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.     

神经科学决定论与自由意志——兼论自由意志与自我是否可能?

神经科学的最新研究成果为决定论提供了科学依据,由此推断没有自由意志和恒定不变的自我。而传统生命伦理学中我们对其它生命体的伦理义务乃是基于这个生命体具备自由意志,即有自我的精神生活。神经科学技术对自由意志和自我的挑战不会对我们的伦理实践产生重要影响。只有在实践生活中人们采用了科学研究结论,从神经科学的发现到影响我们伦理实践的范式转换才会发生。从相容性与非相容性、物理系统自身的识别、神经科学的其它证据等方面探讨了怀疑的内在原因,认为不会因为神经科学家的新发现而否认自由意志和恒定自我。     

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。     

Investigating the Role of Goal Orientation in Job Seekers’ Experience of Value Congruence

There is still limited understanding of how goal orientations influence the association between value congruence (VC) and organisational attraction for job seekers. We address this issue by investigating the impact of individuals’ goal orientations on the VC–attraction relationship. Our investigation using different measurement approaches to congruence across two studies also allowed us to examine the implications of different methods to operationalising VC in job search contexts. Two prominent types of goal orientation in job search—learning-approach goal orientation (LAGO) and performance-avoid goal orientation (PAGO)—were hypothesised to moderate the relationship between VC and organisational attraction. In study 1, value congruence based on direct molar perceptions displayed a stronger positive relationship with attraction among low LAGO individuals. Study 2, using separate atomistic judgments of person and organisational values, also demonstrated that LAGO moderates the effects of VC on attraction. However, the form of moderation effects varied across different types of work values (i.e., relationships and security). These findings demonstrate the need to contextualise the study of job seekers’ VC within a goal-striving context, where different ways of operationalising VC can also shed more light on the psychological processes underlying judgments of congruence.     

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。     

肿瘤药品临床试验中的知情同意

肿瘤学的发展一直伴随抗肿瘤新药的研发与临床试验.获取受试者的知情同意是完成临床试验过程中最重要的一步.如何顺利而有效地获取知情同意并保护其合法权益不受侵犯成为研究者最为关注的话题.本文就如何解决这一过程中存在的问题进行了初步探讨.     

图形型归纳推理的神经机制:一项fMRI研究

利用fMRI脑成像技术探讨图形型归纳推理的神经机制。设计了一种由图形形状和条纹方向描述的简单几何图形组成的归纳推理任务,这种图形型任务与以往研究中常用的语句型归纳推理任务是同质的。根据两个图形共享特征数量的不同设计了两种实验任务:共享两个特征(2T)和共享一个特征(1T),以休息基线(Rest)作为控制任务。2T和1T任务均为归纳推理任务,但2T任务包含知觉特征整合成分,而1T任务不包括。结果发现:与控制任务相比,归纳推理任务在前额区(BA6、9、11、46、47)、尾状核、壳核和丘脑等脑区有显著激活,反映了"前额皮层-纹状体-丘脑"通路在图形型归纳推理中的重要作用;图形型归纳推理中的知觉信息整合与右侧额下回(BA47)、双侧尾状核头部、壳核等脑区有关。     

变革型领导对员工绩效和满意度的影响：心理资本的中介作用及程序公平的调节作用

通过对国内一家企业共785位员工及其直接主管的问卷调查, 考察了下属心理资本在变革型领导与下属工作绩效及满意度之间关系的中介作用以及程序公平对该关系的调节作用。研究结果显示：1)下属的心理资本与其工作绩效和满意度正向相关; 2)下属的心理资本部分中介了变革型领导对下属工作绩效及满意度的正向关系; 3) 下属的程序公平调节了变革型领导对下属心理资本的影响。具体而言, 下属的程序公平感越高, 变革型领导与下属心理资本的正向关系越强, 反之越弱; 4) 进一步地, 程序公平调节了下属心理资本对变革型领导－工作绩效和满意度的中介作用, 即：程序公平感越高, 变革型领导通过心理资本对下属的工作绩效和满意度所产生的作用就越强, 反之越弱。最后讨论了该研究的理论意义和应用价值。