Using physical vapor deposition, cadmium sulfide (CdS) films, Ag nanoparticle films, and Ag/CdS composite films were successfully fabricated on substrates. The surface morphology, crystal structure, and optical bandgap of the samples were systematically characterized using scanning electron microscopy, x-ray diffraction, and ultraviolet–visible spectrophotometry, respectively. Using femtosecond Z-scanning technology, the nonlinear optical properties of composite materials were investigated at a wavelength of 800 nm. By adjusting the laser energy, the evolution of their nonlinear optical response with excitation intensity was systematically examined. The results indicate that, in comparison to single-component thin films, the Ag/CdS composite demonstrates significant characteristics of nonlinear absorption and nonlinear refraction. These characteristics are specifically manifested as saturated absorption behavior and self-defocusing effects. Notably, the incorporation of Ag nanoparticles effectively enhances the nonlinear optical response of the composite system, with this enhancement becoming increasingly pronounced as the Ag deposition power rises. Furthermore, the saturation absorption effect of the composite material gradually intensifies with rising laser energy. These outstanding nonlinear properties indicate that Ag/CdS composites hold significant application potential for integrated optoelectronic functional devices.

Waste has always been a major problem in the environment due to the lack of public knowledge in waste management. One type of waste commonly generated by people daily is plastic waste. One of the efforts that can be made to utilize plastic waste is to incorporate it as a mixture material in the production of paving blocks. The purpose of this study is to compare the mechanical properties of paving blocks for each type of plastic used, both in terms of compressive strength and water absorption. The methods employed include data collection and analysis, as well as laboratory testing. The findings indicate that HDPE plastic exhibits the highest compressive strength among the three types, while PP plastic shows the best water absorption performance, with HDPE also demonstrating favorable absorption characteristics. These results imply that plastic waste, particularly HDPE, can be effectively utilized as a sustainable alternative material in non-structural construction applications such as paving blocks, contributing to waste reduction efforts and promoting environmentally friendly construction practices. Thus, it is hoped that this research can serve as a reference in the processing of plastic waste in the fields of both architecture and environmental engineering.

This study investigates the quasi-static and dynamic crushing behavior of a bio-inspired cactus geometry core structure manufactured from ABS polymer using fused deposition modeling. The mechanical response and energy absorption characteristics of the structure were examined experimentally under a wide range of strain rates, including quasi-static compression, drop-weight, and direct impact Split Hopkinson Pressure Bar (SHPB) tests. Corresponding finite element models were developed in LS-DYNA using the piecewise linear plasticity material model with Cowper–Symonds rate sensitivity parameters calibrated from material characterization tests. The experimental and numerical results showed close agreement in both quasi-static and dynamic regimes. Increasing loading rate led to higher initial peak forces and energy absorption values, while delaying the onset of folding. The strain-rate and inertial contributions to the crushing response were quantitatively separated, revealing that inertia dominated in the early elastic region, whereas strain-rate effects governed the plastic deformation stage. The cactus-inspired core exhibited stable deformation and significant energy dissipation, indicating its potential as a lightweight protective component in impact and crashworthiness applications.

This study presents a SCAPS-1D-based numerical optimization of an organic ultraviolet (UV) photodetector employing an FTO/PTB7/Spiro-OMeTAD/Au device architecture. The novelty of this work lies in a simulation-guided, UV-specific optimization strategy that combines thickness engineering, controlled doping, and contact work-function tuning to achieve intrinsic spectral selectivity without external optical filters. We systematically optimize material and device parameters, including active layer thicknesses, donor and acceptor densities, and the metal electrode work function, to enhance responsivity, detectivity, and spectral performance. Simulations identify optimal thicknesses of 1200 nm for PTB7 and 1000 nm for Spiro-OMeTAD, with donor concentrations of 1 × 1020 cm-3 and 1 × 1018 cm-3, respectively. A comparative contact analysis demonstrates that replacing aluminum with gold (Au) forms a near-ohmic back contact, leading to improved hole extraction and suppressed dark current due to favorable energy-level alignment. The optimized device achieves a peak external quantum efficiency of approximately 80% in the 300-400 nm ultraviolet range, with a responsivity up to 0.4 A/W. The UV selectivity originates from the absorption characteristics of PTB7 combined with suppressed long-wavelength charge collection, resulting in a negligible response in the visible-near-infrared region. These results confirm the device's strong potential for high-sensitivity, solar-blind UV photodetection. By integrating practical material selection with physically consistent SCAPS-1D optoelectronic modeling, this work provides a robust design framework to guide the development of next-generation organic UV photodetectors for environmental sensing, biomedical diagnostics, and wearable optoelectronics.

