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71.
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.  相似文献   
72.
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.  相似文献   
73.

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.  相似文献   
74.

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.  相似文献   
75.
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.  相似文献   
76.
Cellular precipitation (also known as discontinuous precipitation) has been observed at the grain boundaries of a newly developed nickel-based Inconel740H alloy designed for use at 700?°C in advanced ultrasupercritical coal-fired power plants. By means of element mapping and selected area diffraction, the cellular precipitates were identified as Cr-rich M23C6 carbides. The onset of cellular precipitation was found to follow a pucker mechanism in Inconel740H. The cellular precipitates at the grain boundaries, even at low volume fractions, were severely detrimental to the creep strength at 750?°C. The creep rupture life of Inconel740H containing cellular precipitates at grain boundaries was only one-tenth of that for the alloy without cellular precipitates. The reason for the drastically decreased creep rupture life is attributed to the poor resistance of cellular precipitates to crack propagation during creep.  相似文献   
77.
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.  相似文献   
78.
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.  相似文献   
79.
高旭 《管子学刊》2013,(1):44-50
《淮南子》对墨子持有复杂的政治认识与态度,这在秦汉思想史上具有一定的代表性。从黄老道家的根本立场出发,“批墨”是《淮南子》政治思想的基本主张,但与此同时,《淮南子》也内在地显示出“尊墨”的政治情怀,进而试图对墨子政治思想有所借鉴和汲取,达到“融墨”之理论目的。对待墨子及其政治思想的历史态度,既凸显出《淮南子》立足黄老,融通诸子的博大精神,也彰显出墨子在秦汉政治思想发展中独特的历史影响。  相似文献   
80.
William James conceptualized I, the self as subject as a stream of consciousness. When this conception is augmented with George Herbert Mead's view of self as a radically socialized and enculturated process, a result is the James-Mead model of dynamic self as a stream of enculturated consciousness. In this paper, we argue that connectionism is best suited to theorize this challenging notion. Based on the view that a connectionist model should describe psychological processes that carry out psychological functions grounded in a biological living system, we propose the I-SELF (Imitative and Sequence Learning Functional) model, which is designed to capture the temporal dynamics of a stream of consciousness whose content can be acquired via symbolically mediated social interaction with others in society. We identify four implications of the James-Mead model of dynamic self (embodiment, narrative and self, individual and collective self, and culture and self), and report computer simulations to show the utility of I-SELF in conceptualizing the dynamic self-processes in the contemporary social psychological literature. Theoretical and metatheoretical implications of the connectionist approach to self are discussed.  相似文献   
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