Prevalence and associated factors of poly‐victimization in Chinese adolescents

Multiple types of victimization or poly‐victimization (PV) can occur simultaneously during childhood, resulting in outcomes that are detrimental and difficult to reverse. Very few studies have focused on PV in Chinese adolescents. The present study is based on information collected from a stratified cluster sample of 1,561 females and 1,594 males aged 12–18 years living in Shandong Province, China. A self‐administered questionnaire was used to assess background information, the Juvenile Victimization Questionnaire was used to measure the extent of victimization and PV, the Screen for Child Anxiety Related Emotional Disorders was used to measure anxiety levels, and a Depression Self‐rating Scale for Children was used to ascertain depression. A majority of the study sample (66.2%) had experienced at least one form of victimization over the past year. Prevalence of PV was 16.9%, and was significantly higher among males (21.1%) than females (12.5%). Younger ages, one‐child families, and lower socioeconomic status were positively associated with PV. Logistic regression analysis indicated that smoking, alcohol consumption, exposure to pornography, and anxiety‐ and depression‐like symptoms were risk factors of PV. Results of this study highlight the need for further exploration of factors related to the PV of Chinese adolescents.     

Exposure to violence reduces empathetic responses to other’s pain

Past researches showed that empathy for pain not only triggers a resonance mechanism between other and self, but also is modulated by contextual factors. Using functional magnetic resonance imaging, the present study demonstrated that short-term media violence exposure reduced both pain ratings and also the activation of anterior insula and anterior mid-cingulate cortex to other’s pain. Thus, violence exposure modulated empathic responses to other’s pain based on a physiological desensitization.     

真实火灾和模拟火灾情境下小鼠的逃生决策比较*

探讨并比较真实火灾和模拟火灾情境下小鼠是否采用直觉性逃生决策。研究包括一个预备训练和两个主实验。预备训练的目的：首先训练小鼠获得有关迷宫路线及出口的经验,然后再经过遗忘处理使它们遗忘相关经验。两个主实验均采用3(情境：真实火灾,模拟火灾,普通情境)×2(记忆：遗忘前和遗忘后)混合实验设计,因变量均为逃生决策。实验组被试为72只经过训练的小鼠,控制组为24只未经过训练的小鼠。通过考察小鼠在不同情境和不同记忆条件下的逃生时间和对逃生出口的选择探测并比较真实火灾和模拟火灾情境下小鼠的逃生决策差异。主要结果：(1)实验组在真实火灾情境下的逃生时间无论遗忘前后都明显比模拟火灾情境下短;(2)实验组在真实火灾和模拟火灾情境下的逃生时间都明显比控制组短;(3)当熟悉和陌生出口均开启同时熟悉出口处有烟雾条件下,真实火灾组在遗忘前后均倾向于选择熟悉出口逃生,其他两组则倾向于选择陌生出口离开。结论：真实火灾和模拟火灾情境下小鼠的逃生决策存在明显差异：真实火灾情境下受过训练的小鼠倾向于直觉性逃生决策;模拟火灾情境下受过训练的小鼠不倾向于直觉性逃生决策。     

Mechanical behaviour of an Al–matrix composite reinforced with nanocrystalline Al-coated B4C particulates

In metal–matrix composites (MMCs), interfacial bonding between the metal matrix and the ceramic reinforcement plays a crucial role in their mechanical performance. In the present study, B₄C particles were cryomilled with an Al alloy to produce a composite powder, in which the B₄C was uniformly distributed in nanocrystalline Al. The cryomilling developed a strong bond between the B₄C and the Al, allowing the nanocrystalline Al to act as a coating with a strong ceramic–metal interface. This cryomilled composite powder was then introduced, as a reinforcement, into a conventional Al alloy to strengthen the material. After consolidation, the result was a bulk Al–matrix composite reinforced with B₄C particles encapsulated in nanocrystalline Al. This composite exhibits greatly improved strength and stiffness.     

Interactions between interfacial dislocations and γ/γ′ interface during high temperature – low stress creep in nickel-based single crystal superalloy

ABSTRACT

The interaction between interfacial dislocations and γ/γ′ interface is critical to the high temperature creep properties of single crystal superalloys. However, only a few studies have paid attention to the detailed structure such as local interfacial morphologies and the elemental distribution around interfacial dislocations. In this paper, the interfacial protrusions and related dislocations in a single crystal superalloy after creep at high temperature – low stress have been investigated in detail. It is found that the morphology and size of the interfacial protrusions remain almost the same during the early and middle stages of high temperature creep, which indicates a local equilibrium at the interfacial protrusions. Steps at different height are formed at the γ/γ′ interface at the initial stage of high temperature creep since dislocations could move along the γ/γ′ interface, which indicates that dislocation motion at different creep stage may affect the morphology of γ/γ′ interface.     

Locating dysprosium dopant atoms in the Bi2Sr2CaCu2Oy unit cell: Direct-space chemical crystallography

The position of Dy in the unit cell of Bi2Sr2CaCu2Oy has been determined by a real-space method. This is compared with the reciprocal-space atom location by channelling-enhanced microanalysis (ALCHEMI) method.     

Aggregation behavior of Au atoms and atomic islands on liquid surfaces

The aggregation behavior of Au atoms and atomic islands on silicone oil surfaces has been systematically investigated by analyzing the evolution of surface coverage. The apparent Au surface coverage increases linearly with the nominal film thickness at low thicknesses and the rate of increase is almost independent of deposition flux. However, as the deposition flux increases, the surface coverage goes up linearly. Further analysis reveals that the deposition flux strongly affects the system free-energy of the island-oil system and therefore the aggregation behavior of the Au atoms and islands.     

Dependence of normal contact stress on the surface morphology of solid surfaces

Contact problems between two solids are essential to interpret the loading-unloading behaviour in indentation tests. Using linear elastic theory, a general relationship between the normal stress and the surface deformation for elastic contact of two solids was derived, in which the normal stress is a function of the mean curvature of the undeformed surface.     

Influence of Hostile Media Perception on Willingness to Engage in Discursive Activities: An Examination of Mediating Role of Media Indignation

This study examines the mediating role of media indignation, a set of negative emotional reactions to media coverage perceived to have partisan bias, between hostile media perception (HMP) and its consequences in behavioral willingness, more specifically, willingness to engage in discursive activities. It is examined together with a cognitive pathway through individuals' inference on opinion climate. Data from a web-based survey of university students (N = 696) on three controversial issues were analyzed. Findings showed that the degree of perceived partisan bias in mainstream media coverage on an issue was positively related to the intensity of media indignation and levels of incongruity between one's own opinion and perceived majority opinion. Media indignation in turn had a significant and positive effect on willingness to engage in discursive activities across all three issues, mediating the effect of HMP on behavioral willingness, whereas self-majority opinion incongruity did not. Theoretical implications of the findings are discussed.     

Mapping the time course of the positive classification advantage: An ERP study

The aim of the present study was to investigate the time course of the positive advantage in the expression classification of faces by recording event-related potentials (ERPs). Although neutral faces were classified more quickly than either happy or sad faces, a significant positive classification advantage (PCA)—that is, faster classification for happy than for sad faces—was found. For ERP data, as compared with sad faces, happy faces elicited a smaller N170 and a larger posterior N2 component. The P3 was modulated by facial expressions with higher amplitudes and shorter latencies for both happy and neutral stimuli than for sad stimuli, and the reaction times were significantly correlated with the amplitude and latency of the P3. Overall, these data showed robust PCA in expression classification, starting when the stimulus has been recognized as a face revealed by the N170 component.