1,404 research outputs found

    Projected shell model study for the yrast-band structure of the proton-rich mass-80 nuclei

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    A systematic study of the yrast-band structure for the proton-rich, even-even mass-80 nuclei is carried out using projected shell model approach. We describe the the energy spectra, transition quadrupole moments and gyromagnetic factors. The observed variations in energy spectra and transition quadrupole moments in this mass region are discussed in terms of the configuration mixing of the projected deformed Nilsson states as a function of shell filling.Comment: 22 pages, 7 figure

    Superconductivity and single crystal growth of Ni0:05TaS2

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    Superconductivity was discovered in a Ni0:05TaS2 single crystal. A Ni0:05TaS2 single crystal was successfully grown via the NaCl/KCl flux method. The obtained lattice constant c of Ni0:05TaS2 is 1.1999 nm, which is significantly smaller than that of 2H-TaS2 (1.208 nm). Electrical resistivity and magnetization measurements reveal that the superconductivity transition temperature of Ni0:05TaS2 is enhanced from 0.8 K (2H-TaS2) to 3.9 K. The charge-density-wave transition of the matrix compound 2H-TaS2 is suppressed in Ni0:05TaS2. The success of Ni0:05TaS2 single crystal growth via a NaCl/KCl flux demonstrates that NaCl/KCl flux method will be a feasible method for single crystal growth of the layered transition metal dichalcogenides.Comment: 13pages, 6 figures, Published in SS

    Impurity effects on s+g-wave superconductivity in borocarbides Y(Lu)Ni_2B_2C

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    Recently a hybrid s+g-wave pairing is proposed to describe the experimental observation for a nodal structure of the superconducting gap in borocarbide YNi2_2B2_2C and possibly LuNi2_2B2_2C. In this paper the impurity effects on the s+g-wave superconductivity are studied in both Born and unitarity limit. The quasiparticle density of states and thermodynamics are calculated. It is found that the nodal excitations in the clean system are immediately prohibited by impurity scattering and a finite energy gap increases quickly with the impurity scattering rate. This leads to an activated behavior in the temperature dependence of the specific heat. Qualitative agreement with the experimental results is shown. Comparison with d-wave and some anisotropic s-wave studied previously is also made.Comment: 6 pages, 6 eps figure

    New mechanism and improved kinetics of hydrogen absorption and desorption of Mg(In) solid solution alloy milling with CeF 3

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    Abstract(#br)This paper presents improving the hydrogen absorption and desorption of Mg(In) solid solution alloy through doped with CeF 3 . A nanocomposite of Mg 0.95 In 0.05 -5 wt% CeF 3 was prepared by mechanical ball milling. The microstructures were systematically investigated by X-ray diffraction, scanning electron microscopy, scanning transmission electron microscopy. And the hydrogen storage properties were evaluated by isothermal hydrogen absorption and desorption, and pressure-composition-isothermal measurements in a temperature range of 230 °C–320 °C. The mechanism of hydrogen absorption and desorption of Mg 0.95 In 0.05 solid solution is changed by the addition of CeF 3 . Mg 0.95 In 0.05 -5 wt% CeF 3 nanocomposite transforms to MgH 2 , MgF 2 and intermetallic compounds of MgIn and CeIn 3 by hydrogenation. Upon dehydrogenation, MgH 2 reacts with the intermetallic compounds of MgIn and CeIn 3 forming a pseudo-ternary Mg(In, Ce) solid solution, which is a fully reversible reaction with a reversible hydrogen capacity~4.0 wt%. The symbiotic nanostructured CeIn 3 impedes the agglomeration of MgIn compound, thus improving the dispersibility of element In, and finally improving the reversibility of hydrogen absorption and desorption of Mg(In) solution alloy. For Mg 0.95 In 0.05 -5 wt% CeF 3 nanocomposite, the dehydriding enthalpy is reduced to about 66.1 ± 3.2 kJ⋅mol −1 ⋅H 2 , and the apparent activation energy of dehydrogenation is significantly lowered to 71.9 ± 10.0 kJ⋅mol −1 ⋅H 2 , a reduction of ~73 kJ⋅mol −1 ⋅H 2 relative to that for Mg 0.95 In 0.05 solid solution. As a result, Mg 0.95 In 0.05 -5 wt% CeF 3 nanocomposite can release ~57% H 2 in 10 min at 260 °C. The improvements of hydrogen absorption and desorption properties are mainly attributed to the reversible phase transition of Mg(In, Ce) solid solution combing with the multiphase nanostructure

    The effects of the bacterial interaction with visible-light responsive titania photocatalyst on the bactericidal performance

