20,793 research outputs found

    Colloquialisation and the evolution of Australian English A cross-varietal and cross-generic study of Australian, British, and American English from 1931 to 2006

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    This paper investigates whether colloquialisation - a stylistic shift by which written genres come to be more similar to spoken genres - has played a role in the endonormativisation of the grammar of Australian English, a variety which has long been noted for its penchant for colloquialism. The study tracks changes in grammatical colloquialism from the early 20th century against the historical backdrop of the progressive decline in Britishness in Australia and the pervasive effects of “Americanisation”. The data are derived from a suite of parallel Brown-family corpora representing British, American, and Australian English of the 1930s, 1960s, 1990s and 2006. Multivariate techniques are used to delimit 26 “colloquial” and “anti-colloquial” grammatical features from a set of 83 potentially relevant features, and to examine changes in their frequencies between 1931 and 2006, in the three varieties, and across the three major genres of fiction, learned writing and press reportage

    In-plane thermal conductivity of large single crystals of Sm-substituted (Y1−x_{1-x}Smx_{x})Ba2_{2}Cu3_{3}O7−ή_{7-\delta}

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    We have investigated the in-plane thermal conductivity Îșab(T,H)\kappa_{ab}(T,H) of large single crystals of optimally oxygen-doped (Y1−x_{1-x},Smx_{x})Ba2_{2}Cu3_{3}O7−ή_{7-\delta} (xx=0, 0.1, 0.2 and 1.0) and YBa2_{2}(Cu1−y_{1-y}Zny_{y})3_{3}O7−ή_{7-\delta}(yy=0.0071) as functions of temperature and magnetic field (along the c axis). For comparison, the temperature dependence of Îșab\kappa_{ab} for as-grown crystals with the corresponding compositions are presented. The nonlinear field dependence of Îșab\kappa_{ab} for all crystals was observed at relatively low fields near a half of TcT_{c}. We make fits of the Îș(H)\kappa(H) data to an electron contribution model, providing both the mean free path of quasiparticles ℓ0\ell_{0} and the electronic thermal conductivity Îșe\kappa_{e}, in the absence of field. The local lattice distortion due to the Sm substitution for Y suppresses both the phonon and electron contributions. On the other hand, the light Zn doping into the CuO 2_{2} planes affects solely the electron component below TcT_{c}, resulting in a substantial decrease in ℓ0\ell_{0} .Comment: 7 pages,4 figures,1 tabl

    Prewetting transition on a weakly disordered substrate : evidence for a creeping film dynamics

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    We present the first microscopic images of the prewetting transition of a liquid film on a solid surface. Pictures of the local coverage map of a helium film on a cesium metal surface are taken while the temperature is raised through the transition. The film edge is found to advance at constant temperature by successive avalanches in a creep motion with a macroscopic correlation length. The creep velocity varies strongly in a narrow temperature range. The retreat motion is obtained only at much lower temperature, conforming to the strong hysteresis observed for prewetting transition on a disordered surface. Prewetting transition on such disordered surfaces appears to give rise to dynamical phenomena similar to what is observed for domain wall motions in 2D magnets.Comment: 7 pages, 3 figures, to be published in Euro.Phys.Let

    Covariant description of shape evolution and shape coexistence in neutron-rich nuclei at N\approx60

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    The shape evolution and shape coexistence phenomena in neutron-rich nuclei at N≈60N\approx60, including Kr, Sr, Zr, and Mo isotopes, are studied in the covariant density functional theory (DFT) with the new parameter set PC-PK1. Pairing correlations are treated using the BCS approximation with a separable pairing force. Sharp rising in the charge radii of Sr and Zr isotopes at N=60 is observed and shown to be related to the rapid changing in nuclear shapes. The shape evolution is moderate in neighboring Kr and Mo isotopes. Similar as the results of previous Hartree-Fock-Bogogliubov (HFB) calculations with the Gogny force, triaxiality is observed in Mo isotopes and shown to be essential to reproduce quantitatively the corresponding charge radii. In addition, the coexistence of prolate and oblate shapes is found in both 98^{98}Sr and 100^{100}Zr. The observed oblate and prolate minima are related to the low single-particle energy level density around the Fermi surfaces of neutron and proton respectively. Furthermore, the 5-dimensional (5D) collective Hamiltonian determined by the calculations of the PC-PK1 energy functional is solved for 98^{98}Sr and 100^{100}Zr. The resultant excitation energy of 02+0^+_2 state and E0 transition strength ρ2(E0;02+→01+)\rho^2(E0;0^+_2\rightarrow0^+_1) are in rather good agreement with the data. It is found that the lower barrier height separating the two competing minima along the Îł\gamma deformation in 100^{100}Zr gives rise to the larger ρ2(E0;02+→01+)\rho^2(E0;0^+_2\rightarrow0^+_1) than that in 98^{98}Sr.Comment: 1 table, 11 figures, 23 page

