This paper aims at studying the band gap phenomena of three-dimensional phononic crystals using the finite difference time domain (FDTD) method and a PC cluster system. In the paper, Bloch's theorem is applied to the wave equation and to the boundary conditions of the periodic structure. We calculate the variations of displacements and take discrete Fourier transform to acquire the resonances of the structures. Then, the dispersion relations of the bulk acoustic wave can be obtained and the band gaps are predicted accordingly. On the other hand, because of larger data calculation in three-dimensional phononic crystals, we introduce the PC cluster system and parallel FDTD programs written with respect to the architecture of a PC cluster system. Finally, we discuss the numerical calculation of two-dimensional and three-dimensional phononic crystals consisting of steel/epoxy and draw conclusions regarding the band gap phenomena between these phononic crystals.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1109/tuffc.2006.1588400 | DOI Listing |
ACS Omega
January 2025
Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
Zintl compounds have garnered research interest due to their diverse technological applications. Utilizing first-principles calculations, we performed a systematic study of ABX (A = Li, Na, K, Rb, or Cs; B = Si, Ge, Sn, or Pb; and X = P, As, Sb, or Bi) Zintl materials with the 6 KSnSb-type structure. Notably, six ABX Zintl compounds (RbSiBi, CsSiBi, LiGeBi, KGeBi, RbGeBi, and CsGeBi) were found to have topologically nontrivial phases, as demonstrated by the invariant computed using the hybrid functional HSE06.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin 150001, China. Electronic address:
The demand for lightweight heat dissipation design in highly miniaturized and portable electronic devices with high thermal density is becoming increasingly urgent. Herein, highly thermal conductive carbon nanotubes (CNTs) reinforced aluminum foam composites were prepared by catalyst chemical bath and subsequent in-situ growth approach. The dense CNTs show the intertwined structure features and construct high-speed channels near the surface of the skeletons for efficient thermal conduction, promoting the transport efficiency of heat flow.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
The development of molecular switches with tunable properties has garnered considerable interest over several decades. A novel spin-crossover (SCO) material based on iron(II) complexes incorporating 4-acetylpyridine (4-acpy) and [Hg(SCN)] anions was synthesized and formulated as [Fe(4-acpy)][Hg(μ-SCN)] (1). Compound 1 is crystallized in a three-dimensional network in the non-centrosymmetric orthorhombic space group Pna2 with two octahedral [Fe(4-acpy)(NCS)] entities featuring two distinct Fe centers (Fe1 and Fe2).
View Article and Find Full Text PDFNat Commun
November 2024
State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, China.
Group-III nitride semiconductors such as GaN have various important applications based on their three-dimensional form. Previous work has demonstrated the realization of buckled two-dimensional GaN, which can be used in GaN-based nanodevices. However, the understanding of buckled two-dimensional GaN remains limited due to the difficulties in experimental characterization.
View Article and Find Full Text PDFNano Lett
December 2024
Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!