6,277 research outputs found
The Patent Paradox Revisited: Determinants of Patenting in the US Semiconductor Industry, 1980-94
This paper examines the patenting behavior of firms in an industry characterized by rapid technological change and cumulative innovation. Recent evidence suggests that semiconductor firms do not rely heavily on patents, despite the strengthening of US patent rights in the early 1980s. Yet the propensity of semiconductor firms to patent has risen dramatically over the past decade. This paper explores this apparent paradox by analyzing the patenting activities of almost 100 US semiconductor firms during 1980-94. The results suggest that stronger patents may have facilitated entry by firms in niche product markets, while spawning patent portfolio races' among capital-intensive firms.
The organization of 2,3-iron-naphthalocyanine molecules on substrate as revealed by scanning tunneling microscopy
Surface morphology of thin molecular layer of 2,3-Iron-naphthalocyanine (2,3 FeNPc) was studied by scanning tunneling microscopy (STM) at the ambient conditions. Organic layer with thickness of 40 nm was vapour phase deposited on amorphous carbon substrate. The STM images have revealed the pecularities of surface molecular organization from large range (hundreds of nm) down to atomic scale. Arrays of locally ordered linear stuctures have been distinguished as the main morphological features of the examined surface. At several places the well-ordered STM patterns have been distinguished at the atomic scale. They can be described as stacks of periodicity approximatelly 0.4 nm in a row and 1.5 nm between stacks. These results can be explained by arrangement of 2,3-FeNPh molecules in stacks with a main plane being perpendicular to the substrate surface
Exotic quark effects on the Higgs sector of the USSM at the LHC
The Higgs sector of the U(1)-extended supersymmetric model is studied with
great detail. We calculate the masses of the Higgs bosons at the one-loop
level. We also calculate at the one-loop level the gluon-involving processes
for the productions and decays of the scalar Higgs bosons of the model at the
energy of the CERN Large Hadron Collider (LHC), where the radiative corrections
due to the loops of top, bottom, and exotic quarks and their scalar partners
are taken into account. We find that the exotic quark and exotic scalar quarks
in the model may manifest themselves at the LHC, since the production of the
heaviest scalar Higgs boson via gluon fusion processes is mediated virtually by
the loops of exotic quark and exotic scalar quarks, for a reasonable parameter
set of the model.Comment: 36 pages, 13 figures, JP
Explosive Ballooning Flux Tubes in Tokamaks
Tokamak stability to, potentially explosive, `ballooning' displacements of
elliptical magnetic flux tubes is examined in large aspect ratio equilibrium.
Above a critical pressure gradient the energy stored in the plasma may be
lowered by finite (but not infinitesimal) displacements of such tubes
(metastability). Above a higher pressure gradient, the linear stability
boundary, such tubes are linearly and nonlinearly unstable. The flux tube
displacement can be of the order of the pressure gradient scale length. Plasma
transport from displaced flux tubes may result in rapid loss of confinement.Comment: 4 pages, 6 figure
Generation of macroscopic superposition states with small nonlinearity
We suggest a scheme to generate a macroscopic superposition state
(Schrodinger cat state) of a free-propagating optical field using a beam
splitter, homodyne measurement and a very small Kerr nonlinear effect. Our
scheme makes it possible to considerably reduce the required nonlinear effect
to generate an optical cat state using simple and efficient optical elements.Comment: Significantly improved version, to be published in PRA as a Rapid
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