Browse Articles
Discover research articles across all indexed journals
Optimization and microstructural study of friction riveted carbon-Kevlar and aluminum joints for aerospace applications
Vesuvius volcano turned this brain to glass
Construction of a prediction model for coronary heart disease in type 2 diabetes mellitus: a cross-sectional study
Daily briefing: An unvaccinated child is first US measles death in a decade
Scaling and networking a modular photonic quantum computer
Reply to: Causal claims, causal assumptions and protected area impact
Author Correction: High fatigue resistance in a titanium alloy via near-void-free 3D printing
Author Correction: A map of the rubisco biochemical landscape
Combine AI with citizen science to fight poverty
Superelastic titanium alloy has potential for space missions
Streamflow shifts with declining snowfall
Can AI help beat poverty? Researchers test ways to aid the poorest people
Continued Atlantic overturning circulation even under climate extremes
Abstract The Atlantic Meridional Overturning Circulation (AMOC), vital for northwards heat transport in the Atlantic Ocean, is projected to weaken owing to global warming 1 , with significant global climate impacts 2 . However, the extent of AMOC weakening is uncertain with wide variation across climate models 1,3,4 and some statistical indicators suggesting an imminent collapse 5 . Here we show that the AMOC is resilient to extreme greenhouse gas and North Atlantic freshwater forcings across 34 climate models. Upwelling in the Southern Ocean, driven by persistent Southern Ocean winds, sustains a weakened AMOC in all cases, preventing its complete collapse. As Southern Ocean upwelling must be balanced by downwelling in the Atlantic or Pacific, the AMOC can only collapse if a compensating Pacific Meridional Overturning Circulation (PMOC) develops. Remarkably, a PMOC does emerge in almost all models, but it is too weak to balance all of the Southern Ocean upwelling, suggesting that an AMOC collapse is unlikely this century. Our findings reveal AMOC-stabilizing mechanisms with implications for past and future AMOC changes, and hence for ecosystems and ocean biogeochemistry. They suggest that better understanding and estimates of the Southern Ocean and Indo-Pacific circulations are urgently needed to accurately predict future AMOC change.
Reply to: Streamflow shifts with declining snowfall
Quantum technologies need big investments to deliver on their big promises
A lightweight shape-memory alloy with superior temperature-fluctuation resistance
Abstract In advanced applications such as aerospace and space exploration, materials must balance lightness, functionality and extreme thermal fluctuation resistance1,2. Shape-memory alloys show promise with strength, toughness and substantial strain recovery due to superelasticity, but maintaining low mass and effective operation at cryogenic temperatures is challenging3–6. We hereby introduce a new shape-memory alloy that adheres to these stringent criteria. Predominantly composed of Ti and Al with a chemical composition of Ti75.25Al20Cr4.75, this alloy is characterized by a low density (4.36 × 103 kg m− 3) and a high specific strength (185 × 103 Pa m3 per kg) at room temperature, while showing excellent superelasticity. The superelasticity, owing to a reversible stress-induced phase transformation from an ordered body-centred cubic parent phase to an ordered orthorhombic martensite, allows for a recoverable strain exceeding 7%. This functionality persists across a broad range of temperatures, from deep cryogenic 4.2 K to above room temperature, arising from an unconventional temperature dependence of transformation stresses. Below a certain threshold during cooling, the critical transformation stress inversely correlates with temperature. We interpret this behaviour from the perspective of a temperature-dependent anomalous lattice instability of the parent phase. This alloy holds potential in everyday appliances requiring flexible strain accommodation, as well as components designed for extreme environmental conditions such as deep space and liquefied gases.