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High reproductive compatibility between crops and their wild relatives can provide benefits for crop breeding but also poses risks for agricultural weed evolution. Weedy rice is a feral relative of rice that infests paddies and causes severe crop losses worldwide. In regions of tropical Asia where the wild progenitor of rice occurs, weedy rice could be influenced by hybridization with the wild species. Genomic analysis of this phenomenon has been very limited. Here we use whole genome sequence analyses of 217 wild, weedy and cultivated rice samples to show that wild rice hybridization has contributed substantially to the evolution of Southeast Asian weedy rice, with some strains acquiring weed-adaptive traits through introgression from the wild progenitor. Our study highlights how adaptive introgression from wild species can contribute to agricultural weed evolution, and it provides a case study of parallel evolution of weediness in independently-evolved strains of a weedy crop relative.

 

High entropy oxide nanoparticles (HEO NPs) with multiple component elements possess improved stability and multiple uses for functional applications, including catalysis, data memory, and energy storage. However, the synthesis of homogenous HEO NPs containing five or more immiscible elements with a single-phase structure is still a great challenge due to the strict synthetic conditions. In particular, several synthesis methods of HEO NPs require extremely high temperatures. In this study, we demonstrate a low cost, facile, and effective method to synthesize three- to eight-element HEO nanoparticles by a combination of electrospinning and low-temperature ambient annealing. HEO NPs were generated by annealing nanofibers at 330 °C for 30 minutes under air conditions. The average size of the HEO nanoparticles was ∼30 nm and homogenous element distribution was obtained from post-electrospinning thermal decomposition. The synthesized HEO NPs exhibited magnetic properties with the highest saturation magnetization at 9.588 emu g −1 and the highest coercivity at 147.175 Oe for HEO NPs with four magnetic elements while integrating more nonmagnetic elements will suppress the magnetic response. This electrospun and low-temperature annealing method provides an easy and flexible design for nanoparticle composition and economic processing pathway, which offers a cost- and energy-effective, and high throughput entropy nanoparticle synthesis on a large scale. 

Crystalline metals generally exhibit good deformability but low strength and poor irradiation tolerance. Amorphous materials in general display poor deformability but high strength and good irradiation tolerance. Interestingly, refining characteristic size can enhance the flow strength of crystalline metals and the deformability of amorphous materials. Thus, crystalline–amorphous nanostructures can exhibit an enhanced strength and an improved plastic flow stability. In addition, high-density interfaces can trap radiation-induced defects and accommodate free volume fluctuation. In this article, we review crystalline–amorphous nanocomposites with characteristic microstructures including nanolaminates, core–shell microstructures, and crystalline/amorphous-based dual-phase nanocomposites. The focus is put on synthesis of characteristic microstructures, deformation behaviors, and multiscale materials modelling.

 

Non-Hermitian meta-gratings enable unidirectional excitation and reflection of optical surface waves at the nanoscale.