Metal Matrix Cast Composites (United States)

Quantum dot (QD)-based scintillators show promise for use as flexible X-ray imaging screens due to their high performance and scalable characteristics. However, conventionally used QD-based scintillators face severe limitations, including poor chemical stability and unavoidable toxic issues arising from heavy metals such as cadmium (Cd) or lead (Pb). Herein, a Cd/Pb-free liquid scintillator based on ZnSeTe-based core-shell QDs and an energy transfer donor molecule of 2,5-diphenyloxazole (PPO) is reported, which offers high efficiency and scalability. By adjusting the Te/Se ratios of ZnSeTe, an optimal balance between X-ray absorption and radioluminescence efficiency of ZnSeTe-based core-shell QDs is achieved, resulting in a blue-emitting scintillator with a light yield of 11222 (±2%) photons MeV-1 beyond commercial Bi3Ge4O12. Furthermore, halogen passivation effectively eliminates trap states on the surface of ZnSeTe-based core-shell QDs, doubling the X-ray-excited fluorescence intensity. Consequently, the composite liquid scintillator, fabricated using PPO-composited ZnSeTe-based QDs, achieves a high light yield of 33450 (±5%) photons MeV-1 and a low detection limit of 788.4nGys-1. High-performance X-ray imaging with a spatial resolution of 6.7 line pairs (lp) mm-1 is achieved. This work introduces a novel approach for the development of eco-friendly QD-based scintillators with structural and optical modulation for high-performance X-ray imaging.

The growing global energy sector demands battery systems with enhanced stability and operational safety. Aqueous zinc-ion energy-storage-integrated batteries have emerged as potential candidates due to their high theoretical capacity and environmentally benign aqueous electrolytes. Despite continuous advances in battery-related technologies, current systems still face challenges in balancing mechanical robustness with energy density for structural energy-storage applications. To address these limitations, we developed a triangular stabilized ether–water–epoxy hybrid structural membrane system by incorporating a tetraglyme additive into zinc trifluoromethanesulfonate solution, which was infused into a porous epoxy resin membrane. This ether–water–epoxy hybrid structural membrane system effectively inhibits zinc dendrite formation while exploiting its antiswelling characteristics to preserve mechanical integrity (swelling ratio <2% after 48 h immersion and maintained a tensile strength of 6.8 MPa). The optimized battery demonstrated exceptional cycling stability (>880 h at 1.0 mA cm–2 and 1.0 mAh cm–2) while achieving 83.2% capacity retention over 400 cycles at 1 C. Furthermore, the structural energy device retained >80% capacity after 100 cycles under 0.5 C while withstanding bending stresses exceeding 400 MPa. Remarkably, the structural energy device achieved complete in situ full mechanical and electrochemical recyclability under 300 MPa bending stress, demonstrating a great potential for application in the field of both sustainable materials and structural energy-storage devices.

Estratégias lúdicas aplicadas ao ensino de matemática na educação infantil -Belo Horizonte, MG -

Abstract Organomorphic composites are obtained by pyrolysis of heat‐treated molded polymer fibers followed by compacting the resulting Ipresskon ® preform using carbon or silicon carbide. The structure of these materials features the most uniform volume distribution of a fiber and a matrix. The carbon–carbon (C/C) composite bushings made in this way show a very high compressive strength (up to 390 MPa) and a radial tensile strength (150 MPa). These characteristics ensure high performance of hot pressing molds for ceramics conventionally made of isostatic graphite characterized by much lesser tensile strength. This paper describes the microstructure and properties of C/C‐Ipresskon ® composite that was used instead of graphite as a hot pressing mold die. The material structure was found to show a slight transformation after 22 cycles of high‐temperature thermal/mechanical loading at a temperature up to 2000°C and 30–35 MPa.

Inspired by the tunable coupling of pigment cells and iridocytes, a tunable thermoregulatory material is designed. The metamaterial can tune the solar absorptive quality from 0.9 to 0.03 while keeping the radiative quality small.

In this contribution, we reported an approach to functionalize polyethylene with quadruple hydrogen bonds.

As an eco-friendly and renewable energy source, hydrogen energy has attracted widespread attention.

Photocatalysis is considered a remarkable green method in the catalytic degradation of wastewater; however, the collection and loading of the powdered catalyst is still a problem.