19,976 research outputs found

    Anomalous physical properties of underdoped weak-ferromagnetic superconductor RuSr2_2EuCu2_{2}O8_{8}

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    Similar to the optimal-doped, weak-ferromagnetic (WFM induced by canted antiferromagnetism, TCurie_{Curie} = 131 K) and superconducting (Tc_{c} = 56 K) RuSr2_{2}GdCu2_{2}O8_{8}, the underdoped RuSr2_{2}EuCu2_{2}O8_{8} (TCurie_{Curie} = 133 K, Tc_{c} = 36 K) also exhibited a spontaneous vortex state (SVS) between 16 K and 36 K. The low field (±\pm20 G) superconducting hysteresis loop indicates a weak and narrow Meissner state region of average lower critical field Bc1ave_{c1}^{ave}(T) = Bc1ave_{c1}^{ave}(0)[1 - (T/TSVS_{SVS})2^{2}], with Bc1ave_{c1}^{ave}(0) = 7 G and TSVS_{SVS} = 16 K. The vortex melting transition (Tmelting_{melting} = 21 K) below Tc_{c} obtained from the broad resistivity drop and the onset of diamagnetic signal indicates a vortex liquid region due to the coexistence and interplay between superconductivity and WFM order. No visible jump in specific heat was observed near Tc_{c} for Eu- and Gd-compound. This is not surprising, since the electronic specific heat is easily overshadowed by the large phonon and weak-ferromagnetic contributions. Furthermore, a broad resistivity transition due to low vortex melting temperature would also lead to a correspondingly reduced height of any specific heat jump. Finally, with the baseline from the nonmagnetic Eu-compound, specific heat data analysis confirms the magnetic entropy associated with antiferromagnetic ordering of Gd3+^{3+} (J = S = 7/2) at 2.5 K to be close to NAk\it{N_{A}k} ln8 as expected.Comment: 7 figure

    An easy-to-use diagnostic system development shell

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    The Diagnostic System Development Shell (DSDS), an expert system development shell for diagnostic systems, is described. The major objective of building the DSDS is to create a very easy to use and friendly environment for knowledge engineers and end-users. The DSDS is written in OPS5 and CommonLisp. It runs on a VAX/VMS system. A set of domain independent, generalized rules is built in the DSDS, so the users need not be concerned about building the rules. The facts are explicitly represented in a unified format. A powerful check facility which helps the user to check the errors in the created knowledge bases is provided. A judgement facility and other useful facilities are also available. A diagnostic system based on the DSDS system is question driven and can call or be called by other knowledge based systems written in OPS5 and CommonLisp. A prototype diagnostic system for diagnosing a Philips constant potential X-ray system has been built using the DSDS

    Prior-based Coregistration and Cosegmentation

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    We propose a modular and scalable framework for dense coregistration and cosegmentation with two key characteristics: first, we substitute ground truth data with the semantic map output of a classifier; second, we combine this output with population deformable registration to improve both alignment and segmentation. Our approach deforms all volumes towards consensus, taking into account image similarities and label consistency. Our pipeline can incorporate any classifier and similarity metric. Results on two datasets, containing annotations of challenging brain structures, demonstrate the potential of our method.Comment: The first two authors contributed equall

    Infrared probe of the anomalous magnetotransport of highly oriented pyrolytic graphite in the extreme quantum limit

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    We present a systematic investigation of the magnetoreflectance of highly oriented pyrolytic graphite in magnetic field B up to 18 T . From these measurements, we report the determination of lifetimes tau associated with the lowest Landau levels in the quantum limit. We find a linear field dependence for inverse lifetime 1/tau(B) of the lowest Landau levels, which is consistent with the hypothesis of a three-dimensional (3D) to 1D crossover in an anisotropic 3D metal in the quantum limit. This enigmatic result uncovers the origin of the anomalous linear in-plane magnetoresistance observed both in bulk graphite and recently in mesoscopic graphite samples

    Weak dipole moment of τ\tau in e+e−e^+e^- collisions with longitudinally polarized electrons

