Polyethylene (PE) film, despite its dominant market presence in food packaging, is fundamentally limited by inadequate oxygen barrier performance and absence of intrinsic antioxidant activity, leading to accelerated oxidative spoilage of packaged foods. To overcome these constraints, this study introduces an innovative coating strategy that functionalizes PE films with a composite layer of polyvinyl alcohol (PVA), silane-modified layered double hydroxide (ALDH) and tannic acid (TA). The optimized film (PE-PVA/ALDH/TA10) demonstrates exceptional properties, achieving an ultra-low oxygen transmission rate of 0.033 cm3 m-2 day-1 atm-1 and a high 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals with a scavenging rate of 79.2%. Structural analysis confirms that ALDH and TA promote the formation of a dense hydrogen-bonded network within the PVA matrix, which significantly reduces oxygen permeability while imparting strong antioxidant activity. Furthermore, the coated film retains high visible-light transparency and exhibits exceptional UV-blocking efficiency, reaching 97.3% in the UVC-UVB range. Preservation tests using bananas validate the material's effectiveness in delaying ripening, minimizing weight loss and maintaining fruit quality. This work presents a scalable, multifunctional packaging solution that combines ultra-high barrier performance with antioxidant functionality for extended food preservation.

Conventional low-voltage electrostatic field (LVEF) preservation, often applied passively during storage with unoptimized voltages, fails to prevent early oxidative damage in fresh-cut produce. To address this limitation, we developed a quantified LVEF pretreatment protocol based on our previous finding of voltage-dependent efficacy. Whole apples were pretreated with LVEF at 200–800 V for 9 h at 4 °C, then freshly cut and stored at 4 °C in the dark. Quality deterioration of fresh-cut apples during storage was characterized by weight loss, firmness, browning index, total soluble solids, titratable acidity, and other related metrics. All experiments were performed with at least three biological replicates, and data were analyzed by one-way analysis of variance (p < 0.05). The 400 V pretreatment achieved optimal efficacy: it reduced weight loss by 20

Postharvest seafood mushroom (Hypsizygus marmoreus) is highly susceptible to rapid dehydration, decay, and softening, rendering single preservation technologies insufficient to effectively address these issues. This study investigated a complementary strategy by integrating a low-voltage electrostatic field (LVEF) with biodegradable poly (butylene adipate-co-terephthalate)/polylactic acid (PBAT/PLA) packaging to extend the mushroom's shelf life. Results showed that compared with conventional low-density polyethylene (LDPE), PBAT/PLA film effectively prevented moisture condensation and maintained lower CO2 concentrations. In contrast, LVEF treatment could suppress respiratory intensity, modulate relevant enzyme activity, and significantly mitigate excessive moisture loss caused by PBAT/PLA films. The findings indicated that the combined treatment effectively increased the mushrooms' antioxidant capacity, maintained cell membrane stability, sustained cell wall polysaccharide levels, and preserved optimal appearance and texture during storage. The combined application of LVEF and PBAT/PLA packaging effectively preserved quality and extended the shelf life at 4 degrees C from 6 to 15 days, offering a promising, eco-friendly strategy for preserving high-respiration edible fungi.

Topology optimization is a method that achieves optimal structural performance by optimizing material distribution and has been widely applied in fields such as aerospace, automotive manufacturing, and biomedical engineering. Although various methods have been developed to address numerical instability issues in topology optimization, such as checkerboard patterns, gray-scale phenomena, and mesh dependence, effectively selecting an appropriate filtering radius remains a key challenge. To address this, this paper proposes a quantitative method based on gray-scale analysis, conducting frequency domain analysis via 2D discrete Fourier transform (DFT) and combining clustering ratio and clustering index. This method systematically investigates the impact of the filtering radius on numerical instability issues and precisely determines the optimal filtering radius. The effectiveness of the proposed method is validated through numerical experiments, where a comprehensive evaluation index S is defined to determine the optimal filtering radius value under different application scenarios. Unlike traditional empirical rules, the method proposed in this paper improves the precision of filtering radius selection through frequency domain feature analysis, significantly reduces numerical instability, and ensures the accuracy and stability of the optimization results. The research results show that the filtering radius selection method based on gray-scale analysis enhances computational efficiency, optimizes structural performance and manufacturability, and avoids the additional costs that may arise from improper filtering radius selection. This study provides a theoretical foundation and quantitative guidance for the parameter selection of filtering techniques in topology optimization, offering significant engineering application value.

