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A series of ballistic experiments were performed to investigate the damage behavior of high velocity reactive material projectiles (RMPs) impacting liquid-filled tanks, and the corresponding hydrodynamic ram (HRAM) was studied in detail. PTFE/Al/W RMPs with steel-like and aluminum-like densities were prepared by a pressing/sintering process. The projectiles impacted a liquid-filled steel tank with front aluminum panel at approximately 1250 m/s. The corresponding cavity evolution characteristics and HRAM pressure were recorded by high-speed camera and pressure acquisition system, and further compared to those of steel and aluminum projectiles. Significantly different from the conical cavity formed by the inert metal projectile, the cavity formed by the RMP appeared as an ellipsoid with a conical front. The RMPs were demonstrated to enhance the radial growth velocity of cavity, the global HRAM pressure amplitude and the front panel damage, indicating the enhanced HRAM and structural damage behavior. Furthermore, combining the impact-induced fragmentation and deflagration characteristics, the cavity evolution of RMPs under the combined effect of kinetic energy impact and chemical energy release was analyzed. The mechanism of enhanced HRAM pressure induced by the RMPs was further revealed based on the theoretical model of the initial impact wave and the impulse analysis. Finally, the linear correlation between the deformation-thickness ratio and the non-dimensional impulse for the front panel was obtained and analyzed. It was determined that the enhanced near-field impulse induced by the RMPs was the dominant reason for the enhanced structural damage behavior. •Enhanced structural damage behavior of RMPs impacting liquid-filled tanks was verified.•Impact-induced fragmentation/deflagration led to an ellipsoidal cavity with a conical front.•Damage effect strongly depends on the initial kinetic energy and the initiation ratio.•The enhanced front panel damage is closely related to the enhanced near-field impulse.•Combined effect of kinetic energy and chemical energy is the determinant mechanism.

Composite concrete structures, commonly found in urban infrastructures, such as highways and runways, are pivotal research object in the protection field. To study the dynamic response of composite concrete structures subjected to reactive jet penetration coupled with an explosive effect, a full-scale damage experiment of composite structures under the action of 150 mm caliber shaped charges was performed, to derive the dynamic damage modes of different concrete thicknesses under the combined kinetic and chemical energy damage effects. The results indicated that under aluminum jet penetration, concrete layers exhibited minor funnel craters and penetration holes. However, concrete layers displayed a variety of damage modes, including central penetration holes, funnel craters, bulges, and radial/circumferential cracks when subjected to the PTFE/Al jet. The area of the funnel crater expanded as the thickness of the concrete increased, while the height of the bulge and the number of radial cracks decreased. The diameter of penetration holes increased by 76.9% and the area of funnel crater increased by 578% in comparison to Al jet penetration damage. A modified-RHT concrete model that reflected concrete tensile failure was established, utilizing AUTODYN. Segmented numerical simulations of damage behavior were performed using the FEM-SPH algorithm and a restart approach combined with reactive jet characteristics. The spatial distribution characteristic of the reactive jet and the relationship between kinetic penetration and explosion-enhanced damage were obtained by the simulation, which showed good concordance with the experimental results. This study provides important reference data and a theoretical basis for the design of composite concrete structures to resist penetration and explosion.

Quasi-static tension tests, quasi-static compression tests and dynamic compression tests were conducted to investigate the mechanical properties, constitutive behaviors and failure criteria of aluminum-polytetrafluoroethylene-tungsten (Al-PTFE-W) reactive materials with W content from 20% to 80%. The analysis of the quasi-static test results indicated that the strength of the materials may be independent of the stress state and W content. However, the compression plasticity of the materials is significantly superior to its tension plasticity. W content has no obvious influence on the compression plasticity, while tension plasticity is extremely sensitive to W content. Dynamic compression test results demonstrated the strain rate strengthening effect and the thermal softening effect of the materials, yet the dynamic compression strengths and the strain rate sensitivities of the materials with different W content show no obvious difference. Based on the experimental results and numerical iteration, the Johnson–Cook constitutive (A, B, n, C and m) and failure parameters (D1~D5) were well determined. The research results will be useful for the numerical studies, design and application of reactive materials.

The reactive projectile presents a tremendous potential to induce the combined damage effect of kinetic energy and chemical energy to the plate. A series of ballistic impact experiments and numerical simulation studies were carried out to study the penetration behavior of reactive projectile against TC4 plate. The experimental results showed that with the impact velocity of the reactive projectile increasing from 537m/s to 682m/s, the damage mode of the plate gradually changes from bulge, cross crack to plug. According to the experimental results, the ballistic limit velocity of reactive projectile perpendicular penetrating 5mm TC4 is 648.33m/s. The numerical simulation results showed that the reactive projectile reaches GPa high pressure within a few microseconds when it impacted with the plate. During reactive projectile penetrating TC4 plate, the chemical energy release significantly improves the projectile penetrating ability, and the contribution of chemical energy to projectile penetrating can reach 55.07%.

