Equivalent strain-hardening work theorem

A new physical concept, termed ‘equivalent strain-hardening work’, is proposed. The physical concept can be used to redefine the commonly used effective stress and effective strain theory as applied in constructing the constitutive relations of stress and strain, especially when related to an anisotropic strain-hardening material. The concept concerns that part of plastic work which emphasizes the action due to the strain-hardening behaviour of a material. Based on this concept, any one of the strain-hardening stress–strain curves obtained through common experiments on anisotropic materials can be selected as a nominally effective stress and an associated effective strain, and the rest of the strain-hardening relations can all be then transformed to be functions of variables of the nominally effective strain. Thus, any kind of loading path can be characterized by a single relation between effective stress and effective strain. When applied to the isotropic materials, the equivalent strain-hardening work concept is identical with the work-equivalent deformation concept but is more general.     

我国运动员主观幸福感内部结构及外部影响因素研究

通过探索我国运动员主观幸福感的内部结构,并对我国运动员主观幸福感的外部影响因素进行分析。研究结果发现,我国运动员主观幸福感由7个二级指标及38个三级指标构成,其中负性情感、生活环境、训练竞赛、人际关系等二级指标对我国运动员主观幸福感有重要影响。竞赛水平的发挥、教练员对运动员的公平性、运动员伤残补偿制度建设、运动队管理方式、运动成绩提升空间等三级指标是影响运动员幸福感的重要外部因素。     

Cultural and Bilingual Influences on Artistic Creativity Performances: Comparison of German and Chinese Students

Empirical research on the relationship between culture and creativity has thus far yielded no consistent results. Investigations of the differences are mostly post-hoc, and results are inconclusive. A creativity-value-oriented theory is proposed to explain cultural differences, as an alternative to ethnic and language effects. This study was conducted to compare the performances of artistic creativity of Germans and Chinese. Results revealed that the four groups of students examined (German students of Caucasian descent, German students of Asian descent, Chinese students studying abroad, and Chinese students studying in China) differed in their artistic creativity. German participants (Caucasian Germans and Asian Germans) produced more creative and aesthetically pleasing artwork than did their Chinese counterparts (Chinese studying abroad and domestic Chinese). This difference was observed by both German and Chinese judges. There no significant subgroup differences in creative performances—no difference between the two German groups, and no difference between the two Chinese groups. Finally, although there were significant differences between German judges, Chinese judges studying abroad, and domestic Chinese judges in judging the artworks, these were not due to a preference for artwork from students from their own cultural background. Chinese and German judges roughly agreed on what constitutes creativity. These results suggest that cultural differences affect creative performances.     

Relative Leader–Member Exchange Within Team Contexts: How and when Social Comparison Impacts Individual Effectiveness

A multilevel model was developed to examine how and when a focal individual's leader–member exchange (LMX) relative to the LMXs of coworkers within the team (relative LMX, or RLMX) influences individual in‐role performance, organizational citizenship behavior (OCB), and job satisfaction. Results, based on a sample of 275 leader–member dyads within 35 teams of a beverage company, largely supported the hypotheses. Specifically, using multilevel polynomial regression analyses, the results showed that self‐efficacy partially mediated the relationship between RLMX and in‐role performance and job satisfaction, and fully mediated the relationship between RLMX and OCB. Furthermore, the results demonstrated that team identification attenuated RLMX's direct effect on self‐efficacy, and indirect effects on in‐role performance and OCB and team supportive behavior attenuated RLMX's direct effect on self‐efficacy and indirect effect on in‐role performance.     

The development and analysis of tutorial dialogues in AutoTutor Lite

The goal of intelligent tutoring systems (ITS) that interact in natural language is to emulate the benefits that a well-trained human tutor provides to students, by interpreting student answers and appropriately responding in order to encourage elaboration. BRCA Gist is an ITS developed using AutoTutor Lite, a Web-based version of AutoTutor. Fuzzy-trace theory theoretically motivated the development of BRCA Gist, which engages people in tutorial dialogues to teach them about genetic breast cancer risk. We describe an empirical method to create tutorial dialogues and fine-tune the calibration of BRCA Gist’s semantic processing engine without a team of computer scientists. We created five interactive dialogues centered on pedagogic questions such as “What should someone do if she receives a positive result for genetic risk of breast cancer?” This method involved an iterative refinement process of repeated testing with different texts and successively making adjustments to the tutor’s expectations and settings in order to improve performance. The goal of this method was to enable BRCA Gist to interpret and respond to answers in a manner that best facilitated learning. We developed a method to analyze the efficacy of the tutor’s dialogues. We found that BRCA Gist’s assessment of participants’ answers was highly correlated with the quality of the answers found by trained human judges using a reliable rubric. The dialogue quality between users and BRCA Gist predicted performance on a breast cancer risk knowledge test completed after exposure to the tutor. The appropriateness of BRCA Gist’s feedback also predicted the quality of answers and breast cancer risk knowledge test scores.     

