منابع مشابه
Spiral crystal growth
We numerically study the spiral mode of crystal growth using a theory developed by Burton, Cabrera and Frank using a level set method. This method is novel in that it can handle not only closed curves but open curves as well. We use our method to compute interacting spirals and make estimates of growth rates. We also propose a possible coarsening mechanism for a large number of interacting spir...
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Geometrical design of the spiral crystal selector can affect crystal orientation in the final single crystal structure. To achieve a better understanding of conditions associated with the onset of crystal orientation in a spiral crystal selector, temperature field was investigated using three-dimensional finite element method during the process. Different geometries of spiral crystal selec...
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Spiral surface growth is well understood in the limit where the step motion is controlled by the local supersaturation of adatoms near the spiral ridge. In epitaxial thin-film growth, however, spirals can form in a step-flow regime where desorption of adatoms is negligible and the ridge dynamics is governed by the non-local diffusion field of adatoms on the whole surface. We investigate this li...
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Asymmetric cell shape depends on the ability of oriented layers of cellulose microfibrils to channel the nondirectional drive of turgor pressure. Tough microfibrils encircling the cell resist increases in girth and redirect the swelling force to a direction perpendicular to the alignment of the microfibrils. This transformation of an isotropic force into directional growth is crucial for settin...
متن کاملSpiral growth and step edge barriers.
The growth of spiral mounds containing a screw dislocation is compared to the growth of wedding cakes by two-dimensional nucleation. Using phase field simulations and homoepitaxial growth experiments on the Pt(111) surface we show that both structures attain the same large scale shape when a significant step-edge barrier suppresses interlayer transport. The higher vertical growth rate of the sp...
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ژورنال
عنوان ژورنال: The Lancet
سال: 1898
ISSN: 0140-6736
DOI: 10.1016/s0140-6736(01)94263-1