Mechanically driven alloying forces in the fabrication of a Cr–Zr nanocomposite

A highly supersaturated nanocrystalline Cr–25?wt% Zr alloy has been prepared by mechanical alloying of elemental crystalline powders. High-purity powders of Cr and Zr were milled for up to 20?h. The development of the microstructure was investigated by X-ray diffraction (XRD) and scanning electron microscopy. XRD patterns confirmed complete alloying of the Zr and Cr. The contribution of grain boundaries, the chemical potential of a solute atom induced by dislocations, and the elastic strain energy arising from the different sizes of Cr and Zr atoms have been calculated. The alloy formation is discussed with respect to the thermodynamic conditions of the material. The role of internal strains and stored enthalpies by dislocations on solute atoms is the major mechanical driving force for alloying and this is critically assessed in this article.     

伤害回避的脑机制及其生物基础

伤害回避是指个体对厌恶刺激信号做出强烈的反应,并学会被动地回避惩罚的一种倾向,这一倾向使得个体反复思考未来的结局,并谨慎小心地对待不确定情景中的事件,进而更有可能诱发情感障碍。伤害回避涉及的神经网络包括三个子网络,即额顶叶-前扣带皮层的连接、皮层-杏仁核的连接和白质通道的结构性连接,这三个子网络分别与羞怯感-易疲劳性、预期担心以及不确定环境中的害怕情绪有关。而其生物基础则包括单一基因多态性和基因多态间的交互作用。今后的研究应该集中在深化伤害回避神经网络与生物基础间的联合机制、研究三种及以上基因多态间的交互作用、考察其他因素对基因效应的调节作用、注重伤害回避四种亚型相关神经网络之间的连接、探讨5-HT4等其他几种5-羟色胺受体多态性与伤害回避的关系以及分析伤害回避内部机制在抗抑郁治疗中的作用等方面。     

Practice Effects on Motor Control in Healthy Seniors and Patients with Mild Cognitive Impairment and Alzheimer's Disease

ABSTRACT

This research was designed to test the hypothesis that motor practice can enhance the capabilities of motor control in healthy controls (NC) and patients with a diagnosis of probable Alzheimer's disease (AD) and mild cognitive impairment (MCI), and consequently results in better motor performance. Approximately half of the subjects in the NC (n = 31), AD (n = 28), and MCI (n = 29) either received or did not receive practice on a task of fast and accurate arm movement with a digitizer. Changes in movement time (MT), movement smoothness (jerk), and percentage of primary submovement (PPS) were recorded and compared among the three groups across six blocks of trials (baseline and five training sessions). For all subjects, practice improved motor functions as reflected by faster and smoother motor execution, as well as a greater proportion of programming control. Compared to unaffected matched controls, AD and MCI subjects exhibited a greater reduction in movement jerk due to practice. Movement time and PPS data revealed that motor practice appeared to reduce the use of “on-line” correction adopted by the AD or MCI patients while performing the aiming movements. Evidently, their arm movements were quicker, smoother, and temporally more consistent than their untrained peers. The findings of this study shed light on how MCI and AD may affect motor control mechanisms, and suggest possible therapeutic interventions aimed at improving motor functioning in these impaired individuals.     

求职者简历作假行为结构及影响因素研究

求职者简历作假行为是指求职者在简历投递过程中,为提升进入下一轮选拔几率,在简历中表现出虚假信念或信息的行为。研究通过访谈和问卷调查方法,探讨了求职者简历作假行为的结构,以及大学生求职群体简历作假行为的影响因素与特点。结果表明:(1)求职者的简历作假行为包含迎合招聘企业、篡改个人信息、粉饰关键词句和提升匹配程度四个因素。(2)马基雅维利主义倾向可以预测其简历作假行为。(3)大学生求职者的简历作假行为在其简历投递次数以及简历修改次数上存在差异。     

