71 research outputs found
Distribution of particles which produces a "smart" material
If is the scattering amplitude, corresponding to a
potential , where is a bounded domain, and
is the incident plane wave, then we call the radiation
pattern the function , where the unit vector
, the incident direction, is fixed, and , the wavenumber, is
fixed. It is shown that any function , where is the
unit sphere in , can be approximated with any desired accuracy by a
radiation pattern: , where
is an arbitrary small fixed number. The potential ,
corresponding to , depends on and , and can be
calculated analytically. There is a one-to-one correspondence between the above
potential and the density of the number of small acoustically soft particles
, , distributed in an a priori given bounded
domain . The geometrical shape of a small particle is
arbitrary, the boundary of is Lipschitz uniformly with respect to
. The wave number and the direction of the incident upon
plane wave are fixed.It is shown that a suitable distribution of the above
particles in can produce the scattering amplitude ,
, at a fixed , arbitrarily close in the norm of
to an arbitrary given scattering amplitude
, corresponding to a real-valued potential .Comment: corrected typo
The Lymnaea cardioexcitatory peptide (LyCEP) receptor: A G-protein-couplex receptor for a novel member of the RFamide neuropeptide family.
Novel Stress-responsive Genes EMG1 and NOP14 Encode Conserved, Interacting Proteins Required for 40S Ribosome Biogenesis
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