In recent years, with the rise of printed electronics technology, printed flexible sensors have garnered widespread attention. To predict the performance of sensors before actual fabrication, in this paper, the bending strain and resistance response of the sensor’s functional layer were simulated using COMSOL Multiphysics 6.0 software, and the effects of different carbon black/graphene fill ratios on the sensor’s bending performance were explored. The simulation results indicated that resistance increases with the bending angle during the bending process, and the bending-resistance characteristics are better when the carbon black to graphene mass ratio is 2:1. Subsequently, flexible strain sensors were fabricated using screen-printing technology and their bending performance was tested. The experimental results demonstrated that the sensors have good linearity (R2 = 0.9851), favorable response and recovery times (approximately 1 and 2 s, respectively), low hysteresis (4.88%), and better cyclic stability when repeatedly bent at 0∘−20∘ compared to 0∘−90∘. The experimental results were consistent with the simulation results. This study provides a new perspective on the design of flexible strain sensors through synchronized experiments and simulations, which is expected to significantly reduce the cost of prototype development.
The problem of bacterial adhesion, bacterial transmission, and bacterial infection in food packaging has serious implications for the global economy and human health. Therefore, in recent decades, research specialists have worked to develop antibacterial materials which inhibit the growth of bacteria or achieve effective sterilization. To address the issues attributed to bacteria, this study created a superhydrophobic and antibacterial paper by adsorbing a layer of tea polyphenols and the FeCl3 reaction product on the surface of kraft paper, immersing it in AgNO3 solution for the in situ reduction of nanosilver, repeating the process four times, and then treating the surface with palm wax to reduce surface energy. The paper created showed excellent antibacterial properties (S. aureus inhibition rate of 99.963%, E. coli inhibition rate of 99.997%), superhydrophobicity (contact angle of water >155∘, sliding angle <5∘), stability, moisture-resistant performance, and reusability. This superhydrophobic antibacterial paper is extremely suitable for application in food packaging.
Aggregation-induced emission (AIE) polymers have attracted increasing attention due to good processability, film-forming ability, and ease of functionalization. In this study, a series of epoxide polymers doped with AIEgen tetraphenylethene (TPE) are achieved through free-radical-promoted cationic photopolymerization. Free radical photoinitiator acts as a sensitizer for the cationic photopolymerization of epoxides, and the photocuring performance of the TPE-doped photocurable resin is evaluated. UV-Vis absorption and photoluminescence spectra are characterized to investigate the AIE behavior of TPE molecules doped in the epoxy polymer. This research demonstrates that the TPE-doped cationic photocurable resin is capable of generating luminescent film and pattern fabrication, which has significant potential in anti-counterfeiting inks and other optical-functional applications.
Image style transfer, which involves remapping the content of a specified image with a style image, represents a current research focus in the field of artificial intelligence and computer vision. The proliferation of image datasets and the development of various deep learning models have led to the introduction of numerous models and algorithms for image style transfer. Despite the notable successes of deep learning based style transfer in many areas, it faces significant challenges, notably high computational costs and limited generalization capabilities. In this paper, we present a simple yet effective method to address these challenges. The essence of our approach lies in the integration of wavelet transforms into whitening and coloring processes within an image reconstruction network (WTN). The WTN directly aligns the feature covariance of the content image with that of the style image. We demonstrate the effectiveness of our algorithm through examples, generating high-quality stylized images, and conduct comparisons with several recent methods.
The study focuses on the fresh-keeping effect of clove packaging carton on strawberries as well as the preservation and physical properties of the carton. The extraction conditions were optimized by orthogonal test method, and the components of clove extract were analyzed by gas chromatography-mass spectrometry (GC-MS). The physical properties of packaging cartons and the preservation performance of strawberries were studied by comparative experiments. With an increase in the coating amount of clove extract, the empty carton’s compressive strength, bursting strength and edge compressive strength of the carton show a downward trend as a whole, but remain above 85% of the original carton strength, which can meet the needs of use. When the coating amount of clove extract is 150 mL/m2, the preservation performance is the best. At this level, the weight loss rate of strawberry is 34.96%, the soluble solid content is 8.0%, and the titratable acid content is 25%. According to the physical properties and preservation properties of clove extract packaging cartons, the carton with a coating amount of 150 mL/m2 is best suited for meeting food industry’s needs.
