An alternative model of the hexagonal boron nitride (h-BN) on nanomesh on the Rh(111) surface is presented. It explains the observed ultraviolet photoelectron spectroscopy spectra and reproduces experimental STM images introducing, instead of two, only one strongly corrugated layer of h-BN covering the whole Rh surface. In order to optimize the geometry of the BN layer we calculate the forces by density functional theory and analyze the interactions in the system. The final geometry is a result of a competition between BN-metal attraction or repulsion and elastic properties of the isolated h-BN layer. The calculated bonding energy is around 0.33 eV per BN molecule with a corrugation close to 0.55 A.
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http://dx.doi.org/10.1103/PhysRevLett.98.106802 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Institute of Soft-matter and Advanced Functional Materials, Gansu Province Carbon New Material Industry Technology Center, School of Materials and Energy, Lanzhou University, Lanzhou 730000, China.
Hexagonal boron nitride (h-BN), with excellent thermal conductivity and insulation capability, has garnered significant attention in the field of electronic thermal management. However, the thermal conductivity of the h-BN-enhanced polymer composite material is far from that expected because of the insurmountable interfacial thermal resistance. In order to realize the high thermal conductivity of polymer composite thermal interface materials, herein, an in situ exfoliation method has been employed to prepare a boron nitride nanosheet-graphene (BNNS-Gr) hybrid filler.
View Article and Find Full Text PDFSci Rep
January 2025
Environment Division, National Institute of Oceanography and Fisheries (NIOF), Kayet Bey, Elanfoushy, Alexandria, Egypt.
Nature
January 2025
Department of Chemistry and Chemical Biology, Boyce Thompson Institute, Cornell University, Ithaca, NY, USA.
Metabolites derived from the intestinal microbiota, including bile acids (BA), extensively modulate vertebrate physiology, including development, metabolism, immune responses and cognitive function. However, to what extent host responses balance the physiological effects of microbiota-derived metabolites remains unclear. Here, using untargeted metabolomics of mouse tissues, we identified a family of BA-methylcysteamine (BA-MCY) conjugates that are abundant in the intestine and dependent on vanin 1 (VNN1), a pantetheinase highly expressed in intestinal tissues.
View Article and Find Full Text PDFJ Chem Phys
January 2025
MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, China.
By using a tight-binding model, first-principles calculations, and ab initio molecular dynamics simulations, we theoretically demonstrate that the C76-Td-assembled two-dimensional (2D) honeycomb lattice is stable at room temperature and is resistant to mechanical deformation. We disclose that each C76-Td mimics a single carbon atom (geometrically and electronically); hence, it plays the role of one supercarbon. This inspires that the 2D material exhibits an exotic hourglass-like fermion at the Fermi level.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, 2000 Maribor, Slovenia.
In the proposed study, the fatigue analysis of an axisymmetric chiral cellular structure and its modified form, made of stainless steel 316L, is carried out. The main goal of the original structure geometry was to absorb as much mechanical energy as possible with its auxetic behaviour. However, it was found through testing that its response could be improved by modifying the thickness of the struts through the structure.
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