منابع مشابه
Quasicrystals
The discretely diffracting aperiodic crystals termed quasicrystals, discovered at NBS in the early 1980s, have led to much interdisciplinary activity involving mainly materials science, physics, mathematics, and crystallography. It led to a new understanding of how atoms can arrange themselves, the role of periodicity in nature, and has created a new branch of crystallography.
متن کاملRhombellanic Crystals and Quasicrystals
Design of some crystal and quasicrystal networks, based on rhombellane tiling,is presented. [1,1,1]Propellane,is a synthesized organic molecule; its hydrogenated form, the bicyclo[1.1.1]pentane,may be represented by the complete bipartite graph K2,3 which is the smallest rhombellane. Topology of translational and radial structures involving rhombellanes is described in terms of vertex symbol, c...
متن کاملQuasicrystals pdf
In contrast to periodic crystals, quasicrystals exhibit a long range order in spite. The diffraction pattern of quasicrystals shows a dense set of Bragg peaks with.It is argued that the prevailing definition of quasicrystals, requiring them to. Restrict the definition of quasicrystals by requiring that they possess an axis.Abstract. It is argued that the definition of quasicrystals should not i...
متن کاملNatural quasicrystals.
Quasicrystals are solids whose atomic arrangements have symmetries that are forbidden for periodic crystals, including configurations with fivefold symmetry. All examples identified to date have been synthesized in the laboratory under controlled conditions. Here we present evidence of a naturally occurring icosahedral quasicrystal that includes six distinct fivefold symmetry axes. The mineral,...
متن کاملModulated Quasicrystals
There is some confusion in the literature what “modulated quasicrystals” are: Some people treat “modulated quasicrystals” and “deformed model sets” as exchangeable termini (compare [6, 9, 5]), others claim that “[. . .] the projection method becomes powerless against incommensurate modulated structures” (e.g., [12, p. 148]). We use a mathematical approach and propose the following classificatio...
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ژورنال
عنوان ژورنال: Nature
سال: 1989
ISSN: 0028-0836,1476-4687
DOI: 10.1038/340504a0