103,541 research outputs found
Enhancement of singly and multiply strangeness in p-Pb and Pb-Pb collisions at 158A GeV/c
The idea that the reduction of the strange quark suppression in string
fragmentation leads to the enhancement of strange particle yield in
nucleus-nucleus collisions is applied to study the singly and multiply strange
particle production in p-Pb and Pb-Pb collisions at 158A GeV/c. In this
mechanism the strange quark suppression factor is related to the effective
string tension, which increases in turn with the increase of the energy, of the
centrality and of the mass of colliding system. The WA97 observation that the
strange particle enhancement increases with the increasing of centrality and of
strange quark content in multiply strange particles in Pb-Pb collisions with
respect to p-Pb collisions was accounted reasonably.Comment: 8 pages, 3 PostScript figures, in Latex form. submitted to PR
The Effects of Air and Underwater Blast on Composite Sandwich Panels and Tubular Laminate Structures
The resistance of glass-fibre reinforced polymer (GFRP) sandwich panels and laminate tubes to blast in air and underwater environments has been studied. Procedures for monitoring the structural response of such materials during blast events have been devised. High-speed photography was employed during the air-blast loading of GFRP sandwich panels, in conjunction with digital image correlation (DIC), to monitor the deformation of these structures under shock loading. Failure mechanisms have been revealed by using DIC and confirmed in post-test sectioning. Strain gauges were used to monitor the structural response of similar sandwich materials and GFRP tubular laminates during underwater shocks. The effect of the backing medium (air or water) of the target facing the shock has been identified during these studies. Mechanisms of failure have been established such as core crushing, skin/core cracking, delamination and fibre breakage. Strain gauge data supported the mechanisms for such damage. These studies were part of a research programme sponsored by the Office of Naval Research (ONR) investigating blast loading of composite naval structures. The full-scale experimental results presented here will aid and assist in the development of analytical and computational models. Furthermore, it highlights the importance of support and boundary conditions with regards to blast resistant design
Hybrid solid state qubits: the powerful role of electron spins
We review progress on the use of electron spins to store and process quantum
information, with particular focus on the ability of the electron spin to
interact with multiple quantum degrees of freedom. We examine the benefits of
hybrid quantum bits (qubits) in the solid state that are based on coupling
electron spins to nuclear spin, electron charge, optical photons, and
superconducting qubits. These benefits include the coherent storage of qubits
for times exceeding seconds, fast qubit manipulation, single qubit measurement,
and scalable methods for entangling spatially separated matter-based qubits. In
this way, the key strengths of different physical qubit implementations are
brought together, laying the foundation for practical solid-state quantum
technologies.Comment: 54 pages, 7 figure
Splicing-dependent NMD does not require the EJC in Schizosaccharomyces pombe
Nonsense-mediated mRNA decay (NMD) is a translation-linked process that destroys mRNAs with premature translation termination codons (PTCs). In mammalian cells, NMD is also linked to pre-mRNA splicing, usually PTCs trigger strong NMD only when positioned upstream of at least one intron. The exon junction complex (EJC) is believed to mediate the link between splicing and NMD in these systems. Here, we report that in Schizosaccharomyces pombe splicing also enhances NMD, but against the EJC model prediction, an intron stimulated NMD regardless of whether it is positioned upstream or downstream of the PTC and EJC components are not required. Still the effect of splicing seems to be direct—we have found that the important NMD determinant is the proximity of an intron to the PTC, not just the occurrence of splicing. On the basis of these results, we propose a new model to explain how splicing could affect NMD
Entanglement and quantum phase transition in the extended Hubbard model
We study quantum entanglement in one-dimensional correlated fermionic system.
Our results show, for the first time, that entanglement can be used to identify
quantum phase transitions in fermionic systems.Comment: 5 pages, 4 figure
Block-block entanglement and quantum phase transitions in one-dimensional extended Hubbard model
In this paper, we study block-block entanglement in the ground state of
one-dimensional extended Hubbard model. Our results show that the phase diagram
derived from the block-block entanglement manifests richer structure than that
of the local (single site) entanglement because it comprises nonlocal
correlation. Besides phases characterized by the charge-density-wave, the
spin-density-wave, and phase-separation, which can be sketched out by the local
entanglement, singlet superconductivity phase could be identified on the
contour map of the block-block entanglement. Scaling analysis shows that behavior of the block-block entanglement may exist in both
non-critical and the critical regions, while some local extremum are induced by
the finite-size effect. We also study the block-block entanglement defined in
the momentum space and discuss its relation to the phase transition from
singlet superconducting state to the charge-density-wave state.Comment: 8 pages, 9 figure
Sistema agrossilvipastoril para convivência com o semi-arido sergipano.
Publicado também na Revista Brasileira de Agroecologia, v. 4, n. 2, 2009
Gliricídia: formas de plantio e cultivo.
bitstream/item/68652/1/folder-plantio-gliricidia.pd
Implantação e manejo de legumineira com gliricídia (Gliricidia sepium).
bitstream/item/43070/1/ct-63.pd
- …