Broccoli (Brassica oleracea L. var. italica) is prone to begin the senescence process because of cutting and improper storage during post-harvest handling. This study aimed to improve the quality and overall acceptance of fresh-cut broccoli to reduce losses by integrating low voltage electrostatic field (LVEF) with microporous modified atmosphere packaging (MAP-M). The research findings indicated that LVEF effectively preserved color, reduces respiration rate, and controlled relevant enzyme activities. Furthermore, MAP-M not only ensured broccoli moisture preservation but also overcame the limitations of film materials to anaerobic respiration. The results demonstrated that the combined effect of LVEF and MAP-M could minimize odor generation in fresh-cut broccoli, regulate phenols metabolism enzymes, maintaine membrane integrity (47.18 %), and suppress the activity of cell wall-degrading enzymes to maintain cell wall components (49.97 %). The innovative technology of LVEF and MAP-M could extend the shelf life of fresh-cut broccoli stored at 4 degrees C, increasing its shelf-life from 4 days to over 10 days. Therefore, the LVEF+MAP-M treatment offers a superior preservation strategy for prolonging storage life and maintaining the nutritional quality of fresh-cut vegetables.

Certain organic substances in food are susceptible to photo-oxidative degradation under the influence of ultraviolet light, leading to a decline in sensory properties and food spoilage. In this study, by coating lignin with tannic acid in a weakly alkaline aqueous solution and introducing it into a polyvinyl alcohol coated film, the UV resistance and gas barrier properties of the coated film were effectively enhanced. At the optimal mass ratio (with a ratio of AL to TA of 1:3), the PVA/AL@TA-2-PE coating film achieves a UV shielding capability of 99.40 %. Its water vapor permeability (WVP) is 3.65 +/- 0.03 x 10-15 g center dot cm center dot cm- 2 center dot s- 1 center dot Pa- 1, and its oxygen permeability (OP) is 2.29 +/- 0.08 x 10-17 cm3 center dot cm center dot cm- 2 s- 1 center dot Pa- 1. and the tensile strength was increased to 37.38 MPa. Elongation at break increased to 969.69 %. Based on these excellent properties, the use of PVA/AL@TA-2-PE film for packaging of bananas was effective in extending the shelf life. Overall, this study highlights the value-added utilization of biomass polymers and provides evidence of the potential applicability of polyvinyl alcohol coated films (specifically PVA/AL@TA-2-PE) as food packaging candidates.

Topology optimization, as an efficient material distribution design method, faces challenges of numerical instability (such as checkerboard patterns, grayscale phenomena, and mesh dependency) in the field of thermal management. These issues directly affect the manufacturability and thermodynamic performance of the optimization results. This study proposes a quantitative method based on grayscale analysis, conducting frequencydomain analysis of the grayscale distribution in the optimization results through two-dimensional discrete Fourier transform. It systematically investigates the influence mechanism of the filtering radius on numerical instability issues. The research results show that the choice of filtering radius has a significant impact on the numerical stability and thermodynamic performance of the optimization results. When the filtering radius is within the range of 1 to 2 mm, it effectively reduces numerical instability issues while significantly improving the stability and accuracy of the structural performance. By defining a comprehensive metric S and conducting thermal analysis of the topology structure for different filtering radii, the effectiveness of the proposed method is validated. The numerical results indicate that when the filtering radius is 1.5 mm, the optimization results achieve an ideal balance between multiple optimization indicators, including objective function value, computational cost, discretization, and grayscale rate. The objective function value is significantly improved, and heat transfer efficiency is optimized; computational cost is reasonably reduced, and the number of iterations is decreased; optimization of discretization and grayscale rate ensures the uniformity of the structure and the effectiveness of the thermal flow channels, significantly enhancing the accuracy and stability of the topology optimization results. The innovation of this study lies in quantifying the impact of the filtering radius on the optimization results through frequency-domain analysis, providing a theoretical basis for scientifically selecting the filtering radius and avoiding the subjectivity and uncertainty in the traditional methods of selecting the filtering radius. Compared with existing research, this paper not only systematically analyzes the quantitative impact of the filtering radius on numerical stability and thermodynamic performance but also validates the effectiveness of the proposed method through numerical experiments. It provides clear guidance for selecting the filtering radius in topology optimization, contributing to the application of topology optimization techniques in complex thermal management problems and improving engineering design efficiency and manufacturing quality.