Currently, there is a relative insufficiency of research on the feature extraction of braided rivers and the river-scale water system evolution pattern under long time series in China. Therefore, continuous monitoring of surface water and analysis of its evolution process for the Yellow River Delta region have great application value to supplement and improve related knowledge and realize sustainable water resource management. The satellite remote sensing image is an important medium for obtaining surface water change data. Since free high-quality, long time-series high-resolution images are difficult to obtain, this paper selects the Landsat series of image data, which has a longer time span and better consistency, as the data source for the relevant research. In recent years, deep learning models have been gradually applied to the task of extracting surface water bodies from remote sensing images. However, deep learning methods usually have problems such as difficulty in capturing the fine contours of water bodies and poor extraction ability for fine water bodies. Based on this problem, this study proposes an Efficient Local Strip Convolutional Attention model for water system extraction and evolution analysis in the Yellow River Delta region. The experimental results show that the proposed model not only performs best in terms of overall accuracy but also obtains smoother water body boundaries and more complete extraction of small and medium-sized rivers, compared with the water body index methods MNDWI and AWEIsh, the machine learning method SVM, and the semantic segmentation models U-Net, SR-SegNet v2, and FWENet.
The preparation of active food packaging materials with both high gas barrier and antioxidant properties remains a great challenge. Hemicellulose is an abundant raw material with excellent oxygen barrier performance and biodegradability, and tea polyphenols (TPs) are natural antioxidants with the function of reducing water sensitivity of polysaccharide-based films. Herein, a synergistic strategy is reported for the preparation of active-controlled food packaging material by incorporating TP into the poly(vinyl alcohol) hemicellulose (PVA/HC) matrix. The obtained film with 5 wt% addition of TP exhibited the highest tensile strength of 41.09 MPa, which was increased by 84% than that of the PVA/HC film. Meanwhile, water vapor permeability was decreased by 25% to 7.39 × 10−12 g⋅cm/(cm2⋅s⋅Pa) compared to a PVA/HC film. Moreover, the addition of TP improved the thermal stability of the (PVA/HC/TP)n film. The outstanding packaging performances were attributed to the robust hydrogen bonding between TP and the PVA/HC matrix as demonstrated by Fourier transform infrared spectroscopy. The DPPH free radical scavenging of (PVA/HC/TP)15 films reached 87.99%, and the film also exhibited enhanced inhibition efficiency against the microorganism E. coli. Compared with the polyethylene plastic wrap, the film showed excellent food packaging applicability by preventing air oxidation of fresh-cut potato. This study sheds light on a design strategy for active packaging films using a natural substance and easily available biomass.
Electrochromic devices possess a sandwich-like structure and can change their color by changing their optical properties such as absorbance and transmittance through the application of voltage. It is currently a hotspot in the field of electrochemical display research and has significant applications in wearable electronics, response sensors, and flexible displays. This study uses tungsten trioxide (WO3) as the cathode color-changing material, zinc foil as anode, and a water-based ink prepared by mixing nano-WO3, solvent, and polyvinylpyrrolidone (PVP) as the thickener in a predetermined ratio to meet the viscosity, surface tension, and particle size requirements of screen printing. The WO3 ink is then transferred onto a fluorine-doped tin oxide (FTO)-coated conductive glass through screen printing, and after sintering at 500∘C, the color-changing layer is encapsulated with VHB tape to obtain an electrochromic device with two electrodes. The properties of the ink at different PVP addition amounts, the morphology of the prepared films, and the performance of the devices were characterized by laser confocal microscope, scanning electron microscope (SEM), viscosity rheometer, surface tension and contact angle tester, fiber spectrometer, and an electrochemical workstation. The results showed that when isopropanol and deionized water were used as solvents, and 8 wt.% PVP as the thickener; the electrochromic device made after sintering had good transparency and could achieve an optical modulation rate of 55.9% within 36 s. This work can significantly impact the industrial application of large-area, low-cost intelligent windows using screen printing technology.
With the development of China’s new economy, the express industry has also shifted from high-speed development to high-quality development. Joint distribution aims to reduce the repeated waste of resources caused by the separate transportation of various express delivery enterprises by means of joint transportation, and promote the transformation and upgrading of the express delivery industry to high-quality development. Therefore, the purpose of this paper is to effectively reduce the cost of and improve the efficiency of express delivery. In this paper, a dual-objective joint distribution network planning model with the highest efficiency and the lowest total cost of joint distribution network is established, which is solved by a three-stage algorithm. The feasibility of the model and algorithm has been applied for validation in the city of Beijing, and the reasonable planning of the express network provides an effective decision-making basis.