Search Results (1,244)

Tetrodotoxin (TTX) is a potent marine neurotoxin, necessitating sensitive and user-friendly on-site assays. To address long workflows of traditional immunoassays and limited signal amplification in colorimetric microfluidics, we developed a nanozyme-catalyzed colorimetric magnetic microfluidic immunosensor (Nano-CMI). This platform combines an aptamer–antibody sandwich capture format with catalytic amplification via AuNR@Pt@m-SiO₂ (APMS) nanozymes on a magnetically actuated microfluidic chip. Magnetic actuation simplifies sample handling and washing, while APMS catalysis enhances sensitivity and visual readout. The Nano-CMI has been used for the detection of TTX samples ranging from 0.2 to 20 ng/mL with a detection limit of 0.2 ng/mL in 10 min, following the linear equation: y = −31.14ln x + 110.15, and the entire “capture-reaction-detection” workflow can be completed within 1 h. With rapid response, minimal hands-on time, and robust performance, this platform offers a practical, high-sensitivity solution for on-site TTX screening in food safety and customs inspection. Full article

The carved lacquer horse-hoof-shaped box excavated from Yulin, Shaanxi Province, represents a typical example of lacquerware preservation in the arid environment of northern China, exhibiting multiple deterioration phenomena, including substrate deformation, lacquer film peeling, and pigment fading. To systematically analyze its structural composition and craftsmanship features, this study employed multiple analytical techniques, including ultra-depth microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), confocal laser micro-Raman spectroscopy (Raman), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Based on these analyses, a targeted conservation protocol was developed. Results revealed that the carved lacquer horse-hoof-shaped box has a wooden substrate structure, with the lacquer ash layer composed of mixed materials, including calcium carbonate (CaCO₃), quartz (SiO₂), and hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂). The lacquer film layer contains Chinese lacquer and plant oils, with cinnabar applied as surface decoration. Based on these findings, a stratified reinforcement conservation strategy was proposed: under dynamic monitoring with optical fiber sensors and three-dimensional scanning, the wooden substrate was reinforced with moisture-curable polyurethane (MCPU), the lacquer ash layer was strengthened with acrylic emulsion (Primal AC33), aged areas were restored with nano calcium hydroxide (Ca(OH)₂) aqueous dispersion, and polyethylene glycol (PEG 400) poultice application was implemented to restore the flexibility of the lacquer film. This research significantly enhanced the integrity and stability of the carved lacquer horse-hoof-shaped box, providing practical evidence and technical references for the scientific conservation of lacquerware excavated from arid regions of northern China. Full article

In metal cutting industries, optimizing the thermal conductivity and viscosity of vegetable oil-based cutting fluids is critical for ensuring efficient heat dissipation, effective lubrication, and sustainability, directly influencing tool life and machining performance. This study presents a comprehensive experimental analysis employing statistical methods, particularly Taguchi’s Design of Experiments, to evaluate the thermal conductivity and viscosity of Pongamia pinnata, sunflower, and coconut oil incorporated with Silicon Dioxide (SiO₂), Hexagonal Boron Nitride (hBN), and Cupric Oxide (CuO) nanoparticles across different emulsion ratios and nanoparticle volume fractions. The results revealed that Pongamia pinnata oil containing 0.5 (Vol.%) SiO₂ nanoparticles at an emulsion ratio of 1:7 achieved the maximum thermal conductivity, measured at 0.637 W/mK. Additionally, the results revealed that Pongamia pinnata oil at an emulsion ratio of 1:13 exhibited the highest viscosity of 1.33 mPa·S, confirming that both the type of cutting oil and the emulsion ratio are the primary factors influencing viscosity. Further, the ANOVA analysis for thermal conductivity and viscosity highlights that the type of cutting fluid is the dominant factor, accounting for 90.58% of the total variance in thermal conductivity and 70.47% in viscosity, each with a highly significant p-value of 0.00, underscoring its decisive impact on the stability of both properties. Overall, this research offers important guidance for the selection and formulation of vegetable oil-based emulsions with nanoparticle additives. The results support the development of advanced nano lubricants with enhanced performance, catering to the increasing requirements of diverse industrial applications. Full article

