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71.
C. P. Chang 《Philosophical Magazine Letters》2013,93(5):249-250
Abstract Chaki (1988) has recently proposed a model for diffusion-induced grain boundary migration (DIGM). In his Letter he concluded that the interface energy of a grain boundary and the free energy of mixing are responsible for DIGM and, from the equations he derived, it was claimed that they can explain many DIGM experimental results. However, on examining his model closely there appear to be some fundamental difficulties. The following are comments on his Letter: (1) In Chaki's calculation of ΔGs he assumed that, after interface 1 had moved a distance δx, the radius of curvature of this interface increased from R to R + δx, which gives a surface energy drop of 2γVm δx/R2. However from many DIGM observations (for example Balluffi and Cahn (1981)) the curvature of a migrating boundary is increased rather then decreased, that is, the surface free- energy term actually prevents a grain boundary from migrating rather than helping it! (2) Chaki considered ΔGcryst during the migration of interface 2. It is also necessary to consider AGcrys, during the migration of interface 1, since within the migration distance δx the structure is changed from a crystalline structure to a grain boundary core structure. ΔGm should also be considered during the migration of interface 2 since the concentration of the area swept by interface 2 will not be the same as that of a grain boundary core. 相似文献
72.
73.
Won Seok Chang Sun-Ah Song Yun Hwangbo Jae-Hyun Kim Hak-Joo Lee 《Philosophical Magazine Letters》2013,93(8):391-398
Carbon nanotubes have been intensively studied owing to their great potential in nanoelectronics and nanomechanical devices. Recently, experimental results have shown that single-walled carbon nanotubes (SWCNTs) change their electronic properties when subjected to strain. In this study, the electromechanical characteristics of SWCNT networks were investigated for the application of printable strain sensors on flexible substrates. SWCNT films were formed on plastic substrates of poly(ethylene terephthalate) using a spray process. In this manner, we were able to control the transparency and obtain uniform electrical properties of the films. The films are isotropic on account of the random orientation of bundles of SWCNTs. Experimental results showed a nearly linear change in the resistance across a film when it was subjected to tensile strain, even in the inelastic range of the flexible substrate. The results demonstrate the potential use of SWCNT films for highly sensitive printable strain sensors on a macroscale. 相似文献
74.
The microstructure and crystallization behaviour of melt-spun Al88Ni9Ce2Fe1 amorphous alloy and nanophase composites have been studied by means of X-ray diffraction, transmission electron microscopy and scanning and isothermal calorimetry. The diffraction patterns from Al88Ni9Ce2Fe1 amorphous alloys are diffuse, indicating a basically amorphous structure but contain two rings presumed to be associated with quenched-in nuclei. In the cases of Al88Ni9Ce2Fe1 nanophase composites, nanoscale precipitated particles are homogeneously dispersed in an amorphous matrix, and the crystallite diameter and volume fraction are sensitive to quenching conditions. During thermal crystallization, a two-step phase transformation occurs in the amorphous alloy and nanocomposites, which is characterized by a diffusion-controlled precipitation of nanoscale Al particles and the growth of a Al3(Ni, Fe) nanophase prior to a Al11Ce3 nanophase. This study gives insight into structure-control for obtaining nanophases dispersed in an amorphous matrix by rapid quenching. 相似文献
75.
Chingching Chang 《Media Psychology》2013,16(4):415-441
A theoretical framework is proposed to test the influence of opinions of other consumers, based on perceived similarity, in two contexts. The perceived similarity of the source may be diagnostic for consumers who are concerned about mispurchase. Experiment 1, therefore, compared the effects of ads featuring a consumer versus an expert as an endorser, with participant use status as a moderator that may affect concerns about mispurchase. Potential product users rated the consumer endorser higher on perceived similarity, which increased ad credibility and resulted in better ad and brand attitudes. Experiment 2 compared the effects of information about a product delivered on a consumer blog with that of information from the advertiser's official Web site, with concern about mispurchase as a moderator. More concerned consumers rated the blogger higher than the advertiser on perceived similarity, leading to greater information credibility and more favorable attitudes toward the blog and the product. 相似文献
76.