This study aims to investigate the impact of food components on the performance of polyvinyl alcohol (PVA)coated composite films. Food simulants, including deionized water representing aqueous food, 3% acetic acid representing acidic food, and 50% ethanol representing alcoholic food, were used for pouching and packaging of the PVA-coated composite films. The films were also subjected to water bath (80 degrees C for 30 min) and accelerated treatment (80 degrees C for 60 min and 100 degrees C for 60 min) to simulate industrial pasteurization and more severe damage. The morphology, chemical composition, thermal stability, barrier properties, and other characteristics of the materials were evaluated. In this study, it was found that all three simulants had an effect on the barrier properties of the films. Among them, acidic and alcoholic simulants had a relatively large impact on the oxygen barrier properties of the films, with decreases of 44.99% and 79.48%, respectively. The alcoholic simulant also had the largest effect on the moisture barrier properties of the films, with a decrease of 28.33%. Additionally, the addition of the three food simulants led to a significant reduction in the mechanical properties of the films and a significant decrease in transmittance. Microstructural characterization revealed that the above performance changes originated from the harsh conditions when the food simulants first contacted the base film, damaging the internal structure. Subsequently, the barrier layer PVA was penetrated and dissolved, thus affecting the performance. The fragmentation of thin film crystals and the penetration of the simulant were also evidenced by XRD and FTIR. These findings emphasize the influence of food itself on widely used PVA and provide guidance for the design of future PVA high-barrier packaging films.

Lignin is one of the most abundant and underused biopolymers in nature with limited antimicrobial activities. Herein, this work aimed to enhance the antimicrobial activity of lignin extracted from waste rice straw by ultrasonic-alkali integrated extraction (USP-AT) and modify the alkali lignin through Mannich reaction to improve its antimicrobial properties. The effects of ultrasonic pretreatment (USP) time on the chemical structure, morphology, antioxidant, and antibacterial activities of lignin were studied. The results demonstrated that the total phenolic content of USP-AT lignin was higher than that of lignin extracted by alkali treatment. Moreover, the antioxidant activity of USP-AT lignin was increased by 49.69 %-69.42 %. The antibacterial activity of USPAT lignin against Escherichia coli and Staphylococcus aureus increased by more than 40 %. However, the antibacterial capacity of USP-AT lignin is far from meeting the requirements of antibacterial food packaging. The alkali lignin was modified by Mannich reaction in order to improve its antimicrobial properties against common spoilage microorganisms or pathogenic bacteria in food and packaging. The modified USP-AT lignin exhibit remarkable antimicrobial capacities to representative bacteria, molds, and yeasts. The antifungal capacity of modified USP-AT lignin against A. niger and P. citrinum were improved by more than 40 %.

