12,387 research outputs found

    Quality of life in first-admitted schizophrenia patients: a follow-up study

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    http://journals.cambridge.org/action/logi

    Symmetrization and enhancement of the continuous Morlet transform

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    The forward and inverse wavelet transform using the continuous Morlet basis may be symmetrized by using an appropriate normalization factor. The loss of response due to wavelet truncation is addressed through a renormalization of the wavelet based on power. The spectral density has physical units which may be related to the squared amplitude of the signal, as do its margins the mean wavelet power and the integrated instant power, giving a quantitative estimate of the power density with temporal resolution. Deconvolution with the wavelet response matrix reduces the spectral leakage and produces an enhanced wavelet spectrum providing maximum resolution of the harmonic content of a signal. Applications to data analysis are discussed.Comment: 12 pages, 8 figures, 2 tables, minor revision, final versio

    Nuclear energy density functional from chiral pion-nucleon dynamics

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    We calculate the nuclear energy density functional relevant for N=Z even-even nuclei in the systematic framework of chiral perturbation theory. The calculation includes the one-pion exchange Fock diagram and the iterated one-pion exchange Hartree and Fock diagrams. From these few leading order contributions in the small momentum expansion one obtains already a very good equation of state of isospin symmetric nuclear matter. We find that in the region below nuclear matter saturation density the effective nucleon mass M~(ρ)\widetilde M^*(\rho) deviates by at most 15% from its free space value MM, with 0.89M<M~(ρ)<M0.89M<\widetilde M^*(\rho)<M for ρ<0.11fm3\rho < 0.11 {\rm fm}^{-3} and M~(ρ)>M\widetilde M^*(\rho)>M for higher densities. The parameterfree strength of the (ρ)2(\vec\nabla \rho)^2-term, F(kf)F_\nabla(k_f), is at saturation density comparable to that of phenomenological Skyrme forces. The magnitude of FJ(kf)F_J(k_f) accompanying the squared spin-orbit density J2\vec J ^2 comes out somewhat larger. The strength of the nuclear spin-orbit interaction, Fso(kf)F_{so}(k_f), as given by iterated one-pion exchange is about half as large as the corresponding empirical value, however, with the wrong negative sign. The novel density dependencies of M~(ρ)\widetilde M^*(\rho) and F,so,J(kf)F_{\nabla,so,J}(k_f) as predicted by our parameterfree calculation should be examined in nuclear structure calculations (after introducing an additional short range spin-orbit contribution constant in density).Comment: 16 pages, 5 figure

    Do different subjective evaluation criteria reflect distinct constructs?

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    This is not the published version. Published version available from: http://journals.lww.com/jonmd/pages/default.asp

    Scattering of decuplet baryons in chiral effective field theory

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    A formalism for treating the scattering of decuplet baryons in chiral effective field theory is developed. The minimal Lagrangian and potentials in leading-order SU(3) chiral effective field theory for the interactions of octet baryons (BB) and decuplet baryons (DD) for the transitions BBBBBB\to BB, BBDBBB\leftrightarrow DB, DBDBDB\to DB, BBDDBB\leftrightarrow DD, DBDDDB\leftrightarrow DD, and DDDDDD\to DD are provided. As an application of the formalism we compare with results from lattice QCD simulations for ΩΩ\Omega\Omega and NΩN\Omega scattering. Implications of our results pertinent to the quest for dibaryons are discussed.Comment: 26 pages, 6 figures; minor corrections in the text, references adde

    Hyperons in nuclear matter from SU(3) chiral effective field theory

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    Brueckner theory is used to investigate the properties of hyperons in nuclear matter. The hyperon-nucleon interaction is taken from chiral effective field theory at next-to-leading order with SU(3) symmetric low-energy constants. Furthermore, the underlying nucleon-nucleon interaction is also derived within chiral effective field theory. We present the single-particle potentials of Lambda and Sigma hyperons in symmetric and asymmetric nuclear matter computed with the continuous choice for intermediate spectra. The results are in good agreement with the empirical information. In particular, our calculation gives a repulsive Sigma-nuclear potential and a weak Lambda-nuclear spin-orbit force.Comment: 13 pages, 10 figures, 5 tables; v2: published version, minor change

    Electron tunnel sensor technology

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    Researchers designed and constructed a novel electron tunnel sensor which takes advantage of the mechanical properties of micro-machined silicon. For the first time, electrostatic forces are used to control the tunnel electrode separation, thereby avoiding the thermal drift and noise problems associated with piezoelectric actuators. The entire structure is composed of micro-machined silicon single crystals, including a folded cantilever spring and a tip. The application of this sensor to the development of a sensitive accelerometer is described
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