702 research outputs found
Does heterogeneity spoil the basket? The role of productivity and feedback information on public good provision
In a circular neighborhood of eight, each member contributes repeatedly to two local public goods, one with the left and one with the right neighbor. All eight two-person games provide only local feedback information and are structurally independent in spite of their overlapping player sets. Heterogeneity is induced intra-personally by asymmetric productivity in left and right games and inter-personally by two randomly selected group members who are less privileged (LP) by being either less productive or excluded from end-of-period feedback information about their payoffs and neighbors’ contributions. Although both LP-types let the neighborhood as a whole evolve less cooperatively, their spillover dynamics differ. While less productive LPs initiate “spoiling the basket” via their low contributions, LPs with no-end-of-round information are exploited by their neighbors. Furthermore, LP-positioning, closest versus most distant, affects how the neighborhood evolves
Behavioral spillovers in local public good provision: an experimental study
In a circular neighborhood, each member has a left and a right neighbor with whom(s) he interacts repeatedly. From their two separate endowment amounts individuals can contribute to each of their two structurally independent public goods, either shared only with their left, respectively right, neighbor. If most group members are discrimination averse and conditionally cooperating with their neighbors, this implies intra- as well as inter personal spillovers which link all neighbors. Investigating individual adaptations in one’s two games with differing freeriding incentives confirms, through behavioral spillovers, that both individual contributions anchor on the local public good with the smaller free-riding incentive. Therefore asymmetry in gaining from local public goods allows to establish a higher level of voluntary cooperation
Prominent 5d-orbital contribution to the conduction electrons in gold
We have examined the valence-band electronic structures of gold and silver in
the same column in the periodic table with nominally filled d orbitals by means
of a recently developed polarization-dependent hard x-ray photoemission.
Contrary to a common expectation, it is found that the 5d-orbital electrons
contribute prominently to the conduction electrons in gold while the conduction
electrons in silver are to some extent free-electron-like with negligible 4d
contribution, which could be related to a well-known fact that gold is more
stable than silver in air. The 4d electron correlation effects are found to be
essential for the conduction electron character in silver.Comment: 8 pages, 4 figures, to be appeared in New J. Phys
Depth dependence of itinerant character in Mn-substituted Sr3Ru2O7
We present a core-level photoemission study of Sr3(Ru 1-xMnx)2O7, in which we
monitor the evolution of the Ru-3d fine structure versus Mn substitution and
probing depth. In both Ru 3d3/2 and 3d5/2 core levels we observe a clear
suppression of the metallic features, i.e. the screened peaks, implying a sharp
transition from itinerant to localized character already at low Mn
concentrations. The comparison between soft and hard x-ray photoemission, which
provides tunable depth sensitivity, reveals that the degree of
localized/metallic character for Ru is different at the surface than in the
bulk.Comment: 10 pages, 4 figures, 1 tabl
Proximity-induced ferromagnetism and chemical reactivity in few-layer VSe2 heterostructures
Among transition-metal dichalcogenides, mono and few-layers thick VSe2 has gained much recent attention following claims of intrinsic room-temperature ferromagnetism in this system, which have nonetheless proved controversial. Here, we address the magnetic and chemical properties of Fe/VSe2 heterostructure by combining element sensitive x-ray absorption spectroscopy and photoemission spectroscopy. Our x-ray magnetic circular dichroism results confirm recent findings that both native mono/few-layer and bulk VSe2 do not show intrinsic ferromagnetic ordering. Nonetheless, we find that ferromagnetism can be induced, even at room temperature, after coupling with a Fe thin film layer, with antiparallel alignment of the moment on the V with respect to Fe. We further consider the chemical reactivity at the Fe/VSe2 interface and its relation with interfacial magnetic coupling
Electronic Structure of CeFeAsO1-xFx (x=0, 0.11/x=0.12) compounds
We report an extensive study on the intrinsic bulk electronic structure of
the high-temperature superconductor CeFeAsO0.89F0.11 and its parent compound
CeFeAsO by soft and hard x-ray photoemission, x-ray absorption and soft-x-ray
emission spectroscopies. The complementary surface/bulk probing depth, and the
elemental and chemical sensitivity of these techniques allows resolving the
intrinsic electronic structure of each element and correlating it with the
local structure, which has been probed by extended-x-ray absorption fine
structure spectroscopy. The measurements indicate a predominant 4f1 (i.e. Ce3+)
initial state configuration for Cerium and an effective valence-band-to-4f
charge-transfer screening of the core hole. The spectra also reveal the
presence of a small Ce f0 initial state configuration, which we assign to the
occurrence of an intermediate valence state. The data reveal a reasonably good
agreement with the partial density of states as obtained in standard density
functional calculations over a large energy range. Implications for the
electronic structure of these materials are discussed.Comment: Accepted for publication in Phys. Rev.
Adalimumab safety and mortality rates from global clinical trials of six immune-mediated inflammatory diseases
Analysis of Metal-Insulator Crossover in Strained {SrRuO}3 Thin Films by X-ray Photoelectron Spectroscopy
The electronic properties of ultrathin epitaxial films of strontium ruthenate SrRuO3 perovskite oxide are modified by epitaxial strain, as determined by growing by pulsed laser deposition, on different the substrates. Electron transport measurements indicated that tensile strain deformation of the SrRuO3 unit cell reduces the metallicity of the material and reduces the metal-insulator-transition (MIT) temperatures. The shrinkage of the Ru-O-Ru buckling angle due to compressive strain is counterweighted by the increased overlap of the conduction Ru-4d orbitals with the O-2p ones due to the smaller interatomic distances resulting into an increased MIT temperature, i.e. a more conducting material. In the more metallic samples the core level x-ray photoemission spectroscopy lineshapes show the occurrence of an extra-peak at the lower binding energies of the main Ru-3d peaks that is attributed to screening, as observed in volume sensitive photoemission of the unstrained material
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