58 research outputs found

    On the localized wave patterns supported by convection-reaction-diffusion equation

    Full text link
    A set of traveling wave solution to convection-reaction-diffusion equation is studied by means of methods of local nonlinear analysis and numerical simulation. It is shown the existence of compactly supported solutions as well as solitary waves within this family for wide range of parameter values

    Current-induced highly dissipative domains in high Tc thin films

    Full text link
    We have investigated the resistive response of high Tc thin films submitted to a high density of current. For this purpose, current pulses were applied into bridges made of Nd(1.15)Ba(1.85)Cu3O7 and Bi2Sr2CaCu2O8. By recording the time dependent voltage, we observe that at a certain critical current j*, a highly dissipative domain develops somewhere along the bridge. The successive formation of these domains produces stepped I-V characteristics. We present evidences that these domains are not regions with a temperature above Tc, as for hot spots. In fact this phenomenon appears to be analog to the nucleation of phase-slip centers observed in conventional superconductors near Tc, but here in contrast they appear in a wide temperature range. Under some conditions, these domains will propagate and destroy the superconductivity within the whole sample. We have measured the temperature dependence of j* and found a similar behavior in the two investigated compounds. This temperature dependence is just the one expected for the depairing current, but the amplitude is about 100 times smaller.Comment: 9 pages, 9 figures, Revtex, to appear in Phys. Rev.

    Measurements of Ξ(1530)0{\Xi \left( 1530\right) ^{0}} and Ξ(1530)0{\overline{\Xi }\left( 1530\right) ^{0}} production in proton–proton interactions at sNN\sqrt{s_{NN}} = 17.3  = 17.3  GeV \text{ GeV } in the NA61/SHINE experiment

    Get PDF
    Double-differential yields of Ξ(1530)0\Xi\left(1530\right)^{0} and Ξ(1530)0\overline{\Xi}\left(1530\right)^{0} resonances produced in \pp interactions were measured at a laboratory beam momentum of 158~\GeVc. This measurement is the first of its kind in \pp interactions below LHC energies. It was performed at the CERN SPS by the \NASixtyOne collaboration. Double-differential distributions in rapidity and transverse momentum were obtained from a sample of 26\cdot106^6 inelastic events. The spectra are extrapolated to full phase space resulting in mean multiplicity of Ξ(1530)0\Xi\left(1530\right)^{0} (6.73 ±\pm 0.25 ±\pm 0.67)×104\times10^{-4} and Ξ(1530)0\overline{\Xi}\left(1530\right)^{0} (2.71 ±\pm 0.18 ±\pm 0.18)×104\times10^{-4}. The rapidity and transverse momentum spectra and mean multiplicities were compared to predictions of string-hadronic and statistical model calculations

    Lévy HBT results at Na61/SHINE

    Get PDF

    Measurements of Ξ{\Xi }{^-} and Ξ+\overline{\Xi }{^+} production in proton–proton interactions at sNN\sqrt{s_{NN}}=17.3 GeV = 17.3 GeV in the NA61/SHINE experiment

    Get PDF
    International audienceThe production of Ξ(1321)\Xi (1321)^{-} and Ξ(1321)+\overline{\Xi }(1321)^{+} hyperons in inelastic p+p interactions is studied in a fixed target experiment at a beam momentum of 158 GeV ⁣/ ⁣c\hbox {Ge}\hbox {V}\!/\!c. Double differential distributions in rapidity y{y} and transverse momentum pTp_{T} are obtained from a sample of 33M inelastic events. They allow to extrapolate the spectra to full phase space and to determine the mean multiplicity of both Ξ{\Xi }{^-} and Ξ+\overline{\Xi }{^+} . The rapidity and transverse momentum spectra are compared to transport model predictions. The Ξ{\Xi }{^-} mean multiplicity in inelastic p+p interactions at 158 GeV ⁣/ ⁣c\hbox {Ge}\hbox {V}\!/\!c is used to quantify the strangeness enhancement in A+A collisions at the same centre-of-mass energy per nucleon pair

    Convenient synthesis of functionalized cyclopropa[c]coumarin-1a-carboxylates

    No full text
    A simple method has been developed for the synthesis of cyclopropa[c]coumarins, which belong to the donor-acceptor cyclopropane family and, therefore, are promising substrates for the preparation of chromene-based fine chemicals. The method, based on the acetic acid-induced intramolecular transesterification of 2-arylcyclopropane-1,1-dicarboxylates, was found to be efficient for substrates containing hydroxy group directly attached to the aromatic ring. © 2018 by the Authors
    corecore