Coherent displacement of atoms during ion irradiation
Article Abstract:
Collective displacements of atoms have been identified in molecular-dynamics simulations of high-energy self-bombardment of copper and nickel. There are three main categories of behaviour of surface events. In the first, the ion penetrates deep into the sample, with the surface having little impact on damage production. In the second, adatoms, near-surface vacancies and nonlinear sputtering arise as hot liquid from the cascade flows or explodes onto the surface. In the third, the cascade creates a liquid-like region that is deep enough below the surface for the surface not to rupture directly. An adatom island arises as planes of atoms slide coherently along one of the slip directions of face-centred cubic metals towards the surface.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1999
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Wrinkles waiting for G0D(sub 0)T
Article Abstract:
A new study by Fisher et al. describes what may be a molecular mechanism that attempts to explain the deterioration of photoaged skin. Their findings show that sun-damaged skin is characterized by reduced dermal collagen and abnormal elastin. This indicates that wrinkles and elastosis are caused by the degradation of the matrix proteins of the dermis as a result of chronic sunlight exposure. The study concludes that the photoageing of the skin can be prevented. Implications for further studies and the development of new research tools are discussed.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
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Multiscale modelling of plastic flow localization in irradiated materials
Article Abstract:
Research is presented concerning the degredation of the mechanical properties which occurs in metals which have been irradiated by energetic particles. The increasing incidence of stress and decreased ductility are discussed.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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