance, and low-temperature cracking resistance. The 2S2P1D viscoelastic model was used to analyze the evolution of viscoelastic parameters, while gel permeation chromatography (GPC) was adopted to characterize molecular weight changes during aging. The results showed that aging increased the rutting resistance of both binders, but reduced fatigue performance and low-temperature cracking resistance. Among the 2S2P1D viscoelastic model parameters, G_∞, δ, and β were more sensitive to aging than the other parameters and exhibited relatively clear variation trends. Selected viscoelastic parameters also showed significant correlations with rheological performance indices. GPC results indicated that both binder systems progressively evolved toward higher molecular weight during aging, with the molecular weight distribution curves shifting toward the high-molecular-weight region. For RAB, M_w was more sensitive to aging than M_n and showed some fluctuation at intermediate aging stages, reflecting a more complex molecular evolution. Overall, the results indicate that selected 2S2P1D viscoelastic parameters can serve as sensitive indicators of aging evolution and provide a useful basis for interpreting the performance correlations and rheological changes of asphalt binders from a viscoelastic perspective. Full article

Geomembranes are extensively used for seepage control in the reservoir of pumped-storage power stations due to their superior deformability, ease of construction, and low cost. The deformation behavior of geomembranes under high hydraulic pressure is of great importance for seepage-control design and operational safety evaluation. Nevertheless, existing hydrostatic pressure resistance tests cannot effectively measure the hydraulic bulging deformation of geomembranes subjected to water pressure. This study proposes a non-contact binocular vision method to quantify the hydraulic bulging deformation of geomembranes. The method combines underwater camera calibration, image enhancement, stereo matching, triangulation, and three-dimensional reconstruction to achieve both visualization and accurate measurement of geomembrane deformation. After experimental validation and accuracy calibration, the proposed method was preliminary applied to four geomembrane materials, including HDPE, LLDPE, PVC, and TPO, under hydraulic loading. The results show that the measurement error is less than 5% in the large-deformation range under medium and high water pressures. The method can effectively capture the hydraulic bulging behavior of geomembranes and accurately characterize the deformation features of different materials under high hydraulic pressure. This study provides a practical technical approach for underwater deformation measurement of geomembranes and supports seepage-control design and operational safety monitoring. Full article