Modeling of 1-3 piezoelectric composites operating in thickness-stretch vibration mode

For bulk piezoelectric ceramics plates, the fundamental thickness-stretch (TSt) waves are always coupled to the in-plane extension waves and the symmetric thickness-shear waves. The occurrence of these spurious modes in bulk piezoelectric ceramics plates is undesirable as it may interfere with the operation of transducers. 1–3 piezoelectric composites are promising candidates to suppress the spurious modes mentioned above. However, theoretical modelling of multiphase ceramic composite objects is very complex. In this study, a simple analytical TSt vibration model is constructed from three-dimensional equations of linear piezoelectricity. The mechanical damping is considered in the model by introducing a complex elastic constant. The performance of 1–3 piezoelectric composites is analysed and the electrical impedance results from theoretical and experimental analysis are compared. The results show that there is excellent agreement between the experimental electrical impedance and that obtained by the theoretical TSt vibration analysis. This indicates that 1–3 piezoelectric composites can be operated in a nearly pure TSt vibration mode near the fundamental resonance. The analytical model we present is valid for analysing 1–3 piezoelectric composites plates with large aspect ratios quickly and efficiently.     

Gender differences in STEM undergraduates' vocational interests: People–thing orientation and goal affordances

This study addressed why women have greater representation in some STEM (science, technology, engineering, and mathematics) fields compared to others by linking two theoretical approaches, people–thing orientation (PO, TO) and role congruity theory, which emphasizes occupation goal affordances associated with traditionally feminine and masculine roles. Vocational interest and goal affordance ratings (having a positive social impact, family, and occupation status) for occupations characterized as working with people or things were assessed in 1848 students (42% female; 81% white non-Hispanic) majoring in biology (gender balanced), non-biology STEM (male-dominated), and female-dominated health fields. Participant PO and TO interests were also collected. Results indicated that non-biology STEM majors showed lower PO and higher TO interests than biology and health majors. Non-biology STEM majors also endorsed PO and TO interests at similar levels, but the other two major groups indicated higher PO than TO. People Jobs were perceived to more likely afford goals related to family and positive social impact; whereas Thing Jobs were perceived to more likely afford status goals. Interest in People Jobs was similar for women in both STEM major groups. Female non-biology STEM majors were equally interested in People and Thing Jobs; whereas biology majors preferred People Jobs. PO, TO, and goal affordance ratings independently predicted interest in People and Thing Jobs, and gender accounted for very little additional variance. Taken together, the findings point to the importance of using both person–thing orientation and role congruity theory when explaining varied gender representations in different STEM fields.     

类同一性与群体差异性:道德产生的可能性与必然性——兼与易小明商榷

人类最初的生存状态是群聚,群聚是人的类属性的自发聚集,它使人类本能地意识到人类的同一性;群聚之后人类走向群居,群居是人的群体属性的自觉结合,它体现了人类的同一性之外的群体差异性.类同一性使人类能够彼此交往,是道德产生的可能性主体基础;群体差异性使人类必须交往,是道德产生的必然性主体基础,二者都是道德产生的主体基础.     

人与世界:以事观之——杨国荣教授访谈

以事观之,主要是从"事"这一角度出发来对人和世界加以理解,而不是对"事"本身做出某种终极的哲学论述。现实世界与真实存在的生成过程,与人所从事的多样活动——人所作的多样之事——无法相分。西方没有类似"事"这样的概念,这表明了中国哲学的独特意义:中国哲学包含不少其他文化传统所缺乏的概念,后者有助于我们更深入地理解现实世界和人类生活。就意识层面而言,作为意识主体的自我和作为反观对象的自我之间的关联,实在地发生于做事过程。在事的展开过程中,知识与价值的问题密切联系在一起,做事既需要解决做什么的问题,也需要解决怎么做的问题。从事的角度来看,儒道两家的理想人格呈现出不同特点。道家以自然为第一原则,主张"为无为",儒家则更重视参与活动的合目的性。从事的角度来理解世界和人,既着眼于大的哲学问题,也关注于伦理学、语言哲学等具体领域的思考。     

汉语词汇产生中音、形、义三种信息激活的时间进程

采用图-词干扰范式和图片命名方法,探讨语音、语义、字形在汉语词汇产生中激活的时间进程与特点。选择与目标图片名称(如“羊”)具有同音(“阳”)、语义相联(“牛”)、字形相似(“丰”)或无关控制(“冷”)等四种关系的干扰字,依SOA条件呈现在将要被命名的图片上,发现图片命名时间受干扰字的影响：语义干扰效应存在于较早期的SOA(0ms)条件中,在较晚期SOA(150ms)时有很大的减弱;语音促进效应和字形促进效应同时强烈地存在于早期和晚期SOA。实验发现了词条选择(语义激活)和音位编码(语音提取)在激活时间上的重叠现象,与传统的独立两阶段模型的预期存在明显矛盾,倾向于支持交互作用理论的观点。     

老化的年龄标识:主观年龄对老年人主观老化体验的影响

为证明年龄对老化的标识作用,研究假设降低被试的主观年龄可减少老年人的主观老化体验。采取实验组控制组前测后测设计,以主观年龄为自变量,分为"等于年代年龄"(控制组)和"小于年代年龄10±5岁"(实验组)两种水平,随机分配至两组的62名老年被试填写《个人老化体验问卷》,评估其主观老化体验。结果显示,实验组在后测中的主观老化体验不仅显著低于本组前测,也显著低于控制组,且这一结果不受被试最初自评的主观年龄影响。原假设得到证明,支持年龄对老化的标识作用。年龄标识对老化意义的简单化建构了世俗的绝对老化观。     

观察者公正敏感性对不公正信息加工的影响

为考查观察者公正敏感性对不公正信息加工（注意、解释）的影响,该研究开展了两个实验研究。在实验一中,让被试观看不公正影片剪辑或中性剪辑后,要求他们完成视觉探测任务,判断探测刺激是在不公正词汇还是中性词汇的左边或右边;在实验二中,让被试对一个模糊的暗含不公正意义的影片剪辑中的主角进行公正性评价。结果表明,当被试不公正概念被激活后,观察者公正敏感性高的被试比观察者公正敏感性低的被试对不公正信息的注意加工更集中和更自动,同时他们对模糊的信息解释为更不公正。     

Prefrontal cortex dysfunction and income: a study in neuroeconomics

In four samples of adults, individual income was negatively associated with a measure of prefrontal cortex dysfunction even after implementing controls for age, sex, and education. The small association was stronger for men than for women. These results provide support for a neuroeconomic approach to the study of micro-economic variables.     

Buying books online: a replication

In a replication study, purchasing books online by 137 state college students was predicted by computer/Internet skills.