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    It is pointed out that certain CP-odd momentum correlations in the production and subsequent decay of tau pairs in e+e−e^+e^- collisions get enhanced when the e−e^- is longitudinally polarized. Analytic expressions for these correlations are obtained for the single-pion decay mode of τ\tau when τ+τ−\tau^+\tau^- have a ``weak" dipole form factor (WDFF) coupling to ZZ . For e+e−e^+e^- collisions at the ZZ peak, a sensitivity of about 1-5×10−17\times 10^{-17}\mbox{ee cm} for the τ\tau WDFF can be reached using a {\em single} τ+τ−\tau^+\tau^- decay channel, with 106 Z10^6\, Z's likely to be available at the SLC at Stanford with e−e^- polarization of 62\%-75\%.Comment: 9 pages, Latex, PRL-TH-93/17 (Revised

    b-quark decay in the collinear approximation

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    The semileptonic decay of a b-quark, b--> c l nu, is considered in the relativistic limit where the decay products are approximately collinear. Analytic results for the double differential lepton energy distributions are given for finite charm-quark mass. Their use for the fast simulation of isolated lepton backgrounds from heavy quark decays is discussed.Comment: 7 pages, 1 figure, submitted to Phys.Rev.

    Desilting Efficiency Due to Empty Flushing of Agongdian Reservoir

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive

    Replacing the Transfusion of 1-2 Units of Blood with Plasma Expanders that Increase Oxygen Delivery Capacity: Evidence from Experimental Studies.

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    At least a third of the blood supply in the world is used to transfuse 1-2 units of packed red blood cells for each intervention and most clinical trials of blood substitutes have been carried out at this level of oxygen carrying capacity (OCC) restoration. However, the increase of oxygenation achieved is marginal or none at all for molecular hemoglobin (Hb) products, due to their lingering vasoactivity. This has provided the impetus for the development of "oxygen therapeutics" using Hb-based molecules that have high oxygen affinity and target delivery of oxygen to anoxic areas. However it is still unclear how these oxygen carriers counteract or mitigate the functional effects of anemia due to obstruction, vasoconstriction and under-perfusion. Indeed, they are administered as a low dosage/low volume therapeutic Hb (subsequently further diluted in the circulatory pool) and hence induce extremely small OCC changes. Hyperviscous plasma expanders provide an alternative to oxygen therapeutics by increasing the oxygen delivery capacity (ODC); in anemia they induce supra-perfusion and increase tissue perfusion (flow) by as much as 50%. Polyethylene glycol conjugate albumin (PEG-Alb) accomplishes this by enhancing the shear thinning behavior of diluted blood, which increases microvascular endothelial shear stress, causes vasodilation and lowering peripheral vascular resistance thus facilitating cardiac function. Induction of supra-perfusion takes advantage of the fact that ODC is the product of OCC and blood flow and hence can be maintained by increasing either or both. Animal studies suggest that this approach may save a considerable fraction of the blood supply. It has an additional benefit of enhancing tissue clearance of toxic metabolites

    Microscopic Description of Band Structure at Very Extended Shapes in the A ~ 110 Mass Region

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    Recent experiments have confirmed the existence of rotational bands in the A \~ 110 mass region with very extended shapes lying between super- and hyper-deformation. Using the projected shell model, we make a first attempt to describe quantitatively such a band structure in 108Cd. Excellent agreement is achieved in the dynamic moment of inertia J(2) calculation. This allows us to suggest the spin values for the energy levels, which are experimentally unknown. It is found that at this large deformation, the sharply down-sloping orbitals in the proton i_{13/2} subshell are responsible for the irregularity in the experimental J(2), and the wave functions of the observed states have a dominant component of two-quasiparticles from these orbitals. Measurement of transition quadrupole moments and g-factors will test these findings, and thus can provide a deeper understanding of the band structure at very extended shapes.Comment: 4 pages, 3 eps figures, final version accepted by Phys. Rev. C as a Rapid Communicatio
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