The endohedral fullerene LuN@C was examined using in situ high-pressure measurements, which included electrical transport, Fourier-transform infrared spectroscopy, and Raman spectroscopy, in combination with theoretical calculations. LuN@C was found to undergo a reversible n- to p-type conversion at ∼8.9 GPa.
View Article and Find Full Text PDFThis work presents the first demonstration of a mechanochromic organic micro-laser, which exhibits remarkable wide range pressure sensing characteristics. The gain material, pinacolato boronate ester functionalized anthanthrene (AnBPin), is designed by incorporating mechanofluorochromic (MFC) properties into organic laser dye. The AnBPin exhibits a reversible transition between green and orange fluorescence upon grinding annealing and recrystallization cycle, and its micro-crystal exhibits typical organic micro-laser behaviors.
View Article and Find Full Text PDFDeveloping porous adsorbents for the complete sieving of propylene/propane mixtures represents an alternative method to energy-intensive cryogenic distillation processes. However, the similar physical properties of these molecules and the inherent trade-off among adsorption capacity, selectivity, diffusion kinetic and host-guest binding interactions in molecular sieving adsorbents makes their separation challenging. Here we report the separation of propylene/propane mixtures through a crystalline porous material (HAF-1) that features channels and shrinkage throats-the latter defined as narrower channels that connect the main channels and a molecular pocket-where the throat aperture is between the kinetic diameters of propylene and propane.
View Article and Find Full Text PDFThe Pacific saury (Cololabis saira) is a pelagic fish commonly found in the North Pacific Ocean. Its population diversity and migratory lifestyle have long captured global attention. Despite the inherent complexity of the C.
View Article and Find Full Text PDFGlobal marine biodiversity is experiencing significant alterations due to climate change. Incorporating phylogenetic and functional diversity may provide novel insights into these impacts. This study used an ensemble model approach (random forest and boosted regression tree), to predict the habitat distribution of 47 fish species in the Northwestern Pacific under contemporary (2000-2014) and future scenarios (2040-2050, 2090-2100).
View Article and Find Full Text PDFACS Appl Mater Interfaces
October 2024
Hydrides are promising candidates for achieving room-temperature superconductivity, but a formidable challenge remains in reducing the stabilization pressure below a megabar. In this study, we successfully synthesized a ternary lanthanum borohydride by introducing the nonmetallic element B into the La-H system, forming robust B-H covalent bonds that lower the pressure required to stabilize the superconducting phase. Electrical transport measurements confirm the presence of superconductivity with a critical temperature () of up to 106 K at 90 GPa, as evidenced by zero resistance and shift under an external magnetic field.
View Article and Find Full Text PDFThe structure of dislocation cores, the fundamental knowledge on crystal plasticity, remains largely unexplored in covalent crystals. Here, we conducted atomically resolved characterizations of dislocation core structures in a plastically deformed diamond anvil cell tip that was unloaded from an exceptionally high pressure of 360 GPa. Our observations unveiled a series of nonequilibrium dislocation cores that deviate from the commonly accepted "five-seven-membered ring" dislocation core model found in FCC-structured covalent crystals.
View Article and Find Full Text PDFUnlabelled: Mesopelagic fish (meso-fish) are central species within the Southern Ocean (SO). However, their ecosystem role and adaptive capacity to climate change are rarely integrated into protected areas assessments. This is a pity given their importance as crucial prey and predators in food webs, coupled with the impacts of climate change.
View Article and Find Full Text PDFMoiré superlattices formed by twisted stacking in van der Waals materials have emerged as a new platform for exploring the physics of strongly correlated materials and other emergent phenomena. However, there remains a lack of research on the mechanical properties of twisted-layer van der Waals materials, owing to a lack of suitable strategies for making three-dimensional bulk materials. Here we report the successful synthesis of a polycrystalline boron nitride bulk ceramic with high room-temperature deformability and strength.
View Article and Find Full Text PDFGrain boundaries (GBs), with their diversity in both structure and structural transitions, play an essential role in tailoring the properties of polycrystalline materials. As a unique GB subset, {112} incoherent twin boundaries (ITBs) are ubiquitous in nanotwinned, face-centred cubic materials. Although multiple ITB configurations and transitions have been reported, their transition mechanisms and impacts on mechanical properties remain largely unexplored, especially in regard to covalent materials.
View Article and Find Full Text PDFA phase diagram-based screen identifies optimal interface materials for devices that convert heat into electricity.
