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Austenitic stainless steel 316 L, a typical face-centered-cubic (FCC) iron alloy, demonstrates great potential as structural materials in nuclear plant. However, liquid metal (Pb and Bi) embrittlement (LME) constitutes the major bottlenect in its wide application. In this work, first-principles calculations are conducted to reveal the influences of Cr, Mo, Ni, Pb, and Bi on magnetic property, surface energy, stacking fault energy, ductility, as well as electronic structure of FCC Fe under the magnetic ground state of antiferromagnetic double layer (AFMD). It is discovered that the addition of Ni could considerably increase the ductility of FCC Fe, while the effects of Cr and Mo on the increase of ductility of FCC Fe seem much smaller. On the contrary, both Pb and Bi significantly reduce the ductility of FCC Fe. Such a large decrease is mainly attributed to the more reduction of surface energy than that of unstable stacking fault energy as well as a more directional and weaker chemical bonding. The derived results could provide insight into the influence of alloying elements on the various properties of FCC Fe. [ABSTRACT FROM AUTHOR]

First principles calculation shows that hexagonal-close-packed (HCP) is the ground-state structure of solid Pb 45 Bi 55 with the lowest heat of formation among the four studied structures. Ab initio molecular dynamics simulation is then conducted to identify the structural change of the melting process of Pb 45 Bi 55 from HCP to liquid. It is revealed that during the melting process, the second and third peaks of pair correlation function of the solid state disappear, and instead a new peak appears in the liquid state, while the position of the first peak remains unchanged. Simulation also shows that during the solid-to-liquid phase transition, the total energy and coordination number experience an abrupt decrease and increase with the increase of temperature, respectively. Interestingly, Pb and Bi atoms are apt to mix with each other in both solid and liquid states. The derived results are in nice agreement with experimental and calculated data in the literature, and could provide a deep understanding of the melting process of the Pb–Bi eutectic alloy. [ABSTRACT FROM AUTHOR]

First principles calculation is carried out to systematically investigate the effects of transition metal elements (Ti, Zr, Ta, W) on elastic properties, hardness, surface energy, stacking fault energy, and ductility of HfC. It is found that the addition of Ti and Zr would decrease the elastic properties and hardness of HfC, while Ta and W could increase. Calculations also reveal that Ti, Zr, and W decrease both surface energy and stacking fault energy of HfC, and such a decrease is mainly attributed to smaller bond energies of Ti-C, Zr-C, and W-C bonds than that of Hf-C. The addition of Ta increases the surface energy of HfC due to a stronger Ta-C bond, and decreases the stacking fault energy of HfC as a result of a more reduction of bond energy of the Ta-C bond than that of the Hf-C bond. In addition, Ta and W have an important effect to considerably increase the ductility of HfC, while such effects of Ti and Zr are much smaller. • Ti and Zr would decrease the elastic properties and hardness of HfC, while Ta and W could increase. • The effect of Ti, Zr, Ta, W on surface energy and stacking fault energy of HfC are investigated by calculations. • Ta and W have an important effect to increase the ductility of HfC, while such effects of Ti and Zr are much smaller. • The bond energies of Hf-C, Ti-C, Zr-C, Ta-C, and W-C are calculated to understand the mechanism of effect. [ABSTRACT FROM AUTHOR]

First principles calculation is performed to comparatively investigate the effects of Cu and Fe on energetics, cohesion properties, elastic properties, and fracture toughness of the ∑5(310)[001] grain boundary (GB) in body-centered cubic (BCC) W. It shows that both Cu and Fe have a tendency to segregate towards GB of BCC W and increase stability of GB with a lower GB energy. Calculations also indicate that Cu and Fe have a significant effect on decreasing the cohesion and increasing the brittleness of BCC W, which should be fundamentally attributed to lower bond energies of W–Cu and W–Fe bonds than the W–W bonds. The obtained results are interpreted and understood by bond energies and electronic structures, are consistent with existing experimental and theoretical observations, and would clarify the controversy about the effects of Cu and Fe on cohesion properties and brittleness of BCC W in the literature. • Mechanism was found to explain effects of Cu and Fe on cohesion strength and brittleness of BCC W. • Atomic models with 16 atoms for BCC W and BCC W 15 X 1 (X = Cu, Fe) are used to derive the bond energy, for the first time. • Addition of Cu has a greater effect on cohesion strength, Young's modulus and brittleness of BCC W than Fe. • Bond energy and charge density provide deep understanding of effects of Cu and Fe on cohesion and brittleness of BCC W. [ABSTRACT FROM AUTHOR]

Working on well-annealed single-grain samples of YBa2Cu3O7−δ containing 30 mol% of Y2BaCuO5 grown by the seeded melt-growth process, we have obtained values of the field dependence of the free energy, ΔF(Ha,T), and the reversible magnetisation, Mrev(T)=−(∂ΔF/∂Ha)T, through measurements of the electronic specific heat coefficient γ(Ha,T) in a series of fixed applied magnetic fields Ha. The ability to deduce reliable values of Mrev(0) in the irreversible region of a superconductor is an exciting development as hitherto this quantity could only be poorly estimated from magnetic hysteresis data. [Copyright &y& Elsevier]

Describes the growth of yttrium barium copper oxide thin films on polycrystalline metallic substrates using intermediate yttria stabilized zirconia buffer layers. Growth of the buffer layers by pulsed laser deposition using the inclined substrate deposition technique; Microstructure characteristics.

