8,529 research outputs found
Progress of analog-hybrid computation
Review of fast analog/hybrid computer systems, integrated operational amplifiers, electronic mode-control switches, digital attenuators, and packaging technique
Effect of dipolar interactions on optical nonlinearity of two-dimensional nanocomposites
In this work, we calculate the contribution of dipole-dipole interactions to
the optical nonlinearity of the two-dimensional random ensemble of
nanoparticles that possess a set of exciton levels, for example, quantum dots.
The analytical expressions for the contributions in the cases of TM and
TE-polarized light waves propagating along the plane are obtained. It is shown
that the optical nonlinearity, caused by the dipole-dipole interactions in the
planar ensemble of the nanoparticles, is several times smaller than the similar
nonlinearity of the bulk nanocomposite. This type of optical nonlinearity is
expected to be observed at timescales much larger than the quantum dot exciton
rise time. The proposed method may be applied to various types of the
nanocomposite shapes.Comment: 8 page
Reversable heat flow through the carbon nanotube junctions
Microscopic mechanisms of externally controlled reversable heat flow through
the carbon nanotube junctions (NJ) are studied theoretically. Our model
suggests that the heat is transfered along the tube section by
electrons () and holes () moving ballistically in either in parallel or
in opposite directions and accelerated by the bias source-drain voltage (Peltier effect). We compute the Seebeck coefficient , electric
and thermal conductivities and find that their magnitudes
strongly depend on and . The sign reversal of
versus the sign of formerly observed experimentally is interpreted
in this work in terms of so-called chiral tunneling phenomena (Klein paradox)
Spinning Q-balls in the complex signum-Gordon model
Rotational excitations of compact Q-balls in the complex signum-Gordon model
in 2+1 dimensions are investigated. We find that almost all such spinning
Q-balls have the form of a ring of strictly finite width. In the limit of large
angular momentum M_z their energy is proportional to |M_z|^(1/5).Comment: 10 page
Extreme laser pulses for possible development of boron fusion power reactors for clean and lasting energy
Extreme laser pulses driving non-equilibrium processes in high density
plasmas permit an increase of the fusion of hydrogen with the boron isotope 11
by nine orders of magnitude of the energy gains above the classical values.
This is the result of initiating the reaction by non-thermal ultrahigh
acceleration of plasma blocks by the nonlinear (ponderomotive) force of the
laser field, in addition to the avalanche reaction that has now been
experimentally and theoretically manifested. The design of a very compact
fusion power reactor is scheduled to produce then environmentally fully clean
and inexhaustible generation of energy at profitably low costs. The reaction
within a volume of cubic millimetres during a nanosecond can only be used for
controlled power generation.Comment: 10 pages, 5 fugure
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