Airframe noise generated at wing trailing edges and high-lift devices, such as flaps, remains a major challenge during landing, with significant contributions in the low-frequency band of 500-1500 Hz. While solid surfaces reflect this acoustic energy, metallic porous materials can effectively absorb it through viscous and thermal dissipation within their internal pore structure. To address this, the present study examines the acoustic absorption characteristics of open-cell AlSi porous cylinders featuring controlled pore diameters between 0.3 mm and 2.25 mm. Measurements were conducted in an acoustic impedance tube according to the ISO 10534-2:2023 standard, using six cylindrical samples (28 mm diameter, 70 mm length). Two sets of measurements were performed for each sample (front and rear faces), and the average values were used. The findings indicate that the normal-incidence sound absorption coefficient α rises as pore size increases, reaching 0.93-0.97 at low frequencies of 500-700 Hz for the samples with the largest pores (1.8-2.25 mm). These results indicate that open-cell AlSi alloys offer strong low-frequencies sound absorption, positioning them as promising options for aeroacoustic noise mitigation, including applications such as porous trailing edge and hybrid flap designs.

Abstract The kinetic characteristics of resonant absorption of combined left- and right-hand polarized waves with finite amplitude are investigated. The plasma consists of a magnetized 2D slab with linearly inhomogeneous density layers. Using a 2D-3V particle-in-cell-hybrid code, we simulate this system with different layer thicknesses and different angles of the background magnetic field relative to the simulation plane. Resonant absorption excites counterpropagating kinetic Alfvén waves (KAWs) inside the layers, with frequencies consistent with large-scale kink modes. They are observed to interact nonlinearly to generate a parallel electric field, which subsequently produces density structures and accelerates protons. This causes strong heating and flat-topped distribution functions. We derive an analytical estimate for this parallel field that reproduces the most relevant signals of the dispersion relations during and after resonant absorption. The transverse particle dynamics are driven by the cross-field drift, causing the transverse temperature to oscillate and grow exponentially due to small-scale fluctuations. Therefore, the proton distribution functions are largely shaped nonresonantly by the KAW activity.

Emodin, a trihydroxy-methyl anthraquinone abundant in rhubarb, Polygonum species, and other medicinal plants, exemplifies the therapeutic potential and translational complexity of the broader anthraquinone scaffold. Anthraquinone derivatives have demonstrated antiproliferative, anti-inflammatory, metabolic, cardiovascular, antifibrotic, and immunomodulatory effects, consistently reported across diverse preclinical models, targeting pathways such as NF-κB, PI3K/AKT, MAPKs, AMPK, PPARs, NLRP3, and ferroptosis-related axes. Despite strong preclinical efficacy, clinical development has been limited by unfavorable absorption, distribution, metabolism, and excretion (ADME) characteristics, including poor aqueous solubility, extensive first-pass glucuronidation, and active efflux via intestinal and hepatic transporters. These features result in low and variable systemic exposure, while high local concentrations, particularly in the gastrointestinal tract, contribute to context-dependent toxicity signals that complicate risk assessment. The present review integrates pharmacological, toxicological, and formulation-focused evidence to provide a unified assessment of emodin and the anthraquinone scaffold. Particular emphasis is placed on bidirectional, dose- and context-dependent effects on the liver and kidney; the modulation of cytochrome P450 enzymes, UGTs, and transporters; and emerging preclinical formulation strategies that aim to decouple intrinsic bioactivity from pharmacokinetic limitations.

