Researchers have solved a decades-old mystery by showing that a cache of 43 helmets found off the Spanish coast is medieval, not Roman。 The remarkable discovery exposes a thriving weapons trade network that connected Mediterranean powers during a time of piracy, warfare, and growing demand for military equipment
The current density-voltage characteristic (JV) is a critical tool for understanding the behaviour of solar cells. In this article, we present an overview of the key aspects of JV analysis and introduce a user-friendly flowchart that facilitates the swift identification of the most probable limiting process in a solar cell, based mainly on the outcomes of light-intensity-dependent JV measurements. The flowchart was developed through extensive drift-diffusion simulations and a rigorous review of the literature, with a specific focus on perovskite and organic solar cells. Moreover, the flowchart proposes supplementary experiments that can be conducted to obtain a more precise prediction of the primary performance losses. It therefore serves as an optimal starting point to analyse performance losses of solar cells.
The recently reported magnetic ordering in insulating two-dimensional (2D) materials, such as chromium triiodide (CrI$_3$) and chromium tribromide (CrBr$_3$), opens new possibilities for the fabrication of magneto-electronic devices based on 2D systems. Inevitably, the magnetization and spin dynamics in 2D magnets are strongly linked to Joule heating. Therefore, understanding the coupling between spin, charge and heat, i.e. spin caloritronic effects, is crucial. However, spin caloritronics in 2D ferromagnets remains mostly unexplored, due to their instability in air. Here we develop a fabrication method that integrates spin-active contacts with 2D magnets through hBN encapsulation, allowing us to explore the spin caloritronic effects in these materials. The angular dependence of the thermal spin signal of the CrBr$_3$/Pt system is studied, for different conditions of magnetic field and heating current. We highlight the presence of a significant magnetic proximity effect from CrBr$_3$ on Pt revealed by an anomalous Nernst effect in Pt, and suggest the contribution of the spin Seebeck effect from CrBr$_3$. These results pave the way for future magnonic devices using air-sensitive 2D
What if wormholes were never cosmic tunnels at all。 New research suggests Einstein and Rosen’s famous “bridge” may actually reveal something even stranger: time itself could flow in two directions at once。 Instead of connecting distant places in space, these bridges may connect mirror versions of time deep inside quantum physics, potentially solvin
Deer keds rely on flight and vision to find a host, but everything changes once they land。 After shedding their wings forever, these parasites reduce the activity of key vision-related genes by about half。 Scientists believe they are effectively trading sharp eyesight for extra energy that can be used for feeding and reproduction
These are the cleaning robots, water monitors, and toys actually worth buying for pool season
Scientists have uncovered a surprising navigation system in pigeons: iron-filled immune cells in the liver that may act like tiny magnetic sensors。 Birds deprived of these cells struggled to find their way home under overcast skies, indicating they rely on Earth’s magnetic field for guidance。 The discovery could solve a decades-old mystery about an
Scientists have uncovered unexpected quantum complexity inside cobalt, a metal long thought to be fully understood。 Advanced measurements revealed a dense network of topological electronic states that remain robust at room temperature。 These states enable extremely fast electron behavior and can be switched or controlled using magnetism
Scientists have proposed a new method for finding tightly bound supermassive black hole pairs by searching for stars that flash repeatedly as their light is magnified by the black holes’ gravity。 The timing and brightness of these bursts could provide a unique fingerprint of black holes slowly spiraling toward a future collision
A large study found that women taking GLP-1 drugs, the medication class behind Ozempic, Wegovy, Mounjaro, and Zepbound, were about 30% less likely to develop breast cancer。 Researchers say the findings are promising but not yet proof, and clinical trials are now being planned to test whether these drugs could help prevent breast cancer
Scientists have created a global “treasure map” for rare earth elements by uncovering where the strange volcanic rocks that contain them are most likely to form。 By combining thousands of rock samples with seismic images of Earth’s deep interior, the team discovered that these metal-rich rocks tend to appear along the ancient, thick roots of contin
A major mouse study found that some inherited traits are passed down through epigenetic changes that break the classic rules of genetics。 Researchers discovered hundreds of cases where these chemical DNA marks behaved unexpectedly, including some that seemed to emerge out of nowhere。 They also identified the first known naturally occurring paramuta
We have studied the influence of a particular kind of phason-defect on the Landauer resistance of a Fibonacci chain. Depending on parameters, we sometimes find the resistance to decrease upon introduction of defect or temperature, a behavior that also appears in real quasicrystalline materials. We demonstrate essential differences between a standard tight-binding model and a full continuous model. In the continuous case, we study the conductance in relation to the underlying chaotic map and its invariant. Close to conducting points, where the invariant vanishes, and in the majority of cases studied, the resistance is found to decrease upon introduction of a defect. Subtle interference effects between a sudden phason-change in the structure and the phase of the wavefunction are also found, and these give rise to resistive behaviors that produce exceedingly simple and regular patterns.
A major research study is challenging one of evolution’s most influential ideas: that most genetic changes that become permanent are essentially neutral。 Researchers at the University of Michigan found that beneficial mutations are actually far more common than scientists have long assumed。 The puzzle is that these advantageous mutations rarely spr