2,327 research outputs found
Dynamical approach to heavy-ion induced fission using actinide target nuclei at energies around the Coulomb barrier
In order to describe heavy-ion fusion reactions around the Coulomb barrier
with an actinide target nucleus, we propose a model which combines the
coupled-channels approach and a fluctuation-dissipation model for dynamical
calculations. This model takes into account couplings to the collective states
of the interacting nuclei in the penetration of the Coulomb barrier and the
subsequent dynamical evolution of a nuclear shape from the contact
configuration. In the fluctuation-dissipation model with a Langevin equation,
the effect of nuclear orientation at the initial impact on the prolately
deformed target nucleus is considered. Fusion-fission, quasi-fission and deep
quasi-fission are separated as different Langevin trajectories on the potential
energy surface. Using this model, we analyze the experimental data for the mass
distribution of fission fragments (MDFF) in the reactions of
S+U and Si+U at several incident energies
around the Coulomb barrier. We find that the time scale in the quasi-fission as
well as the deformation of fission fragments at the scission point are
different between the Si+U and S+U systems,
causing different mass asymmetries of the quasi-fission.Comment: 11 figure
Effects of the Zero-Mode Landau Level on Inter-Layer Magnetoresistance in Multilayer Massless Dirac Fermion Systems
We report on the experimental results of interlayer magnetoresistance in
multilayer massless Dirac fermion system -(BEDT-TTF)I under
hydrostatic pressure and its interpretation. We succeeded in detecting the
zero-mode Landau level (n=0 Landau level) that is epected to appear at the
contact points of Dirac cones in the magnetic field normal to the
two-dimensional plane. The characteristic feature of zero-mode Landau carriers
including the Zeeman effect is clearly seen in the interlayer
magnetoresistance.Comment: 2 pages, 2 figure
Real-time simulation of jet engines with digital computer. 1: Fabrication and characteristics of the simulator
The fabrication and performance of a real time jet engine simulator using a digital computer are discussed. The use of the simulator in developing the components and control system of a jet engine is described. Comparison of data from jet engine simulation tests with actual engine tests was conducted with good agreement
Thermally Assisted Penetration and Exclusion of Single Vortex in Mesoscopic Superconductors
A single vortex overcoming the surface barrier in a mesoscopic superconductor
with lateral dimensions of several coherence lengths and thickness of several
nanometers provides an ideal platform to study thermal activation of a single
vortex. In the presence of thermal fluctuations, there is non-zero probability
for vortex penetration into or exclusion from the superconductor even when the
surface barrier does not vanish. We consider the thermal activation of a single
vortex in a mesoscopic superconducting disk of circular shape. To obtain
statistics for the penetration and exclusion magnetic fields, slow and periodic
magnetic fields are applied to the superconductor. We calculate the
distribution of the penetration and exclusion fields from the thermal
activation rate. This distribution can also be measured experimentally, which
allows for a quantitative comparison.Comment: 7 pages, 4 figure
Electric-field-induced lifting of the valley degeneracy in alpha-(BEDT-TTF)_2I_3 Dirac-like Landau levels
The relativistic Landau levels in the layered organic material
alpha-(BEDT-TTF)_2I_3 [BEDT-TTF=bis(ethylenedithio)tetrathiafulvalene] are
sensitive to the tilt of the Dirac cones, which, as in the case of graphene,
determine the low-energy electronic properties under appropriate pressure. We
show that an applied inplane electric field, which happens to be in competition
with the tilt of the cones, lifts the twofold valley degeneracy due to a
different level spacing. The scenario may be tested in infrared transmission
spectroscopy.Comment: 4 pages, 1 figure; version with minor corrections published in EP
A method for generating developments using decomposition into the meaningful components of 3D polygon models
We propose a method for generating developments from 3D polygon models automatically. The conventional
method generates the developments whose components are not interfering each together, by using collision
detection between all polygons. However, for the model which consists of a large number of polygons, it is
necessary to decompose the development into several parts manually. Therefore it is difficult to generate the
development which is easy to be assembled. Our method decomposes the polygon model into meaningful
components such as arms, legs, and so on, and develops them. This makes it easy to understand which parts
should be glued together, and handcraft bending or folding the developments when a user assembles the paper
craft
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