The theory of characteristic electron energy losses id discussed in terms of the electronic band structure of a solid The relationship between the observed plasmon energies, the average interband energy gap and the background dielectric constant of the solid is developed
The transmission energy loss spectra of a number of the layer-type transition metal dichalcogenides, MX where M = Zr, Hf, Nb, Ta, Mo and W and X = S and Se, have been measured in the range of 0-50 eV In the experiments, a beam of 50 keV electrons is incident along the c-axis of the crystals and electrons inelastically scattered through an angle of 1 m radian are selected for energy analysis This ensures that the momentum transfer and hence the electric vector for the excitations lies in the basal plane of the crystal (E⊥c)
Kramers-Kronig analysis has been applied to the energy loss data to deduce the complex dielectric function of each material From this function, all other optical ' constants, such as the reflectivity, and the oscillator integral function and joint density of states function have been calculated
The results give substantial support to the existing band model for the family of materials and, in addition, provide the basis for a quantitative understanding of the band structure of individual compounds. [ABSTRACT FROM AUTHOR]

Aspirin is widely used in the prevention of cardiovascular diseases, but the antiplatelet responses vary from one patient to another. To validate aspirin response related transcripts and illustrate their roles in predicting cardiovascular events, we have quantified the relative expression of 14 transcripts previously identified as related to high on-aspirin platelet reactivity (HAPR) in 223 patients with coronary artery disease (CAD) on regular aspirin treatment. All patients were followed up regularly for cardiovascular events (CVE). The mean age of our enrolled population was 75.80 ± 8.57 years. HAPR patients showed no significant differences in terms of co-morbidities and combined drugs. Besides, the relative expression of HLA-DQA1 was significantly lower in low on-aspirin platelet reactivity (LAPR) patients, when compared with HAPR and high normal (HN) group ( p = 0.028). What's more, the number of arteries involved, HAPR status and the relative expression of CLU , CMTM5 and SPARC were independent risk factors for CVE during follow up ( p < 0.05). In addition, overexpression of CMTM5 attenuated endothelial cells (ECs) migration and proliferation, with significantly decreased phosphorylated-Akt levels, while its inhibition promoted these processes in vitro ( p < 0.05).Our study provides evidence that circulating transcripts might be potential biomarkers in predicting cardiovascular events. CMTM5 might exert anti-atherosclerotic effects via suppressing migration and proliferation in the vessel wall. Nevertheless, larger-scale and long-term studies are still needed. [ABSTRACT FROM AUTHOR]

The heavy ion fusion–evaporation reaction study for the high-spin spectroscopy of 75 As has been performed via the reaction channel 70 Zn( 9 Be, 1 p 3 n ) 75 As at a beam energy of 42 MeV. The collective structure especially a dipole band in 75 As is established for the first time. The properties of this dipole band are investigated in terms of the self-consistent tilted axis cranking covariant density functional theory. Based on the theoretical description and the examination of the angular momentum components, this dipole band can be interpreted as a novel stapler band, where the valence neutrons in ( 1 g 9 / 2 ) orbital rather than the collective core are responsible for the closing of the stapler of angular momentum. [ABSTRACT FROM AUTHOR]

Abstract: The first heavy ion fusion–evaporation reaction study for 74Ge has been performed through the reaction channel at beam energies of 30 and 35 MeV. Previously known yrast band is extended to higher spins and five new collective bands are established. Based on comparison with the neighboring 72,76Ge isotopes, an intermediate pattern of energy staggering is observed in the γ band of 74Ge. The collective structure of 74Ge, including the excitation energies and transition probabilities of ground-state band and γ band, is reproduced by the state-of-the-art five-dimensional collective Hamiltonian (5DCH) model constructed from the covariant density functional. By including the 72,76,78Ge isotopes, systematical investigation of the structure evolution in Ge isotopes is performed. Based on the systematic comparisons and analysis, the triaxial evolution with spin in 74Ge is revealed and 74Ge is found to be the crucial nucleus marking the triaxial evolution from soft to rigid in Ge isotopes. [Copyright &y& Elsevier]

The spin asymmetry of internal photo-electron emission over Schottky barriers has been investigated for Fe/GaAs (001) having close-to-ideal current–voltage characteristics. Using a low-power circularly polarised YAG laser operated at its fundamental frequency (λ=1064 nm) as well as a visible diode laser (λ=670 nm) we demonstrate that, by eliminating the photo-current due to inter-band transitions in GaAs with the infrared source, a significant enhancement to the magnetic asymmetry could be achieved. The bias dependence of the asymmetry was also measured. It was found that the values were considerably different for the photo-electrons traversing the barriers in opposite directions. [ABSTRACT FROM AUTHOR]

The techniques described in this work illustrate the type of changes which may be observed, by precise X-ray absorption spectroscopy, XAS measurements of absorbance A vs. temperature T, across a phase transition in the solid state: (i) the changes in the final states relaxation time τ, which are due to the onset of fluctuations near a phase transition at Tc; (ii) the XAS enhancement which is due to the anomalous Bragg diffraction at an absorption edge, coupled to phonon modes in the temperature interval where these are active; (iii) new allowed transitions to finite states near Tc which are due to symmetry changes; (iv) changes in the bond order detected by the measurement of X-ray temperature difference absorption spectra near a phase transition: XTDASTo=XAS(T)-XAS(T0) which identifies the bonds responsible for the phase transition by the progressive changes in the pair correlation term affecting the Debye–Waller factor vs. T, when no other structural changes occur, except in the vibrational modes of a specific bond. The methods have been applied to identify the phenomena that occur near the superconducting transition temperature in layer cuprates and near the metal to insulator transition in NiS2−xSex. [Copyright &y& Elsevier]