99,923 research outputs found
Correction of the definition of mass-flow parameter in dynamic inflow modelling
No abstract available
Averages of shifted convolutions of
We investigate the first and second moments of shifted convolutions of the
generalised divisor function .Comment: 22 page
Iterative Solutions for Low Lying Excited States of a Class of Schroedinger Equation
The convergent iterative procedure for solving the groundstate Schroedinger
equation is extended to derive the excitation energy and the wave function of
the low-lying excited states. The method is applied to the one-dimensional
quartic potential problem. The results show that the iterative solution
converges rapidly when the coupling is not too small.Comment: 14 pages, 4 figure
Microscopic study of induced fission dynamics of Th with covariant energy density functionals
Static and dynamic aspects of the fission process of Th are analyzed
in a self-consistent framework based on relativistic energy density
functionals. Constrained relativistic mean-field (RMF) calculations in the
collective space of axially symmetric quadrupole and octupole deformations,
based on the energy density functional PC-PK1 and a -force pairing, are
performed to determine the potential energy surface of the fissioning nucleus,
the scission line, the single-nucleon wave functions, energies and occupation
probabilities, as functions of deformation parameters. Induced fission dynamics
is described using the time-dependent generator coordinate method in the
Gaussian overlap approximation. A collective Schr\"odinger equation, determined
entirely by the microscopic single-nucleon degrees of freedom, propagates
adiabatically in time the initial wave packet built by boosting the
ground-state solution of the collective Hamiltonian for Th. The
position of the scission line and the microscopic input for the collective
Hamiltonian are analyzed as functions of the strength of the pairing
interaction. The effect of static pairing correlations on the pre-neutron
emission charge yields and total kinetic energy of fission fragments is
examined in comparison with available data, and the distribution of fission
fragments is analyzed for different values of the initial excitation energy.Comment: 25 pages, 14 figures, accepted for publication in Phys. Rev.
Tracers of chromospheric structure. I. CaII HK emission distribution of 13000 F, G and K stars in SDSS DR7 spectroscopic sample
We present chromospheric activity index measurements for over
13,000 F, G and K disk stars with high signal-to-noise ratio ( 60) spectra
in the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) spectroscopic
sample. A parameter S is defined as the difference between
and a `zero' emission line fitted by several of the most inactive stars. The
indices of subgiant stars tend to be much lower than dwarfs, which
provide a way to distinguish dwarfs and giants with relatively low resolution
spectra. Cooler stars are generally more active and display a larger scatter
than hotter stars. Stars associated with the thick disk are in general less
active than those of the thin disk. The fraction of K dwarfs that are active
drops with vertical distance from the Galactic plane. Metallicity affects
measurements differently among F, G and K dwarfs in this sample.
Using the open clusters NGC 2420, M67 and NGC6791 as calibrations, ages of most
field stars in this SDSS sample range from 3-8 Gyr.Comment: 9 pages, 11 figures, AJ, 2013, 145, 14
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