Understanding the object benefit in visual short-term memory: the roles of feature proximity and connectedness

Past research has identified visual objects as the units of information processing in visual short-term memory (VSTM) and has shown that two features from the same object can be remembered in VSTM as well (or almost as well) as one feature of that object and are much better remembered than the same two features from two spatially separated objects. It is not clear, however, what drives this object benefit in VSTM. Is it the shared spatial location (proximity), the connectedness among features of an object, or both? In six change detection experiments, both location/proximity and connectedness were found to be crucial in determining the magnitude of the object benefit in VSTM. Together, these results indicate that location/proximity and connectedness are essential elements in defining a coherent visual object representation in VSTM.     

The development of executive functioning and theory of mind. A comparison of Chinese and U.S. preschoolers

Preschoolers' theory-of-mind development follows a similar age trajectory across many cultures. To determine whether these similarities are related to similar underlying ontogenetic processes, we examined whether the relation between theory of mind and executive function commonly found among U.S. preschoolers is also present among Chinese preschoolers. Preschoolers from Beijing, China (N= 109), were administered theory-of-mind and executive-functioning tasks, and their performance was compared with that of a previously studied sample of U.S. preschoolers (N= 107). The Chinese preschoolers outperformed their U.S. counterparts on all measures of executive functioning, but were not similarly advanced in theory-of-mind reasoning. Nonetheless, individual differences in executive functioning predicted theory of mind for children in both cultures. Thus, the relation between executive functioning and theory of mind is robust across two disparate cultures. These findings shed light on why executive functioning is important for theory-of-mind development.     

Discontinuous precipitation initiated at interphase boundaries in a Zn-rich Zn-6.3 at.% Ag alloy

Discontinuous precipitation in a two-phase Zn-rich Zn-6.3at.%Ag alloy has been studied. It has been shown that the eta/epsilon interphase boundaries have the ability to initiate discontinuous precipitation as do the eta/eta grain boundaries. The back-polishing method is used to show the interconnection between a discontinuous precipitate colony and the eta/epsilon interphase boundary. The reaction front velocity of discontinuous precipitation initiated at the eta/eta grain boundary is 12-90% higher than that of discontinuous precipitation initiated at the eta/epsilon interphase boundary under various ageing temperatures.     

Homogeneous nucleation of dislocation loops under stress in perfect crystals

We present an analysis and results on the homogeneous nucleation of a dislocation loop under stress in a perfect crystal. By using a variational boundary integral method in the Peierls-Nabarro framework, we have determined the saddle-point configurations of embryonic dislocation loops and their associated activation energies under stress levels up to the ideal shear strength. The high-energy barriers under the usual levels of applied shear stresses, differing markedly from the ideal shear strength, confirm the widely held view that thermal motion should play no role in such nucleation. The result provides means for more definitive solutions of fundamental problems involving homogeneous nucleation of dislocation loops and has significant implications for models based on the mechanism of nucleation of dislocations from a perfect crystal.     

Application of the stagnant stage concept for monitoring Mn partitioning at the austenite-ferrite interface in the intercritical region for Fe–Mn–C alloys

The length of the stagnant stage during the new ferrite growth starting from a mixture of austenite and ferrite has been investigated for a Fe-0.17Mn-0.023C (wt%) alloy. It was found that the stagnant stage depends on the thermal path followed to create the mixture, and deduce that the tie-lines for austenite to ferrite transformation are quite different from those for ferrite to austenite transformation. The length of the stagnant stage is determined by the very local partitioning effect at the interface, and it can be used as a tool to monitor the Mn partitioning.     

Understanding scale-dependent yield stress of metals at micrometre scales

The mechanical softening behaviour of micrometre-scale metals (free-standing metal foils and wires) with decreasing either the geometrical or the microstructural scale (i.e. the smaller, the weaker) has recently been reported. Here, we present a mechanism-based model to understand the softening behaviour, which is based on competition between the effects of surface grain relaxation and the interior grain strengthening effect. The model describes well the yield stress of Cu foils with different ratios of the thickness to grain size.     

基因研究中的知情同意之惑

知情同意作为生命伦理的重要原则,在基因研究中同样占据重要的地位,由于基因研究中知情同意的异质性,在基因研究中面临着诸如如何理解其知情同意的异质性、群体知情同意、基因知情与基因隐私、利益冲突等问题.通过分析基因研究中知情同意的特殊性,综合国内外此领域的已有研究,运用理论联系实际的方法,得出结论认为,只有正确区分基因知情与基因隐私的权利主体,用伦理规范来解决利益冲突,在发展中不断完善知情同意,才能够取得科技与伦理的共赢.     

A study of the greater male variability hypothesis in creative thinking in Mainland China: Male superiority exists

This study tested the greater male variability hypothesis in creative thinking with a Chinese student sample in Mainland China. The Test for Creative Thinking-Drawing Production (TCT-DP) was administered to 627 Chinese adolescent boys (n = 332) and girls (n = 295). Results using the boy/girl variance ratio (VR) generally supported the hypothesis that boys have greater variability than girls in creativity test performance. However, results using the boy/girl ratios from different regions of the creativity score distribution revealed a pattern of male superiority. While boys significantly outnumbered girls in the higher extremes, girls tended to outnumber boys in the central region and the lower extremes. Results from an analysis of the means lent further support to the findings of male superiority. Plausible explanations for greater male variability and male superiority in Mainland China are proposed. The theoretical and practical implications of the findings are discussed.     

Some Normal Extensions of K4.3

This paper proves the finite model property and the finite axiomatizability of a class of normal modal logics extending K4.3. The frames for these logics are those for K4.3, in each of which every point has a bounded number of irreflexive successors if it is after an infinite ascending chain of (not necessarily distinct) points.     

Bertrand Russell and the introduction of mathematical logic in China

Bertrand Russell was one of the most prominent figures in the formation and development of mathematical logic. It is widely acknowledged that his work in this field exerted tremendous influence in the West, especially in the first three decades of the twentieth century. The important role he played in inspiring Chinese interest in this subject, however, is virtually unknown. This paper describes Russell's contributions to the introduction of mathematical logic in China through a discussion of his lectures in Beijing in March of 1921, and the subsequent Chinese translations of his Introduction to Mathematical Philosophy and Principia Mathematica.