285 research outputs found
Nanotube Connections in Bilayer Graphene with Elongated Holes
Structures, stability and electronic properties of AA-stacking bigraphene with holes are studied using molecular mechanic and DFT method calculations. It has been shown the zig-zag edges of considered elon-gated holes lead to armchair sp2-nanotube-type connection between these two edges forming all sp2-structure. We consider similar periodic structures with (n,n) nanotubes formed among elongated holes and connected with bigraphene fragments, which edges are also closed edges. The stability and electronic prop-erties of these structures are investigated. Band structures of considered materials have energy gaps 0.20-0.27 eV in the direction of tube axes through jumpers on the connections, and Dirac-like point views in the opposite direction.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3546
Anomalous absorption of bulk shear sagittal acoustic waves in a layered structure with viscous fluid
It is demonstrated theoretically that the absorptivity of bulk shear sagittal
waves by an ultra-thin layer of viscous fluid between two different elastic
media has a strong maximum (in some cases as good as 100%) at an optimal layer
thickness. This thickness is usually much smaller than the penetration depths
and lengths of transverse and longitudinal waves in the fluid. The angular
dependencies of the absorptivity are demonstrated to have significant and
unusual structure near critical angles of incidence. The effect of
non-Newtonian properties and non-uniformities of the fluid layer on the
absorptivity is also investigated. In particular, it is shown that the
absorption in a thin layer of viscous fluid is much more sensitive to non-zero
relaxation time(s) in the fluid layer than the absorption at an isolated
solid-fluid interface.Comment: 14 pages, 8 figure
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