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.     

High-magnetic-field-induced formation of aligned equiaxed grains during directional solidification

The application of a high magnetic field is capable of inducing the formation of aligned equiaxed grains in alloys during directional solidification. The alignment and refinement of the grains is enhanced as the magnetic field intensity increases. The thermoelectric power difference at the liquid/solid interface in four alloys has been measured in situ during directional solidification and it is concluded that the formation of aligned equiaxed grains in a magnetic field should be attributed to the combined action of a thermoelectric magnetic force and a magnetization force.     

Going global: The functions of autobiographical memory in cultural context

This special issue of Memory brings together research from around the globe, from Japanese, Chinese and East Indian cultures, to American and European societies, to the Caribbean, to Turkey and to Australia and New Zealand, which examines how and why people, from childhood to old age, remember the personal past in daily life. This journey highlights the important role of the cultural context in shaping the functional usages of autobiographical memory. We illuminate six major contributions of cross-cultural research to a broader and deeper understanding of the functions of autobiographical memory, and call attention to the filed that memory research must “go global.”     

Knowledge of memory functions in European and Asian American adults and children: The relation to autobiographical memory

This study investigated explicit knowledge of autobiographical memory functions using a newly developed questionnaire. European and Asian American adults (N = 57) and school-aged children (N = 68) indicated their agreement with 13 statements about why people think about and share memories pertaining to four broad functions—self, social, directive and emotion regulation. Children were interviewed for personal memories concurrently with the memory function knowledge assessment and again 3 months later. It was found that adults agreed to the self, social and directive purposes of memory to a greater extent than did children, whereas European American children agreed to the emotion regulation purposes of memory to a greater extent than did European American adults. Furthermore, European American children endorsed more self and emotion regulation functions than did Asian American children, whereas Asian American adults endorsed more directive functions than did European American adults. Children's endorsement of memory functions, particularly social functions, was associated with more detailed and personally meaningful memories. These findings are informative for the understanding of developmental and cultural influences on memory function knowledge and of the relation of such knowledge to autobiographical memory development.     

Towards a better understanding of the relationship between executive control and theory of mind: an intra‐cultural comparison of three diverse samples

Previous research has consistently indicated that theory of mind (ToM) is associated with executive control in the preschool years. However, interpretation of this literature is limited by the fact that most studies have focused exclusively on urbanized Western cultural samples. Consequently, it is not clear whether the association between ToM and executive control reflects the specific features of this particular cohort or instead reflects a universal pattern. The present study provides the first empirical assessment of these two constructs in three diverse groups of Iranian children. Participants were 142 preschoolers (4–5 years old) from high–socioeconomic status (SES) urban (n = 33), low–SES urban (n = 37) and rural villages (n = 77). The results show that there is a robust association between ToM and executive control in all three groups, and that executive control contributes significant unique variance to ToM understanding, even after controlling for a range of variables that have been proposed as potential confounders of this relationship. However, although the three groups were equated in ToM, significant differences in executive control were evident. Moreover, cluster analysis identified three distinct clusters that were relatively homogeneous with respect to executive control and SES. One of these clusters was characterized by both low SES and low executive functioning, and showed little evidence of ToM understanding. Taken together, these findings provide possibly the clearest evidence to date that the association between ToM and executive control is not dependent on children's previous experiences on the tasks, or their family and cultural background. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=dxh_-3gCB8o     

胡塞尔论感知意识的视域结构

视域性是意识行为的一个本质特征。目前学界对感知意识之视域结构的研究主要集中于内视域和外视域。本文将依据新近出版的胡塞尔著作,结合新近有关"弱想象"的研究成果,力图呈现一幅关于感知视域的更全面的图景。本文第一部分将展示感知意识视域结构和功能的基础:滞留和前摄;第二部分分析由感知的本质构成要素"动感"所构成的身体权能的视域,胡塞尔在此区分的动感的两种基本功能对于接下来的阐述具有根本性的指导意义;第三部分分析视域意向性与身体权能性视域的共同作用,内视域和外视域即是由这种共同作用形成的一种视域的可能性;第四部分引入由"弱想象"构成的情景式想象的视域,最后将考察上述几种视域共同作用时的情形。     

论内化于行动的观念

观念是在先于主客二分的实践(行动主义)视角下、内化于个体活动中的意识,它首先与个体活动相关,有别于仅仅在认识论视角(非时间性的上帝视角)下的意识。作为常识理性的观念、作为社会意识的观念、作为默会知识的观念、作为人的活动形式的"观念的东西"、作为赋予意义和价值评价的观念、作为"思想具体"的观念,是"观念"的六种常见用法。     

公共卫生监测中的伦理原则及标准

从理论上概述了各时期监测定义的演变以及相关伦理辩论,列举了公共卫生监测所引发的普遍的伦理问题及适用的主要伦理原则,揭示了临床医学和公共卫生中伦理问题的不同。人权是个人利益和集体利益的共同基础,因此,也可能是临床伦理和公共卫生伦理的共同基础。最后,依据《世界卫生组织关于公共卫生监测中伦理问题的指南》及其他文献列出多种公共卫生伦理标准,试图在实际工作中帮助评估公共卫生监测方案在伦理上的可接受性。