9,562 research outputs found
Extended Optical Model Analyses of Elastic Scattering and Fusion Cross Section Data for the C+Pb System at Near-Coulomb-Barrier Energies by using a Folding Potential
Simultaneous analyses are performed for elastic scattering and
fusion cross section data for the C+Pb system at
near-Coulomb-barrier energies by using the extended optical model approach in
which the polarization potential is decomposed into direct reaction (DR) and
fusion parts. Use is made of the double folding potential as a bare potential.
It is found that the experimental elastic scattering and fusion data are well
reproduced without introducing any normalization factor for the double folding
potential and also that both DR and fusion parts of the polarization potential
determined from the analyses satisfy separately the dispersion
relation. Furthermore, it is shown that the imaginary parts of both DR and
fusion potentials at the strong absorption radius change very rapidly, which
results in a typical threshold anomaly in the total imaginary potential as
observed with tightly bound projectiles such as -particle and O.Comment: 26 pages, 7 figures, submitted to Physical Review
Extended Optical Model Analyses of Elastic Scattering and Fusion Cross Section Data for the 7Li+208Pb System at Near-Coulomb-Barrier Energies using the Folding Potential
Simultaneous analyses previously made for elastic scattering and
fusion cross section data for the Li+Pb system is extended to the
Li+Pb system at near-Coulomb-barrier energies based on the
extended optical model approach, in which the polarization potential is
decomposed into direct reaction (DR) and fusion parts. Use is made of the
double folding potential as a bare potential. It is found that the experimental
elastic scattering and fusion data are well reproduced without introducing any
normalization factor for the double folding potential and that both the DR and
fusion parts of the polarization potential determined from the
analyses satisfy separately the dispersion relation. Further, we find that the
real part of the fusion portion of the polarization potential is attractive
while that of the DR part is repulsive except at energies far below the Coulomb
barrier energy. A comparison is made of the present results with those obtained
from the Continuum Discretized Coupled Channel (CDCC) calculations and a
previous study based on the conventional optical model with a double folding
potential. We also compare the present results for the Li+Pb system
with the analysis previously made for the Li+Pb system.Comment: 7 figures, submitted to PR
Synchronization in networks of networks: the onset of coherent collective behavior in systems of interacting populations of heterogeneous oscillators
The onset of synchronization in networks of networks is investigated.
Specifically, we consider networks of interacting phase oscillators in which
the set of oscillators is composed of several distinct populations. The
oscillators in a given population are heterogeneous in that their natural
frequencies are drawn from a given distribution, and each population has its
own such distribution. The coupling among the oscillators is global, however,
we permit the coupling strengths between the members of different populations
to be separately specified. We determine the critical condition for the onset
of coherent collective behavior, and develop the illustrative case in which the
oscillator frequencies are drawn from a set of (possibly different)
Cauchy-Lorentz distributions. One motivation is drawn from neurobiology, in
which the collective dynamics of several interacting populations of oscillators
(such as excitatory and inhibitory neurons and glia) are of interest.Comment: The original was replaced with a version that has been accepted to
Phys. Rev. E. The new version has the same content, but the title, abstract,
and the introductory text have been revise
Extended Optical Model Analyses of Elastic Scattering and Fusion Cross Sections for 6Li + 208Pb System at Near-Coulomb-Barrier Energies by using Folding Potential
Based on the extended optical model approach in which the polarization
potential is decomposed into direct reaction (DR) and fusion parts,
simultaneous analyses are performed for elastic scattering and
fusion cross section data for the Li+Pb system at
near-Coulomb-barrier energies. A folding potential is used as the bare
potential. It is found that the real part of the resultant DR part of the
polarization potential is repulsive, which is consistent with the results from
the Continuum Discretized Coupled Channel (CDCC) calculations and the
