RESUMEN
Room-temperature bismuth telluride (Bi2Te3) thermoelectrics are promising candidates for low-grade heat harvesting. However, the brittleness and inflexibility of Bi2Te3 are far reaching and bring about lifelong drawbacks. Here we demonstrate good pliability over 1,000 bending cycles and high power factors of 4.2 (p type) and 4.6 (n type) mW m-1 K-2 in Bi2Te3-based films that were exfoliated from corresponding single crystals. This unprecedented bendability was ascribed to the in situ observed staggered-layer structure that was spontaneously formed during the fabrication to promote stress propagation whilst maintaining good electrical conductivity. Unexpectedly, the donor-like staggered layer rarely affected the carrier transport of the films, thus maintaining its superior thermoelectric performance. Our flexible generator showed a high normalized power density of 321 W m-2 with a temperature difference of 60 K. These high performances in supple thermoelectric films not only offer useful paradigms for wearable electronics, but also provide key insights into structure-property manipulation in inorganic semiconductors.
RESUMEN
Thermoelectrics enable direct heat-to-electricity transformation, but their performance has so far been restricted by the closely coupled carrier and phonon transport. Here, we demonstrate that the quantum gaps, a class of planar defects characterized by nano-sized potential wells, can decouple carrier and phonon transport by selectively scattering phonons while allowing carriers to pass effectively. We choose the van der Waals gap in GeTe-based materials as a representative example of the quantum gap to illustrate the decoupling mechanism. The nano-sized potential well of the quantum gap in GeTe-based materials is directly visualized by in situ electron holography. Moreover, a more diffused distribution of quantum gaps results in further reduction of lattice thermal conductivity, which leads to a peak ZT of 2.6 at 673 K and an average ZT of 1.6 (323-723 K) in a GeTe system. The quantum gap can also be engineered into other thermoelectrics, which provides a general method for boosting their thermoelectric performance.
RESUMEN
Drawing from regulatory fit theory and the literature on persuasion, the current study is the first to explore whether the fit between explanation framing and applicants' regulatory foci could enhance applicant reaction. We hypothesized that a positively framed explanation fits with applicants' promotion foci and that a negatively framed explanation fits with applicants' prevention foci. Three studies were conducted in which participants with different regulatory foci rated their perceived procedural fairness and organizational attractiveness after reading differently framed recruitment advertisements, rejection letters, and job offer letters. The results supported our hypothesis by showing significant interactions between explanation framing and participants' regulatory foci on procedural fairness and organizational attractiveness perception in the contexts of recruitment advertising and rejection letters. In these contexts, compared with receiving a negatively framed explanation, promotion-focused recipients reported higher levels of perceived fairness and organizational attractiveness after receiving a positively framed explanation, and promotion-focused recipients' fairness and attractiveness perceptions were higher than prevention-focused recipients', after receiving a positively framed explanation. Moreover, perceived procedural fairness mediated the relationship between regulatory fit and perceived organizational attractiveness. However, regulatory fit effects were not found in the context of job offer letters.
Asunto(s)
Modelos Psicológicos , Selección de Personal , Adolescente , Adulto , Femenino , Humanos , Masculino , Cultura Organizacional , Comunicación Persuasiva , Justicia Social , Lugar de Trabajo/psicología , Adulto JovenRESUMEN
Most of the baby boomers born after the Second World War (WWII) have passed the age of 65, meaning they have gradually lost their social functions and positions, and are facing the need for care. In Taiwan, the lack of a long-term care mechanism is having a certain degree of impact on society as a whole, and thus, it is important to have a mechanism to take care of the elderly. In order to make this system sustainable, sufficient funds and continuous improvement are important factors. In the past, in order to avoid the illegal transfer of benefits, the social welfare mechanism avoided the use of for-profit organizations. However, as the economic environment declines, the role of for-profit organizations should be considered. This study defines the long-term ageing health care system using five major dimensions and 20 criteria. The DANP-mV model was used to analyze Taiwan's current system and identify problems, and then to develop a continuous improvement strategy from the perspective of the source of the problem in order to improve long-term ageing health care.