717 research outputs found
-Electron Ferromagnetism in Metal Free Carbon Probed by Soft X-Ray Dichroism
Elemental carbon represents a fundamental building block of matter and the
possibility of ferromagnetic order in carbon attracted widespread attention.
However, the origin of magnetic order in such a light element is only poorly
understood and has puzzled researchers. We present a spectromicroscopy study at
room temperature of proton irradiated metal free carbon using the elemental and
chemical specificity of x-ray magnetic circular dichroism (XMCD). We
demonstrate that the magnetic order in the investigated system originates only
from the carbon -electron system.Comment: 10 pages 3 color figure
Phosphorus donors in highly strained silicon
The hyperfine interaction of phosphorus donors in fully strained Si thin
films grown on virtual SiGe substrates with is
determined via electrically detected magnetic resonance. For highly strained
epilayers, hyperfine interactions as low as 0.8 mT are observed, significantly
below the limit predicted by valley repopulation. Within a Green's function
approach, density functional theory (DFT) shows that the additional reduction
is caused by the volume increase of the unit cell and a local relaxation of the
Si ligands of the P donor.Comment: 12 pages, 3 figure
Serum S100B is increased during early treatment with antipsychotics and in deficit schizophrenia
Previous studies reported controversial results concerning alterations of astrocytes in schizophrenia. Because S100B may be regarded as a marker for astrocytes, the objective of this study was to examine S100B serum concentrations in 30 patients with schizophrenia with a monoclonal two-site immunoluminometric assay that specifically detects S100B. An ANOVA revealed medication (p0.05). Patients with deficit (250.6±154.9 ng/l) had higher S100B levels than patients with nondeficit schizophrenia (146.7±107.2 ng/l, p<0.05) or controls (p<0.005). S100B was positively correlated with the subscore ‘thought disturbance’ of the Brief Psychiatric Rating Scale (p<0.05). In summary, increased serum levels of S100B may indicate alterations of astrocytes during early treatment with antipsychotics and in deficit schizophrenia. Whether S100B is elevated due to injured astrocytes and a disrupted blood–brain barrier, or by active secretion of S100B by astrocytes, has to be clarified by further studies
Strange Particle Production at RHIC
We report STAR measurements of mid-rapidity yields for the ,
, , , , , and
particles in Cu+Cu and Au+Au GeV
collisions. We show that at a given number of participating nucleons, bulk
strangeness production is higher in Cu+Cu collisions compared to Au+Au
collisions at the same center of mass energy, counter to predictions from the
Canonical formalism. We compare both the Cu+Cu and Au+Au yields to AMPT and
EPOS predictions, and find they reproduce key qualitative aspects of the data.
Finally, we investigate other scaling parameters and find bulk strangeness
production for both the measured data and theoretical predictions, scales
better with the number participants that undergo more than one collision.Comment: Conference proceedings for Hot Quarks 2008, 5 pages and 4 figure
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