Microbial contamination and oxygen ingress are primary drivers of food spoilage, but advanced materials that simultaneously offer high oxygen barrier and effective antibacterial functions remain scarce. To address this dual challenge, we engineered a polyvinyl alcohol-based composite coating, incorporating the natural aggregation-induced emission photosensitizer berberine (BBR) and non-toxic layered double hydroxide nanosheets (LDH NS), on a polyethylene terephthalate substrate. The developed composite film demonstrated a low oxygen transmission rate of 0.06 cm3 m-2 day-1 atm-1. Furthermore, it achieved 100 % inhibition rate against both Staphylococcus aureus and Escherichia coli upon light irradiation. Crucially, we propose and elucidate a novel antimicrobial enhancement mechanism mediated by the orderly-arranged LDH NS for BBR. This mechanism involves (i) promoting BBR molecular aggregation to enhance reactive oxygen species (ROS) generation, and (ii) improving bacterial capture capacity via electrostatic interactions. These effects collectively establish a synergistic "capture-ROS enrichment-bacterial killing" pathway on the film surface. In a practical application, the composite film effectively suppressed microbial growth on packaged bread, extending its shelf life by more than 4-fold compared to conventional packaging. This work not only presents a promising multifunctional material for food preservation but also provides fundamental insights into the design of nanomaterial-enhanced, natural photosensitizer-based systems for advanced active packaging.

Modified atmosphere packaging (MAP) is widely employed for fruit preservation. However, traditional MAP has insufficient antibacterial activity. Here, an oil-in-water-in-oil (O/W/O) Pickering emulsion was prepared via a two-step emulsification method and incorporated into polylactic acid (PLA) matrix. The sustained release of cinnamon essential oil from the O/W/O Pickering emulsions not only produced effective antibacterial activity, but also spontaneously generated abundant micropores within the PLA matrix. These micropore structures provide channels for gas flow, thereby enhancing the gas transmission properties of the PLA films while altering the CO2/O-2 selectivity (ranging from 1.21 +/- 0.06 to 2.96 +/- 0.30). Results demonstrated that incorporating 10 wt % O/W/O Pickering emulsion into the PLA matrix achieved complete inhibition against both Escherichia coli and Staphylococcus aureus (inhibition rate of 100 %), and the Botrytis cinerea inhibition rate reached 91.36 +/- 1.10 %. During strawberry storage, the optimal gas atmosphere (13.27 +/- 0.48 % CO2 and 4.19 +/- 0.82 % O-2) was spontaneously formed inside the packaging, maintaining the appearance and freshness of strawberries at least 7 days. Furthermore, compared to pure PLA film, the elongation at break increased by 110.31-fold, and the shielding efficiencies of Ultraviolet A, Ultraviolet B, and Ultraviolet C reached 48.64 %, 99.95 % and 99.97 %. This functionalized PLA films exhibit sustained antimicrobial activity and tunable gas selectivity, providing a facile, effective, sustainable, and universal strategy for food preservation.

The limited oxygen barrier of polyethylene (PE) films has restricted their further application in food packaging, like emergency foods. Although its oxygen barrier property can be improved by applying a polyvinyl alcohol (PVA) coating, the application of PVA/PE composite films in high-humidity environments is still challenging. Hence, this study aimed to enhance the oxygen barrier properties of PVA/PE composite films in high-humidity environments. Specifically, PVA coatings were modified by the itaconic acid (IA) and magnesium-aluminum layered double hydroxides (LDH), and then applied to PE films as bilayer coating. Because of the unique bilayer coating on the PE surface, the oxygen barrier property of PVA/PE composite film (IA/LDH-p) in high-humidity environments has been further improved. The results confirmed that IA/LDH-p had an oxygen permeability coefficient of 1.92 +/- 0.16 x 10-16 cm3 cm/(cm2 s Pa) under a high-humidity environment test, 82.42% better than that of single-layer coating coated on PE surface. After being stored at RH 90% for 36 h, the tensile strength and elongation at break values of IA/LDH-p were 27.20 MPa and 919.63%, respectively. Overall, this obtained PVA/PE composite films showed great potential for application in emergency foods packaging, particularly in high-humidity environments. The preparation process of composite films with a bi-layer coating structure that has a high oxygen barrier property. image