In this paper, a nano-layered transmission GaAs photocathode structure is proposed. The near-infrared absorption of the photocathode is enhanced by inserting a “sandwich” structure of nano-SiO₂ layer + Si₃N₄ nanopillar array + nano-SiO₂ layer between the cathode optical window and the photocathode. Compared with the flat film structure GaAs photocathode used in the current third-generations image intensifiers, the optical absorption of the optimized “sandwich” structure GaAs photocathode in the near-infrared band has been significantly improved: when the wavelength λ is 868 nm and 896 nm, the optical absorption is increased by 41.69%, 55.08%, respectively. The effects of structural parameters including film thickness and grating filling medium on the light absorption of photocathode are investigated. The results show that the near-infrared light absorption enhancement is the most obvious when Si₃N₄ is selected as the grating filling medium for the current design, and the deposition of SiO₂ film with 10 nm thickness could effectively prevent the damage of Si₃N₄ during bonding with the photocathode. The theoretical analyses offer important guidance in material selection and structural optimization in the grating cathode optical window used in the third-generation image intensifier for improving performance. Full article

Micro-segregation of solute elements is inevitable during the casting process of Al–Mg–Si alloys, significantly influencing the precipitation behavior of dispersed phases during subsequent heat treatment, ultimately influencing alloy performance. Mn and Si are typical positive segregation elements and the principal constituents of the dispersed phases in aluminum alloys, and their diffusion behavior directly affects the precipitation of nano-scale α-Al(MnCr)Si phases within grains during subsequent annealing. This study systematically investigates the effects of different annealing conditions (430 °C × 12 h and 530 °C × 12 h) on the precipitation behavior of α-Al(MnCr)Si phases in the Al–Mg–Si–Mn alloy. After annealing at 430 °C, the relatively low diffusion rate promoted the dispersed precipitation of α-Al(MnCr)Si phases as high-density, nano-scale particles within grains. In contrast, annealing at 530 °C substantially enhanced the elements diffusion, accelerating both nucleation and growth of α-Al(MnCr)Si phases and inducing notable Ostwald ripening, resulting in larger α-Al(MnCr)Si phases with a lower number density within grains. This study indicates that the control of annealing parameters can effectively tailor the size, distribution, and number density of nano-scale α-Al(MnCr)Si phases. The findings provide critical theoretical and practical guidance for optimizing annealing processes in Al-Mg-Si-Mn alloys. Full article

The strength of cement paste backfill (CPB) is crucial for ensuring the safe and efficient operation of the horizontal layered approach backfill mining method. To effectively improve CPB strength, a series of experiments were carried out to systematically examine the effects of nano-SiO₂ (NS) on the mechanical properties, hydration process, setting time, and microstructure of CPB. The results show that at a content of 1.5%, NS fully utilizes its pozzolanic, filling, and nucleation effects, accelerating cement hydration, filling internal pores, and thereby increasing matrix density and CPB strength. Conversely, at 2.5%, severe agglomeration of NS into large-sized aggregates weakens these three effects of NS, increases specimen porosity, reduces matrix density, and consequently impairs the mechanical properties of CPB. This study clarifies the mechanism by which an appropriate amount of NS improves CPB mechanical properties, as well as the intrinsic reasons for the performance degradation caused by NS overdosage. The findings provide a theoretical basis and experimental support for the rational application of NS in mine backfill. Full article

Freshwater scarcity is increasing day by day and has already reached a threatening level, especially in remotely populated areas. One of the technological solutions to this rising concern could be the use of the solar-based humidification–dehumidification (SHDH) method for water desalination. This technology is a promising solution but has challenges such as solar intermittency. This challenge can be solved by integrating SHDH with the phase change material as a solar energy storage medium. Therefore, a novel nano-enhanced binary eutectic phase change material (NEPCM) was developed in this project. PCM consisting of 70 wt.% stearic acid (ST) and 30 wt.% suberic acid (SBU) with a varying concentration of silicon carbide (SiC) nanoparticles (NPs) (0.1 to 3 wt.%) was synthesized specifically considering the need of SHDH application. The systematic thermophysical characterization was conducted to investigate their energy storage capacity, thermal durability, and performance consistency over repeated cycles. DSC analysis revealed that the addition of SiC NPs preserved the thermal stability of the NEPCM, while the phase transition temperature remained nearly unchanged with a variation of less than 0.74%. The value of latent heat is inversely related to the nanoparticle concentration, i.e., from 142.75 kJ/kg for the base PCM to 131.24 kJ/kg at 3 wt.% loading. This corresponds to reductions in latent heat ranging between 0.98% and 8.06%. The FTIR measurement confirms that no chemical reactions or no new functional groups were formed. All original functional groups of ST and SBU remained intact, showing that incorporating the SiC NP to the PCM lead to physical interactions (e.g., hydrogen bonding or surface adsorption). The TGA analysis showed that the SiC NPs in the NEPCM act as supporting material, and its nano-doping enhanced the final degradation temperature and thermal stability. There was negligible change in thermal conductivity for nanoparticle loadings of 0.1% and 0.4%; however, it increased progressively by 5.2%, 10.8%, 23.12%, and 25.8% at nanoparticle loadings of 0.7%, 1%, 2%, and 3%, respectively, at 25 °C. Thermal reliability was analyzed through a DSC thermal cycling test which confirmed the suitability of the material for the desired applications. Full article

