高分子材料导热性能影响因素研究进展

介绍了高分子材料导热性能影响因素研究进展，重点阐释了聚合物基体的结构特性（链结构、分子间相互作用、取向、结晶度等）、导热填料（种类、含量、形态、尺寸等）以及制备方法等对高分子材料导热性能的影响。     

Public perceptions on artificial intelligence driven disaster management: Evidence from Sydney,Melbourne and Brisbane

In recent years, artificial intelligence (AI) is being increasingly utilised in disaster management activities. The public is engaged with AI in various ways in these activities. For instance, crowdsourcing applications developed for disaster management to handle the tasks of collecting data through social media platforms, and increasing disaster awareness through serious gaming applications. Nonetheless, there are limited empirical investigations and understanding on public perceptions concerning AI for disaster management. Bridging this knowledge gap is the justification for this paper. The methodological approach adopted involved: Initially, collecting data through an online survey from residents (n = 605) of three major Australian cities; Then, analysis of the data using statistical modelling. The analysis results revealed that: (a) Younger generations have a greater appreciation of opportunities created by AI-driven applications for disaster management; (b) People with tertiary education have a greater understanding of the benefits of AI in managing the pre- and post-disaster phases, and; (c) Public sector administrative and safety workers, who play a vital role in managing disasters, place a greater value on the contributions by AI in disaster management. The study advocates relevant authorities to consider public perceptions in their efforts in integrating AI in disaster management.     

Color determinants of surface stratification

Although color plays a crucial role in the demarcation of surfaces in the visual field, its role in depth perception is not well understood. Certain special effects of color on depth perception that arise from optical factors such as chromatic aberration (chromostereopsis) have been studied, but less is known about the role of perceptual factors of color in determining depth relations. The present study explores the role that the different attributes of color such as hue, chroma, and lightness play in the stratification of surfaces in depth. In two experiments, subjects manipulated specific dimensions of colors (hue, chroma, lightness, and whiteness) while making judgments of coplanarity of either two or more abutting surfaces. The results demonstrate that for surfaces to appear coplanar, their lightness has to be proportional to the natural (intrinsic) lightness of the hues. No meaningful effects of chroma, whiteness, or blackness were found in depth stratification. The results suggest a primary role of the natural lightness of hues in depth perception.     

Cyberbullying: Effect of emergency perception on the helping tendencies of bystanders

The effect of the emergency perception of bystanders of cyberbullying victims on helping behaviors is often neglected in research on cyberbullying. In this study, we explored the influence of this cognitive factor on cyber-bystanders’ helping tendencies as well as elucidated possible underlying processes. The results of two studies were reported. In Study 1, 150 undergraduates read a true case of a girl experiencing cyberbullying. The results indicated that when the participants perceived the victim’s situation to be more critical (i.e., higher emergency perception), their helping tendencies were stronger, partly through increased state empathy followed by feelings of responsibility to help. In Study 2, we randomly assigned 300 undergraduates to two groups. The low emergency group read the same cyberbullying case as Study 1, whereas the cyberbullying case read by the high emergency group contained additional emergency information of the victim. The results indicated that the high emergency group expressed stronger helping tendencies than did the low emergency group. This effect was caused by a stronger perception that the victim was in an emergency situation, which not only strengthened the participants’ helping tendencies directly but also indirectly through increasing their state empathy and feelings of responsibility to help.     

Competitive growth of Al2O3/YAG/ZrO2 eutectic ceramics during directional solidification: Effect of interfacial energy

