Stability of the F2-(Al-Pd-Mn) phase

The stability of the F2-(Al-Pd-Mn) phase has been studied by in-situ neutron diffraction on a single quasicrystal with composition Al_69.8Pd_21.4Mn_8.8. We find that the F2 phase is not stable and corresponds to a transient state in the process of the transformation of the icosahedral phase to the F2_M phase. The icosahedral-to-F2_Mphase transition occurs at around 715^oC. In the F2 phase a large amount of diffuse scattering is located close to the icosahedral Bragg reflection in place of the S ₁ superstructure reflections characteristic of the F2_m phase.     

Experimental determination of trapping efficiency of optical tweezers

We report an experimental determination of trapping efficiency of optical fields acting on spherical particles diluted in viscous fluids. This parameter was derived from experimentally calculated trap stiffness for micron-sized silica beads with particle radii of 1.5 and 4.8 microns, respectively. In order to obtain the trap stiffness, we used the equipartition theorem, and introduced an experimental procedure to calibrate the optical tweezers set-up. The method consists of the calculation of the trapping efficiency by using the curves of the trap stiffness vs. the incident power. Using this approach we measured the efficiency for different values of displacements of the beads in the optical trap, and compared these results with numerical and theoretical calculations reported in the literature, and an excellent agreement was found. We have shown that the ratio of efficiencies is very close to the ratio of the particle radii.     

Economic cooperation in western Asia

Any changing system both develops and evolves (individuates). The evolution of the biosphere must therefore be taken in context of the development of the earth, which appears to have followed typical developmental rules of dissipative structures. Two different perspectives are possible on dissipative structures—the classical externalist perspective, which views open systems as becoming progressively negentropic, and the newer, internalist perspective, which views them from within as becoming increasingly disorderly. A history of the universe can be traced, alternately stressing the one and the other perspective, which can form the basic structure of a modern, science‐based creation myth.     

The influence of visual noise in the binding of irrelevant features to responses

ABSTRACT

In order to efficiently control our actions, stimuli and responses made to them are stored and integrated into event files. This integration is not restricted to relevant stimuli. Even irrelevant stimuli or features that co-occur at responding can be integrated with the response. In the presence of only one irrelevant feature, binding effects for that feature are generally observed. In the presence of more than one irrelevant features, empirical evidence is inconsistent. The present experiments tested feature-response binding effects for irrelevant features when more than one irrelevant feature was present. In two experiments feature-response binding effects for three irrelevant features (colour, shape, and location) were tested in a block-wise manner. In each block one feature was orthogonally varied to the response while the others were held constant (Experiment 1) or always changed (Experiment 2). Significant binding effects were observed for each of three features when the other two were held constant (Exp. 1). However, when the other two features were varied, significant binding effects were only observed for colour and location, but not for shape (Exp. 2). The results suggest that strength of feature-response binding effects is influenced by the variation of simultaneously presented features.     

视觉特征捆绑：基于时间同步还是基于相同空间位置？

通过操纵客体呈现的空间位置和时间顺序,来考察视觉特征捆绑是基于相同空间位置线索还是基于时间邻近线索。在两个实验中,给被试在固定的注视点位置（固定呈现条件）或在注视点上/下位置（变换呈现条件）快速地系列呈现刺激,记录靶子前后各两个时间位置（-2、-1、+1、+2）的错觉性结合（IC）率。结果发现,在固定呈现条件下,IC更多地出现在-1和+1的时间位置上;而在变换呈现条件下,错觉性结合更多地出现在-2和+2时间位置上。为了进一步排除特定实验范式的影响,在实验3中,我们采用特征分离范式,使被分离的刺激特征同时呈现在相同（相同位置同步）或不同（不同位置同步）的空间位置上。结果表明,这两种条件下的IC率无显著差异,这说明错觉性结合不受时间同步模式的影响。综上所述,来自三个实验的结果表明,时间范围内的特征捆绑机制是按空间位置,而不是按时间邻近,线索进行的：若特征的空间位置相同,时间邻近的特征才被捆绑起来;若空间位置不同,即使时间邻近的特征也不能被捆绑到一起。     

Kinetic study of static recrystallization in an Fe–Al–O ultra-fine-grained nanocomposite

A nearly abrupt coarsening of grains is observed in a newly developed Fe–Al–O ultra-fine-grained nanocomposite with a significant volume fraction (4%) of alumina nano-precipitates. The microstructure of the alloy was analysed in different states (as-received and annealed) by means of scanning electron microscopy, transmission electron microscopy (TEM) and hardness. The initial grain size 150–200 nm increases up to 50 μm during annealing 1000 °C/8 h and thereafter demonstrates saturation. A linear correlation between volume fraction of coarse grains and hardness was found. It was identified by TEM that alumina nano-precipitates stabilize the dislocation microstructure against recovery very effectively and the grain coarsening is due to fast growth of very few dislocation free grains. Thus, the observed grain coarsening has the attributes of static recrystallization.     

Teacher performance goal practices and elementary students' behavioral engagement: a developmental perspective

We investigated growth trajectories for classroom performance goal practices and for student behavioral engagement across grades 2 to 5 for 497 academically at-risk elementary students. This study is the first longitudinal investigation of performance goal practices in the early elementary years. On average, teacher use of performance goal practices increased and students' behavioral engagement declined across the four years. Using autoregressive latent trajectory (ALT) models, we examined the synchronous relations between teacher-reported performance goal practices and teacher-reported student behavioral engagement. As expected, as students move into classrooms with a new teacher with less emphasis on performance goal practices, they become more behaviorally engaged in school. Gender did not moderate these results. Implications for teacher professional development are discussed.     

‘Oh I do like to be beside the seaside’: opportunity structures for four un/underemployed young people living in English coastal towns

Long-term unemployed young people are a ‘social concern’ in many countries. The focus for research is usually cities, but may also include rural areas. The qualitative study described in this paper focuses instead on four young people living in coastal towns in South East England. The study suggests that their experiences in education and employment markets are shaped, negatively, by their particular location and the ongoing opportunity structures. The paper outlines their views and discusses the three main themes that emerged from the analysis: opportunity structures, supported resilience and the impact of living in a coastal town. Implications for targeted youth guidance are considered, alongside a consideration of the reflexive role of the researcher in such work.     

Reconceptualizing adult attachment relationships: A network perspective

This article explores attachment relationships from a network theory perspective: Correlations among behaviors, beliefs, and feelings related to attachment are hypothesized to stem from causal relations. The authors used two data sets that assessed relationships with four attachment figures (mother, father, romantic partner, and best friend) using the Relationship Structures Questionnaire. Separate networks (Gaussian Graphical Models) were estimated based on 10 items for each attachment figure. Across networks in Study 1 (N = 310), items related to anxiety, seeking support, and discomfort disclosing feelings clustered with other items from their respective domains; a trust‐related item bridged the clusters. Study 2 replicated these findings in a larger and more diverse sample (N = 3,710). The potential of network analysis for advancing the study of attachment is discussed.     

类别标签与典型性程度对类别特征推理的影响

本研究采用学习-测试二阶段实验范式,探讨了类别标签及典型性程度对类别特征推理任务的共同影响,结果表明,类别标签及典型性程度都会影响类别特征推理任务,而且,类别标签及典型性程度之间存在交互作用,典型性程度为高条件下类别标签对类别特征推理任务的影响要高于典型性程度为低条件,类别标签匹配条件下,典型性程度对类别特征推理任务的影响要高于类别标签不匹配条件。