10,925 research outputs found
Study of the earth's magnetic field with the aid of radiation belts
Electron belt detected during flights of Elektron-1 and Elektron-
Hyperbolic chaos in self-oscillating systems based on mechanical triple linkage: Testing absence of tangencies of stable and unstable manifolds for phase trajectories
Dynamical equations are formulated and a numerical study is provided for
self-oscillatory model systems based on the triple linkage hinge mechanism of
Thurston -- Weeks -- Hunt -- MacKay. We consider systems with holonomic
mechanical constraint of three rotators as well as systems, where three
rotators interact by potential forces. We present and discuss some quantitative
characteristics of the chaotic regimes (Lyapunov exponents, power spectrum).
Chaotic dynamics of the models we consider are associated with hyperbolic
attractors, at least, at relatively small supercriticality of the
self-oscillating modes; that follows from numerical analysis of the
distribution for angles of intersection of stable and unstable manifolds of
phase trajectories on the attractors. In systems based on rotators with
interacting potential the hyperbolicity is violated starting from a certain
level of excitation.Comment: 30 pages, 18 figure
photoproduction on the quasi-free nucleons in the chiral quark model
A chiral quark-model approach is adopted to study the photoproduction
off the quasi-free neutron and proton from a deuteron target. Good descriptions
of the differential cross sections, total cross sections and beam asymmetries
for these two processes are obtained in the low energy region. For , the dominant resonances are ,
, , and . While for
the process, the dominant resonances are
, , , and
. Furthermore, the channel backgrounds have significant
contributions to the photoproduction processes. The configuration
mixings in the and can be extracted,
i.e. and . It shows that the
narrow bump-like structure around GeV observed in can be naturally explained by the constructive
interferences between and . In contrast, the
destructive interference between and produces the
shallow dip around GeV in . The wave
interfering behaviors in the proton and neutron reactions are correlated with
each other in the quark model framework, and no new exotic nucleon resonances
are needed in these two reactions.Comment: 12 pages, 11 figures, helicity amplitudes are added, to be published
in PR
Generalized dimensions of Feigenbaum's attractor from renormalization-group functional equations
A method is suggested for the computation of the generalized dimensions of
fractal attractors at the period-doubling transition to chaos. The approach is
based on an eigenvalue problem formulated in terms of functional equations,
with a coefficient expressed in terms of Feigenbaum's universal fixed-point
function. The accuracy of the results is determined only by precision of the
representation of the universal function.Comment: 6 pages, 2 table
Brushless asynchronous induction machines with leading VAR capability
Imperial Users onl
- …