1,140,530 research outputs found
Nonequilibrium Fock space for the electron transport problem
Based on the formalism of thermo field dynamics we propose a concept of
nonequilibrium Fock space and nonequilibrium quasiparticles for quantum
many-body system in nonequilibrium steady state. We develop a general theory as
well as demonstrate the utility of the approach on the example of electron
transport through the interacting region. The proposed approach is compatible
with advanced methods of electronic structure calculations such as coupled
cluster theory and configuration interaction
Single Z' production at CLIC based on e^- gamma collisions
We analyze the potential of CLIC based on e- gamma collisions to search for
new gauge boson. Single Z' production at e-gamma colliders in two SU(3)_C
X SU(3)_L X U(1)_N models: the minimal model and the model with right-handed
(RH) neutrinos is studied in detail. Results show that new Z' gauge bosons can
be observed at the CLIC, and the cross sections in the model with RH neutrinos
are bigger than those in the minimal one.Comment: 11 pages, 4 figures, To appear in JET
On the Cooling of the Neutron Star in Cassiopeia A
We demonstrate that the high-quality cooling data observed for the young
neutron star in the supernova remnant Cassiopeia A over the past 10 years--as
well as all other reliably known temperature data of neutron stars--can be
comfortably explained within the "nuclear medium cooling" scenario. The cooling
rates of this scenario account for medium-modified one-pion exchange in dense
matter and polarization effects in the pair-breaking formations of superfluid
neutrons and protons. Crucial for the successful description of the observed
data is a substantial reduction of the thermal conductivity, resulting from a
suppression of both the electron and nucleon contributions to it by medium
effects. We also find that possibly in as little as about ten years of
continued observation, the data may tell whether or not fast cooling processes
are active in this neutron star.Comment: 4 pages, 3 figure
Physiological Aspects of Genetics
A considerable amount of evidence indicates that desoxyribonucleic acid is capable of duplicating itself, a property also possessed by genes. (By a self-duplicating material, we mean one which plays some essential role in its own production.) Watson & Crick (1) have proposed a new structure for desoxyribonucleic acid which not only takes into account the existing analytical and x-ray diffraction data but also seems capable of explaining the mechanism of duplication. Their model consists of two helical chains coiled around the same axis, the purine and pyrimidine bases on the inside, the phosphate groups on the outside. The chains are held together by hydrogen bonds between the bases, the adenine residues of either chain being bonded specifically to thymine in the other, and similarly guanine to cytosine. The sequence of bases along one chain is not restricted, but once fixed the sequence along the other chain is determined. This complementarity, which is the most novel feature of the structure, suggests that duplication takes place by separation of the two chains, followed by the synthesis of its complement alongside each chain. The model is supported by recent x-ray diffraction studies (2, 3)
Nonlocality effects on Color Spin Locking condensates
We consider the color spin locking (CSL) phase of two-flavor quark matter at
zero temperature for nonlocal instantaneous, separable interactions. We employ
a Lorentzian-type form factor allowing a parametric interpolation between the
sharp (Nambu-Jona-Lasinio (NJL) model) and very smooth (e.g. Gaussian) cut-off
models for systematic studies of the influence on the CSL condensate the
deviation from the NJL model entails. This smoothing of the NJL model form
factor shows advantageous features for the phenomenology of compact stars: (i)
a lowering of the critical chemical potential for the onset of the chiral phase
transition as a prerequisite for stability of hybrid stars with extended quark
matter cores and (ii) a reduction of the smallest pairing gap to the order of
100 keV, being in the range of values interesting for phenomenological studies
of hybrid star cooling evolution.Comment: 8 pages, 8 figures, 1 table, accepted for publication in Phys.Rev.
Silver-base ternary alloy proves superior for slip ring lead wires
Slip ring lead wires composed of ternary alloys of silver, have high electrical conductivity, a tensile strength of at least 30,000 psi, high ductility, and are solderable and weldable. An unexpected advantage of these alloys is their resistance to discoloration on heating in air
Visual focus stimulator aids in study of the eye's focusing action
Optical apparatus varies apparent distance of a target image from the eye by means of reflectors that are moved orthogonally to the optical axis between fixed lenses. Apparatus can be pointed at any object, test pattern, or other visual display
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