8,752 research outputs found

    Anisotropic, multi-carrier transport at the (111) LaAlO3_3/SrTiO3_3 interface

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    The conducting gas that forms at the interface between LaAlO3_3 and SrTiO3_3 has proven to be a fertile playground for a wide variety of physical phenomena. The bulk of previous research has focused on the (001) and (110) crystal orientations. Here we report detailed measurements of the low-temperature electrical properties of (111) LAO/STO interface samples. We find that the low-temperature electrical transport properties are highly anisotropic, in that they differ significantly along two mutually orthogonal crystal orientations at the interface. While anisotropy in the resistivity has been reported in some (001) samples and in (110) samples, the anisotropy in the (111) samples reported here is much stronger, and also manifests itself in the Hall coefficient as well as the capacitance. In addition, the anisotropy is not present at room temperature and at liquid nitrogen temperatures, but only at liquid helium temperatures and below. The anisotropy is accentuated by exposure to ultraviolet light, which disproportionately affects transport along one surface crystal direction. Furthermore, analysis of the low-temperature Hall coefficient and the capacitance as a function of back gate voltage indicates that in addition to electrons, holes contribute to the electrical transport.Comment: 11 pages, 9 figure

    Better Late than Never: Information Retrieval from Black Holes

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    We show that, in order to preserve the equivalence principle until late times in unitarily evaporating black holes, the thermodynamic entropy of a black hole must be primarily entropy of entanglement across the event horizon. For such black holes, we show that the information entering a black hole becomes encoded in correlations within a tripartite quantum state, the quantum analogue of a one-time pad, and is only decoded into the outgoing radiation very late in the evaporation. This behavior generically describes the unitary evaporation of highly entangled black holes and requires no specially designed evolution. Our work suggests the existence of a matter-field sum rule for any fundamental theory.Comment: Change of title to reflect information return. The physics of "energetic curtains" remains unchange

    A comparative study on morphometric and meristic characters of Nemipterus japonicus (Bloch, 1791) in the coasts of India

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    A total of 200 threadfin bream Nemipterus japonicus was collected from Chennai in the east coast and Kochi in the west coast during January to February 2013 and studied for their morphometric and meristic characters. In total, 21 characters were analyzed out of which 3 characters namely dorsal, ventral and anal fins were not considered since they were unaltered. The findings indicate that 91% of the total variation in the data can be accounted for by three clusters. Small values of 1-R**2 ratio for the three clusters obtained indicate good clustering. The small values of p (≤0.0001) indicate that there are significant differences in the variables of Chennai and Kochi data which are shown through MANOVA. This might depict that the fish of Chennai and Kochi might be of 2 different stocks. Moreover, the study has also aided in identifying the importance of regular monitoring of stock assessment and the biology of commercially important fishes

    Probing the C-H Activation of Linear and Cyclic Ethers at (PNP)Ir

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    Interaction of the amido/bis(phosphine)-supported (PNP)Ir fragment with a series of linear and cyclic ethers is shown to afford, depending on substrate, products of α,α-dehydrogenation (carbenes), α,β-dehydrogenation (vinyl ethers), or decarbonylation. While carbenes are exclusively obtained from tert-amyl methyl ether, sec-butyl methyl ether (SBME), n-butyl methyl ether (NBME), and tetrahydrofuran (THF), vinyl ethers or their adducts are observed upon reaction with diethyl ether and 1,4-dioxane. Decarbonylation occurs upon interaction of (PNP)Ir with benzyl methyl ether, and a mechanism is proposed for this unusual transformation, which occurs via a series of C−H, C−O, and C−C bond cleavage events. The intermediates characterized for several of these reactions as well as the α,α-dehydrogenation of tert-butyl methyl ether (MTBE) are used to outline a reaction pathway for the generation of PNP-supported iridium(I) carbene complexes, and it is shown that the long-lived, observable intermediates are substrate-dependent and differ for the related cases of MTBE and THF. Taken together, these findings highlight the variety of pathways utilized by the electron-rich, unsaturated (PNP)Ir fragment to stabilize itself by transferring electron density to ethereal substrates through oxidative addition and/or the formation of π-acidic ligands

    Electroweak Fermion-loop Contributions to the Muon Anomalous Magnetic Moment

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    The two-loop electroweak corrections to the anomalous magnetic moment of the muon, generated by fermionic loops, are calculated. An interesting role of the top quark in the anomaly cancellation is observed. New corrections, including terms of order Gμαmt2G_\mu \alpha m_t^2, are computed and a class of diagrams previously thought to vanish are found to be important. The total fermionic correction is (23±3)×1011-(23\pm 3) \times 10^{-11} which decreases the electroweak effects on g2g-2, predicted from one-loop calculations, by 12\%. We give an updated theoretical prediction for g2g-2 of the muon.Comment: Corrected versio

    Resistance training leads to large improvements in strength and moderate improvements in physical function in adults who are overweight or obese: a systematic review

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    QuestionsWhat are the effects of resistance training on muscle strength, physical function and muscle power in adults who are overweight or obese? Which factors moderate the effects?DesignSystematic review of randomised controlled trials, with random effects meta-analyses and meta-regressions.ParticipantsAdults who are overweight or obese.InterventionResistance training lasting ≥ 4 weeks.Outcome measuresMuscle strength, muscle power and physical function.ResultsThirty trials with 1,416 participants met the eligibility criteria. Pooled analyses indicated that resistance training has a large beneficial effect on muscle strength (SMD 1.39, 95% CI 1.05 to 1.73, I2 = 85%) and a moderate effect on physical function (SMD 0.67, 95% CI 0.25 to 1.08, I2 = 71%) in adults who are overweight or obese. However, the effect of resistance training on muscle power was unclear (SMD 0.42, 95% CI −3.3 to 4.2, I2 = 46%). The effect of resistance training on strength was greatest for the upper body (versus lower/whole body: β = 0.35, 95% CI 0.05 to 0.66) and in dynamic strength tests (versus isometric/isokinetic: β = 1.20, 95% CI 0.60 to 1.81), although trials judged to have good methodological quality reported statistically smaller effects (versus poor/fair quality: β = −1.21, 95% CI −2.35 to −0.07). Concomitant calorie restriction did not modify strength gains but reduced the effect of resistance training on physical function (β = −0.79, 95% CI −1.41 to −0.17). Small study effects were evident for strength outcomes (β = 5.9, p < 0.001).ConclusionsResistance training has a large positive effect on muscle strength and a moderate effect on physical function in adults who are overweight or obese. However, the effect of resistance training on muscle power is uncertain. In addition, concomitant calorie restriction may compromise the functional adaptations to resistance training
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