Search Results (290)

This study addresses the complex challenges associated with flexible mattress (soft mattress) installation in the sharply curved and deep-water sections of the Yangtze River, particularly in the Yaozui revetment reconstruction project. Under extreme hydrodynamic conditions—water depths exceeding 30 m and velocities over 2.5 m/s—the risk of structural failures such as displacement, flipping, or tearing of the mattress becomes significant. To improve construction safety and stability, the study integrates numerical modeling and on-site strain monitoring to analyze the mechanical response of flexible mattresses during deployment. A three-dimensional finite element model based on the catenary theory was developed to simulate stress distributions under varying flow velocities and angles, revealing stress concentrations at the mattress’s upper edge and reinforcement junctions. Concurrently, a real-time monitoring system using high-precision strain sensors was deployed on critical shipboard components, with collected data analyzed through a remote IoT platform. The results demonstrate strong correlations between mattress strain, flow velocity, and water depth, enabling the identification of high-risk operational thresholds. The proposed monitoring and early-warning framework offers a practical solution for managing construction risks in extreme riverine environments and contributes to the advancement of intelligent construction management for underwater revetment works. Full article

The rapid advancement of underwater wireless communication technologies is critical to unlocking the full potential of marine resource exploration and environmental monitoring. This paper reviews recent progress in three primary modalities: underwater acoustic communication, radio frequency (RF) communication, and underwater optical wireless communication (UWOC), each designed to address specific challenges posed by complex underwater environments. Acoustic communication, while effective for long-range transmission, is constrained by ambient noise and high latency; recent innovations in noise reduction and data rate enhancement have notably improved its reliability. RF communication offers high-speed, short-range capabilities in shallow waters, but still faces challenges in hardware miniaturization and accurate channel modeling. UWOC has emerged as a promising solution, enabling multi-gigabit data rates over medium distances through advanced modulation techniques and turbulence mitigation. Additionally, bio-inspired approaches such as electric field communication provide energy-efficient and robust alternatives under turbid conditions. This paper further examines the practical integration of these technologies in underwater platforms, including autonomous underwater vehicles (AUVs), highlighting trade-offs between energy efficiency, system complexity, and communication performance. By synthesizing recent advancements, this review outlines the advantages and limitations of current underwater communication methods and their real-world applications, offering insights to guide the future development of underwater communication systems for robotic and vehicular platforms. Full article

In this study, a composite film with dual antioxidant and antibacterial properties was prepared by combining 2% chitosan and 7% gelatin (2:1, w:w), with D-carvone (0–4%) as the primary active component. The effect of D-carvone content on the performance of the composite films was systematically investigated. The results showed that adding 1% D-carvone increased the water contact angle by 28%, increased the elongation at break by 35%, and decreased the WVTR by 18%. FTIR and SEM confirmed that ≤2% D-carvone uniformly bonded with the substrate through hydrogen bonds, and the film was dense and non-porous. In addition, the DPPH scavenging rate of the 1–2% D-carvone composite film increased to about 30–40%, and the ABTS⁺ scavenging rate increased to about 35–40%; the antibacterial effect on Escherichia coli and Staphylococcus aureus increased by more than 70%. However, when the addition amount was too high (exceeding 2%), the composite film became agglomerated, microporous, and phase-separated, affecting the film performance, and due to its own taste, it reduced the sensory quality of the noodles. Comprehensively, the composites showed better performance when the content of D-carvone was 1–2% and also the best effect for freshness preservation in Xinjiang ramen. This study provides a broad application prospect for natural terpene compound-based composite films in the field of high-moisture, multi-fat food preservation, and provides a theoretical basis and practical guidance for the development of efficient and safe food packaging materials. In the future, the composite film can be further optimized, and the effect of flavor can be further explored to meet the needs of different food preservation methods. Full article