Decoupling carboxyl position and annulation site effects on ICT, pH response, and serum albumin binding in dual-regioisomeric benzoindole fluorophores.

Vehicle side impact accidents have high fatality rates due to limited deformation buffer and insufficient energy absorption of side structures. Simply enhancing structural stiffness and energy absorption characteristics may lead to increased occupant injury risk under side impact. To simultaneously improve side crashworthiness and occupant protection, this study proposes an origami-inspired honeycomb reinforced side structure and conducts systematic research. First, a full-scale finite element model of mobile deformable barrier (MDB) side impact has been established and verified with test data. Although besides impact simulation results reveal qualified structural crashworthiness, the occupant injury especially the head injury criterion (HIC15) is too high due to excessive intrusion of the vehicle body side structure. To address this problem, an origami-inspired honeycomb structure has been designed and embedded into the B-pillar and threshold beam. Then a meta-model based multi-objective optimization has been performed to improve the crashworthiness and occupant protection of the vehicle. Finally, crashworthiness comparison results demonstrate that the optimized reinforced structure significantly improved energy absorption and intrusion resistance, reducing occupant head and abdomen injuries.

Abstract In this article, we investigate the propagation of electromagnetic waves (EW) within a different type of transmission line, combining a theoretical analysis based on the Transfer Matrix Method (TMM) and a numerical study based on the Finite Element Method (FEM). The proposed structure is composed of a segment filled with a right-handed material (RHM,〖 ε〗_1> 0 and 〖 μ〗_1> 0), coupled to a closed lateral transmission line resonator filled with a metamaterial ENG, RHM or an absorber with effective permittivity (ε_2 (f) and 〖 μ〗_2> 0). The transmission line resonator is modeled as a microwave circuit with lumped elements, including a series capacitor (C), a shunt inductor (L), and a resistor (R). The results demonstrate that adjusting the resonator length and its electrical parameters allows multiple transmission bands over a wide frequency range (up to 10 GHz), while finely controlling the reflection and absorption characteristics, resulting in very narrow resonance modes. These features make the proposed structure suitable as an integrated gigahertz selective filter for optimized filtering in advanced signal processing, telecommunications, radar, and satellite applications.

This study presents a tunable far-infrared (FIR) metamaterial absorber integrating vanadium dioxide (VO 2 ) and graphene to achieve dynamic switching between ultra-broadband and narrowband absorption. The proposed absorber leverages the insulator-to-metal transition of VO 2 and the tunable conductivity of graphene to modulate absorption characteristics in the FIR region (13.8–29.1 µm). When VO 2 is in its metallic state, the absorber achieves over 90% absorptance across a broadband range, while in the insulating state, it exhibits a narrowband absorption peak at 17 µm with 97.86% absorptance. The design incorporates a titanium cylinder, a patterned graphene layer, an SiO 2 dielectric with embedded VO 2 cross strips, and a gold substrate. Electromagnetic simulations using the finite-difference time-domain method, combined with impedance matching theory and electric field distribution analysis, elucidate the absorption mechanisms. The proposed absorber offers active tuning via both electrical and thermal stimuli, enabling broadband perfect absorption for infrared stealth, narrowband resonance for biosensing, and reversible temperature-triggered optical switching.

Abstract Ash content is a critical coal quality indicator that determines coal grade and commercial applications, making its rapid and accurate measurement essential. Traditional slow ashing methods are operationally cumbersome, time-consuming, and pose environmental and safety concerns. Hyperspectral imaging technology offers a promising alternative with its non-contact detection and superior spatial-spectral information fusion capabilities. However, existing machine learning and deep learning approaches, while capable of modeling complex spectral-analyte relationships, often overlook spatial information and struggle to effectively capture the heterogeneous distribution characteristics of ash minerals in coal samples. Therefore, this study proposes a fast estimation method of hyperspectral coal ash based on graph neural network, using a hybrid GCN-GAT encoder and an adaptive spatial-spectral edge construction strategy. This method models the mineral distribution pattern by constructing a spatial graph, constructs a spectrogram to capture the mineral spectral characteristics, and optimizes it for different ash content ranges. In the experiments of concentrated coal (ash range from 9% to 18%) and tailings coal samples (ash range from 49% to 77 %), the average absolute errors of this method are 0.862 % and 1.18 %, respectively, which are significantly better than traditional machine learning methods and deep learning methods. The interpretability analysis shows that the absorption characteristics of hydroxyl-containing minerals corresponding to the 1200-1400 nm band contribute the most to the ash estimation, which verifies the effectiveness of the graph neural network in coal quality analysis and provides practical guidance for coal automatic characterization and industrial quality control.

