| 1. |
- Hadynska-Klek, K., et al.
(författare)
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Quadrupole collectivity in Ca-42 from low-energy Coulomb excitation with AGATA
- 2018
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Ingår i: Physical Review C. - : AMER PHYSICAL SOC. - 2469-9985 .- 2469-9993. ; 97:2
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Tidskriftsartikel (refereegranskat)abstract
- ACoulomb-excitation experiment to study electromagnetic properties of Ca-42 was performed using a 170-MeV calcium beam from the TANDEM XPU facility at INFN Laboratori Nazionali di Legnaro. gamma rays from excited states in Ca-42 were measured with the AGATA spectrometer. The magnitudes and relative signs of ten E2 matrix elements coupling six low-lying states in Ca-42, including the diagonal E2 matrix elements of 2(1)(+) and 2(2)(+) states, were determined using the least-squares code GOSIA. The obtained set of reduced E2 matrix elements was analyzed using the quadrupole sum rule method and yielded overall quadrupole deformation for 0(1),(+)(2) and 2(1,2)(+) states, as well as triaxiality for 0(1,2)(+) states, establishing the coexistence of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca-42. The experimental results were compared with the state-of-the-art large-scale shell-model and beyond-mean-field calculations, which reproduce well the general picture of shape coexistence in Ca-42.
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| 2. |
- Hadynska-Klek, K., et al.
(författare)
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Superdeformed and Triaxial States in Ca-42
- 2016
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 117:6
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Tidskriftsartikel (refereegranskat)abstract
- Shape parameters of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca-42 were determined from E2 matrix elements measured in the first low-energy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new state-of-the-art large-scale shell model and beyond-mean-field calculations. Experimental evidence for superdeformation of the band built on 0(2)(+) has been obtained and the role of triaxiality in the A similar to 40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time.
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| 3. |
- Hadynska-Klek, K., et al.
(författare)
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Towards The Determination Of Superdeformation In Ca-42
- 2013
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Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 44:3, s. 617-625
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Tidskriftsartikel (refereegranskat)abstract
- The Coulomb excitation experiment to study electromagnetic structure of low-lying states in Ca-42 with a focus on a possible superdeformation in this nucleus was performed at the Laboratori Nazionali di Legnaro in Italy. Preliminary values of the determined quadrupole deformation parameters for both the ground state band and the presumed superdeformed band are presented.
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| 4. |
- ODonnell, Michael, et al.
(författare)
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Registered Replication Report: Dijksterhuis and van Knippenberg (1998)
- 2018
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Ingår i: Perspectives on Psychological Science. - : SAGE PUBLICATIONS LTD. - 1745-6916 .- 1745-6924. ; 13:2, s. 268-294
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Tidskriftsartikel (refereegranskat)abstract
- Dijksterhuis and van Knippenberg (1998) reported that participants primed with a category associated with intelligence (professor) subsequently performed 13% better on a trivia test than participants primed with a category associated with a lack of intelligence (soccer hooligans). In two unpublished replications of this study designed to verify the appropriate testing procedures, Dijksterhuis, van Knippenberg, and Holland observed a smaller difference between conditions (2%-3%) as well as a gender difference: Men showed the effect (9.3% and 7.6%), but women did not (0.3% and -0.3%). The procedure used in those replications served as the basis for this multilab Registered Replication Report. A total of 40 laboratories collected data for this project, and 23 of these laboratories met all inclusion criteria. Here we report the meta-analytic results for those 23 direct replications (total N = 4,493), which tested whether performance on a 30-item general-knowledge trivia task differed between these two priming conditions (results of supplementary analyses of the data from all 40 labs, N = 6,454, are also reported). We observed no overall difference in trivia performance between participants primed with the professor category and those primed with the hooligan category (0.14%) and no moderation by gender.
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| 5. |
- He, Z., et al.
(författare)
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Processing and characterization of nano-structured ZrO2/ CoSb3 thermoelectric composites
- 2006
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Konferensbidrag (refereegranskat)abstract
- The addition of ceramic inclusion to a thermoelectric matrix could reduce the thermal conductivity of the composite, which is attributed to phonon scattering on the generated interfaces. The electrical conductivity of the composite, however, could also be reduced due to additional charge carrier scattering. The performance of the thermoelectric composite, therefore, depends on the resulting ratio of electrical conductivity to thermal conductivity, which results from the entire scattering effects on phonons and charge carriers. In the present work, nano-sized ZrO2 powders of different contents, which were expected to minimize their scattering impact on charge carriers, were dispersed into submicron-sized CoSb3 powders via ball milling. The as-milled powders were consolidated into dense compacts by hot pressing. The phase, the microstructure, and the thermoelectric properties of the prepared compacts were characterized. The correlation of phase purity, microstructure, and thermoelectric properties (electrical conductivity, thermal conductivity, and ratio of electrical conductivity to thermal conductivity), with the ceramic content and sintering temperature is presented. The results show how the performance of the investigated thermoelectric composites can be affected by the dispersion of nano-sized ceramic inclusions. It is noted that the selection of appropriate inclusion content is crucial to maintaining or improving the ratio of electrical conductivity to thermal conductivity.
