1,009 research outputs found

    Anomalous behavior of the Debye temperature in Fe-rich Fe-Cr alloys

    Full text link
    Debye temperature, ΘD\Theta_D, of Fe-rich Fe100x_{100-x}Crx_x disordered alloys with 0x22.30\le x \le 22.3 was determined from the temperature dependence of the central shift of M\"ossbauer spectra recorded in the temperature range of 60 -- 300 K. Its compositional dependence shows a maximum at x5x \approx 5 with a relative increase of 30\sim 30% compared to a pure iron. The composition at which the effect occurs correlates well with that at which several other quantities, e. g. the Curie temperature and the spin-wave stiffness coefficient, D0D_0, show their maxima, but the enhancement of ΘD\Theta_D is significantly greater and comparable with the enhancement of the hyperfine field (spin-density of itinerant ss-like electrons) in the studied system. The results suggest that the electron-phonon interaction is important in this alloy system

    Genes for tesin, villin and desmin are linked on mouse Chromosome 1

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47016/1/335_2004_Article_BF00354299.pd

    Asymbiotic germination of immature seeds, plantlet development and ex vitro establishment of plants of Dendrobium tosaense Makino - A medicinally important orchid

    Get PDF
    Shi-hu (Dendrobium spp. or Dendrobii Herba) is one of the important traditional Chinese medicines. The commercially available crude drug in the traditional medicine market is composed mainly of three species: Dendrobium tosaense, D. nobile, and D. moniliforme. An efficient method of propagation has been developed via asymbiotic germination of seeds in vitro for the medicinally important D. tosaense. Seeds from capsules of D. tosaense collected 8-14 wk after artificial pollination germinated after being cultured on full-strength or half-strength Murashige and Skoog (MS) medium devoid of plant growth regulators and with 3% sucrose. Germination of seeds varied with the medium type and seed maturity. Germinated seedlings after transfer to MS medium with 1.5% sucrose and 8% banana homogenate or potato juice or coconut water and 20 wk of incubation developed into healthy plantlets. Well-developed plantlets were transplanted to moss or moss and tree fern or tree fern as substrates in plastic trays and transferred to a greenhouse for hardening. All plants survived, attained maturity, and developed normal flower and capsule after one and a half years. This protocol of successful plant regeneration by asymbiotic seed germination should permit rapid propagation and conservation of this medicinally important Dendrobium species

    Effects of communication and utility-based decision making in a simple model of evacuation

    Full text link
    We present a simple cellular automaton based model of decision making during evacuation. Evacuees have to choose between two different exit routes, resulting in a strategic decision making problem. Agents take their decisions based on utility functions, these can be revised as the evacuation proceeds, leading to complex interaction between individuals and to jamming transitions. The model also includes the possibility to communicate and exchange information with distant agents, information received may affect the decision of agents. We show that under a wider range of evacuation scenarios performance of the model system as a whole is optimal at an intermediate fraction of evacuees with access to communication.Comment: 9 pages, 9 figure

    Architectural aspects of QoS-aware personal networks

    Get PDF
    Personal Networks (PN) are future communication systems that combine wireless and infracuture based networks to provide users a variety of services anywhere and anytime. PNs introduce new design challenges due to the heterogeneity of the involved technologies, the need for self-organization, the dynamics of the system composition, the application-driven nature, the co-operation with infrastructure-based networks, and the security hazards. This paper discusses the challenges of security and QoS provisioning in designing self-organized personal networks and combines them all into an integrated architectural framework

    Tests of the random phase approximation for transition strengths

    Get PDF
    We investigate the reliability of transition strengths computed in the random-phase approximation (RPA), comparing with exact results from diagonalization in full 0ω0\hbar\omega shell-model spaces. The RPA and shell-model results are in reasonable agreement for most transitions; however some very low-lying collective transitions, such as isoscalar quadrupole, are in serious disagreement. We suggest the failure lies with incomplete restoration of broken symmetries in the RPA. Furthermore we prove, analytically and numerically, that standard statements regarding the energy-weighted sum rule in the RPA do not hold if an exact symmetry is broken.Comment: 11 pages, 7 figures; Appendix added with new proof regarding violation of energy-weighted sum rul

    Vacuum oscillation solution to the solar neutrino problem in standard and non-standard pictures

    Get PDF
    The neutrino long wavelength (just-so) oscillation is revisited as a solution to the solar neutrino problem. We consider just-so scenario in various cases: in the framework of the solar models with relaxed prediction of the boron neutrino flux, as well as in the presence of the non-standard weak range interactions between neutrino and matter constituents. We show that the fit of the experimental data in the just-so scenario is not very good for any reasonable value of the 8B^8B neutrino flux, but it substantially improves if the non-standard τ\tau-neutrino--electron interaction is included. These new interactions could also remove the conflict of the just-so picture with the shape of the SN 1987A neutrino spectrum. Special attention is devoted to the potential of the future real-time solar neutrino detectors as are Super-Kamiokande, SNO and BOREXINO, which could provide the model independent tests for the just-so scenario. In particular, these imply specific deformation of the original solar neutrino energy spectra, and time variation of the intermediate energy monochromatic neutrino (7Be^7Be and peppep) signals.Comment: Latex, 14 pages, 9 figures (avalilable by fax or postscript files requested to [email protected]) -- some textual and Latex errors are corrected and few references adde
    corecore