منابع مشابه
Cosmic-ray Exposure Histories of Gas-rich Brecciated Meteorites
Introduction: Isotopic shifts in 150 Sm/ 149 Sm and 158 Gd/ 157 Gd caused by neutron capture effects are useful indicators to characterize the interaction of cosmic rays with planetary materials in space, because 149 Sm and 157 Gd have very large thermal neutron capture cross sections. A recent neutron capture study of the Sm and Gd isotopes of Pesyanoe also shows significant variations of neut...
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We present a decentralized, behavior-based approach to assembling and maintaining robot formations. Our approach dynamically grows formations from single robots into line segments and ultimately larger and more complex formations. Formation growth occurs by negotiation when robots are in close proximity. The approach has been validated using simulation as well as experiments with physical robot...
متن کاملFeather formations
The individual feathers in the skin of a developing chicken embryo are arranged in a precise array within a series of so-called 'tracts'. The images above show nascent feather buds in the legs of embryos at 8–9 days of incubation. Buds are added sequentially across the forming feather tract, as shown by the range of developmental stages in the image at top left. (In all three upper images, buds...
متن کاملNorthwest Africa 1109 and Camel Donga: Metal-bearing Brecciated Eucrites
Introduction: HED (howardites, eucrites, diogenites) meteorites are the largest group of achondrites. HED meteorites are products of earliest magmatic activity in a large asteroid (4Vesta) 4.56 Ga ago. The textures and bulk compositions suggest that almost all HED meteorites experienced impact events shortly after the formation. Some polymict breccias of HED meteorites (e.g., polymict eucrites,...
متن کاملFlocks and Formations
Given a large number (the “flock”) of moving physical objects, we investigate physically reasonable mechanisms of influencing their orbits in such a way that they move along a prescribed course and in a prescribed and fixed configuration (or “in formation”). Each agent is programmed to see the position and velocity of a certain number of others. This flow of information from one agent to anothe...
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ژورنال
عنوان ژورنال: Geological Magazine
سال: 1867
ISSN: 0016-7568,1469-5081
DOI: 10.1017/s0016756800208790