normalization factors needed for the folding potentials. Further, it is found
that both DR and fusion parts of the polarization potential satisfy separately
the dispersion relation.Comment: 6 figure
Extended Optical Model Analyses of Elastic Scattering, Direct Reaction, and Fusion Cross Sections for the 9Be + 208Pb System at Near-Coulomb-Barrier Energies
Based on the extended optical model approach in which the polarization
potential is decomposed into direct reaction (DR) and fusion parts,
simultaneous analyses are performed for elastic scattering, DR, and
fusion cross section data for the Be+Pb system at
near-Coulomb-barrier energies. Similar analyses are also performed
by only taking into account the elastic scattering and fusion data as was
previously done by the present authors, and the results are compared with those
of the full analysis including the DR cross section data as well. We find that
the analyses using only elastic scattering and fusion data can produce very
consistent and reliable predictions of cross sections particularly when the DR
cross section data are not complete. Discussions are also given on the results
obtained from similar analyses made earlier for the Be+Bi system.Comment: 5 figure
Parallel super-resolution imaging
Massive parallelization of scanning-based super-resolution imaging allows fast imaging of large fields of view
Exact Results for the Kuramoto Model with a Bimodal Frequency Distribution
We analyze a large system of globally coupled phase oscillators whose natural
frequencies are bimodally distributed. The dynamics of this system has been the
subject of long-standing interest. In 1984 Kuramoto proposed several
conjectures about its behavior; ten years later, Crawford obtained the first
analytical results by means of a local center manifold calculation.
Nevertheless, many questions have remained open, especially about the
possibility of global bifurcations. Here we derive the system's complete
stability diagram for the special case where the bimodal distribution consists
of two equally weighted Lorentzians. Using an ansatz recently discovered by Ott
and Antonsen, we show that in this case the infinite-dimensional problem
reduces exactly to a flow in four dimensions. Depending on the parameters and
initial conditions, the long-term dynamics evolves to one of three states:
incoherence, where all the oscillators are desynchronized; partial synchrony,
where a macroscopic group of phase-locked oscillators coexists with a sea of
desynchronized ones; and a standing wave state, where two counter-rotating
groups of phase-locked oscillators emerge. Analytical results are presented for
the bifurcation boundaries between these states. Similar results are also
obtained for the case in which the bimodal distribution is given by the sum of
two Gaussians.Comment: 28 pages, 7 figures; submitted to Phys. Rev. E Added comment
Hidden light carbon in the Earth\u27s core?: Evidence from high pressure high temperature experiments in the Fe-C system.
第2回極域科学シンポジウム/第34回南極隕石シンポジウム 11月18日(金) 国立国語研究所 2階講
Dose-dependent and combined effects of N-methyl-D-aspartate receptor antagonist MK-801 and nitric oxide synthase inhibitor nitro-L-arginine on the survival of retinal ganglion cells in adult hamsters
This study investigated the effects of daily intraperitoneal injections of N-methyl-D-aspartate receptor antagonist MK-801 and nitric oxide synthase inhibitor nitro-L-arginine (L-NA) on the survival of retinal ganglion cells (RGCs) at 1 and 2 weeks after unilateral optic nerve transection in adult hamsters. The left optic nerves of all animals were transected intraorbitally 1 mm from the optic disc and RGCs were retrogradely labeled with Fluorogold before they received different daily dosages of single MK-801 or L-NA as well as daily combinational treatments of these two chemicals. All experimental and control animals survived for 1 or 2 weeks after optic nerve transection. Our results revealed that the mean numbers of surviving RGCs increased and then decreased when the dosage of MK-801 (1.0, 3.0 and 4.5 mg/kg) and L-NA (1.5, 3.0, 4.5 and 6.0 mg/kg) increased at both 1 and 2 weeks survival time points. Daily combinational use of 1.0 mg/kg MK-801 and 1.5 mg/kg L-NA lead to a highest RGC number that was even higher than the sum of the RGC numbers in 1.0 mg/kg MK-801 and 1.5 mg/kg L-NA subgroups at 2 weeks. These findings indicated that both MK-801 and L-NA can protect axotomized RGCs in a dose-dependent manner and combinational treatment of these chemicals possesses a potentiative and protective effect.published_or_final_versio
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