Driven by the rapid development of e-commerce and intelligent logistics, the volume of express delivery services has surged, making the efficient and accurate identification of shipping information a core requirement for automatic sorting systems. However, traditional Optical Character Recognition (OCR) technology struggles to meet the accuracy and real-time demands of complex logistics scenarios due to challenges such as image distortion, uneven illumination, and field overlap. This paper proposes a three-level collaborative recognition method based on deep learning that facilitates structured information extraction through regional normalization, dual-path parallel extraction, and a dynamic matching mechanism. First, the geometric distortion associated with contour detection and the lightweight direction classification model has been improved. Second, by integrating the enhanced YOLOv5s for key area localization with the upgraded PaddleOCR for full-text character extraction, a dual-path parallel architecture for positioning and recognition has been constructed. Finally, a dynamic space–semantic joint matching module has been designed that incorporates anti-offset IoU metrics and hierarchical semantic regularization constraints, thereby enhancing matching robustness through density-adaptive weight adjustment. Experimental results indicate that the accuracy of this method on a self-constructed dataset is 89.5%, with an F1 score of 90.1%, representing a 24.2% improvement over traditional OCR methods. The dynamic matching mechanism elevates the average accuracy of YOLOv5s from 78.5% to 89.7%, surpassing the Faster R-CNN benchmark model while maintaining a real-time processing efficiency of 76 FPS. This study offers a lightweight and highly robust solution for the efficient extraction of order information in complex logistics scenarios, significantly advancing the intelligent upgrading of sorting systems. Full article

As a key insulating material in power equipment, epoxy resins (EP) are often limited in practical applications due to space charge accumulation and mechanical degradation. This study systematically investigates the effects of SiO₂ nanoparticle doping on the electrical and mechanical properties of SiO₂/EP composites through molecular dynamics simulations and first-principles calculations. The results demonstrate that SiO₂ doping enhances the mechanical properties of EP, with notable improvements in Young’s modulus, bulk modulus, and shear modulus, while maintaining excellent thermal stability across different temperatures. Further investigations reveal that SiO₂ doping effectively modulates the interfacial charge behavior between EP and metals (Cu/Fe) by introducing shallow defect states and reconstructing interfacial dipoles. Density of states analysis indicates the formation of localized defect states at the interface in doped systems, which dominate the defect-assisted hopping mechanism for charge transport and suppress space charge accumulation. Potential distribution calculations show that doping reduces the average potential of EP (1 eV for Cu layer and 1.09 eV for Fe layer) while simultaneously influencing the potential distribution near the polymer–metal interface, thereby optimizing the interfacial charge injection barrier. Specifically, the hole barrier at the maximum valence band (VBM) after doping significantly increased, rising from the initial values of 0.448 eV (Cu interface) and 0.349 eV (Fe interface) to 104.02% and 209.46%, respectively. These findings provide a theoretical foundation for designing high-performance epoxy-based composites with both enhanced mechanical properties and controllable interfacial charge behavior. Full article

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a class of synthetic fluorine-containing organic compounds that exhibit chemical and thermal stability due to the highly stable carbon–fluorine bonds present in their molecular structures. This characteristic makes them slow to degrade in the natural environment. With the widespread application of these compounds in the industrial and consumer goods sectors, environmental media such as water, air, soil, and food have been severely polluted, posing a range of significant threats to public health. Therefore, the development of efficient, economical, and environmentally friendly PFAS removal technologies has become a current research hotspot. This review systematically summarizes the current technologies for removing PFASs from four perspectives—physical, chemical, biological, and combined treatments—enabling a clear understanding of the existing treatment strategies to be discussed. In addition, suggestions for future research on PFAS removal are provided. Full article

Hydroxyl-terminated-polybutadiene (HTPB)-based composite solid propellants are extensively used in aerospace and defense applications due to their high energy density, thermal stability, and processability. However, the presence of highly sensitive energetic components in their formulations leads to a significant risk of accidental ignition under electrostatic discharge, posing serious safety concerns during storage, transportation, and handling. To address this issue, this study explores the prediction of electrostatic sensitivity in HTPB propellants using machine learning techniques. A dataset comprising 18 experimental formulations was employed to train and evaluate six machine learning models. Among them, the Random Forest (RF) model achieved the highest predictive accuracy (R² = 0.9681), demonstrating a strong generalization capability through leave-one-out cross-validation. Feature importance analysis using SHAP and Gini index methods revealed that aluminum, catalyst, and ammonium perchlorate were the most influential factors. These findings provide a data-driven approach for accurately predicting electrostatic sensitivity and offer valuable guidance for the rational design and safety optimization of HTPB-based propellant formulations. Full article

