On the length scale of cyclic strain localization in fine-grained copper films

Fine-grained copper films on a flexible substrate were cyclically deformed under constant strain range control. It was found that cyclic dislocation plasticity through individual dislocation glide is still dominant at the submicrometer scale, while the ability of irreversible slip of dislocations gradually decreases and the damage was changed from extrusion-induced localization to cracking along grain boundary. Statistical evaluation of the mean spacing between slip bands and/or lines leads to a critical scale (～28 nm) below which dislocation-controlled cyclic strain localization would be shut down.     

Structural characteristics of a high-quality Al?Ni?Ru decagonal quasicrystal with 1.6nm periodicity,studied by atomic-scale electron microscopy observations

We report the structural characteristics of a high-quality stable decagonal quasicrystal (D phase) with 1.6nm periodicity, formed in Al₇₅Ni₁₅Ru₁₀ alloy annealed at 890°C for 24h. The tiling structure and the arrangement of transition-metal atoms (Ru and Ni) in this Al-Ni-Ru D phase have been clearly revealed by high-resolution electron microscopy (HREM) and by highangle annular detector dark-field (HAADF) scanning transmission electron microscopy (STM) respectively. On the basis of the HREM and HAADF STM observations, the relationship between the arrangement of local structural units and the formation of the long-range quasiperiodic tiling structure is discussed.     

The role of learning experience on the perceptual organization of Chinese characters

The effect of learning experience on the perceived graphemic similarity of Chinese characters was examined by comparing results of the constrained (Experiment 1) and unconstrained (Experiment 2) shape-sorting tasks obtained from various groups of participants with different learning experiences and ages. The results from hierarchical cluster analysis showed that both Taiwanese and Japanese undergraduates classified characters in relation to their configurational structures, whereas American undergraduates, Taiwanese illiterate adults, and kindergartners categorized characters based on strokes or components. Although a trend of developmental changes from local details to more globally defined patterns was found, the identification of structure as consistently perceived by skilled readers has to be nourished by learning experience and cannot be obtained solely through maturation.     

The effect of spatial and nonspatial contextual information on visual object memory

Recent research has found visual object memory can be stored as part of a larger scene representation rather than independently of scene context. The present study examined how spatial and nonspatial contextual information modulate visual object memory. Two experiments tested participants’ visual memory by using a change detection task in which a target object's orientation was either the same as it appeared during initial viewing or changed. In addition, we examined the effect of spatial and nonspatial contextual manipulations on change detection performance. The results revealed that visual object representations can be maintained reliably after viewing arrays of objects. Moreover, change detection performance was significantly higher when either spatial or nonspatial contextual information remained the same in the test image. We concluded that while processing complex visual stimuli such as object arrays, visual object memory can be stored as part of a comprehensive scene representation, and both spatial and nonspatial contextual changes modulate visual memory retrieval and comparison.     

Conditional estimation of exponential random graph models from snowball sampling designs

A complete survey of a network in a large population may be prohibitively difficult and costly. So it is important to estimate models for networks using data from various network sampling designs, such as link-tracing designs. We focus here on snowball sampling designs, designs in which the members of an initial sample of network members are asked to nominate their network partners, their network partners are then traced and asked to nominate their network partners, and so on. We assume an exponential random graph model (ERGM) of a particular parametric form and outline a conditional maximum likelihood estimation procedure for obtaining estimates of ERGM parameters. This procedure is intended to complement the likelihood approach developed by  Handcock and Gile (2010) by providing a practical means of estimation when the size of the complete network is unknown and/or the complete network is very large. We report the outcome of a simulation study with a known model designed to assess the impact of initial sample size, population size, and number of sampling waves on properties of the estimates. We conclude with a discussion of the potential applications and further developments of the approach.     

Taiwanese junior college students' needs for and perceptions of a career planning course

A 30-item survey was developed to assess the career planning needs of junior college students in Taiwan. 159 men and 493 women were surveyed about career planning needs and perceptions of a proposed course model to answer whether women differ from men in such needs and upper and lower division students differ. A series of two-way analyses of variance identified 7 items on which the women expressed needs more strongly than the men and another 8 items on which the responses of lower division students were significantly different from those of upper division students. Students' perceptions of a course model provided recommendations for a course in career education.     

Self-verification and contextualized self-views

Whereas most self-verification research has focused on people's desire to verify their global self-conceptions, the present studies examined self-verification with regard to contextualized selfviews-views of the self in particular situations and relationships. It was hypothesized that individuals whose core self-conceptions include contextualized self-views should seek to verify these self-views. In Study 1, the more individuals defined the self in dialectical terms, the more their judgments were biased in favor of verifying over nonverifying feedback about a negative, situation-specific self-view. In Study 2, consistent with research on gender differences in the importance of relationships to the self-concept, women but not men showed a similar bias toward feedback about a negative, relationship-specific self-view, a pattern not seen for global self-views. Together, the results support the notion that self-verification occurs for core self-conceptions, whatever form(s) they may take. Individual differences in self-verification and the nature of selfhood and authenticity are discussed.     

Economic pressure in African American families: a replication and extension of the family stress model

This study of 422 two-caregiver African American families, each with a 10-11-year-old focal child (54% girls), evaluated the applicability of the family stress model of economic hardship for understanding economic influences on child development in this population. The findings generally replicated earlier research with European American families. The results showed that economic hardship positively relates to economic pressure in families. Economic pressure was related to the emotional distress of caregivers, which in turn was associated with problems in the caregiver relationship. These problems were related to disrupted parenting practices, which predicted lower positive child adjustment and higher internalizing and externalizing symptoms. The results provide significant support for the family stress model of economic hardship and its generalizability to diverse populations.     

Comparison of ganglion cell signals and psychophysical localization of moving targets can help define central motion mechanisms

Vernier acuity thresholds can be related to visibility of targets. This is considered in relation to retinal signals. Spatial precision of macaque ganglion cell responses to moving targets was assessed by neurometric analysis and compared with psychophysical performance. Under some conditions the amplitude of ganglion cell signals per se may relate target visibility to spatial precision of psychophysical performance. Other conditions are more complex; we suggest central mechanisms may adapt their properties, eg their dimensions, depending on the stochastic properties of ganglion cell signals. Thus, the relation of Vernier acuity to the visibility of targets is a rule of thumb which has a complex relation to physiological substrates.     

Effects of openness, problem solving, and blaming on learning: an experiment in China

Researchers have considered interdependence and interaction among individuals and groups as critical for promoting learning in organizations. In an experiment with 80 participants in China, the present authors found that (a) open discussion compared with avoiding discussion and (b) problem solving compared with blaming stimulated the exploration, integration, and adoption of alternative ideas in addition to strengthening interpersonal relationships. The results also indicated the possibility that openness and problem solving have these effects by developing a perceived cooperative interdependence that encourages people to believe that incorporating alternative ideas can help them succeed. Avoidance and blaming, on the other hand, seemed to result in a competitive struggle to see who could impose their ideas on the other, leaving people committed to their original thinking.