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    Bactericidal activity of traditional titanium dioxide (TiO2) photocatalyst is effective only upon irradiation by ultraviolet light, which restricts the potential applications of TiO2 for use in our living environments. Recently carbon-containing TiO2 was found to be photoactive at visible-light illumination that affords the potential to overcome this problem; although, the bactericidal activity of these photocatalysts is relatively lower than conventional disinfectants. Evidenced from scanning electron microscopy and confocal Raman spectral mapping analysis, we found the interaction with bacteria was significantly enhanced in these anatase/rutile mixed-phase carbon-containing TiO2. Bacteria-killing experiments indicate that a significantly higher proportion of all tested pathogens including Staphylococcus aureus, Shigella flexneri and Acinetobacter baumannii, were eliminated by the new nanoparticle with higher bacterial interaction property. These findings suggest the created materials with high bacterial interaction ability might be a useful strategy to improve the antimicrobial activity of visible-light-activated TiO2

    Thermodynamic properties of the two-dimensional S=1/2 Heisenberg antiferromagnet coupled to bond phonons

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    By applying a quantum Monte Carlo procedure based on the loop algorithm we investigate thermodynamic properties of the two-dimensional antiferromagnetic S=1/2 Heisenberg model coupled to Einstein phonons on the bonds. The temperature dependence of the magnetic susceptibility, mean phonon occupation numbers and the specific heat are discussed in detail. We study the spin correlation function both in the regime of weak and strong spin phonon coupling (coupling constants g=0.1, w=8J and g=2, w=2J, respectively). A finite size scaling analysis of the correlation length indicates that in both cases long range Neel order is established in the ground state.Comment: 10 pages, 13 figure

    Cranked Relativistic Hartree-Bogoliubov Theory: Superdeformed Bands in the A190A\sim 190 Region

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    Cranked Relativistic Hartree-Bogoliubov (CRHB) theory is presented as an extension of Relativistic Mean Field theory with pairing correlations to the rotating frame. Pairing correlations are taken into account by a finite range two-body force of Gogny type and approximate particle number projection is performed by Lipkin-Nogami method. This theory is applied to the description of yrast superdeformed rotational bands observed in even-even nuclei of the A190A\sim 190 mass region. Using the well established parameter sets NL1 for the Lagrangian and D1S for the pairing force one obtains a very successful description of data such as kinematic (J(1)J^{(1)}) and dynamic (J(2)J^{(2)}) moments of inertia without any adjustment of new parameters. Within the present experimental accuracy the calculated transition quadrupole moments QtQ_t agree reasonably well with the observed data.Comment: 6 pages including 4 PostScript figures, uses RevTex, revised version, Phys.Rev. C, Rapid Communications, in pres

    Genetic characterisation and cytological identification of a male sterile mutant in maize (Zea mays L.)

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    Male sterile mutants play an important role in the utilisation of crop heterosis. Male sterile plants were found in S5 generations of maize hybrid ZH2, through continuous sib-mating by using the fertile plants in the same population, we obtained a male sterile sibling population K932MS including sterile plants K932S and a fertile plant K932F. The objective of this study was to clarify the genetic characterisation and abortion characteristics by nucleus and cytoplasm effect analyses, cytoplasm grouping, and cytological observation. The results showed that no difference was found between K932S and K932F in the vegetative growth stage, but K932S had no emerging anther or pollen grains. The segregation ratio of fertile plants to sterile plants was 1:1 in the sibling progenies, while it was 3:1 in self-crossing progenies of K932F. The sterility of K932S could be restored among reciprocal progenies when seven normal inbred lines were used as females respectively. The fertility expression of K932S crossed with 30 testers would be changed in different test-crosses and some backcross progenies. The C-type restorer Zifeng-1 (Rf4Rf4) was able to restore the fertility of K932S, and the specific PCR amplification bands of K932MS were consistent with CMSCMo17. The anther of K932S began abortion at dyad with its tapetum expanded radically and vacuolated: this induced abnormality in the shapes of both dyads and tetrads. The microspore could not develop normally, and then it collapsed and gradually disappeared. Hence, K932MS is a C-type cytoplasmic male sterile mutant with a pollen-free, stable inheritance: it has potential application value for further research

    Magneto-Transport Properties of Doped RuSr2_2GdCu2_2O8_8

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    RuSr2_2GdCu2_2O8_8, in which magnetic order and superconductivity coexist with TMagneticT_{Magnetic}\ggTcT_c, is a complex material which poses new and important questions to our understanding of the interplay between magnetic and superconducting (SC) order. Resistivity, Hall effect and thermopower measurements on sintered ceramic RuSr2_2GdCu2_2O8_8 are presented, together with results on a broad range of substituted analogues. The Hall effect and thermopower both show anomalous decreases below TMagneticT_{Magnetic} which may be explained within a simple two-band model by a transition from localized to more itinerant behavior in the RuO2_2 layer at TMagneticT_{Magnetic}.Comment: 10 pages, 7 figures, submitted to Phys. Rev. B., correspondence to [email protected]
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