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To obtain the filling material with good compression mechanical properties, two kinds of orthogonal trapezoidal honeycomb aluminum with different structures were manufactured（90°orthogonal trapezoidal honeycomb aluminum and 45° orthogonal trapezoidal honeycomb aluminum）, the mechanical properties of the material under quasi-static axial loading was analyzed. Two kinds of orthogonal trapezoidal honeycomb aluminum were filled with polyurethane foam, and the effect of polyurethane filling on the orthogonal trapezoidal honeycomb aluminum was analyzed. The results show that compared with 45° orthogonal trapezoidal aluminum honeycomb, the performance of 90° orthogonal trapezoidal honeycomb aluminum is better, and the peak stress, plateau stress and unit volume absorption energy of the two kinds of orthogonal trapezoidal honeycomb aluminum are improved after polyurethane filling. However, the energy absorption efficiency is not significantly improved after being filled with polyurethane, and the strain corresponding to the maximum energy absorption efficiency decreases.

In order to verify the strength of polyvinyl chloride（pvc） plastic sheet lap joint with different surface roughness, the pvc plate was polished with different mesh sandpaper（polished length was 30 mm）. The surface roughness was measured with a surface roughness instrument and the surface was examined with a high power microscope. The results show that different types of sandpaper abrasive sheet will produce different surface roughness. 60 mesh to 400 mesh sandpaper polished sheet surface roughness decreased gradually, the performance of the Ra value from 10.840 μm reduced to 1.503 μm. Tensile strength test was carried out by bonding the sheet with different surface roughness to the silicone rubber, and the overlapped plate material with different surface roughness produced different overlapping strength. The maximum tensile force that can be sustained by the lap joint with 60 mesh to 100 mesh sandpaper increased from 1.858 kN to 2.063 kN, and the overlap strength increased gradually. The maximum tensile force that can be sustained by the lap joint with 100-400 mesh sandpaper was reduced from 1.563 kN to 1.567 kN, and the overlap strength is reduced gradually. The control group has no surface treatment of the plate lap joints, can withstand the maximum tensile force of 1.380 kN, is the lowest overlap strength. So for the pvc plastic sheet and silicone rubber lap joints, with 100 mesh sandpaper grinding,the lap performance is the best.

Hierarchical zeolites have attracted significant attention from both academic and industrial communities due to their exceptional mass transport and accessibility to active sites while maintaining the shape selectivity of the zeolite. However, creating a hierarchical structure over small-pore zeolites remains a formidable challenge. In this study, we propose a novel approach that utilizes a methanol-mediated NH4F etching method to fabricate hierarchical SSZ-13 zeolite with well-distributed mesopores. Unlike the conventional aqueous NH4F etching process, the utilization of methanol as a solvent allows for the effective suppression of NH4F reactivity during its transport into the zeolite channels. NH4F remains inactive until exposed to resident water molecules in zeolite, and the subsequent hydrolysis process in situ activates the release of etching species, effectively eliminating the framework Si and Al species and allowing for uniform and controllable etching. Solid-state nuclear magnetic resonance spectroscopy provides in-depth insight into the etchant interactions with the framework defect sites and the evolution of aluminate and silicate species from framework to extra-framework, elucidating the structural and chemical changes occurring during the process. Our work presents an efficient strategy for the preparation of hierarchical zeolites with well-dispersed mesopores, offering opportunities for tailored pore engineering and holding potential for various applications such as catalysis, adsorption, and separation. [ABSTRACT FROM AUTHOR]

With the increasing number of automobiles on the road, passive safety has become a particularly important issue. In this paper, an energy-absorbing material, origami aluminum honeycomb, was manufactured by a welding process for use as an automobile energy absorbing box. The mechanical properties and deformation of welded origami aluminum honeycomb in three directions were studied through quasi-static and dynamic compression tests. The results show that the origami aluminum honeycomb had good mechanical energy absorption performance, and the optimal directions are identified. Combined with theoretical analysis, the errors between experiments and simulations are shown. The origami honeycomb structure was designed for use as an automobile energy absorbing box. Analysis shows that it could absorb at least 10% of the kinetic energy of a vehicle during a collision, and could play a role in protecting the interior of the vehicle. [ABSTRACT FROM AUTHOR]

Bi-directional corrugated honeycomb aluminum has two-way energy absorption performance intended to be used as impact limiter filling material for nuclear spent fuel transport casks. It is made of aluminum plate, corrugated plate and adhesive. The bonding parameters determine the bonding effect of Bi-directional corrugated honeycomb aluminum thus affect the energy absorption performance. This paper verifies the bonding parameters from three aspects (type of adhesive, surface roughness, and thickness of the adhesive layer). The results show that when an acrylic adhesive is used to perform the compression test, no matter which bonding parameters are used, all samples debond. When an epoxy resin is used, except for the sample with an adhesive layer thickness of 0.2 mm and the surface was polished with the grit number of 320 sandpaper, samples with other parameters showed debonding to varying degrees. In addition, the bonding parameters have a great influence on the energy absorption performance of the specimen. The deformation and the energy absorption was also discussed. [ABSTRACT FROM AUTHOR]

In this paper, a porous material–bi-directional corrugated honeycomb aluminum (Bi-DCHA) was manufactured, and quasi-static compression experiments were performed in axial (Y/Z-direction) and radial (X-direction) directions. It was concluded that the mechanical properties in the Y/Z directions were better than those in X-direction. Further, to verify the effect of expanded polypropylene (EPP) on the properties of Bi-DCHA, three different density EPP were used to fill them, and the property of Y/Z-direction was performed. As a result, compared with Bi-DCHA unfilled with EPP, the performance of Bi-DCHA filled with EPP improved, and is better than the sum of EPP and Bi-DCHA unfilled with EPP. Observing the stress-strain curves of the four groups of samples, we can find that the initial peak stress (σP) of the Bi-DCHA filled with EPP is lower than Bi-DCHA; the stress in the plateau zone (σpl) increases with the increase of the EPP density. Observing the deformation process of the specimen, it was found that after filling the EPP, the deformation process of the specimen changed from global buckling/tilt mode to local compact plastic deformation mode. The energy absorption effect of Bi-DCHA filled with EPP is stronger than that of unfilled specimen. [ABSTRACT FROM AUTHOR]

Catalytic NH 3 synthesis and decomposition offer a new promising way to store and transport renewable energy in the form of NH 3 from remote or offshore sites to industrial plants. To use NH 3 as a hydrogen carrier, it is important to understand the catalytic functionality of NH 3 decomposition reactions at an atomic level. Here, we report for the first time that Ru species confined in a 13X zeolite cavity display the highest specific catalytic activity of over 4000 h -1 for the NH 3 decomposition with a lower activation barrier, compared to most reported catalytic materials in the literature. Mechanistic and modeling studies clearly indicate that the N-H bond of NH 3 is ruptured heterolytically by the frustrated Lewis pair of Ru δ+ -O δ- in the zeolite identified by synchrotron X-rays and neutron powder diffraction with Rietveld refinement as well as other characterization techniques including solid-state nuclear magnetic resonance spectroscopy, in situ diffuse reflectance infrared transform spectroscopy, and temperature-programmed analysis. This contrasts with the homolytic cleavage of N-H displayed by metal nanoparticles. Our work reveals the unprecedented unique behavior of cooperative frustrated Lewis pairs created by the metal species on the internal zeolite surface, resulting in a dynamic hydrogen shuttling from NH 3 to regenerate framework Brønsted acid sites that eventually are converted to molecular hydrogen.