流动儿童疏离感的特点及其与应对方式、学校态度的关系

采取整群抽样的方法,对成都及重庆两地591名流动儿童和272名城市儿童进行问卷调查,考察流动儿童疏离感的特点及其与应对方式和学校态度的关系。结果发现:(1)流动儿童疏离感各维度显著高于城市儿童;流动初中生的疏离感显著高于流动小学生,且男生的疏离感显著高于女生;(2)流动儿童疏离感的三个维度之间存在显著差异,其中社会疏离感最高,其次是环境疏离感,人际疏离感最低;(3)流动儿童疏离感对学校喜欢有显著的负向影响,而对学校回避有显著的正向影响;应对方式在流动儿童疏离感对学校态度的影响中起着部分中介作用。     

国外积极偏离行为的研究述评

偏离行为的研究在社会学和组织行为学领域都有较丰富的成果,然而其关注点主要集中于对社会或组织产生负面作用的消极偏离行为。近年来相关领域的学者越来越关注积极偏离行为（Positive Deviance, PD）的研究。该文综述了关于积极偏离行为的定义的各方观点,同时分析了积极偏离行为与相似构念的差异,并综述了积极偏离行为的测量方式,以及积极偏离行为的前因变量和结果变量。最后对积极偏离行为未来的研究方向进行了展望。     

什么是临时内在性问题？

Lewis的临时内在性问题出名地难以理解,也许是因为它质疑了某些我们认为理所当然的基本概念。本文通过简明地陈述问题和对若干可能解法的分析试图使之易于理解。此外,本文给出了一个产生Bradley倒退的简明易懂的方法。     

两例先天性无痛症患者的心理生理特点研究 Ⅱ.对致痛性强刺激的知觉和反应

本工作对两例先天性无痛症患者对于致痛性强刺激的知觉和反应进行了研究(例1女,10岁,例2男,13岁)。对照组为20例正常儿童,性别和年龄均与患儿相匹配。 结果:1),生活中痛:两例患儿均无(包括痛感觉和痛反应)。2)实验性痛:①痛感觉:两例患儿均无;②“痛”反应:例1有“痛”反应(脉搏和呼吸的变化以及行为反应明显,大致与正常儿童相似)。例2无“痛”反应(脉搏和呼吸的变化轻微,无行为反应,与正常儿童不同)。 由结果看来,先天性无痛症患者似乎可分为两种类型:不完全型(如同例1)和完全型(如同例2)。存在有“痛”反应而无痛感觉的无痛症患者。 本工作结果从另一侧面为痛的两成分学说提供了依据。     

As the Flocks Gather: How Religion Affects Voluntary Association Participation

This study investigates the relationship between different dimensions of religiosity and voluntary association participation using data from Queen'sUniversity's 1996 "God and Society in North America" survey. I look at the participatory, devotional, affiliative, and theological dimensions of religiosity and examine how they affect voluntary association participation at three different levels: membership, volunteering, and serving on a committee. The results show that all four religious dimensions have considerable, but distinctive, influences on secular voluntary association participation.     

中学教师处理学生心理健康问题策略特点探析

采用问卷法考察了268名中学教师在厌学、退缩行为、自我中心、攻击性行为和考试焦虑五种问题情境下教师对处理学生心理健康问题的策略有效性和使用可能性的评定以及性别、教龄因素对教师评定策略有效性的影响。结果表明:(1)中学教师处理学生心理健康问题策略具有情境性,教师对处理学生心理健康问题的策略的有效性的认可和真正在具体情境中采取的策略不尽相同。在厌学和退缩行为情境中,教师倾向于认为情感关爱型策略更有效;自我中心情境中,行为疏导型策略更有效;攻击行为情境中,惩罚约束型策略更有效;在焦虑情境中,言语疏导型策略更有效。在采用可能性的评定中,对学生的厌学、退缩行为、自我中心和焦虑问题,教师都更倾向于采用言语疏导型策略;在攻击行为情境中,教师更倾向于采用行为疏导型策略。(2)与性别相比,教龄是影响教师评定处理学生心理健康问题策略有效性的较为敏感的变量。在厌学情境中,20年以上教龄的教师认为责任转移型策略和情感关爱型策略更有效;在自我中心情境中,20年以上教龄的教师认为责任转移型策略更有效。