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271.
We report the mechanical properties and microstructures of titanium-microalloyed interstitial-free (IF) steels with different carbon contents smelted and rolled in the laboratory. The results show an increase of yield strength and tensile strength with carbon content, which are enhanced with lower coiling temperature (CT). Microstructure analysis reveals that the ferrite grain size varies from 11 to 23?μm, while the average size of TiC as the main second-phase particle ranges from 10 to 35?nm. The sample with 80?ppm carbon and 853?K CT reaches a mechanical strength close to that of high-strength IF steels. The increase of yield strength is mainly attributed to both grain-refining and precipitation strengthening.  相似文献   
272.
Eye movements were measured to examine whether item-method directed forgetting involved a spatial overt attention shift. Experiment 1 showed that participants’ eyes were moved away from the study word following the forget and ignore cues, but not the remember cue. Experiment 2 revealed that the eyes were moved away from the area that covered by the study word even when the study word disappeared upon the presentation of the memory cue. Both the study word and memory cue were presented auditorily in Experiment 3. In all experiments, the to-be-remembered words were recalled better than both to-be-forgotten and to-be-ignored words. More importantly, mental effort, as indexed by the pupil size, increased following the remember, as compared with the forget and ignore cues. These findings are discussed in terms of controlling spatial overt attention after encoding to withdraw attention from irrelevant information and to allocate cognitive resources to relevant information for long-term retention.  相似文献   
273.
Burnout is a highly prevalent globalized health issue that causes significant physical and psychological health problems. In Latin America research on this topic has increased in recent years, however there are no studies comparing results across countries, nor normative reference cut-offs. The present meta-analysis examines the intensity of burnout (emotional exhaustion, cynicism and personal accomplishment) in 58 adult nonclinical samples from 8 countries (Argentina, Brazil, Chile, Colombia, Ecuador, Mexico, Peru and Venezuela). We found low intensity of burnout but there are significant differences between countries in emotional exhaustion explained by occupation and language. Social and human service professionals (police officers, social workers, public administration staff) are more exhausted than health professionals (physicians, nurses) or teachers. The samples with Portuguese language score higher in emotional exhaustion than Spanish, supporting the theory of cultural relativism. Demographics (sex, age) and study variables (sample size, instrument), were not found significant to predict burnout. The effect size and confidence intervals found are proposed as a useful baseline for research and medical diagnosis of burnout in Latin American countries.  相似文献   
274.
Handwritten signatures have been traditionally associated with personality traits. In this study, we examined the relationship of signature size with intrasexual competition, aggressive and sociable dominance, narcissism, and self-esteem in a sample of Uruguayan university students (N = 340). The study went methodologically beyond current research by examining three different operationalizations of signature size, and by controlling for potential confounders: number of characters in the printed name, average character area in the printed name—a proxy for overall writing size—, and signature style. After controlling for these potential confounders and demographic variables, our results showed a significant link between signature size and sociable dominance, both for males and females, while narcissism was only in females significantly associated with signature size.  相似文献   
275.
The relationship between affect and metacognitive processes has been largely overlooked in both the affect and the metacognition literatures. While at the core of many affect-cognition theories is the notion that positive affective states lead people to be more confident, few studies systematically investigated how positive affect influences confidence and strategic behaviour. In two experiments, when participants were free to control answer interval to general knowledge questions (e.g. question: “in what year”, answer: “it was between 1970 and 1985”), participants induced with positive affect outperformed participants in a neutral affect condition. However, in Experiment 1 positive affect participants showed larger overconfidence than neutral affect participants. In Experiment 2, enhanced salience of social cues eliminated this overconfidence disadvantage of positive affect relative to neutral affect participants, without compromising their enhanced performance. Notably, in both experiments, positive affect led to compromised social norms regarding the answers’ informativeness. Implications for both affect and metacognition are discussed.  相似文献   
276.
