Atomic structure and solute segregation of a Σ = 3, [110]/{111} grain boundary in an yttria-stabilized cubic zirconia bicrystal

The atomic structure and chemical composition of a =3, [110]/{111} symmetric tilt grain boundary in an yttria-stabilized cubic zirconia bicrystal has been investigated by high-resolution transmission electron microscopy (HRTEM) and nanoprobe energy-dispersive X-ray spectroscopy. The experimental HRTEM images are compared with simulated images for a model obtained by lattice statics calculations. It is found that the grain boundary has two individual mirror symmetrical planes in cation and anion sublattices. In this case, the cations are forced to form sevenfold coordination in the vicinity of the boundary owing to the restraint of the boundary structure, while the cations in the cubic fluorite structure have eightfold coordination. The segregation of yttrium ions was experimentally detected at the = 3 boundary, a finding that is considered to be closely related to the change in the local coordination at the boundary.     

Plato's Hypothetical Inquiry in the Meno

This paper argues that the hypothesis proposed in the Meno is the proposition ‘virtue is good’ alone, and that its epistemic nature is essentially insecure. It has been an object of huge scholarly debate which other hypothesis Socrates posited with regard to the relationship between virtue and knowledge. This debate is, however, misleading in the sense of making us believe that the hypothesis that virtue is good is regarded as a truism in the light of the process of positing a higher hypothesis described in the Phaedo and the Republic. I argue that the hypothesis in question is presented as a result of the earlier discussion of Meno's third definition of virtue (77b2–79a2), which implies the consequence that morally correct actions are beneficial whether or not accompanied by conventional goods such as wealth and honour. The underlying role of presenting it as a hypothesis is therefore to postpone demonstrating the truth of a controversial thesis which needs a substantial justification. In conclusion, I suggest that Plato's real intention in introducing the method of hypothesis in the dialogue is not to answer the original question but to lead Meno to seek for knowledge.     

Prosocial behavior is related to later executive function during early childhood: A longitudinal study

ABSTRACT

Previous research has shown that executive function is correlated with prosocial behavior during early childhood. Whether early prosocial behaviors were associated with later executive function during preschool years or vice versa was thus examined in a longitudinal design. The prosocial behaviors and executive function of children (N = 64) aged 42 to 65 months were evaluated twice (Times 1 and 2), based on teachers’ reports and children’s performance on hot and cool executive function tasks. Results revealed that prosocial behaviors at Time 1 were associated with later hot executive function at Time 2, but executive function at Time 1 was not related to prosocial behaviors at Time 2. These findings suggest that prosocial behaviors may enhance children’s hot executive function.