21,546 research outputs found
Late Archean greenstone tectonics: Evidence for thermal and thrust-loading lithospheric subsidence from stratigraphic sections in the Slave Province, Canada
How late Archean tectonics could be seen to have operated in the Slave Province is illustrated. Lithospheric thinning and stretching, with the formation of rifted margins (to continental or island arc fragments), and lithospheric flexural loading of the kind familiar in arcs and mountain belts could be discerned
A -adic RanSaC algorithm for stereo vision using Hensel lifting
A -adic variation of the Ran(dom) Sa(mple) C(onsensus) method for solving
the relative pose problem in stereo vision is developped. From two 2-adically
encoded images a random sample of five pairs of corresponding points is taken,
and the equations for the essential matrix are solved by lifting solutions
modulo 2 to the 2-adic integers. A recently devised -adic hierarchical
classification algorithm imitating the known LBG quantisation method classifies
the solutions for all the samples after having determined the number of
clusters using the known intra-inter validity of clusterings. In the successful
case, a cluster ranking will determine the cluster containing a 2-adic
approximation to the "true" solution of the problem.Comment: 15 pages; typos removed, abstract changed, computation error remove
Out With the Old, In With the New: Are Western Commodity Producers Ready for Buyouts?
Agricultural and Food Policy,
Odd Parity and Line Nodes in Non-Symmorphic Superconductors
Group theory arguments have been invoked to argue that odd parity order
parameters cannot have line nodes in the presence of spin-orbit coupling. In
this paper we show that these arguments do not hold for certain non-symmorphic
superconductors. Specifically, we demonstrate that when the underlying crystal
has a twofold screw axis, half of the odd parity representations vanish on the
Brillouin zone face perpendicular to this axis. Many unconventional
superconductors have non-symmorphic space groups, and we discuss implications
for several materials, including UPt3, UBe13, Li2Pt3B and Na4Ir3O8.Comment: 4 page
First and Second Sound Modes of a Bose-Einstein Condensate in a Harmonic Trap
We have calculated the first and second sound modes of a dilute interacting
Bose gas in a spherical trap for temperatures () and for
systems with to particles. The second sound modes (which exist
only below ) generally have a stronger temperature dependence than the
first sound modes. The puzzling temperature variations of the sound modes near
recently observed at JILA in systems with particles match
surprisingly well with those of the first and second sound modes of much larger
systems.Comment: a shorten version, more discussions are given on the nature of the
second sound. A long footnote on the recent work of Zaremba, Griffin, and
Nikuni (cond-mat/9705134) is added, the spectrum of the (\ell=1, n_2=0) mode
is included in fig.
Spin domain formation in spinor Bose-Einstein condensation
The spatial structure of the spinor Bose-Einstein condensates with the spin
degrees of freedom is analyzed based on the generalized Gross-Pitaevskii
equation (GP) in the light of the present spin domain experiment on m_F=\pm 1,
and 0 of the hyperfine state F=1 of ^{23}Na atom gases. The GP solutions in
three- and one-spatial dimensional cases reproduce the observed spin domain
structures, revealing the length scale associated with the existence of the
weak interaction of the spin-spin channel, other than the ordinary coherence
length related to the density-density channel. The obtained domain structure in
GP is compared with the result in Thomas-Fermi approximation. The former
solution is found to better describe the observed features than the latter.Comment: 9 pages, 14 figure
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