    Ultra-White BaSO4 Paint and Film with Remarkable Radiative Cooling Performance

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    Radiative cooling is a passive cooling technology that offers great promises to reduce space cooling cost, combat the urban island effect, and alleviate the global warming. To achieve passive daytime radiative cooling, current state-of-the-art solutions often utilize complicated multilayer structures or a reflective metal layer, limiting their applications in many fields. Attempts have been made to achieve passive daytime radiative cooling with single-layer paints, but they often require a thick coating or show partial daytime cooling. In this work, we experimentally demonstrate remarkable full-daytime subambient cooling performance with both BaSO4 nanoparticle films and BaSO4 nanocomposite paints. BaSO4 has a high electron band gap for low solar absorptance and phonon resonance at 9 Όm for high sky window emissivity. With an appropriate particle size and a broad particle size distribution, the BaSO4 nanoparticle film reaches an ultrahigh solar reflectance of 97.6% and a high sky window emissivity of 0.96. During field tests, the BaSO4 film stays more than 4.5 °C below ambient temperature or achieves an average cooling power of 117 W/m2. The BaSO4-acrylic paint is developed with a 60% volume concentration to enhance the reliability in outdoor applications, achieving a solar reflectance of 98.1% and a sky window emissivity of 0.95. Field tests indicate similar cooling performance to the BaSO4 films. Overall, our BaSO4-acrylic paint shows a standard figure of merit of 0.77, which is among the highest of radiative cooling solutions while providing great reliability, convenient paint form, ease of use, and compatibility with the commercial paint fabrication process

    Triaxially deformed relativistic point-coupling model for Λ\Lambda hypernuclei: a quantitative analysis of hyperon impurity effect on nuclear collective properties

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    The impurity effect of hyperon on atomic nuclei has received a renewed interest in nuclear physics since the first experimental observation of appreciable reduction of E2E2 transition strength in low-lying states of hypernucleus Λ7^{7}_\LambdaLi. Many more data on low-lying states of Λ\Lambda hypernuclei will be measured soon for sdsd-shell nuclei, providing good opportunities to study the Λ\Lambda impurity effect on nuclear low-energy excitations. We carry out a quantitative analysis of Λ\Lambda hyperon impurity effect on the low-lying states of sdsd-shell nuclei at the beyond-mean-field level based on a relativistic point-coupling energy density functional (EDF), considering that the Λ\Lambda hyperon is injected into the lowest positive-parity (Λs\Lambda_s) and negative-parity (Λp\Lambda_p) states. We adopt a triaxially deformed relativistic mean-field (RMF) approach for hypernuclei and calculate the Λ\Lambda binding energies of hypernuclei as well as the potential energy surfaces (PESs) in (ÎČ,Îł)(\beta, \gamma) deformation plane. We also calculate the PESs for the Λ\Lambda hypernuclei with good quantum numbers using a microscopic particle rotor model (PRM) with the same relativistic EDF. The triaxially deformed RMF approach is further applied in order to determine the parameters of a five-dimensional collective Hamiltonian (5DCH) for the collective excitations of triaxially deformed core nuclei. Taking Λ25,27^{25,27}_{\Lambda}Mg and Λ31^{31}_{\Lambda}Si as examples, we analyse the impurity effects of Λs\Lambda_s and Λp\Lambda_p on the low-lying states of the core nuclei...Comment: 15 pages with 18 figures and 1 table (version to be published in Physical Review C
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