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| 6. |
- Lomot, D, et al.
(författare)
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Hydrogenolysis of ethane on silica-supported cobalt catalysts
- 2002
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Ingår i: Journal of Molecular Catalysis A: Chemical. - 1381-1169. ; 186:1-2, s. 163-172
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Tidskriftsartikel (refereegranskat)abstract
- The kinetics of ethane hydrogenolysis over cobalt catalysts supported on silica has been investigated. The results compare well with previous data from Sinfelt et al., Haddad and Goodwin, and Babernics et al. The data were found to be characterized by an isokinetic temperature, T-iso = 490+/-40 K and it was therefore possible to apply the model of selective energy transfer (SET). This approach indicates that either there is an energy transfer from the catalyst by full resonance to a vibration mode of the reactant with v = 680 cm(-1) corresponding to a metal (M)=CH2 bond, or there is an energy transfer to an M-CH3 vibration mode in the region of 400 cm(-1), most likely at 355 cm(-1). In any case, these interpretations indicate that it is the breaking of one or two metal-carbon bonds that determine the reaction, not the cleavage of the carbon-carbon bond of ethane. This is in agreement with recent views of Sinfelt.
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| 7. |
- Palkopoulou, Eleftheria, et al.
(författare)
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A comprehensive genomic history of extinct and living elephants
- 2018
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 115:11, s. E2566-E2574
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Tidskriftsartikel (refereegranskat)abstract
- Elephantids are the world's most iconic megafaunal family, yet there is no comprehensive genomic assessment of their relationships. We report a total of 14 genomes, including 2 from the American mastodon, which is an extinct elephantid relative, and 12 spanning all three extant and three extinct elephantid species including an similar to 120,000-y-old straight-tusked elephant, a Columbian mammoth, and woolly mammoths. Earlier genetic studies modeled elephantid evolution via simple bifurcating trees, but here we show that interspecies hybridization has been a recurrent feature of elephantid evolution. We found that the genetic makeup of the straight-tusked elephant, previously placed as a sister group to African forest elephants based on lower coverage data, in fact comprises three major components. Most of the straight-tusked elephant's ancestry derives from a lineage related to the ancestor of African elephants while its remaining ancestry consists of a large contribution from a lineage related to forest elephants and another related to mammoths. Columbian and woolly mammoths also showed evidence of interbreeding, likely following a latitudinal cline across North America. While hybridization events have shaped elephantid history in profound ways, isolation also appears to have played an important role. Our data reveal nearly complete isolation between the ancestors of the African forest and savanna elephants for similar to 500,000 y, providing compelling justification for the conservation of forest and savanna elephants as separate species.
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| 8. |
- Stiewe, C., et al.
(författare)
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Control of thermoelectric properties in ZrO2/CoSb3 nano-dispersed composites
- 2007
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Ingår i: Materialwissenschaft und Werkstofftechnik. - : Wiley. - 0933-5137 .- 1521-4052. ; 38:9, s. 773-776
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Tidskriftsartikel (refereegranskat)abstract
- Nano-dispersed ZrO2/CoSb3 composites of various composition were prepared by uniaxial hot pressing of nano-sized powders of thermoelectric CoSb3 intermixed with ceramic nano-powders. The phase purity, the niicrostructure, and the temperature dependent transport parameters of the composites were investigated. Non-dispersed samples from nano-sized CoSb3 powders show higher electrical conductivity compared to melt-grown material which is attributed to the presence of a small excess of metallic Sb, but they exhibit lower thermal conductivity due to the fine-grained structure. Addition of 5 at.-% ZrO2 enhances the ratio of electrical to thermal conductivity, whereas hardly affects the See-beck coefficient. In this manner the nano-dispersion method provides an effective approach to improving the materials thermoelectric performance.
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| 9. |
- Welp, U., et al.
(författare)
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Anisotropic phase diagram and superconducting fluctuations of single-crystalline SmFeAsO(0.85)F(0.15)
- 2011
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 83:10, s. 100513-
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Tidskriftsartikel (refereegranskat)abstract
- We report on the specific-heat determination of the anisotropic phase diagram of single crystals of optimally doped SmFeAsO(1-x)F(x). In zero field, we find a clear cusplike anomaly in C/T with Delta C/T(c) = 24 mJ/mol K(2) at T(c) = 49.5 K. In magnetic fields along the c axis, pronounced superconducting fluctuations induce broadening and suppression of the specific-heat anomaly which can be described using three-dimensional lowest-Landau-level scaling with an upper critical field slope of -3.5 T/K and an anisotropy of Gamma = 8. The small value of Delta C/T(c) yields a Sommerfeld coefficient gamma similar to 8 mJ/mol K(2), indicating that SmFeAsO(1-x)F(x) is characterized by a modest density of states and strong coupling.
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