Using 3D sonic crystals as acoustic higher-order topological insulators (HOTIs), 2D surface states described by spin-1 Dirac equations at the interfaces between the two sonic crystals with distinct topology but the same crystalline symmetry are discovered. It is found that the Dirac mass can be tuned by the geometry of the two sonic crystals. The sign reversal of the Dirac mass reveals a surface topological transition where the surface states exhibit zero refractive index behavior. When the surface states are gapped, 1D hinge states emerge due to the topology of the gapped surface states. The zero refractive index behavior and the emergent topological hinge states are confirmed experimentally. This study reveals a multidimensional Wannier orbital control that leads to extraordinary properties of surface states and unveils an interesting topological mechanism for the control of surface waves.
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http://dx.doi.org/10.1002/advs.202201568 | DOI Listing |
Acta Crystallogr C Struct Chem
January 2025
College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, People's Republic of China.
A new twofold interpenetrated 3D metal-organic framework (MOF), namely, poly[[μ-aqua-diaqua{μ-2,2'-[terephthaloylbis(azanediyl)]diacetato}barium(II)] dihydrate], {[Ba(CHNO)(HO)]·2HO}, (I), has been assembled through a combination of the reaction of 2,2'-[terephthaloylbis(azanediyl)]diacetic acid (TPBA, HL) with barium hydroxide and crystallization at low temperature. In the crystal structure of (I), the nine-coordinated Ba ions are bridged by two μ-aqua ligands and two carboxylate μ-O atoms to form a 1D loop-like Ba-O chain, which, together with the other two coordinated water molecules and μ-carboxylate groups, produces a rod-like secondary building unit (SBU). The resultant 1D polynuclear SBUs are further extended into a 3D MOF via the terephthalamide moiety of the ligand as a spacer.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Faculty of Geography, Lomonosov Moscow State University, 119991, Moscow, Russia.
The content of 39 metals and metalloids (MMs) in submicron road dust (PM fraction) was studied in the traffic zone, residential courtyards with parking lots, and on pedestrian roads in parks in Moscow. The geochemical profiles of PM vary slightly between different types of roads and courtyards but differ significantly from those in parks. In Moscow, compared to other cities worldwide, submicron road dust contains less As, Sb, Mo, Cr, Cd, Sn, Tl, Ca, Rb, La, Y, U, but more Cu, Zn, Co, Fe, Mn, Ti, Zr, Al, V.
View Article and Find Full Text PDFSci Rep
January 2025
State Key Laboratory of Geohazard Prevention and GeoEnvironment Protection, Chengdu University of Technology, Chengdu, 610059, Sichuan, China.
Pakistan's geographic location makes it an important land hub between Central Asia, Middle East-North Africa, and China. However, the railways, roads, farmland, riverways, and residential quarters in the Piedmont plains of Baluchistan province in northwestern Pakistan are under serious threat of flooding in the summer of 2022. The urgency and severity of climate change's impact on humanity are underscored by the significant threats posed to human life and property in Piedmont Plains environments through extreme flood events, which has garnered widespread concerns.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Endocrinology, The Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, China.
This study aimed to identify the correlation of serum 25(OH)D level with sarcopenia and its components in Chinese elderly aged 65 years and above from rural areas. A total of 368 Chinese elderly aged 65 years and above in rural areas were enrolled. Indicators of muscle mass and strength, including the appendicular skeletal muscle mass (ASM), skeletal muscle index (SMI) and hand grip strength (HGS) were measured.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, China.
The development of mechanically robust super-lubrication hydrogel materials with sustained lubricity at high contact pressures is challenging. In this work, inspired by the durable lubricity feature of the earthworm epidermis, a multilevel structural super-lubrication hydrogel (MS-SLH) system, the so-called lubricant self-pumping hydrogel, is developed. The MS-SLH system is manufactured by chemically dissociating a double network hydrogel to generate robust and wrinkled lubrication layer, and then laser etching was used to generate cylindrical texture pores as gland-like pockets for storing lubricants.
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