Microstructural characterization of the M23C6 carbide in a long-term aged Ni-based superalloy

The microstructural features of M₂₃C₆ carbide in a long-term aged heat- and corrosion-resistant Ni-based superalloy have been investigated in detail using various kinds of transmission electron microscope (TEM) techniques. It is found that TEM contrast, which is related to structural and chemical inhomogeneities inside the grains, always exists in the interior of grains in the alloy. The structure of these inhomogeneous regions has been determined to be the same as that of the γ′ and t-M₂₃C₆ phases, where t-M₂₃C₆ indicates a transitional and metastable phase. Although possessing the same structure as the M₂₃C₆ phase, the chemical composition of the t-M₂₃C₆ is different from that of the M₂₃C₆ phase. Compared with M₂₃C₆, t-M₂₃C₆ is richer in Ni, Co, Al and Ti but poorer in W, Mo and Cr. This phenomenon of structural and chemical inhomogeneity demonstrates that pristine M₂₃C₆ carbide (p-M₂₃C₆) precipitated in standard heat-treated samples is unstable. Therefore, upon long-term ageing treatment, Ni, Co, Al and Ti may locally enrich inside the p-M₂₃C₆ phase, finally forming the γ′ phase, which can be described by the decomposition reaction p-M₂₃C₆ → M₂₃C₆ + γ′.     

Formation of yittrium oxide in cemented carbides

Rare-earth (RE) elements are helpful in improving the mechanical properties of cemented carbides. In this work, the formation of Y₂O₃ in functionally graded cemented carbides is investigated using transmission electron microscopy. The results indicate that Y₂O₃ can stabilize the Co phase with the face-centred cubic structure (α-Co), since it has a cubic structure similar to the high-temperature Co phase. The α-Co phase has a higher plasticity than ε-Co, and this suggests a possible mechanism for the role of RE elements in toughening cemented carbides.     

The influence of visual mental imagery size on metamemory accuracy in judgment of learning

Many studies have found the font size of to-be-remembered words has a significant influence on judgments of learning (JOLs). However, few studies have investigated whether JOLs are affected by the mental imagery size of to-be-remembered words, even when the font sizes themselves are kept identical in study materials. This study investigated whether the visual mental imagery size influences the participants’ JOLs and what the underlying mechanisms are. In Experiments 1 and 2, participants learned words with identical font sizes, mentally generated large or small imageries and then made JOLs. We found that JOLs under the large imagery condition were significantly higher than those under the small imagery condition, but actual recall performance exhibited no significant difference. In Experiment 3, participants pressed a button immediately after mental imagery generation and showed that it took significantly longer to generate large imageries than to generate small imageries, and the difference in JOLs between two conditions was no longer significant. In Experiment 4, we used a questionnaire to investigate the contribution of beliefs and found that participants believed large imageries were easier to remember. These findings indicate that imagery size has a significant impact on JOLs, in which beliefs may play a leading role.     

Effects of a ‘Learn to Think’ intervention programme on primary school students

Background. Methods for teaching thinking may be described as out‐of‐context or infusion. Both approaches have potential to raise students’ general cognitive processing ability and so raise academic achievement, but each has disadvantages. Aims. To describe and evaluate a theory‐based learn to think (LTT) curriculum for primary school students, which draws on the strengths of both out‐of‐context and infusion approaches. Sample. One‐hundred and sixty‐six students in three classes of Grade 1 (6+ years old), Grade 2 (7+ years old), and Grade 3 (8+ years old) in a primary school in Shanxi province, China, randomly ascribed to experimental (90) and control (76) groups. Methods. All students were pre‐tested for non‐verbal intelligence and academic achievement. Experimental students followed the LTT curriculum (one activity every 2 weeks) for 4 school years. All were post‐tested on three occasions for thinking ability and four times for academic achievement. Results. Grade 1 and Grade 2 students showed effects of LTT from 1 year after their start and increasing: on thinking ability d= .78–1.45; on Chinese d= .68–1.07; on maths .58–.87. Grade 3 students showed effects from 6 months after their start: on thinking ability .90–1.37; Chinese .77–1.32; maths .65–1.29. The effects were concentrated in students in the middle band of initial ability. Conclusions. A curriculum for teaching thinking based on a structured theoretical model that combines elements of out‐of‐context and infusion methods has been shown to have long‐term far transfer effects on students’ thinking ability and academic achievement. More work is needed to meet the needs of a wider range of abilities.