16,281 research outputs found
A new mechanical structural damage feature index based on HHT
A new damage feature index is presented for the structural health monitoring based on Hilbert-Huang transform (HHT). The energy marginal spectrum of the dynamic signal is used to construct damage characteristic parameter, which can reflect the signal energy variation and benefit the structural damage detection. A sinusoidal wave with frequency change and a composite plate vibration experiment with pre-defined damage are designed to verify the effectiveness of characteristic parameter in damage detection. Results obtained from simulation and test show that the extracted non-model-based damage feature index is available and sensitive in damage detection of time-varying system.Peer Reviewe
LFV couplings of the extra gauge boson Z' and leptonic decay and production of pseudoscalar mesons
Considering the constraints of the lepton flavor violating (LFV) processes
and on the LFV couplings
, in the contexts of the models, the left-right
(LR) models, the "alternative" left-right (ALR) models and the 331 models, we
investigate the contributions of the extra gauge boson to the decay rates
of the processes ,
and with and
. Our numerical results show that the maximal values of the branching
ratios for these processes are not dependent on the mass at
leader order. The extra gauge boson predicted by the models
can make the maximum value of the branching ratio
reach . All
models considered in this paper can produce significant contributions to the
process . However, the value of
is far below its corresponding experimental upper bound.Comment: 14 pages, 2 figures; matches published versio
Chiral phase transition and meson spectrum in improved soft-wall AdS/QCD
We investigate in detail the chiral thermal transition of QCD in an improved
soft-wall AdS/QCD model with a simply modified 5D conformal mass of the bulk
scalar field. We also present a calculation in this model for the light meson
spectra and other low-energy characteristic quantities including the pion form
factor, the pi-rho coupling constant and the decay constants of pi, rho, a_1,
which are shown to result in a good agreement with experimental data except for
the pion decay constant. The thermal behavior of chiral condensate is studied.
It is found that such a simply improved soft-wall model incorporates the
crossover behavior of chiral thermal transition indicated by lattice
simulations. The expected chiral transition temperature can be obtained
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