The bioinspired superhydrophobic surfaces have demonstrated many fascinating performances in fields such as self-cleaning, anti-corrosion, anti-icing, energy-harvesting devices, and antibacterial coatings. However, developing a low-cost, feasible, and scalable production approach to fabricate robust superhydrophobic surfaces has remained one of the main challenges in the past decades. In this paper, we propose an uncommon method for the fabrication of a durable superhydrophobic coating on the surface of the glass slide (GS). By utilizing the screen printing method and high-temperature curing, the epoxy resin grid (ERG) coating was uniformly and densely loaded on the surface of GS (ERG@GS). Subsequently, the hydrophobic silica (H-SiO₂) was deposited on the surface of ERG@GS by the impregnation method, thereby obtaining a superhydrophobic surface (H-SiO₂@ERG@GS). It is demonstrated that the micro-grooves in ERG can provide a large specific surface area for the deposition of low surface energy materials, while the micro-columns can offer excellent protection for the superhydrophobic coating when it is subjected to mechanical wear. It is important to note that micro-columns, micro-grooves, and nano H-SiO₂ jointly form the micro–nano structure, providing a uniform and robust rough structure for the superhydrophobic surface. Therefore, the combination of a micro–nano rough structure, low surface energy material, and air cushion effect endow the material with excellent durability and superhydrophobic property. The results show that H-SiO₂@ERG@GS possesses excellent self-cleaning property, mechanical durability, and chemical stability, indicating that this preparation method of the robust superhydrophobic coating has significant practical application value. Full article

Sintered nano-silver is widely investigated as a die-attach material for next-generation power electronic modules due to its high thermal conductivity, favorable electrical performance, and stability at elevated temperatures. However, how bonding pressure and joint thickness jointly affect densification, interfacial diffusion, and mechanical reliability has not been systematically clarified, especially under the low-pressure conditions required for large-area SiC and GaN devices. In this work, nano-silver lap-shear joints with three bond-line thicknesses (50, 70, and 100 μm) were fabricated under two applied pressures (1.0 and 1.5 MPa) using a controlled sintering fixture. Shear testing and cross-sectional SEM were employed to evaluate the relationships between microstructural evolution and joint integrity. When the bonding pressure was increased from 1.0 to 1.5 MPa, more effective particle rearrangement and reduced pore connectivity were observed, together with improved metallurgical bonding at the Ag–Au interface, leading to a strength increase from 15.3 to 28.2 MPa. Although thicker joints exhibited slightly higher bulk relative density due to greater heat retention and accelerated local sintering, this densification advantage did not lead to improved mechanical performance. Instead, the lower strength of thicker joints is attributed to a narrower Ag–Au interdiffusion region, which limited the formation of continuous load-bearing paths at the interface. Fractographic analyses confirmed that failure occurred predominantly by interfacial delamination rather than cohesive fracture, indicating that the reliability of the joints under low-pressure sintering is governed by the quality of interfacial bonding rather than by overall densification. The experimental results show that, under low-pressure sintering conditions (1.0–1.5 MPa), variations in bonding pressure and bond-line thickness lead to distinct effects on joint performance, with the extent of Ag–Au interfacial interaction playing a key role in determining the mechanical robustness of the joints. Full article

Photocatalytic degradation of organic molecules using TiO₂ has attracted attention in wastewater treatment because it can decompose organic compounds that are difficult to decompose by other methods. Meanwhile, efficient photocatalytic water treatment is difficult because it is not easy to separate nano-sized photocatalysts from water. In this review, we have described two approaches to solve the water separation challenge in the suspension type TiO₂ photocatalysts, which are uniformly distributed in water: magnetic TiO₂/SiO₂/Fe₃O₄ nanoparticles and TiO₂-polystyrene beads. The preparation, characterization, and photocatalytic performance of the two types of photocatalysts and their application are discussed. Finally, we compare two types of photocatalysts while focusing on the respective advantages and disadvantages of each, and the future direction of research. Full article

This work introduces a new method for creating patterned SiO₂ electrets using stamp-assisted capacitive coupling (SACC), enabling surface functionalisation without direct electrode contact. SACC applies an alternating current through capacitive coupling between a conductive stamp and an insulating substrate in high-humidity conditions, forming a nano-electrochemical cell that drives localised reactions. Using thermally grown SiO₂ films, we achieve submicrometre patterning with minimal topographical impact but significant electronic alterations. Characterisation via Kelvin Probe Force Microscopy and Electric Force Microscopy confirms the formation of charged regions replicating the stamp pattern, with adjustable surface potential shifts up to −1.7 V and charge densities reaching 300 nC·cm⁻². The process can be scaled to areas of 1 cm² and is compatible with conventional laboratory equipment, offering a high-throughput alternative to scanning-probe lithography. SACC combines simplicity, accuracy, and scalability, opening new opportunities for patterned electret production and functional surface engineering. Full article

