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Fe-SiOC nanocomposites with core-shell (crystal-amorphous) columnar structures exhibit size dependent, anisotropic mechanical properties. When loading along the columns, the yield strength of Fe-SiOC increases from 2.6 GPa to 3.5 GPa as the column diameter decreases from ~14.0 nm to ~3.7 nm. In contrast, the yield strength of Fe-SiOC decreases from 3.1 GPa to 2.5 GPa when the loading is perpendicular to the columns. Combining with transmission electron microscope (TEM) analysis, the anisotropic mechanical properties were attributed to the size-dependent transition of deformation mechanisms from co-deformation (Fe and SiOC) to grain boundaries mediated cracking. 

ABSTRACT Global understanding of how plant diversity responds to multiple, co‐occurring global change drivers (e.g., elevated CO₂, climate change, and nitrogen addition) remains fragmented, largely due to the highly context‐dependent nature of responses and disparate experimental evidence. To address this, we conducted a global meta‐analysis synthesising 6832 control‐treatment comparisons from 465 studies. We found that for individual drivers, elevated CO₂had no effect on species richness, whereas increased precipitation enhanced it. In contrast, warming, decreased precipitation, and nitrogen addition generally reduced richness, with nitrogen addition consistently decreasing Shannon diversity and Pielou evenness. When drivers combined, warming‐driven losses were offset by elevated CO₂and increased precipitation and those of nitrogen addition were counteracted by both increased and decreased precipitation. Interaction analyses further revealed that additive effects between drivers predominated, though significant antagonisms emerged for specific pairs. Importantly, these responses were strongly context‐dependent, being mediated by a combination of site‐specific conditions (i.e., local climate, soil, and background diversity) and experimental methodologies (i.e., treatment duration, intensity, and plot and sampling area). Our synthesis underscores that predicting future biodiversity trajectories necessitates that models evolve beyond main effects to explicitly represent both multi‐driver interactions and the critical, often‐dominant, moderating role of local contexts and experimental conditions. 

Diameter estimates for K\"ahler metrics are established which require only an entropy bound and no lower bound on the Ricci curvature. The proof builds on recent PDE techniques for $$L^\infty$$ estimates for the Monge-Amp\`ere equation, with a key improvement allowing degeneracies of the volume form of codimension strictly greater than one. As a consequence, diameter bounds are obtained for long-time existence of the K\"ahler-Ricci flow and finite-time solutions when the K\"ahler class is big, as well as for special vibrations of Calabi-Yau manifolds.