Different studies on how well people take sample size into account have found a wide range of solution rates. In a recent review, Sedlmeier and Gigerenzer (1997) suggested that a substantial part of the variation in results can be explained by the fact that experimenters have used two different types of sample-size tasks, one involving frequency distributions and the other sampling distributions. This suggestion rested on an analysis of studies that, with one exception, did not systematically manipulate type of distribution. In the research reported in this paper, well-known sample-size tasks were used to examine the hypothesis that frequency distribution versions of sample-size tasks yield higher solution rates than corresponding sampling distribution versions. In Study 1, a substantial difference between solution rates for the two types of task was found. Study 2 replicated this finding and ruled out an alternative explanation for it, namely, that the solution rate for sampling distribution tasks was lower because the information they contained was harder to extract than that in frequency distribution tasks. Finally, in Study 3 an attempt was made to reduce the gap between the solution rates for the two types of tasks by giving participants as many hints as possible for solving a sampling distribution task. Even with hints, the gap in performance remained. A new computational model of statistical reasoning specifies cognitive processes that might explain why people are better at solving frequency than sampling distribution tasks. Copyright© 1998 John Wiley & Sons, Ltd.  相似文献   
277.
以自定步调学习时间和习得试验次数为加工流畅性指标,通过操纵不同字号的词对考察了加工流畅性对学习判断字体大小效应的影响。结果发现:(1)字体大小影响学习判断,但不影响回忆成绩;(2)不同字体大小的词对在加工流畅性(学习时间和学习次数)上存在差异,仅自定步调学习时间测量的加工流畅性对学习判断字体大小效应有贡献。这些结果说明学习判断的字体大小效应是一种元认知错觉现象,部分支持了加工流畅性假说。  相似文献   
278.
Publication bias is the disproportionate representation of studies with large effects and statistically significant findings in the published research literature. If publication bias occurs in single-case research design studies on applied behavior-analytic (ABA) interventions, it can result in inflated estimates of ABA intervention effects. We conducted an empirical evaluation of publication bias on an evidence-based ABA intervention for children diagnosed with autism spectrum disorder, response interruption and redirection (RIRD). We determined effect size estimates for published and unpublished studies using 3 metrics, percentage of nonoverlapping data (PND), Hedges' g, and log response ratios (LRR). Omnibus effect size estimates across all 3 metrics were positive, supporting that RIRD is an effective treatment for reducing problem behavior maintained by nonsocial consequences. We observed larger PND for published compared to unpublished studies, small and nonsignificant differences in LRR for published compared to unpublished studies, and significant differences in Hedges' g for published compared to unpublished studies, with published studies showing slightly larger effect. We found little, if any, difference in methodological quality between published and unpublished studies. While RIRD appears to be an effective intervention for challenging behavior maintained by nonsocial consequences, our results reflect some degree of publication bias present in the RIRD research literature.  相似文献   
279.
Communal litter defence by sister and nonsister female mice can provide a valuable experimental paradigm to test whether females invest preferentially in kin. Since females within sister and nonsister pairs have different coefficients of relatedness with the young, the cumulative litter has more fitness value for related than for unrelated partners. Sister and nonsister paired females that gave birth simultaneously (n = 18), or at least within 7 days from each other (n = 12), were tested for maternal aggression on post partum day 7, or 10 days after the first delivery, respectively. Sister (n = 14) and nonsister pairs (n = 16) did not differ in cumulative values of post partum aggression or in the extent to which aggression was balanced within the pair. The aggressive behavior of each female was not correlated with her relative proportion of pups in the litter. Rather, the combined scores of aggression within the pairs were found to be positively correlated with the cumulative litter size. The analysis of mouse litter defence behavior shows that, under conditions of communal nesting, kinship does not seem to affect parental investment in the young significantly. Rather, the cumulative litter size could be used by paired females as a major indicator for parental investment allocation.  相似文献   
280.
Interval estimates of the Pearson, Kendall tau-a and Spearman correlations are reviewed and an improved standard error for the Spearman correlation is proposed. The sample size required to yield a confidence interval having the desired width is examined. A two-stage approximation to the sample size requirement is shown to give accurate results.  相似文献   
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