Microscopic Study of Superdeformed Rotational Bands in 151Tb

Structure of eight superdeformed bands in the nucleus 151Tb is analyzed using the results of the Hartree-Fock and Woods-Saxon cranking approaches. It is demonstrated that far going similarities between the two approaches exist and predictions related to the structure of rotational bands calculated within the two models are nearly parallel. An interpretation scenario for the structure of the superdeformed bands is presented and predictions related to the exit spins are made. Small but systematic discrepancies between experiment and theory, analyzed in terms of the dynamical moments, J(2), are shown to exist. The pairing correlations taken into account by using the particle-number-projection technique are shown to increase the disagreement. Sources of these systematic discrepancies are discussed -- they are most likely related to the yet not optimal parametrization of the nuclear interactions used.Comment: 32 RevTeX pages, 15 figures included, submitted to Physical Review

Schumpeterian patterns of innovation and the sources of breakthrough inventions : evidence from a data-set of R&D awards

This paper examines the relationship between Schumpeterian patterns of innovation and the generation of breakthrough inventions. Our data source for breakthrough inventions is the “R&D 100 awards” competition organized each year by the magazine Research & Development. Since 1963, this magazine has been awarding this prize to 100 most technologically significant new products available for sale or licensing in the year preceding the judgment. We use instead USPTO patent data to measure the relevant dimensions of the technological regimes prevailing in each sector and, on this basis of this information, we provide a characterization of each sector in terms of the Schumpeter Mark I/Schumpeter Mark II archetypes. Our main finding is that breakthrough inventions are more likely to emerge in “turbulent” Schumpeter Mark I type of contexts

White luminescence from Si+ and C+ ion-implanted SiO2 films

The microstructural and optical analysis of SiO2 layers emitting white luminescence is reported. These structures have been synthesized by sequential Si+ and C+ ion implantation and high-temperature annealing. Their white emission results from the presence of up to three bands in the photoluminescence (PL) spectra, covering the whole visible spectral range. The microstructural characterization reveals the presence of a complex multilayer structure: Si nanocrystals are only observed outside the main C-implanted peak region, with a lower density closer to the surface, being also smaller in size. This lack of uniformity in their density has been related to the inhibiting role of C in their growth dynamics. These nanocrystals are responsible for the band appearing in the red region of the PL spectrum. The analysis of the thermal evolution of the red PL band and its behavior after hydrogenation shows that carbon implantation also prevents the formation of well passivated Si/SiO2 interfaces. On the other hand, the PL bands appearing at higher energies show the existence of two different characteristics as a function of the implanted dose. For excess atomic concentrations below or equal to 10%, the spectra show a PL band in the blue region. At higher doses, two bands dominate the green¿blue spectral region. The evolution of these bands with the implanted dose and annealing time suggests that they are related to the formation of carbon-rich precipitates in the implanted region. Moreover, PL versus depth measurements provide a direct correlation of the green band with the carbon-implanted profile. These PL bands have been assigned to two distinct amorphous phases, with a composition close to elemental graphitic carbon or stoichiometric SiC

Schumpeterian patterns of innovation and the sources of breakthrough inventions : evidence from a data-set of R&D awards

This paper examines the relationship between Schumpeterian patterns of innovation and the generation of breakthrough inventions. Our data source for breakthrough inventions is the “R&D 100 awards” competition organized each year by the magazine Research & Development. Since 1963, this magazine has been awarding this prize to 100 most technologically significant new products available for sale or licensing in the year preceding the judgment. We use instead USPTO patent data to measure the relevant dimensions of the technological regimes prevailing in each sector and, on this basis of this information, we provide a characterization of each sector in terms of the Schumpeter Mark I/Schumpeter Mark II archetypes. Our main finding is that breakthrough inventions are more likely to emerge in “turbulent” Schumpeter Mark I type of contexts

Schumpeterian patterns of innovation and the sources of breakthrough inventions : evidence from a data-set of R&D awards

This paper examines the relationship between Schumpeterian patterns of innovation and the generation of breakthrough inventions. Our data source for breakthrough inventions is the “R&D 100 awards” competition organized each year by the magazine Research & Development. Since 1963, this magazine has been awarding this prize to 100 most technologically significant new products available for sale or licensing in the year preceding the judgment. We use instead USPTO patent data to measure the relevant dimensions of the technological regimes prevailing in each sector and, on this basis of this information, we provide a characterization of each sector in terms of the Schumpeter Mark I/Schumpeter Mark II archetypes. Our main finding is that breakthrough inventions are more likely to emerge in “turbulent” Schumpeter Mark I type of contexts