Electromechanical behavior of single-walled carbon nanotube thin films

Carbon nanotubes have been intensively studied owing to their great potential in nanoelectronics and nanomechanical devices. Recently, experimental results have shown that single-walled carbon nanotubes (SWCNTs) change their electronic properties when subjected to strain. In this study, the electromechanical characteristics of SWCNT networks were investigated for the application of printable strain sensors on flexible substrates. SWCNT films were formed on plastic substrates of poly(ethylene terephthalate) using a spray process. In this manner, we were able to control the transparency and obtain uniform electrical properties of the films. The films are isotropic on account of the random orientation of bundles of SWCNTs. Experimental results showed a nearly linear change in the resistance across a film when it was subjected to tensile strain, even in the inelastic range of the flexible substrate. The results demonstrate the potential use of SWCNT films for highly sensitive printable strain sensors on a macroscale.     

Sol-gel-hydrothermal growth of oxide thin films at low temperatures

Lead zirconate titanate (PZT) (Pb(Zr_0.52Ti_0.48)O₃) and barium titanate (BaTiO₃) thin films have been successfully prepared using a novel sol-gel- hydrothermal (SG-HT) technique at low temperatures, which involves a combination of the conventional sol-gel process and a hydrothermal method. Highly (111)-oriented PZT thin films with a single perovskite phase and polycrystalline BaTiO thin films with well developed crystallites were obtained at a processing temperature as low as 160⁰C. The microstructural characteristics demonstrate that the SG-HT-derived PZT and BaTiO₃ thin films with good crystallinity and surface morphology are converted from the amorphous phase to the desired perovskite phase on platinum-coated and bare silicon substrates at a low processing temperature of 100-200 C. These results suggest that the SGHT technique, which is of great significance because of its low processing temperature, will become a potential and promising process for fabricating PZT, BaTiO₃ and other oxide thin films.     

自尊的遗传性:来自双生子研究的证据

自尊是个体差异的一个重要方面,迄今已有许多研究从行为遗传学角度探讨自尊个体差异的来源。通过梳理现有关于自尊的双生子研究,发现:1)自尊有中等的遗传度,其个体差异来自遗传和非共享环境;2)遗传对自尊的稳定性有较大作用;3)自尊与认知、情感的联系主要源自共同的遗传基础。总之,遗传对自尊具有重要影响。未来双生子研究可拓展到自尊波动性、内隐自尊等领域,并考虑极端人群的遗传特异性和文化对自尊遗传性的影响。     

文化产品研究——文化心理学的独特视角

作为行为研究的重要补充,文化产品研究在文化心理学领域发挥了重要的作用.文化产品研究主要采用内容分析的方法,可以揭示不同时空下文化本身、人们的心理与行为的特征.中国未来的心理学研究可以利用文化产品来研究揭示不同民族、不同国家的文化和心理差异,以及近几十年社会巨变对中国人的和行为的影响,最终促进国家进步、人民幸福、社会和谐.     

贪婪:态度、动机与决策机制

贪婪是人性的重要特点之一,也是哲学、经济学等领域经常讨论的话题.本文首先梳理了贪婪的概念,并将问题聚焦在对于物质的贪婪上.然后总结了贪婪的特点,并提出贪婪的定义.接着阐述了情境因素如何影响个体对贪婪的态度,以及贪婪动机如何影响自利行为.贪婪决策是个体决定是否做出贪婪行为的心理过程,受到自我意识和情绪的影响.贪婪决策过程模型整合了控制性、自动化两类加工方式,阐释了自利倾向与道德自觉相互作用的机制.本文对以上内容逐次进行讨论,并提出了未来研究的方向.     

杏仁核对感觉刺激的情绪性加工:自动化过程和注意调控过程的整合

利用有限的认知资源应对多变的环境刺激,选择性注意和情绪加工一个重要的共同机制是优先化关键信息的加工。尽管情绪性刺激(特别是威胁刺激)能够影响注意资源的分配,但一些关键脑区(如杏仁核)的对情绪性刺激的加工是自动化过程还是受到注意调节一直是个有争议的问题。最新的结合高时间分辨率和高空间分辨率的神经生理记录研究表明,情绪加工的重要核团,杏仁核,对情绪性刺激的加工包含早期快速的不依赖于注意资源和认知加工负荷的自动化加工成分和晚期受到额-顶叶皮层自上而下的注意调控成分,这种功能整合证实杏仁核情绪性加工存在并行的皮层下和皮层通路。     

The influence of visual short-term memory on size perception

We show that perceived size of visual stimuli can be altered by matches between the contents of visual short-term memory and stimuli in the scene. Observers were presented with a colour cue (to hold in working memory or to merely identify) and subsequently had to indicate which of the two different-coloured objects presented simultaneously on the screen appeared bigger (or smaller). One of the two objects for size judgements had the same colour as the cue (matching stimulus) and the other did not (mismatching stimulus). Perceived object size was decreased by the reappearance of the recently seen cue, as there were more size judgement errors on trials where the matching stimulus was physically bigger (relative to the mismatching stimulus) than on trials where the matching stimulus was physically smaller. The effect occurred regardless of whether the visual cue was actively maintained in working memory or was merely identified. The effect was unlikely generated by the allocation of attention, because shifting attention to a visual stimulus actually increased its perceived size. The findings suggest that visual short-term memory, whether explicit or implicit, can decrease the perceived size of subsequent visual stimuli.     

Engaging the motor system with masked orthographic primes: A kinematic analysis

We report two experiments in which participants categorized target words (e.g., BLOOD or CUCUMBER) according to their canonical colour of red or green by pointing to a red square on the left or a green square on the right. Unbeknownst to the participants, the target words were preceded by the prime words “red” or “green”. We found that the curvature of participants’ pointing trajectories was greater following incongruent primes (green–BLOOD) than it was following congruent primes, indicating that individuals initiated a response on the basis of the prime and then corrected that response mid-flight. This finding establishes that the processing of masked orthographic stimuli extends down to include the formulation of an overt manual response.     

A neural autopilot theory of habit: Evidence from consumer purchases and social media use

This article applies a two-process “neural autopilot” model to field data. The autopilot model hypothesizes that habitual choice occurs when the reward from a behavior has low numerical “doubt” (i.e., reward prediction errors are small). The model toggles between repeating a previous choice (habit) when doubt is low and making a goal-directed choice when doubt is high. The model has ingredients established in animal learning and cognitive neuroscience and is simple enough to make nonobvious predictions. In two empirical applications, we fit the model to field data on purchases of canned tuna and posting on the Chinese social media site Weibo. This style of modeling is called “structural” because there is a theoretical model of how different variables influence choices by agents (the “structure”), which tightly restricts how hidden variables lead to observed choices. There is empirical support for the model, more strongly for tuna purchases than for Weibo posting, relative to a baseline “reduced-form” model in which current choices are correlated with past choices without a mechanistic (structural) explanation. An interesting set of predictions can also be derived about how consumers react to different kinds of changes in prices and qualities of goods (this is called “counterfactual analysis”).