Low voltage electrostatic field (LVEF), a novel non-thermal processing technology, shows promise for food preservation. However, the absence of clear definition and quantification of the core concept "low voltage" obstructs the effective application of LVEF. This study assessed the efficiency of various LVEF intensities (100, 200, 300 V) on cherry tomato preservation, revealing significant differences in preservation efficiency. Compared to the control, samples treated with different intensities showed varied reductions in weight loss (6.26-25.45 %), firmness changes (5.17-28.91 %), and decay incidence (47.91-70.89 %). Quantitative analysis elucidated that the differential preservation efficiency may arise from a dose-response relationship between electric field strength and hydrogen peroxide (H2O2) content， identifying an optimal H2O2 content range of 21.18-27.01 mmol kg-1 for the effective preservation of cherry tomatoes under LVEF. These findings highlight the importance of precise LVEF intensity control for effective food preservation and offer insights for developing optimal LVEF treatment intensities for diverse produce.

This study aims to optimize the pipeline structure design of the secondary loop steam generators in nuclear power plants to enhance thermal cycle efficiency. This is crucial for reducing energy consumption, lowering costs, and minimizing environmental impact. A dual-region topology optimization method based on the SIMP model was employed for heat conduction path planning. The effects of optimization parameters such as the penalty factor, filter radius, and high thermal conductivity material ratio on the topology structure were analyzed, and new quantitative analysis methods were introduced to determine the optimal heat path. This approach provides a new theoretical framework and computational tools for designing more efficient heat exchangers and other thermal management systems. The results indicate that, compared to the unoptimized control group (Case 0), the optimal heat conduction structure design obtained through topology optimization (Case 1) achieved a 240 % improvement in thermal cycle efficiency, with more effective heat transfer paths and enhanced structural characteristics. Although there was an increase in pressure drop in Case 1, this impact is relatively minor given the significant enhancement in thermal conduction performance and is therefore acceptable. These findings support the adoption of more optimized thermal recovery and circulation strategies in nuclear power plants.

At present, improving the energy absorption capacity of lightweight degradable polymer honeycombs is crucial for one of the future engineering applications and bio-inspired strategy based on hierarchy is considered an efficient method for designing honeycomb structures. To improve the energy absorption performance and stability of polymer honeycombs, this study develops three central self-similar bio-inspired honeycombs combining the microstructure of horsetails and designs different connections between the two walls and connecting structures for the central self-similar honeycombs. Bio-inspired honeycombs are fabricated using toughened polylactic acid (PolyMaxTM PLA) through fused deposition modelling and subjected to axial compression tests. The finite element (FE) models of the bio-inspired honeycombs are developed to simulate the axial compression process and verified with experimental results. Results show that the connecting structures distributed on the outer wall of the central self-similar honeycombs considerably improve the energy absorption performance of the bio-inspired honeycombs. In the double-cell honeycombs, connecting structures interact with the cell walls, leading to the formation of more folding lobes on the cell walls and increased cell wall utilisation. Furthermore, the effects of geometrical parameters on the energy absorption performance of the bio-inspired honeycombs are investigated. Suitable connecting structure size and cell wall thickness can improve the energy absorption performance and stability of the honeycombs. In addition, the theoretical calculation models of the three bio-inspired honeycombs are established, and the errors with the FE calculation results are within 6%, which verifies the accuracy of the theoretical models.

Polyvinyl alcohol (PVA) coating has attracted intense attention due to its biodegradability and high gas barrier properties. However, the high gas barrier properties deteriorate at elevated humidity. Herein, we aimed to prepare PVA based coating with high water resistance by incorporating nano-SiO2 (S) and citric acid (CA), and polyethylene (PE) film was selected as a substrate model. The results showed that the PVA/S/CA coated PE films had better water vapor and oxygen barrier performance than the uncoated PE films. With an optimized mass ratio (PVA/S/CA10