This study investigated sustainable activation strategies for residual slag micro powder derived from recycled waste concrete aggregates, aiming to advance circular economy principles in construction materials. An experimental study was carried out to explore the activation mechanisms of slag micro powder from recycled waste concrete aggregates to enhance its utility in building materials. Three methods—mechanical grinding, high-temperature calcination, and mechanical grinding–thermal activation—were evaluated comparatively. The results showed high-temperature calcination at 750 °C for 10 min proved most effective, achieving a 95.85% activity index. High-temperature calcination may contribute to the release of active SiO₂ and Al₂O₃ substances of slag micro powder, thereby improving the hydration performance of slag micro powder and its cement mortar’s compressive strength. The flexural strength of cement mortar after different activation treatments was also analyzed. Mechanical grinding alone showed limited benefits, only achieving a less than 65.59% activity index, while the combined method negatively impacted the mechanical properties of cement mortar samples. An SEM (scanning electron microscope) and EDS (energy dispersive X-ray spectrometer) microstructural analysis supported these findings, highlighting enhanced hydration product formation after calcination at 750 °C for 10 min. This work may contribute to sustainable construction practices through the resource-efficient utilization of industrial by-products. Full article

Pile–raft foundations are widely used in soft soil engineering due to their good integrity and high stiffness. However, traditional design methods independently design pile–raft foundations and superstructures, ignoring their interaction. This leads to significant deviations from actual conditions when the superstructure height increases, resulting in excessive costs and adverse effects on building stability. This study experimentally investigates the interaction characteristics of pile–raft foundations and superstructures in soft soil under different working conditions using a 1:10 geometric similarity model. The superstructure is a cast-in-place frame structure (beams, columns, and slabs) with bamboo skeletons with the same cross-sectional area as the piles and rafts, cast with concrete. The piles in the foundation use rectangular bamboo strips (side length ~0.2 cm) instead of steel bars, with M1.5 mortar replacing C30 concrete. The raft is also made of similar materials. The results show that the soil settlement significantly increases under the combined action of the pile–raft and superstructure with increasing load. The superstructure stiffness constrains foundation deformation, enhances bearing capacity, and controls differential settlement. The pile top reaction force exhibits a logarithmic relationship with the number of floors, coordinating the pile bearing performance. Designers should consider the superstructure’s constraint of the foundation deformation and strengthen the flexural capacity of inner pile tops and bottom columns for safety and economy. Full article

Laccase, a member of the blue multicopper oxidase family, is widely distributed across diverse taxonomic groups, including fungi, bacteria, plants, and insects. This enzyme drives biocatalytic processes through the oxidation of phenolic compounds, aromatic amines, and lignin derivatives, underpinning its significant potential in the food industry, cosmetics, and environmental remediation. However, wild-type laccases face critical limitations, such as low catalytic efficiency, insufficient expression yields, and poor stability. To address these bottlenecks, this review systematically examines optimization strategies for heterologous laccase expression by fungal and bacterial systems. Additionally, we discuss protein engineering for laccase modification, with a focus on the structural basis and active-site redesign. The comprehensive analysis presented herein provides strategic suggestions for advancing laccase engineering, ultimately establishing a theoretical framework for developing high-efficiency, low-cost engineered variants for large-scale biomanufacturing and green chemistry applications. Full article

DNA methylation, also known as 5-methylcytosine, is an epigenetic modification that has crucial functions in multiple important biological processes in fish, such as gonadal development. The cellular DNA methylation level is tightly regulated by DNA methyltransferases (Dnmt). However, detailed investigations of this family in fish are very scarce. In this study, our results confirmed that teleost genomes contain 4 to 16 Dnmt genes, with diversity likely resulting from a combination of whole-genome duplication (WGD), tandem duplication, and gene loss. Differences were observed in tissue distribution, transcription abundance, and protein structure of Dnmt duplicates, supporting their subfunctionalization or neofunctionalization after duplication. Interestingly, we found that fish Dnmt3b duplicates likely have acquired the functions of mammalian Dnmt3l, which may compensate for the absence of fish Dnmt3l. Furthermore, transcriptome analysis and qPCR results indicated that DNA methyltransferase genes (Dnmt1, Dnmt3aa, Dnmt3ab, Dnmt3ba, and Dnmt3bb.1) possibly play important roles in the natural sex change of protandrous hermaphrodite blackhead seabream (Acanthopagrus schlegelii) and inferred that global remodeling of gonadal DNA methylation, regulated by DNA methyltransferase genes, was closely associated with sex change in sequentially hermaphroditic fishes. Overall, our results may help provide a better understanding of the evolution and function of DNA methyltransferases in fish. Full article