Spinel-based glass-ceramics face challenges such as a narrow crystallization window for the target phase and the difficulty in suppressing the competitive Li_xAl_xSi_1−xO₂ crystals. This study proposes a method to regulate the phase formation in ZnO-MgO-Al₂O₃-SiO₂ glass by precisely controlling the heat treatment temperature. The microstructural evolution was analyzed by DSC, XRD, Raman spectroscopy, SEM, TEM, and XPS. The results indicate that the heat treatment at a nucleation temperature of 780 °C for 2 h and a crystallization temperature of 880 °C for 2 h effectively inhibits the precipitation of the Li_xAl_xSi_1−xO₂ secondary phase, yielding a glass-ceramic with nano-sized MgAl₂O₄, ZnAl₂O₄ spinel as the primary crystalline phase. The obtained glass-ceramic exhibits excellent mechanical properties, including a Vickers hardness of 922.6 HV, a flexural strength of 384 MPa, and an elastic modulus of 113 GPa, while maintaining a high visible light transmittance of 84.3%. This work provides a clear processing window and theoretical basis for fabricating high-performance, highly transparent spinel-based glass-ceramics through tailored heat treatment. Full article

Spent mushroom substrate (SMS)-derived bio-based polyurethane coatings typically exhibit poor hydrophobicity and short nutrient release durations, limiting their ability to satisfy long-term crop requirements. This study developed improved controlled-release urea by preparing water-repellent and compact bio-polymer coatings from recyclable SMS using non-toxic siloxane and nano-SiO₂ modifiers through simple processes. The dual modification markedly reduced water absorption (from 6.60% to 4.43%) and porosity (from 6.32% to 3.92%), creating a dense coating with lotus-leaf-like nanoscale surface protrusions and fewer intermembrane pores. As a result, the nitrogen (N) release period of the dual-modified bio-polymer-polyurethane-coated urea (SBPCU) with a 7% coating thickness was extended from 23 days to 42 days. Phytotoxicity assessments confirmed the excellent biosafety of the bio-polymer coating, revealing no adverse effects on maize growth and even promotional effects at low concentrations. This approach offers a sustainable, eco-friendly, and scalable strategy for producing bio-polymer-coated urea from agricultural waste, serving as a viable alternative to petrochemical coatings while improving nutrient use efficiency and biosafety. Full article

Recently, the kinetic improvement of the nitrogenation reaction of lithium hydride (LiH) to form lithium imide (Li₂NH) by adding a scaffold was reported. The scaffold prevents agglomeration of Li₂NH and maintains the activity of LiH, achieving a reduction in reaction temperature and an increase in reaction rate. In this work, a Li–Si alloy, Li₂₂Si₅, was used as a starting material to form nano-sized LiH dispersed in a Li alloy matrix. Lithium nitride (Li₃N) is generated by the reaction between Li₂₂Si₅ and N₂ to form Li₇Si₃, and then Li₃N is converted to LiH with ammonia (NH₃) generation during heat treatment under H₂ flow conditions. Since Li₃N is formed at the nano-scale on the surface of alloy particles, LiH generated from the above nano-Li₃N is also nano-scale. The differential scanning calorimetry results indicate that direct nitrogenation of LiH in the alloy matrix occurred from around 280 °C, which is much lower than that of the LiH powder itself. Such a highly active state might be achieved due to the nano-crystalline LiH confined by the Li alloy as a self-transformed scaffold. From the above experimental results, the nano-confined LiH in the alloy matrix was recognized as a potential NH₃ synthesis technique based on the LiH-Li₂NH type chemical looping process. Full article

We investigated the radio frequency (RF) performance of AlGaN/GaN high electron mobility transistors (HEMTs) fabricated on silicon carbide substrates, featuring two distinct T-shaped gate structures. A comparative analysis between a silicon nitride (SiN_x)-passivated T-gate and a floating T-gate design reveals significant differences in parasitic capacitance and high-frequency behavior. The floating gate structure effectively reduces fringe capacitance, resulting in improved cut-off frequency (f_T) and maximum oscillation frequency (f_max), achieving f_T = 82.7 GHz and f_max = 80.2 GHz, respectively. These enhancements underscore the critical importance of optimizing gate structures to advance GaN-based HEMTs for high-speed and high-power applications. The findings provide valuable insights for the design of future RF and millimeter-wave (mm-wave) devices. Full article