The reactive materials filled structure (RMFS) is a structural penetrator that replaces high explosive (HE) with reactive materials, presenting a novel self-distributed initiation, multiple deflagrations behavior during penetrating multi-layered plates, and generating a multipeak overpressure behind the plates. Here analytical models of RMFS self-distributed energy release and equivalent deflagration are developed. The multipeak overpressure formation model based on the single deflagration overpressure expression was promoted. The impact tests of RMFS on multi-layered plates at 584 m/s, 616 m/s, and 819 m/s were performed to validate the analytical model. Further, the influence of a single overpressure peak and time intervals versus impact velocity is discussed. The analysis results indicate that the deflagration happened within 20.68 mm behind the plate, the initial impact velocity and plate thickness are the crucial factors that dominate the self-distributed multipeak overpressure effect. Three formation patterns of multipeak overpressure are proposed. •The space distribution model of equivalent deflagration points of reactive material filled structure (RMFS) is developed.•The analytical model describing the self-distributed deflagration behavior of RMFS is developed.•The formation mechanism of multi-peak overpressure subjected to sequential impact and chemical deflagration is revealed.•Three multipeak overpressure patterns caused by spatiotemporal and multi-source deflagration are discussed.

The reactive materials filled structure (RMFS) is a structural penetrator that replaces high explosive (HE) with reactive materials, presenting a novel self-distributed initiation, multiple deflagrations behavior during penetrating multi-layered plates, and generating a multipeak overpressure behind the plates. Here analytical models of RMFS self-distributed energy release and equivalent deflagration are developed. The multipeak overpressure formation model based on the single deflagration overpressure expression was promoted. The impact tests of RMFS on multi-layered plates at 584 m/s, 616 m/s, and 819 m/s were performed to validate the analytical model. Further, the influence of a single overpressure peak and time intervals versus impact velocity is discussed. The analysis results indicate that the deflagration happened within 20.68 mm behind the plate, the initial impact velocity and plate thickness are the crucial factors that dominate the self-distributed multipeak overpressure effect. Three formation patterns of multipeak overpressure are proposed.

Varicella-zoster virus (VZV) is the etiological agent of chickenpox and herpes zoster, while herpes simplex virus 1 (HSV-1) causes oral and genital herpes. Both infections manifest with skin blisters from which the viruses are transmitted to new hosts either via aerosol (VZV) or skin microabrasions (HSV-1). VZV reaches the skin through the blood route, and in the skin epidermis it first infects undifferentiated keratinocytes of the basal layer. Conflicting evidence exists for HSV-1, making it unclear whether HSV-1 infects undifferentiated or differentiated keratinocytes. Here, we developed models of primary human epidermal keratinocytes' differentiation to recapitulate infection of distinct layers of the epidermis by VZV and HSV-1. Our data show that replication of both viruses is restricted, VZV more than HSV-1, if initial infection occurs in differentiated keratinocytes, but not if initial infection occurs in basal undifferentiated keratinocytes. Like VZV, HSV-1 downregulates expression of proteins associated with keratinocyte differentiation, such as the suprabasal keratin K10. However, whereas downregulation of K10 occurs soon after VZV infection and before the virus has replicated, HSV-1-mediated K10 downregulation appears to require full viral replication. These observations provide insights into the potential for VZV and HSV-1 interactions with epidermal differentiation to yield strategies for developing host and pathogen-directed antiviral agents.

With the widespread application of sandwich composites, the performance of the core structure in the sandwich composites has received particular attention. As the typical representative of lightweight core structure, honeycombs have excellent designability and are widely used. The emerging fibre reinforced composite honeycombs have incomparable performance advantages over traditional metal or chopped fibre honeycombs. This means that design, manufacturing technologies and performance evaluation of composite honeycombs are important. In this review, grid, hexagonal, Kagome, corrugated and origami structure honeycombs and their associated manufacturing strategies have been summarised. In addition, more attention has been paid to textile structure composite honeycombs fabricated by weaving, braiding, or knitting techniques. Their mechanical performances have been extensively reviewed to clarify the relationship between structure and properties. Based on existing studies, the damage mechanisms of composite honeycomb structures are found to be insufficient; especially for the load-bearing mechanisms and predicting methods for honeycombs, which is a challenge for further development. This review hopes to inspire the innovation in fibre reinforced composite honeycombs from the view of structure design and performance evaluation.

Brain-inspired computing has emerged as a promising paradigm to overcome the energy-efficiency limitations of conventional intelligent systems by emulating the brain's partitioned architecture and event-driven sparse computation. However, existing brain-inspired chips often suffer from rigid network topology constraints and limited neuronal programmability, hindering their adaptability. To address these challenges, we present TaiBai, an event-driven, programmable many-core brain-inspired processor that leverages temporal and spatial spike sparsity to minimize bandwidth and computational overhead. TaiBai chip contains three key features: First, a brain-inspired hierarchical topology encoding scheme is designed to flexibly support arbitrary network architectures while slashing storage overhead for large-scale networks; Second, a multi-granularity instruction set enables programmability of brain-like spiking neuron or synapses with various dynamics and on-chip learning rules; Third, a co-designed compiler stack optimizes task mapping and resource allocation. After evaluating across various tasks, such as speech recognition, ECG classification, and cross-day brain-computer interface decoding, we found spiking neural networks embedded on the TaiBai chip could achieve more than 200 times higher energy efficiency than a standard NVIDIA RTX 3090 GPU at a comparable accuracy. These results demonstrated its high potentiation as a scalable, programmable, and ultra-efficient solution for both multi-scale brain simulation and brain-inspired computation.