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Composite sandwich structures are widely used in the aerospace field due to their advantages of high strength, lightweight, and fatigue resistance. However, these structures are prone to damage with very-low-energy impacts. In order to improve the impact resistance of aircraft skin structure, a low-velocity impact resistance of sandwich structure specimens was tested by means of drop hammer impact, and the impact damage area was scanned by ultrasonic C-scan, and obtains the impact damage of specimens with different impact energies and different ply sequences. Combined with the Hashin failure criterion, the finite element equivalent model of composite sandwich structure under low-velocity impact was established. The errors between the simulation results and the C-scan results of the test piece were less than 10%, in which the experimental measurements and numerical predictions were in close agreement. Finally, the finite element equivalent model was applied to optimize the application of model sandwich, which was used for fuselage skin of a certain electric aircraft. The total thickness of the laminate structure remains unchanged before and after optimization, but the impact resistance was significantly enhanced. The ±45° lay-up was beneficial for the structure to absorb the impact energy.

Zinc oxide (ZnO) has been widely acknowledged as a highly effective photocatalyst for the degradation of organic pollutants. In this study, we presented silver nanoparticles (AgNPs) embedded ZnO foam photocatalyst (Ag−ZnO) on glass substrates by the chemical bath in‐situ co‐deposition method. Our findings demonstrat that at low Ag‐loading content, metallic Ag0 NPs are embedded within the ZnO foam, while at high Ag‐loading content, they accumulates increasingly from inside to the surface of the foam. With the increase of AgNPs loading from 0.1 mM to 1.5 mM, the absorption of Ag−ZnO foams in the visible light region gradually enhances. The photocatalytic degradation efficiency of rhodamine B (RhB) is the highest in Ag−ZnO foams when the Ag loading concentration reaches 0.8 mM, suggesting an optimal content of Ag for enhanced performance. This trend is attributed to the photo‐induced charge transfer behavior of Ag−ZnO samples. The AgNPs embedded inside the ZnO foam enhance the separation of photo‐induced charges and prevent their recombination. As a result, Ag−ZnO(0.8 mM) foam with more photo‐induced holes participate in the photocatalytic reaction, leading to a remarkably high photocatalytic activity. [ABSTRACT FROM AUTHOR]

This study focuses on incorporating liquid molecules, different from the bulk solution, into the immobilized enzyme carrier to regulate the distribution effect and diffusion‐limiting impact of the carrier's microenvironment for substrates, which generally is difficult to achieve due to the instability of the materials with liquid inclusions. A freestanding liquid‐holding particle carrier, with bi‐component hydrophobic ionic liquid gel microspheres with poly (glycidyl methacrylate) as the network and 1‐butyl‐3‐methylimidazolium hexafluorophosphate as the dispersing medium, is proposed, which is stable in air aqueous solution, and can extract proteins and organic small molecules into its interior due to the mobility of its dispersing medium. Horseradish peroxidase is covalently immobilized into the microspheres, forming a liquid compartment enzyme microreactor. The microreactor exhibits superior stability, enzymatic activity, and catalytic performance for Basic Orange II degradation compared to free enzyme and liquid‐free immobilized enzymes. This is attributed to the biocompatibility of the ionic liquid, its role in substrate enrichment in its interior, and its rapid mass transfer capability. This contribution shows the effectiveness of regulating the carrier's microenvironment with liquid molecules, offering fresh perspectives and strategies for enzyme technology. [ABSTRACT FROM AUTHOR]