To investigate the effects of gas adsorption on coal expansion and deformation during the injection of water into gas-containing coal seams as well as their permeability and absorption characteristics, based on the mechanism of gas adsorption in coal, a coal porosity model for expansion and deformation was derived in this study. The existing spontaneous coal infiltration model was improved by combining Hagen Poiseuille’s law and fractal dimension; the result is a fractal model of spontaneous infiltration considering gas adsorption conditions. Through the use of a self-developed experimental system for spontaneous infiltration of moisture into gas-containing coal, experiments were conducted at different pressures to verify the accuracy of the model. Research has shown that coal expansion deformation induced by gas adsorption has a significant impact on spontaneous imbibition. As the gas pressure gradient increases, the coal expansion strain exhibits nonlinear enhancement characteristics. This deformation reduces the effective porosity by compressing pores, and the evolution of the pore structure significantly increases the capillary force-dominated imbibition driving force, thereby significantly increasing the maximum imbibition height [Formula: see text]. This study provides important theoretical guidance for the study of spontaneous infiltration and absorption of gas-containing coal and for improving water injection technology for gas-containing coal.

Abstract This work was conducted to prepare the transglutaminase (TGase) cross-linked collagen gel (CGL) by using pork skin as raw material, and to systematically investigate its digestive and absorptive properties and serum metabolism regulation in mice. The analysis of peptidomics revealed that CGL exhibited a lower average molecular weight of peptides (803.78 Da) and a higher proportion of small molecular peptides (11.22% of < 500 Da) in the gastric digestion stage, indicating that the crosslinked structure significantly enhanced the hydrolysis efficiency of pepsin. After entering the small intestine, the proportion of small peptides (< 500 Da) in the CGL group decreased compared to the gastric stage, and the number of small peptides in the CGL group decreased compared to the collagen sol (CSL) group, indicating that small peptides in the CGL group were rapidly absorbed in the small intestine stage. Meanwhile, the proportion of peptides in the 500–1000 Da range in the CGL group (53.42%) was higher than that in the CSL group (35.50%), suggesting that intestinal proteases can continuously degrade the large-molecule peptides in the CGL group. This also resulted in the CGL group maintaining a high number of characteristic peptides (161 unique peptides) in the cecum stage. The serum analysis revealed obviously increased collagen peptide counts (205 peptides) and hydroxyproline peptide ratios (93.66%) in the CGL group, with specific peptide segments primarily originating from the cross-linking active sites (Lys644, Gln972). These findings confirm the absorption advantage of the CGL group. In addition, CGL optimized the amino acid absorption pattern by cross-linking modification while maintaining the basic nutritional properties of collagen. The metabolomics results showed that CGL regulated key metabolic pathways such as steroid hormone synthesis, glutathione metabolism and tryptophan metabolic pathway. This study reveals the progressive “gastric degradation - intestinal absorption” mechanism of crosslinked collagen gel. Its unique peptide release pattern and metabolic regulation provide a theoretical basis for developing functional collagen-based products targeting intestinal absorption. Graphical Abstract

