Effects of partner choice and role assignation in the spatial ultimatum game

Hitherto, there has been an increasing interest in the ultimatum game, an elegant metaphor constituted for decoding the self-organization of fair behavior. Most previous studies have been done in the context of unbiased partner selection and symmetric role assignation. However, this is not always the case. To investigate the role of partner choice and role allocation on fairness, we develop a co-evolutionary ultimatum game in which agents can dynamically choose interacting neighbors as well as allocate game roles based on the real-time feedback from interactions. By the Monte Carlo simulation, we find that the related biases always play a crucial role in transforming the evolution of fairness. More specifically, the fairness level can be strikingly promoted when agents often aspire for interactions with more successful players and frequently designate reputable ones as proposers in the ultimatum game. For other cases, however, fairness is often remarkably inhibited. Compared with weak selection, strong selection turns out to be more favorable to the evolution of fair behavior. Finally, with proper parameters we witness the spontaneous emergence of social fairness in a totally self-regarding population under the noisy condition. Copyright (C) EPLA, 2015Physics, MultidisciplinarySCI(E)[email protected]; [email protected]; [email protected]; [email protected]

X-ray spectra induced in highly charged Ar-40(q+) interacting with Au surface

By use of optical spectrum technology, the spectra of X-ray induced by highly charged Ar-40(q+) ions interacting with Au surface have been studied. The results show that the argon K alpha X-ray were emitted from the hollow atoms formed below the surface. There is a process of multi-electron exciting in neutralization of the Ar16+ ion, with electronic configuration 1s(2) in its ground state below the solid surface. The yield of the projectile K alpha X-ray is related to its initial electronic configuration, and the yield of the target X-ray is related to the projectile kinetic energy

Kinetic energy and charge state effects in the X-ray emission of Mo surface induced by Xeq+ (q=25, 29) ions

L-shell X-ray spectra of Mo surface induced by Xe25+ and Xe29+ were measured. The X-ray intensity was obtained in the kinetic energy range of the incident ions from 350 to 600 keV. The relationship of X-ray intensity with kinetic energy of the projectile and its charge state were studied, and the simple explanation was given

Slow isocharged sequence ions with helium collisions: Projectile core dependence

The collisions of the isocharged sequence ions of q=6 (C6+, N6+, O6+, F6+, Ne6+, Ar6+, and Ca6+), q=7 (F7+, Ne7+, S7+, Ar7+, and Ca7+), q=8 (F8+, Ne8+, Ar8+, and Ca8+), q=9 (F9+, Ne9+, Si9+, S9+, Ar9+, and Ca9+) and q=11 (Si11+, Ar11+, and Ca11+) with helium at the same velocities were investigated. The cross-section ratios of the double-electron transfer (DET) to the single-electron capture (SEC) sigma(DET)/sigma(SEC) and the true double-electron capture (TDC) to the double-electron transfer sigma(TDC)/sigma(DET) were measured. It shows that for different ions in an isocharged sequence, the experimental cross-section ratio sigma(DET)/sigma(SEC) varies by a factor of 3. The results confirm that the projectile core is another dominant factor besides the charge state and the collision velocity in slow (0.35-0.49v(0); v(0) denotes the Bohr velocity) highly charged ions (HCIs) with helium collisions. The experimental cross-section ratio sigma(DET)/sigma(SEC) is compared with the extended classical over-barrier model (ECBM) [A. Barany , Nucl. Instrum. Methods Phys. Res. B 9, 397 (1985)], the molecular Coulombic barrier model (MCBM) [A. Niehaus, J. Phys. B 19, 2925 (1986)], and the semiempirical scaling laws (SSL) [N. Selberg , Phys. Rev. A 54, 4127 (1996)]. It also shows that the projectile core properties affect the initial capture probabilities as well as the subsequent relaxation of the projectiles. The experimental cross-section ratio sigma(TDC)/sigma(DET) for those lower isocharged sequences is dramatically affected by the projectile core structure, while for those sufficiently highly isocharged sequences, the autoionization always dominates, hence the cross-section ratio sigma(TDC)/sigma(DET) is always small