High-strength and anti-corrosion of Al-Cu-Mg alloy by controlled ageing process

ABSTRACT

The evolution of strength and corrosion behaviour induced by ageing treatment in Al-Cu-Mg alloy is poorly understood. In this work, correlations among strength, intergranular corrosion and pitting corrosion induced by precipitates were studied by various corrosion performance tests and hardness tests. The susceptibility of intergranular corrosion is decreased and pitting corrosion sensitivity is increased as the ageing temperature and time are increased. Retrogression and re-ageing treatments not only transform the size of the intragranular precipitates from greater than 500?nm to be less than 10?nm but also lead to the discontinuous distribution of grain boundary precipitates. The microstructural changes in the grain interior and grain boundary together promote the Al-Cu-Mg alloys to have high-strength and excellent resistance to intergranular corrosion and pitting corrosion.     

Hot isostatic pressing of bulk magnesium diboride: Mechanical and superconducting properties

Hot isostatic pressing with glass encapsulation (pressure, 200MPa; temperature, 1000C over 200min; cooling under pressure) was used to synthesize bulk MgB 2 with diameters up to 20mm and thicknesses up to 10mm from MgB 2 powder. A sharp superconducting transition was measured at 38.5K. This method can be scaled to larger sample sizes and complex shapes. The data for density, microhardness, fracture toughness and sound speed for bulk magnesium diboride are presented. Ball milling the powder results in a more homogeneous final microstructure with a higher resistivity and with a similar superconducting transition.     

行为决策中的基线比例忽略：心理机制与影响因素

基线比例忽略是指个体进行决策和判断时不能充分利用或者忽略基线比例而偏好新信息的现象。该现象普遍存在于日常行为与决策的许多领域,尤其显著表现在临床医疗领域,因此对这一现象的研究具有重要的应用价值。目前,基线比例忽略的心理机制主要有双加工理论和因果贝叶斯框架等。基线比例忽略的影响因素主要包括认知能力、年龄、基线比例的表述形式等。未来的研究需要从基线比例忽略的神经机制、影响因素以及应用研究的拓展等方面着手。     

Refining the two‐parameter testlet response model by introducing testlet discrimination parameters

For testlet response data, traditional item response theory (IRT) models are often not appropriate due to local dependence presented among items within a common testlet. Several testlet‐based IRT models have been developed to model examinees' responses. In this paper, a new two‐parameter normal ogive testlet response theory (2PNOTRT) model for dichotomous items is proposed by introducing testlet discrimination parameters. A Bayesian model parameter estimation approach via a data augmentation scheme is developed. Simulations are conducted to evaluate the performance of the proposed 2PNOTRT model. The results indicated that the estimation of item parameters is satisfactory overall from the viewpoint of convergence. Finally, the proposed 2PNOTRT model is applied to a set of real testlet data.     

Abstract Rule Learning in 11- and 14-Month-Old Infants

This study tests the hypothesis that distributional information can guide infants in the generalization of word order movement rules at the initial stage of language acquisition. Participants were 11- and 14-month-old infants. Stimuli were sentences in Russian, a language that was unknown to our infants. During training the word order of each sentence was transformed following a consistent pattern (e.g., ABC–BAC). During the test phase infants heard novel sentences that respected the trained rule and ones that violated the trained rule (i.e., a different transformation such as ABC–ACB). Stimuli words had highly variable phonological and morphological shapes. The cue available was the positional information of words and their non-adjacent relations across sentences. We found that 14-month-olds, but not 11-month-olds, showed evidence of abstract rule generalization to novel instances. The implications of this finding to early syntactic acquisition are discussed.     

Biological motion cues trigger reflexive attentional orienting

The human visual system is extremely sensitive to biological signals around us. In the current study, we demonstrate that biological motion walking direction can induce robust reflexive attentional orienting. Following a brief presentation of a central point-light walker walking towards either the left or right direction, observers' performance was significantly better on a target in the walking direction compared with that in the opposite direction even when participants were explicitly told that walking direction was not predictive of target location. Interestingly, the effect disappeared when the walker was shown upside-down. Moreover, the reflexive attentional orienting could be extended to motions of other biological entities but not inanimate objects, and was not due to the viewpoint effect of the point-light figure. Our findings provide strong evidence that biological motion cues can trigger reflexive attentional orienting, and highlight the intrinsic sensitivity of the human visual attention system to biological signals.     

Team Training in China: Testing and Applying the Theory of Cooperation and Competition1

The theory of cooperation and competition has the potential both to understand the conditions when organizational groups are productive and major ways to strengthen these groups. Work teams based in a high‐technology company in Beijing, China, participated in a training workshop and a 2‐month follow of feedback and development. Structural equation analyses of data taken before and after the workshop support the hypotheses. In addition, results suggest that the training and follow‐up activities developed cooperative goals and constructive controversy. Findings also indicate that relationships among groups affected the productivity of individual teams. Results were interpreted as suggesting that cooperative goals and constructive controversy contribute to potent, creative, and productive teams in China and perhaps other countries as well.     

加工深度与随意编码条件下母亲参照效应的对比研究

该研究采用新的研究范式在加工深度与随意编码条件下将母亲与自我进行对比研究.结果发现,在新的加工深度与随意编码研究范式下自我参照条件与母亲参照条件下的人格特质形容词的自由回忆率均没有显著差异.结果说明,新的研究范式可以用来探究母亲参照效应;中国人的自我概念中包括母亲.这一发现既是对前人研究结果的一种验证也是对母亲参照效应研究范式的一种扩展.     

论积极心理学视野下的心理韧性

心理韧性是积极心理学领域全新的研究热点之一。以往对于心理韧性的研究,经历了探索个人韧性特质与保护因子的阶段和关注韧性形成的动态过程阶段。在积极心理学思潮的影响下,文章从心理潜能的视角对心理韧性的内涵予以新的诠释;提出促进韧性潜能实现的策略;介绍多种心理韧性测量工具;并以心理韧性当前的研究现状为依据,阐述未来研究的发展趋势:开展实证性研究、注重生物学影响因素、扩大研究领域、实施干预研究。