(C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 2591-2596, 2011″
“The thermoelectric performance of materials is dependent on the interplay or competition among three key components, the electrical conductivity, thermopower, and thermal conductivity, which can be written as integrals of a single function, the transport distribution function (TDF). Mahan and Sofo [Proc. Natl. Acad. Sci. USA 93, 7436 (1996)] found that, mathematically, the thermoelectric properties could be maximized by a delta-shaped transport distribution, Selonsertib in vitro which was associated with a narrow distribution of the energy of the electrons participating

in the transport process. In this work, we revisited the shape effect this website of TDF on thermoelectric figure of merit. It is confirmed both heuristically and numerically that among all the normalized TDF the Dirac delta function leads to the largest thermoelectric figure of merit. Whereas, for the case of TDF being bounded, a rectangular-shape distribution is instead found to be the most favorable

one, which could be achieved through nanoroute. Our results also indicate that high thermoelectric figure of merit is associated with appropriate violations of the Wiedemann Franz law. (C) 2011 American Institute of Physics. [doi:10.1063/1.3563097]“
“Current predictions on species responses to climate change strongly rely on projecting altered environmental conditions on species distributions. However, it is increasingly acknowledged that climate change also influences species Combretastatin A4 ic50 interactions. We review and synthesize literature information on biotic interactions and use it to argue that the abundance of species and the direction of selection

during climate change vary depending on how their trophic interactions become disrupted. Plant abundance can be controlled by aboveground and belowground multitrophic level interactions with herbivores, pathogens, symbionts and their enemies. We discuss how these interactions may alter during climate change and the resulting species range shifts. We suggest conceptual analogies between species responses to climate warming and exotic species introduced in new ranges. There are also important differences: the herbivores, pathogens and mutualistic symbionts of range-expanding species and their enemies may co-migrate, and the continuous gene flow under climate warming can make adaptation in the expansion zone of range expanders different from that of cross-continental exotic species. We conclude that under climate change, results of altered species interactions may vary, ranging from species becoming rare to disproportionately abundant. Taking these possibilities into account will provide a new perspective on predicting species distribution under climate change.