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51.
ABSTRACT

The fundamental origin of the reversal transition during crystal growth has been investigated by Monte Carlo simulations. Evidence is provided supporting the geometrical nature of the transition, arising from the broken translational invariance at the growth front and the interactions of multipoles of opposed parity. The range of interactions, the details of the force field and model are irrelevant to the occurrence and only determine the functional behaviour of the relevant physical quantities like the localisation of the critical point and the morphology of the phase diagram.  相似文献   
52.
This article describes a design strategy deployed in developing ultra-ductile Mg alloys based on a microalloying concept, which aims to restrict grain growth considerably during alloy casting and forming. We discuss the efficiency of the design approach, and evaluate the resulting microstructural and mechanical properties. After processing, the so-designed alloys ZQCa3 (Mg–3Zn–0.5Ag–0.25Ca–0.15Mn, in wt.%) and ZKQCa3 (Mg–3Zn–0.5Zr–0.5Ag–0.25Ca–0.15Mn, in wt.%) reveal very fine grains (<10 µm), high ductility (elongation to fracture of up to 30%) at moderate strength or high strength (ultimate tensile strength of up to 350 MPa) at reasonable ductility. These properties are explained based on thermodynamic modelling, microstructure analysis including transmission electron microscopy studies, and microstructural and mechanical testing after annealing, and are compared to a related commercial alloy (ZK31).  相似文献   
53.
The author's purpose in this study was to test 4 hypotheses that proposed different paths for the influences of children's television viewing on their academic achievement. Data were drawn from the 1997 Child Development Supplement (CDS) to the Panel Study of Income Dynamics (PSID). The population for this study included 1,203 children between the ages of 6 and 13 years from the CDS-PSID data set. The author used structural equation modeling to test pathways from children's television viewing to their academic achievement. The author assumed that children's television viewing hindered their academic achievement by reducing certain traits that related to academic achievement. Results showed that 3 hypothetical models fit the data—the time-displacement hypothesis, the mental effort-passivity hypothesis, and the attention-arousal hypothesis. A 4th hypothetical model, the learning-information hypothesis, which proposed that children's television viewing practices stimulate their academic achievement, was not supported. In sum, children who watched more television tended to spend less time doing homework, studying, and reading for leisure. In addition, their behaviors became more impulsive, which resulted in an eventual decrease in their academic achievement.  相似文献   
54.
Although research has established a connection between career growth and turnover intentions, there continues to be a need to study how employee career growth contributes positively to organizations. In the present research, we studied in particular how employees' organizational career growth is related to voice behavior. Employing theories of social exchange, organization-based self-esteem, and psychological attachment, we developed six hypotheses pertinent to this relationship, including the mediating role of affective organizational commitment and the moderating effect of gender. We tested our hypotheses using data from 328 employees in Mainland China over three time periods. As we hypothesized, we found positive relationships between the three dimensions of organizational career growth and subsequent voice behavior. Our results also verified that these relationships are partially mediated by affective organizational commitment and partially moderated by gender.  相似文献   
55.
We evaluated video modeling and reinforcement for teaching perspective-taking skills to 3 children with autism using a multiple baseline design. Video modeling and reinforcement were effective; however, only 2 children were able to pass an untrained task, indicating limited generalization. The findings suggest that video modeling may be an effective technology for teaching perspective taking if researchers can continue to develop strategies for enhancing the generalization of these new skills.  相似文献   
56.
57.
Archival studies of within-family prosocial behavior (Judge & Hrdy, 1992; Smith, Kish, & Crawford, 1987) have shown that inheritance patterns support Hamilton’s (1964) theory of inclusive fitness, such that people will more of their estates to relatives of closer genetic relatedness. In a survey-based simulation of these studies, students allocated one of three lotteries to their blood relatives. As expected, participants allocated greater proportions of their lotteries to relatives of greater genetic relatedness. This effect became stronger with decreasing lottery amounts. Relatives of certain relatedness were favored over relatives of uncertain relatedness (via paternal uncertainty), and this effect was stronger among those with less money to allocate. Male participants tended to favor their young female relatives over their young male relatives when given the smallest lottery, but this sex preference reversed when male participants were given the largest lottery. In general, scarcer resources led to more evolutionarily conservative investment strategies.  相似文献   
58.
A large orthographic neighborhood (N) facilitates lexical decision for central and left visual field/right hemisphere (LVF/RH) presentation, but not for right visual field/left hemisphere (RVF/LH) presentation. Based on the SERIOL model of letter-position encoding, this asymmetric N effect is explained by differential activation patterns at the orthographic level. This analysis implies that it should be possible to negate the LVF/RH N effect and create an RVF/LH N effect by manipulating contrast levels in specific ways. In Experiment 1, these predictions were confirmed. In Experiment 2, we eliminated the N effect for both LVF/RH and central presentation. These results indicate that the letter level is the primary locus of the N effect under lexical decision, and that the hemispheric specificity of the N effect does not reflect differential processing at the lexical level.  相似文献   
59.
管理评价判断模型与策略获取   总被引:2,自引:0,他引:2  
李德忠  王重鸣 《心理科学》2005,28(1):133-134
管理评价是在不确定情景中的一种多特征决策,非补偿策略是决策者所采用的主导判断模型。作为一种结构建模程序,策略捕捉可以建构包含决策标准及其权重的统计模型,获取决策内在过程和预测判断。多层线性模型能够方便地考察人内和人间变异,表征判断非线性结构,是分析策略捕捉数据的恰当方法。管理评价设计可以借鉴行为经济学和实验经济学的思路,实现对现实管理决策过程的抽象模拟。  相似文献   
60.
Chardie L. Baird 《Sex roles》2008,58(3-4):208-221
The effects of community context on occupational aspirations are examined in a national sample of young women in high school in the USA in 1979 (n = 2,210). Multilevel statistical models indicate that young women living in counties with a lower divorce rate, a lower percentage of women working, and more people employed in the wholesale and retail industrial sector tended to be less likely to aspire to paid work than young women living in areas with a higher divorce rate, a higher percentage of women working, and fewer people employed in the wholesale and retail industrial sector. Community context does not affect the level of young women’s occupational aspirations as predicted by prior scholarship. An earlier version of this paper was presented at the 2006 Southern Sociological Society Annual Meetings. The author thanks John Reynolds, Patricia Yancey Martin, Irene Padavic, Robert Kunovich, Jennifer Keene, Mary Guy, and the editor and reviewers at Sex Roles for their helpful comments on previous drafts of this paper.  相似文献   
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