907 research outputs found
Ultra-Low-Power Superconductor Logic
We have developed a new superconducting digital technology, Reciprocal
Quantum Logic, that uses AC power carried on a transmission line, which also
serves as a clock. Using simple experiments we have demonstrated zero static
power dissipation, thermally limited dynamic power dissipation, high clock
stability, high operating margins and low BER. These features indicate that the
technology is scalable to far more complex circuits at a significant level of
integration. On the system level, Reciprocal Quantum Logic combines the high
speed and low-power signal levels of Single-Flux- Quantum signals with the
design methodology of CMOS, including low static power dissipation, low latency
combinational logic, and efficient device count.Comment: 7 pages, 5 figure
Asymptotic behavior of age-structured and delayed Lotka-Volterra models
In this work we investigate some asymptotic properties of an age-structured
Lotka-Volterra model, where a specific choice of the functional parameters
allows us to formulate it as a delayed problem, for which we prove the
existence of a unique coexistence equilibrium and characterize the existence of
a periodic solution. We also exhibit a Lyapunov functional that enables us to
reduce the attractive set to either the nontrivial equilibrium or to a periodic
solution. We then prove the asymptotic stability of the nontrivial equilibrium
where, depending on the existence of the periodic trajectory, we make explicit
the basin of attraction of the equilibrium. Finally, we prove that these
results can be extended to the initial PDE problem.Comment: 29 page
Content Analysis of the Psychology of Men and Masculinity (2000 to 2008)
In 2010, the Psychology of Men and Masculinity (PMM) celebrates the 10th anniversary of its inception as the official journal of the Society for the Psychological Study of Men andMasculinity. This article commemorates this significant milestone by examining the journal’s current trends and future directions through a content analysis of 154 articles published in PMM from 2000 to 2008. The authors found that PMM scholarship was dominated by theories associated with the gender role strain paradigm, addressed clinically-related topics, relied largely on White male college samples, and had a growing impact on clinically-focused scholarly journals and books. Recommendations for addressing theoretical orientations, topics, and populations underrepresented in PMM scholarship are provided
Approximate particle number projection for finite range density dependent forces
The Lipkin-Nogami method is generalized to deal with finite range density
dependent forces. New expressions are derived and realistic calculations with
the Gogny force are performed for the nuclei Er and Er. The
sharp phase transition predicted by the mean field approximation is washed out
by the Lipkin-Nogami approach; a much better agreement with the experimental
data is reached with the new approach than with the Hartree-Fock_Bogoliubov
one, specially at high spins.Comment: 5 pages, RevTeX 3.0, 3 postscript figures included using uufiles.
Submitted to Phys. Rev. Let
Total and Parity-Projected Level Densities of Iron-Region Nuclei in the Auxiliary Fields Monte Carlo Shell Model
We use the auxiliary-fields Monte Carlo method for the shell model in the
complete -shell to calculate level densities. We introduce
parity projection techniques which enable us to calculate the parity dependence
of the level density. Results are presented for Fe, where the calculated
total level density is found to be in remarkable agreement with the
experimental level density. The parity-projected densities are well described
by a backshifted Bethe formula, but with significant dependence of the
single-particle level-density and backshift parameters on parity. We compare
our exact results with those of the thermal Hartree-Fock approximation.Comment: 14 pages, 3 Postscript figures included, RevTe
On the equivalence of pairing correlations and intrinsic vortical currents in rotating nuclei
The present paper establishes a link between pairing correlations in rotating
nuclei and collective vortical modes in the intrinsic frame. We show that the
latter can be embodied by a simple S-type coupling a la Chandrasekhar between
rotational and intrinsic vortical collective modes. This results from a
comparison between the solutions of microscopic calculations within the HFB and
the HF Routhian formalisms. The HF Routhian solutions are constrained to have
the same Kelvin circulation expectation value as the HFB ones. It is shown in
several mass regions, pairing regimes, and for various spin values that this
procedure yields moments of inertia, angular velocities, and current
distributions which are very similar within both formalisms. We finally present
perspectives for further studies.Comment: 8 pages, 4 figures, submitted to Phys. Rev.
Atomic motion in tilted optical lattices
This paper presents a formalism describing the dynamics of a quantum particle
in a one-dimensional, time-dependent, tilted lattice. The formalism uses the
Wannier-Stark states, which are localized in each site of the lattice, and
provides a simple framework allowing fully-analytical developments. Analytic
solutions describing the particle motion are explicit derived, and the
resulting dynamics is studied.Comment: 6 pages, 2 figs, submitted to EPJD, Springer Verlag styl
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