742 research outputs found
The marginally stable Bethe lattice spin glass revisited
Bethe lattice spins glasses are supposed to be marginally stable, i.e. their
equilibrium probability distribution changes discontinuously when we add an
external perturbation. So far the problem of a spin glass on a Bethe lattice
has been studied only using an approximation where marginally stability is not
present, which is wrong in the spin glass phase. Because of some technical
difficulties, attempts at deriving a marginally stable solution have been
confined to some perturbative regimes, high connectivity lattices or
temperature close to the critical temperature. Using the cavity method, we
propose a general non-perturbative approach to the Bethe lattice spin glass
problem using approximations that should be hopeful consistent with marginal
stability.Comment: 23 pages Revised version, hopefully clearer that the first one: six
pages longe
A unified stability property in spin glasses
Gibbs' measures in the Sherrington-Kirkpatrick type models satisfy two
asymptotic stability properties, the Aizenman-Contucci stochastic stability and
the Ghirlanda-Guerra identities, which play a fundamental role in our current
understanding of these models. In this paper we show that one can combine these
two properties very naturally into one unified stability property
Stress-induced thermoelastic martensitic transformations and functional properties in [011]-oriented NiTiHfPd single crystals
The stress-induced martensitic transformation in the [011]-oriented Ni45.3Ti29.7Hf20Pd5 (at. %) single crystals in as-grown, homogenized and aged states were investigated in compression. It is experimentally shown that heat treatments of single crystals result in increase in martensitic transformation temperatures, two-fold decrease in reversible strain and increase in strain-hardening coefficient. As-grown single crystals demonstrate large temperature range of superelasticity (up to 140 K), large reversible strain (up to 4.3%) and large work output in comparison with homogenized and aged crystals
Evolution of the double neutron star merging rate and the cosmological origin of gamma-ray burst sources
Evolution of the coalescence rate of double neutron stars (NS) and neutron
star -- black hole (BH) binaries are computed for model galaxies with different
star formation rates. Assuming gamma-ray bursts (GRB) to originate from NS+NS
or NS+BH merging in distant galaxies, theoretical logN--logS distributions and
tests of gamma-ray bursts (GRB) are calculated for the first time
taking the computed merging rates into account. We use a flat cosmological
model (Omega=1) with different values of the cosmological constant Lambda and
under various assumptions about the star formation history in galaxies. The
calculated source evolution predicts a 5-10 times increase of the source
statistics at count rates 3-10 times lower than the exising BATSE sensitivity
limit. The most important parameter in fitting the 2nd BATSE catalogue is the
initial redshift of star formation, which is found to be z_*=2-5 depending on a
poorly determined average spectral index of GRB.Comment: 13 pages, compressed uuencoded postscript, 6 figures. This paper has
been accepted for publication in the Astrophysical Journal part
Stable Cliff Climbing For Hexapod Robot With Articulated Body
The paper describes kinematic control for hexapod robot with three{segment articulated body. Forward and inverse kinematics for articulated body de- scribed. Static stability studied in case of climbing the so{called cli obstacle. Conditions for static stability during climbing sequence provided
PLATELET FUNCTION TEST FOR THE ASSESSMENT OF THROMBOSIS AND BLEEDING RISK IN CHD PATIENTS TAKING ANTIPLATELET MEDICATIONS
The review concerns on the testing of platelet function in Chd patients receiving antiplatelet medications. the results are shown of the main large-scale studies demonstrating the relationship of the residual platelet activity level with the development of ishemic and hemorrhagic complications. the analysis is done of the causes of insufficient suppressing of platelet function as the response to clopidogrel. the guidelines of major international expert organizations are discussed on problem of sensitivity to aggregants testing and possible modification of antiplatelet treatment
INTEGRAL observations of SS433, a supercritically accreting microquasar with hard spectrum
Observations of SS433 by INTEGRAL carried out in March -- May 2003 are
presented. SS433 is evidently detected on the INTEGRAL images of the
corresponding sky region in the energy bands 25-50 and 50-100 keV. The
precessional variability of the hard X-ray flux is clearly seen. The X-ray
eclipse caused by the binary orbital motion is also detected. A possible origin
of the hard continuum is briefly discussed.Comment: 5 pages, 6 figures. Accepted to A&A INTEGRAL special volum
- …