Semantic communication has recently gained significant attention in theoretical analysis due to its potential to improve communication efficiency by focusing on meaning rather than exact signal reconstruction. In this paper, we extend the Blahut–Arimoto (BA) algorithm, a fundamental method in classical information theory (CIT) for computing the rate-distortion (RD) function, to semantic communication by proposing the extended Blahut–Arimoto (EBA) algorithm, which iteratively updates transition and reconstruction distributions to calculate the semantic RD function based on synonymous mapping in semantic information theory (SIT). To address scenarios where synonymous mappings are unknown, we develop an optimization framework that combines the EBA algorithm with simulated annealing. Initialized with a syntactic mapping, the framework progressively merges syntactic symbols and identifies the mapping with a maximum synonymous number that satisfies objective constraints. Furthermore, by considering the semantic knowledge base (SKB) as a specific instance of synonymous mapping, the EBA algorithm provides a theoretical approach for analyzing and predicting the SKB size. Numerical results validate the effectiveness of the EBA algorithm. For Gaussian sources, the semantic RD function decreases with an increasing synonymous number and becomes significantly lower than its classical counterpart. Additionally, analysis on the CUB dataset demonstrates that larger SKB sizes lead to higher semantic communication compression efficiency. Full article

Catastrophic floods in monsoon-driven river systems pose significant challenges to flood resilience. In July 2020, China’s Huai River Basin (HRB) encountered an unprecedented basin-wide flood event characterized by anomalous southward displacement of the rain belt. This event established a new historical record with the three typical hydrological stations (Wangjiaba, Runheji, and Lutaizi sections) along the mainstem of the Huai River exceeded their guaranteed water levels within 11 h and synchronously reached peak flood levels within a 9-h window, whereas the inter-station lag times during the 2003 and 2007 floods ranged from 24 to 48 h, causing a critical emergency in the flood defense. By integrating operational hydrological data, meteorological reports, and empirical rainfall-runoff model schemes for the Meiyu periods of 2003, 2007, and 2020, this research systematically dissects the 2020 flood’s spatial composition patterns. Comparative analyses across spatiotemporal rainfall distribution, intensity metrics, and flood peak response dynamics reveal distinct characteristics of southward-shifted torrential rain and flood variability. The findings provide critical technical guidance for defending against extreme weather events and unprecedented hydrological disasters, directly supporting revisions to flood control planning in the Huai River Ecological and Economic Zone. Full article

Utilizing biomass resources to develop carbon-based microwave-absorbing materials adheres to the principles of sustainable development. Nevertheless, the single loss mechanism of pure carbon materials is limited. Additionally, the carbonization of artificially synthesized polymers has poor environmental performance and involves complex processes. These issues restrict their performance and broader applicability. In this study, cobalt-doped seaweed sludge porous carbon (Co/SSPC) with different cobalt contents was synthesized via a simple grinding–carbonization treatment. The addition of cobalt can regulate the graphitization degree of porous carbon, achieving a suitable amorphous-to-crystalline carbon ratio of 2.05. This not only enhances magnetic loss but also modifies dielectric loss and optimizes impedance matching. The construction of synergistic magnetic and dielectric loss mechanisms enables Co/SSPC to exhibit excellent microwave absorption performance. Specifically, Co/SSPC achieved a minimum reflection loss (RL_min) of −66.91 dB at a thickness of 4.79 mm and an effective absorption bandwidth (EAB) of 5.09 GHz at a thickness of 1.6 mm. This study provides a practical approach for the functional application of natural polymer waste algal sludge and highlights its potential in the low-cost production of microwave absorbing materials. Full article

Japanese encephalitis (JE), a mosquito-borne viral disease caused by the Japanese encephalitis virus (JEV), remains a significant public health threat in Asia. Although vaccination programs have successfully reduced the incidence of JE, challenges persist in the adult population, and the emergence of rare JEV genotypes poses additional risks. In this study, a phylogenetic analysis of the whole JEV genome sequence, along with a temporal–spatial analysis of isolates and a host–vector analysis, was used to examine the changes in JEV transmission dynamics before and after 2012. The results revealed persistent differences between the dominant G1 and G3 genotypes, as well as the re-emergence of G4 and G5 genotypes. Although JEV has been detected in non-traditional vectors and atypical mammalian hosts, Culex tritaeniorhynchus and pigs remain the primary vector and amplifying host, respectively. These findings underscore the need to enhance existing JEV genotype surveillance while addressing emerging threats from genotype diversity, host expansion, and geographic spread. Full article