258,873 research outputs found
-adic exponential sums of polynomials in one variable
The -adic exponential sum of a polynomial in one variable is studied. An
explicit arithmetic polygon in terms of the highest two exponents of the
polynomial is proved to be a lower bound of the Newton polygon of the
-function of the T-adic exponential sum. This bound gives lower bounds for
the Newton polygon of the -function of exponential sums of -power order
Reduced O diffusion through Be doped Pt electrodes
Using first principles electronic structure calculations we screen nine
elements for their potential to retard oxygen diffusion through
poly-crystalline Pt (p-Pt) films. We determine that O diffuses preferentially
as interstitial along Pt grain boundaries (GBs). The calculated barriers are
compatible with experimental estimates. We find that Be controls O diffusion
through p-Pt. Beryllium segregates to Pt GBs at interstitial (i) and
substitutional (s) sites. i-Be is slightly less mobile than O and it repels O,
thus stuffing the GB. s-Be has a high diffusion barrier and it forms strong
bonds to O, trapping O in the GB. Experiments confirm our theoretical
predictions.Comment: 3 pages, 2 figure
Resonant systems for dynamic evaluation of pressure transducers
Tests were conducted with contrived inlet modulated sinusoidal pressure generator to study possible use in calibrating pressure sensors. Results indicate concept is feasible and applicable to transducer evaluation
The classification of traveling wave solutions and superposition of multi-solutions to Camassa-Holm equation with dispersion
Under the traveling wave transformation, Camassa-Holm equation with
dispersion is reduced to an integrable ODE whose general solution can be
obtained using the trick of one-parameter group. Furthermore combining complete
discrimination system for polynomial, the classifications of all single
traveling wave solutions to the Camassa-Holm equation with dispersion is
obtained. In particular, an affine subspace structure in the set of the
solutions of the reduced ODE is obtained. More general, an implicit linear
structure in Camassa-Holm equation with dispersion is found. According to the
linear structure, we obtain the superposition of multi-solutions to
Camassa-Holm equation with dispersion
Representations and classification of traveling wave solutions to Sinh-G{\"o}rdon equation
Two concepts named atom solution and combinatory solution are defined. The
classification of all single traveling wave atom solutions to Sinh-G{\"o}rdon
equation is obtained, and qualitative properties of solutions are discussed. In
particular, we point out that some qualitative properties derived intuitively
from dynamic system method aren't true. In final, we prove that our solutions
to Sinh-G{\"o}rdon equation include all solutions obtained in the paper[Fu Z T
et al, Commu. in Theor. Phys.(Beijing) 2006 45 55]. Through an example, we show
how to give some new identities on Jacobian elliptic functions.Comment: 12 pages. accepted by Communications in theoretical physics (Beijing
: An Excellent Candidate of Tetraquarks
We analyze various possible interpretations of the narrow state
which lies 100 MeV above threshold. This interesting state
decays mainly into instead of . If this relative branching
ratio is further confirmed by other experimental groups, we point out that the
identification of either as a state or more generally
as a state in the representation is probably
problematic. Instead, such an anomalous decay pattern strongly indicates
is a four quark state in the representation
with the quark content . We discuss its
partners in the same multiplet, and the similar four-quark states composed of a
bottom quark . Experimental searches of other members
especially those exotic ones are strongly called for
Spin Hall Effect in Atoms
We propose an optical means to realize a spin hall effect (SHE) in neutral
atomic system by coupling the internal spin states of atoms to radiation. The
interaction between the external optical fields and the atoms creates effective
magnetic fields that act in opposite directions on "electrically" neutral atoms
with opposite spin polarizations. This effect leads to a Landau level structure
for each spin orientation in direct analogy with the familiar SHE in
semiconductors. The conservation and topological properties of the spin
current, and the creation of a pure spin current are discussed.Comment: 4 pages, 2 figure; Final versio
Lattice study on kaon nucleon scattering length in the I=1 channel
Using the tadpole improved clover Wilson quark action on small, coarse and
anisotropic lattices, scattering length in the I=1 channel is calculated
within quenched approximation. The results are extrapolated towards the chiral
and physical kaon mass region. Finite volume and finite lattice spacing errors
are also analyzed and a result in the infinite volume and continuum limit is
obtained which is compatible with the experiment and the results from Chiral
Perturbation Theory.Comment: 15 pages, 4 figures, typeset by latex using elsart.cls,minor change
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