Polymer-based matrix composites are familiar in automotive applications. Due to their high strength-to-weight ratio, improved chemical resistance, and ease of processing. However, the epoxy-based composites are found to be more brittle, with reduced impact toughness and limited flexibility. This research on polymer composites is developed using a polyester matrix, embedded with 16 wt% of short neem (treated) fibers and varying wt% of titanium nanoparticles (Ti, 50nm), via a hot compression mould process. The effectiveness of Ti nanoparticle loading on the functional properties of polyester/neem (treated) fibers is studied and compared. Given the significance of the hot-compression process, the Ti nanoparticles and neem (treated) fibers are effectively dispersed in the polyester matrix, as confirmed by transmission electron microscopy (TEM). The strong interface between the fiber/particle combination and the polyester matrix improved tensile, impact, hardness, and moisture-absorption resistance. According to the investigation results, the polyester composite made with 16 wt% neem fiber and 6 wt% Ti nanoparticles exhibits the highest tensile stress (89.6MPa), improved impact toughness (4.3J/mm2), high microhardness (34 HV), and reduced moisture (water) absorption (1.5% at 14 days). Moreover, the addition of Ti nanoparticles decreased the elongation from 45.5% to 39.5% and also enhanced its thermal stability 11.3% than polyester matrix (base). The novel composite sample is the trade for automotive cabinet and seat frame applications.

This paper proposes a circularly polarized (CP) metasurface antenna array integrating absorbers with polarization conversion metasurfaces (PCMs). By synergistically deploying PCM units and absorber units, the antenna array combines the scattering control properties of PCM units with the electromagnetic energy absorption characteristics of absorber units and ultimately achieves broadband radar cross section (RCS) reduction. Simulation results indicate that the array exhibits an impedance bandwidth of 12% (11.8-13.3 GHz), a 3 dB axial ratio (AR) bandwidth of 12.9% (11.78-13.4 GHz), and a 3 dB gain bandwidth of 9.7% (11.64-13 GHz). Within the wideband range of 10.2-20.9 GHz (68.8%), the array achieves 10 dB RCS reduction both out-of-band and in-band, with a maximum reduction of 33.2 dB. A prototype of the antenna array was fabricated and tested, with measured results showing good agreement with simulations, validating the design effectiveness.

Abstract This article presents a novel broadband metamaterial absorber (MMA) that leverages machine learning to enhance performance in terahertz applications. The MMA consists of a vanadium dioxide (VO2) resonator placed above a dielectric spacer and a conductive ground layer. By altering the conductivity of VO2, the MMA modulates its absorption characteristics. At high temperatures, the absorber demonstrates over 80% absorption across the frequency range of 1.22 to 3.14 THz, achieving peak absorption levels of 99.99% at 4.84 THz and 99.90% at 5.82 THz. The study further explores how geometric adjustments influence the absorption characteristics. The MMA exhibits polarization independence and wide-angle absorption, further enhancing its adaptability. Machine learning models—k-nearest neighbor (KNN), LightGBM (LGBM), and Histogram-based Gradient Boosting (HGB)—are employed to predict absorption coefficients at intermediate frequency, periodic dimensions, and substrate thickness. These regression models are evaluated using root mean squared error (RMSE), mean absolute error (MAE), and R 2 score across test sizes ranging from 0.4 to 0.6. The KNN model demonstrates outstanding performance, with R 2 values of 0.9977 for feature ‘a’ and 0.9982 for feature ‘ h s ’ at a test size of 0.4. The regression analysis suggests that ML-based MMAs can reduce simulation time and resource usage by up to 60%. This work establishes a framework for broadband MMA design using machine learning techniques, offering promising applications in terahertz modulation, sensing, and tunable devices.