View Article and Find Full Text PDFThree novel hexagonal Si-C-N structures, namely SiCN, SiCN, and SiCN, were constructed on the basis of the α-SiN crystal structure. The stability of the three structures is demonstrated by analyzing their elastic constants and phonon dispersion spectra and by calculating their formation energies. The calculated band structures and partial densities of states suggest that the SiCN and SiCN structures possess hole conductivity.
View Article and Find Full Text PDFMaterials that possess the ability to self-heal cracks at room temperature, akin to living organisms, are highly sought after. However, achieving crack self-healing in inorganic materials, particularly with covalent bonds, presents a great challenge and often necessitates high temperatures and considerable atomic diffusion. Here we conducted a quantitative evaluation of the room-temperature self-healing behaviour of a fractured nanotwinned diamond composite, revealing that the self-healing properties of the composite stem from both the formation of nanoscale diamond osteoblasts comprising sp- and sp-hybridized carbon atoms at the fractured surfaces, and the atomic interaction transition from repulsion to attraction when the two fractured surfaces come into close proximity.
View Article and Find Full Text PDFUnlabelled: The complex life histories of demersal fishes are artificially separated into multiple stages along with changes in morphology and habitat. It is worth exploring whether the phenotypes expressed earlier and later during the life cycle are related or decoupled. The life stages of first year Pacific cod () were tracked over different hatch years and regions to test whether the early life history had a long-lasting effect on subsequent growth.
View Article and Find Full Text PDFThe optimal carrier concentration of thermoelectric materials increases with increasing temperature. However, conventional aliovalent doping usually provides an approximately constant carrier concentration over the whole temperature range, which can only match the optimal carrier concentration in a narrow temperature range. In this work, n-type indium and aluminum codoped PbTe were prepared with high-pressure synthesis, followed by spark plasma sintering.
View Article and Find Full Text PDFJ Phys Chem Lett
February 2023
Boron-rich compounds have attracted much attention due to their interesting structures and excellent properties. Here, we performed an extensive study on the different B-P stoichiometries under pressure by combining a particle swarm optimization method with first-principles calculations. At 1 atm, BP and BP are thermodynamically stable, while other stoichiometries are metastable.
View Article and Find Full Text PDFTraditional ceramics or metals cannot simultaneously achieve ultrahigh strength and high electrical conductivity. The elemental carbon can form a variety of allotropes with entirely different physical properties, providing versatility for tuning mechanical and electrical properties in a wide range. Here, by precisely controlling the extent of transformation of amorphous carbon into diamond within a narrow temperature-pressure range, we synthesize an in situ composite consisting of ultrafine nanodiamond homogeneously dispersed in disordered multilayer graphene with incoherent interfaces, which demonstrates a Knoop hardness of up to ~53 GPa, a compressive strength of up to ~54 GPa and an electrical conductivity of 670-1,240 S m at room temperature.
View Article and Find Full Text PDFValence fluctuation of interacting electrons plays a crucial role in emergent quantum phenomena in correlated electron systems. The theoretical rationale is that this effect can drive a band insulator into a superconductor through charge redistribution around the Fermi level. However, the root cause of such a fluctuating leap in the ionic valency remains elusive.
View Article and Find Full Text PDFClimate change is one of the most concerning topics in the Anthropocene. Increasing sea water temperature will trigger a series of ecological consequences, altering the various functions and services that marine ecosystems provide for humans. Fisheries, specifically, will likely face the most direct impact.
View Article and Find Full Text PDFThe observation of fracture behaviors in perfect and twinned B C crystals via in situ transmission electron microscopy (TEM) mechanical testing is reported. The crystal structure of the synthesized B C, composed of B C icosahedra connected by boron-deficient C-▫-C chains in a chemical formula of B C , is determined by state-of-the-art aberration-corrected scanning TEM. The in situ TEM observations reveal that cracking is preferentially initiated at the twin boundaries (TBs) in B C under both indentation and tension loading.
View Article and Find Full Text PDFThe Pacific saury (Cololabis saira) is one of the most commercially important pelagic fishes in Asia-Pacific countries. The oceanographic environment, especially the Oyashio Current, significantly affects the distribution of Pacific saury, and may lead to variations in their migration route and the formation of fishing grounds in Japanese coastal region and the high seas. In this study, six oceanographic factors, sea surface temperature (SST), sea surface chlorophyll-a concentration (SSC), sea surface salinity (SSS), sea surface height (SSH), mixed layer depth (MLD), and eddy kinetic energy (EKE), were associated with the monthly catch per unit effort 1 (monthly CPUE, ton/vessel) and the monthly CPUE (ton/day) of Pacific saury from Chinese fishing vessels during the optimal fishing periods (September-November) in 2014-2017.
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