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Kleckner D Marshall W de Dood MJ Dinyari KN Pors BJ Irvine WT Bouwmeester D 《Physical review letters》2006,96(17):173901
We report on the demonstration of a high finesse micro-optomechanical system and identify potential applications ranging from optical cooling to weak force detection to massive quantum superpositions. The system consists of a high quality diameter flat dielectric mirror cut from a larger substrate with a focused ion beam and attached to an atomic force microscope cantilever. Cavity ring-down measurements performed on a 25 mm long Fabry-Pérot cavity with the 30 microm mirror at one end show an optical finesse of 2100. Numerical calculations show that the finesse is not diffraction limited and that orders of magnitude higher finesse should be possible. A mechanical quality factor of more than 10(5) at pressures below 10(-3) mbar is demonstrated for the cantilever with a mirror attached. 相似文献
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Given a regular –-hermitian form on an n-dimensional vector space V over a commutative field K of characteristic 2 (
). Call an element of the unitary group a quasi-involution if is a product of commuting quasi-symmetries (a quasi-symmetry is a unitary transformation with a regular (n–1)-dimensional fixed space). In the special case of an orthogonal group every quasi-involution is an involution. Result: every unitary element is a product of five quasi-involutions. If K is algebraically closed then three quasi-involutions suffice. 相似文献
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Joanne H Gibson Barry Slobedman Harikrishnan KN Sarah L Williamson Dimitri Minchenko Assam El-Osta Joshua L Stern John Christodoulou 《BMC neuroscience》2010,11(1):53
Background
The Rett Syndrome (RTT) brain displays regional histopathology and volumetric reduction, with frontal cortex showing such abnormalities, whereas the occipital cortex is relatively less affected. 相似文献
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