ABSTRACT To address the limitations of traditional acoustic materials characterised by ‘high absorption but low load-bearing capacity, and high load-bearing but poor absorption,’ this study focuses on developing a multifunctional integrated structure that combines broadband high-efficiency sound absorption with excellent load-bearing performance. Based on additive manufacturing technology, three types of structures were designed and fabricated using sheet Diamond-TPMS as the skeleton: the pristine sheet Diamond-TPMS structure, the micro-perforated sheet Diamond-TPMS structure, and the sheet Diamond-TPMS/polyimide interpenetrating composite structure. The regulation mechanism of volume fraction on their sound absorption performance was systematically investigated. The results show that the sheet Diamond-TPMS/polyimide interpenetrating composite structure exhibits optimal comprehensive performance at a volume fraction of 20%. Its average sound absorption coefficient reaches 0.76, representing significant improvements of 55.1% and 72.7% compared to the pristine sheet Diamond-TPMS and micro-perforated sheet Diamond-TPMS structures, respectively. Moreover, it achieves efficient broadband sound absorption across the 450–6400 Hz frequency range. This performance advantage stems from the synergistic mechanism of porous dissipation and structural resonance. Ultimately, the composite structure successfully integrates acoustic and mechanical properties, achieving ultra-broadband sound absorption (relative bandwidth of 166.3%) while maintaining high load-bearing capacity, providing a reliable solution for the design of next-generation multifunctional acoustic materials.

All-inorganic cesium lead halide perovskite quantum dots, CsPbX3(X = Cl, Br, I), exhibit exceptional potential in nonlinear optical (NLO) applications. This is due to their outstanding optoelectronic properties, including high photoluminescence quantum yield, tunable band gaps, and strong absorption coefficients. However, their practical utility is severely limited by their environmental instability against ambient air and moisture. In this study, CsPbBr3QDs were encapsulated in a SiO2matrix using a sol-gel method to fabricate CsPbBr3/SiO2gel-glass composites. Structural characterization (transmission electron microscopy, x-ray diffraction, and Fourier transform infrared) confirmed the uniform dispersion and complete encapsulation of the QDs within the amorphous SiO2network. Optical analyses revealed that the composites retained the intrinsic absorption and emission characteristics of the CsPbBr3QDs (bandgap: 2.29 eV; fluorescence peak: 510 nm), while exhibiting tunable linear transmittance (50%-82%).Z-scan measurements under 532 nm picosecond pulsed laser excitation revealed significant nonlinear absorption coefficients (β) of up to 0.85 cm GW-1and a low optical limiting threshold (OL) of 0.22 J cm-2. Importantly, SiO2encapsulation markedly enhanced the environmental stability of the CsPbBr3QDs, and their NLO properties remained stable after 365 d of storage under ambient air conditions. This work provides a viable strategy for realizing halide perovskite-based OL devices and establishes a promising platform for further development. Future device-level integration and cycling tests will be essential for practical deployment.

Hydrogen is a possible clean energy solution to mitigate the global energy problem and environmental issues. The Mg 2 QH 6 (Q= Cr, Mn) hydrides have attracted interest due to their substantial hydrogen storage capabilities and advantageous characteristics. The pressure-induced physical characteristics of Mg 2 QH 6 (Q= Cr, Mn) have been methodically examined by density functional theory (DFT) to assess their viability for hydrogen storage and energy-related applications. A comprehensive examination of their structural stability, hydrogen storage properties, electronic band structures, optical absorption characteristics, elastic constants, mechanical stability, and thermodynamic aspects was conducted at applied pressures from 0 to 40 GPa. The gravimetric hydrogen storage capacities of Mg 2 CrH 6 and Mg 2 MnH 6 are determined to be 5.67 and 5.52 wt%, demonstrating their significant prospects for practical hydrogen storage applications. The electronic structure simulations validate the metallic characteristics of both Mg 2 CrH 6 and Mg 2 MnH 6 hydrates over the whole pressure spectrum, signifying exceptional electrical conductivity, beneficial for electrochemical and catalytic applications. The imaginary component of the dielectric function displays pronounced peaks at 8.682 eV (40 GPa) for Mg 2 CrH 6 and 8.335 eV (40 GPa) for Mg 2 MnH 6 , indicating robust optical activity. Thermodynamic analysis confirms the stability of both substances under pressure. The elastic and mechanical evaluations validate their stability and ductility under compression, affirming their dependability under highpressure conditions. These theoretical findings offer significant insights into the pressure-tunable properties of Mg 2 QH 6 hydrides, underscoring their potential for complex hydrogen storage systems and multifunctional optoelectronic devices.