Wear behaviour of a gradient surface produced by a punching process in a Cu-30 Ni alloy

The grain size variation in a gradient surface produced by a punching and recovery process on a Cu-30Ni alloy has been observed by atomic force microscopy. The friction characteristics of the gradient surface in a 3.5 wt% NaCl solution were investigated using a micro-indenter probe, a pin-on-disc type tribometer, a strain sensor and an optical microscope. The results showed that the hardness and grain size can be well represented by the Hall–Petch relationship when the gain size is more than 30?nm. The wear rate, friction coefficient and adhesive force all increase depth below the surface. These variations are attributed to a gradual increasing grain size with depth. The morphologies of the worn track were also studied to understand further the corrosive wear behaviour of gradient surfaces.     

Understanding scale-dependent yield stress of metals at micrometre scales

The mechanical softening behaviour of micrometre-scale metals (free-standing metal foils and wires) with decreasing either the geometrical or the microstructural scale (i.e. the smaller, the weaker) has recently been reported. Here, we present a mechanism-based model to understand the softening behaviour, which is based on competition between the effects of surface grain relaxation and the interior grain strengthening effect. The model describes well the yield stress of Cu foils with different ratios of the thickness to grain size.     

Short-term memory for emotional faces in dysphoria

The study aimed to determine if the memory bias for negative faces previously demonstrated in depression and dysphoria generalises from long- to short-term memory. A total of 29 dysphoric (DP) and 22 non-dysphoric (ND) participants were presented with a series of faces and asked to identify the emotion portrayed (happiness, sadness, anger, or neutral affect). Following a delay, four faces were presented (the original plus three distractors) and participants were asked to identify the target face. Half of the trials assessed memory for facial emotion, and the remaining trials examined memory for facial identity. At encoding, no group differences were apparent. At memory testing, relative to ND participants, DP participants exhibited impaired memory for all types of facial emotion and for facial identity when the faces featured happiness, anger, or neutral affect, but not sadness. DP participants exhibited impaired identity memory for happy faces relative to angry, sad, and neutral, whereas ND participants exhibited enhanced facial identity memory when faces were angry. In general, memory for faces was not related to performance at encoding. However, in DP participants only, memory for sad faces was related to sadness recognition at encoding. The results suggest that the negative memory bias for faces in dysphoria does not generalise from long- to short-term memory.     

Keeping an eye on the truth? Pupil size changes associated with recognition memory

During recognition memory tests participants' pupils dilate more when they view old items compared to novel items. We sought to replicate this “pupil old/new effect” and to determine its relationship to participants' responses. We compared changes in pupil size during recognition when participants were given standard recognition memory instructions, instructions to feign amnesia, and instructions to report all items as new. Participants' pupils dilated more to old items compared to new items under all three instruction conditions. This finding suggests that the increase in pupil size that occurs when participants encounter previously studied items is not under conscious control. Given that pupil size can be reliably and simply measured, the pupil old/new effect may have potential in clinical settings as a means for determining whether patients are feigning memory loss.     

《心理统计学》教学内容的新探索

本文在对当前国内外主要心理统计学教材进行比较的基础上,指出与上个世纪八十年代的心理统计学教材内容相比较,在内容上的新探索主要体现在（1）由“假设检验”的内容中发展出“统计检验力”和“效果大小”的统计指标和估计方法;（2）引进一般线性模型来统合方差分析和回归分析这两种统计方法;（3）适度增加一些“多元统计分析”的内容等三个方面.本文对前两个方面的新内容作了简要评述,并对教材内容的编排方面提出了新的思路.     

Network Hubs and Opportunity for Complex Thinking Among Young British Muslims

This study examines whether individuals in a network esteem peers who think in integratively complex ways about religious issues in the context of a small‐group educational course comprised of young British Muslims. Integrative complexity (IC) measures the degree to which an individual's information processing is characterized by (a) rigid, black‐and‐white thinking or (b) ability to recognize the validity of, and integrate, multiple perspectives. A novel measurement procedure was developed for this research called the Social Field Generator. Results from seven groups (n = 55) showed that (a) participants with levels of IC were described by their peers with more positive sentiment than their low‐IC counterparts; (b) the higher the IC scores of participants, the closer peers felt toward them; and (c) the highest IC individuals were consistently selected as sources of advice, whereas the lowest IC individuals were not viewed as sources of advice. This research shows that within an educational environment aimed at promoting complex thinking, group processes and grassroots religious leadership can encourage higher levels of IC as a group norm.     

Development of a Screening Instrument for Early Language Delay in Hong Kong Chinese: A Preliminary Study

Having language delay—one of the common neurodevelopmental difficulties during childhood—does not only imply an impairment in communication in the 1st few years of life. Previous studies have suggested that language problems have long-term implications for social, emotional, and intellectual development. Researchers have found that early identification and intervention of speech and language delay yields better treatment effects. However, unlike most of the motor developmental assessment tools, language assessment tools are not readily transferred across cultures because of the different linguistic features and the developmental stages of such features in a particular language or dialect. The present study presents an empirical example of the initial development of a culturally sensitive screening protocol, using vocabulary size as the indicator to minimize the effect of linguistic differences.     

Overgeneral autobiographical memory predicts changes in depression in a community sample

This study investigated whether overgeneral autobiographical memory (OGM) predicts the course of symptoms of depression and anxiety in a community sample, after 5, 6, 12 and 18 months. Participants (N = 156) completed the Autobiographical Memory Test and the Depression Anxiety Stress Scales-21 (DASS-21) at baseline and were subsequently reassessed using the DASS-21 at four time points over a period of 18 months. Using latent growth curve modelling, we found that OGM was associated with a linear increase in depression. We were unable to detect changes over time in anxiety. OGM may be an important marker to identify people at risk for depression in the future, but more research is needed with anxiety.     

Addendum to: Heterogeneity Coefficients for Mahalanobis' D as a Multivariate Effect Size

In a previous paper (Del Giudice, 2017 [Heterogeneity coefficients for Mahalanobis' D as a multivariate effect size. Multivariate Behavioral Research, 52, 216–221]), I proposed two heterogeneity coefficients for Mahalanobis' D based on the Gini coefficient, labeled H and EPV. In this addendum I discuss the limitations of the original approach and note that the proposed indices may overestimate heterogeneity under certain conditions. I then describe two revised indices H₂ and EPV₂, and illustrate the difference between the original and revised indices with some real-world data sets.     

Size does matter: Women mentally rotate large objects faster than men

Performance in a computerized “mental rotation” task was measured in groups of males and females while they rotated Shepard‐Metzler‐like cube assemblies on either a standard laptop screen (size = 36 cm) or on a large display wall (584 cm) where the stimuli appeared at considerably larger sizes and within a much wider field of view than that typically used in most spatial tasks. Males and females did not differ significantly in performance in the standard size condition with regards to response time but females performed faster than males in the large display condition. Males were also found to be significantly more accurate than females, regardless of display. We found no sign of trading accuracy for speed for either of the sexes or screen size conditions. We surmise that such an effect may be due to differences in task‐solving strategies between the sexes, where a holistic strategy – which may be preferred by males is negatively affected by large object sizes, whereas a piecemeal approach, that may be preferred by females, is virtually unaffected by display size.