Verifying properties of concepts spontaneously requires sharing resources with same-modality percept
Nicolas Vermeulen Betty Chang Olivier Corneille Gordy Pleyers Martial Mermillod 《Cognitive processing》2013,14(1):81-87
In the present experiments, participants had to verify properties of concepts but, depending on the trial condition, concept-property pairs were presented via headphones or on the screen. The results showed that participants took longer and were less accurate at verifying conceptual properties when the channel used to present the CONCEPT-property pair and the type of property matched in sensory modality (e.g., LEMON-yellow on screen; BLENDER-loud in headphones) compared to when properties and channel did not match (e.g., LEMON-yellow in headphones; BLENDER-loud on screen). Such interference is consistent with theories of embodied cognition holding that knowledge is grounded in modality-specific systems (Barsalou in Behav Brain Sci 22:577–660, 1999). When the resources of one modality are burdened during the task, processing costs are incurred in a conceptual task (Vermeulen et al. in Cognition 109:287–294, 2008). 相似文献
77.
Flashing a homogeneous light mask after the presentation of a masked target reduces the deleterious effects of the mask, a phenomenon often called target recovery. Target recovery has been studied using masking paradigms in which a target object is presented in isolation prior to the presentation of a mask, thus capturing attention. In the present study, we examined whether target recovery is possible when a target does not benefit from attentional capture. We hypothesized that target recovery would be eliminated when a target must compete with distractors for perceptual attention. Replicating classic studies, we observed target recovery when pattern and light masks followed an isolated target. However, target recovery was not observed when a light mask followed a masked visual search target. Furthermore, using an attentional-capture paradigm we found that sudden onset search targets were recoverable whereas nononset targets were not. The present findings indicate that attentional capture by a target prior to masking plays a critical role in the subsequent recovery of the target. 相似文献
78.
Artemis Chang Shu-Chen Chen Shu-Cheng Steve Chi 《European Journal of Work and Organizational Psychology》2013,22(6):859-874
This study examined the effects of role demand on both work–family conflict and family–work conflict, and the moderating effects of role salience and support on these relationships. Based on 391 dual-career (managerial and blue-collar employees) couples from a Taiwanese company in China, the results of this survey study showed clear gender differences in the patterns of relationships observed. For men, the most important demands that negatively impacted on work–family conflict were frequency of overtime and frequency of socializing for work purposes (yingchou), and supervisory support buffered the negative impact of frequent overtime. For women however, strong supervisory support and low work role salience were more important for reducing work–family conflict, and there was no significant main effect found for any of the role demand factors. Furthermore, women with high work role salience were more likely to feel the impact of yingchou on work–family conflict. In the family domain, the most influential demand for men was hours spent on household tasks, but for women, it was the frequency of family-related leave. Interestingly, males reported higher family role salience than females and spouse support intensified rather than buffered the positive impact of hours spent on household tasks on family–work conflict for males. 相似文献
79.
Dan Li Chung-Ju Huang Sin-Chi Liu Kung-Hung Chang 《Neuropsychology, development, and cognition. Section B, Aging, neuropsychology and cognition》2013,20(6):865-881
ABSTRACTThis study investigated the association between exercise type and inhibition of prepotent responses and error detection. Totally, 75 adults (M = 68.88 years) were classified into one of three exercise groups: those who were regular participants in open- or closed-skill forms of exercise, and those who exercised only irregularly. The participants completed a Stroop and task-switching tasks with event-related brain potentials (ERPs) recorded. The results revealed that regular exercisers displayed faster reaction times (RTs) in the Stroop task compared with irregular exercisers. The open-skill exercisers exhibited smaller N200 and larger P300a amplitudes in the Stroop task compared with irregular exercisers. Furthermore, the open-skill exercisers showed a tendency of shorter error-related negativity latencies at the task-witching test. The findings suggest that older adults may gain extra cognitive benefits in areas such as inhibition functioning and error processing from participating in open-skill forms of physical exercises. 相似文献
80.
The present study aimed to investigate the psychological displacement paradigm in diary-writing (PDPD) had both immediate and short-term psychological benefits. Participants were randomly assigned to write about their recent negative life experiences two times a week for 2 weeks in PDPD group or comparison group. Results revealed that the PDPD group displayed a decrease in negative emotion and an increase in positive emotion immediately after each writing session; they also showed an increase in psychological well-being relative to the comparison group for at least 2 weeks. Implications for PDPD are discussed. 相似文献