The microstructure evolution and growth behavior of the Al₂O₃/Y₃Al₅O₁₂(YAG)/ZrO₂ ternary eutectic ceramics during directional solidification were well investigated. During directional solidification of the Al₂O₃/YAG/ZrO₂ ternary eutectic ceramics, {} Al₂O₃ paralleled with {001}ZrO₂ while they did not parallel with {001}YAG at the same time in the competitive growth stage. All of the interfaces parallel to each other finally. The area percentage of the Al₂O₃/ZrO₂ and YAG/ZrO₂ interfaces are 40.4 ± 0.2% and 30.8 ± 0.1%, respectively, higher than that of the Al₂O₃/YAG (28.8 ± 0.2%). The content of Al₂O₃ and YAG phases are 39.9% and 41.1%, respectively, almost double of that of ZrO₂. The interfaces of Al₂O₃/ZrO₂ and YAG/ZrO₂ are shorter and more dispersed than that of the Al₂O₃/YAG. It was found that the interfacial energy of Al₂O₃/ZrO₂ and YAG/ZrO₂ interfaces are lower than that of Al₂O₃/YAG. It can be concluded that interfacial energy plays a decisive role in affecting the crystallographic orientation and interfaces distribution in the Al₂O₃/YAG/ZrO₂ eutectic since the interfaces of Al₂O₃/ZrO₂ and YAG/ZrO₂ with lower interfacial energy can be formed more easily during directional solidification. Therefore, the contents of Al₂O₃/ZrO₂ and YAG/ZrO₂ interfaces are higher. This study can provide theoretical guidance for interface design of multi-phase materials.     

The effect of the nutri-score label on consumer’s attitudes,taste perception and purchase intention: An experimental pilot study

A large number of studies has emerged on the environmental impacts of diets, with most studies concluding that a diet rich in plant-based foods, that are low in salt, sugar, and fat, and score high in nutritional values, confers both improved health and environmental benefits. Currently, new interventions are being implemented to improve people’s eating behavior, because most people overconsume unhealthy snacks, containing high proportions of salt, sugar and fat. The purpose of the current pilot study was to investigate the effects of the Nutri-Score label on three different snack bars on consumers’ attitudes, taste perception, and purchase intention towards these food products. An experimental study was conducted with a between subject design (food packaging with Nutri-Score label versus without) among 192 participants (M_age 31.7 years, SD 14.3 years; 63% female). Results showed that there were no effects found for the effect of the Nutri- Score label on consumers’ attitudes, taste perception and purchase intention. Bayesian analyses support the conclusion that the null hypothesis is accepted. These findings show that integrating the Nutri-Score label on food packages did not modify cognitive responses of consumers towards these food products. Changing consumption behaviors is challenging and more empirical and theoretical understanding is needed.     

Rayleigh-Type Wave in A Rotated Piezoelectric Crystal Imperfectly Bonded on a Dielectric Substrate

Propagation characteristics of Rayleigh-type wave in a piezoelectric layered system are theoretically investigated. The piezoelectric layer is considered as a cubic crystal with finite thickness rotated about Y-axis and is imperfectly bonded onto a semi-infinite dielectric substrate. The imperfect interface between the two constituents is assumed to be mechanically compliant and dielectrically weakly conducting. The exact dispersion relations for electrically open or shorted boundary conditions are obtained. The numerical results show that the phase velocity of Rayleigh-type wave is symmetric with respect to the cut orientation of 45。 and can achieve the maximum propagation speed in this orientation. The mechanical imperfection plays an important role in the dispersion relations, further the normal imperfection can produce a significant reduction of phase velocity comparing with the tangential imperfection. Comparing with the mechanical imperfection the electrical imperfection makes a relatively small reduction of phase velocity of Rayleigh-type wave. The obtained results can provide some fundamentals for understanding of piezoelectric semiconductor and for design and application of piezoelectric surface acoustic wave devices.     

A lightweight autonomous MAV for indoor search and rescue

Micro Aerial Vehicles (MAVs) have great potentials to be applied for indoor search and rescue missions. In this paper, we propose a modular lightweight design of an autonomous MAV with integrated hardware and software. The MAV is equipped with the 2D laser scanner, camera, mission computer and flight controller, running all the computation onboard in real time. The onboard perception system includes a laser‐based SLAM module and a custom‐designed visual detection module. A dual Kalman filter design provides robust state estimation by multiple sensor fusion. Specifically, the fusion module provides robust altitude measurement in the circumstance of surface changing. In addition, indoor‐outdoor transition is explicitly handled by the fusion module. In order to efficiently navigate through obstacles and adapt to multiple tasks, a task tree‐based mission planning method is seamlessly integrated with path planning and control modules. The MAV is capable of searching and rescuing victims from unknown indoor environments effectively. It was validated by our award‐winning performance at the 2017 International Micro Air Vehicle Competition (IMAV 2017), held in Toulouse, France. The performance video is available on https://youtu.be/8H19ppS_VXM .