Radio-photovoltaic cells, as a kind of nuclear battery, have a high energy density but low energy conversion efficiency (ECE). Scientists in China have developed a high-efficiency RPVC using multilayer-stacked GAGG:Ce scintillation waveguides and ⁹⁰Sr radioisotopes, which achieves a record ECE of 2.96%. Remarkably, the cells retain 86.2% of its initial performance after exposure to 50 years of equivalent irradiation at a milliwatt-level output. This breakthrough provides a maintenance-free power solution for extreme environments such as deep-sea exploration and space missions.

The subducted oceanic crusts are regarded as the major source of lower-mantle heterogeneity. However, the limited knowledge about the physical properties of major components in the subducted oceanic crusts prevents us from fully understanding the complex features of the related geophysical anomalies. Here, we comprehensively investigated the phase transition of (Al, H)-bearing stishovite at simultaneously high P-T conditions. These results contribute to our understanding on the complex depth distribution of the mid-lower mantle seismic scatterers.

A University of Queensland researcher has developed a new mathematical model to explain the evolution of the universe which for the first time includes collapsing regions of matter and expanding voids.

Kyoto, Japan -- As space programs evolve and we continue to mistreat our own planet, human dreams of space tourism and planetary colonization seem increasingly common. However, features of spaceflight such as gravitational changes and circadian rhythm disruption -- not to mention radiation -- take a toll on the body, including muscle wasting and decreased bone density. These may even affect our ability to produce healthy offspring.

Studying the impact of spaceflight on germ cells -- egg and sperm precursor cells -- is particularly important because they directly influence the next generation, and any irreversible damage done to these will likely be transmitted to offspring. Previous examinations of embryonic stem cells that have undergone spaceflight have revealed abnormalities, but the exact cause of the damage has remained unknown.

This inspired a team of researchers at Kyoto University to test the potential damage to spermatogonial stem cells during spaceflight and the resulting offspring. The team utilized stem cells from mice, which have a much shorter reproductive life span than humans.

We theoretically and experimentally demonstrate that a cylinder with arbitrary cross section, composed of a homogeneous electromagnetic medium featuring nontrivial second Chern numbers c₂ in a synthetic five-dimensional space, host topologically protected intrinsic Higher-order topological insulators (HOTI) type hinge states. Our work introduces the concept of boundary gauge fields and establishes the link between synthetic-space c₂ and real-space HOTI states.

Physicists from the University of Copenhagen have begun using the gigantic magnetic fields of galaxy clusters to observe distant black holes in their search for an elusive particle that has stumped scientists for decades.