The bandgap expansion with the reduction of Si QD size is well supported by the first-principles calculations based on quantum confinement. (c) 2011 American Institute of Physics. [doi:10.1063/1.3561439]“
“Light quality and,

in particular, its content of blue light is involved in plant functioning and morphogenesis. Blue light variation frequently occurs within a stand as shaded zones are characterized by a simultaneous decrease of PAR and blue light levels which both affect plant functioning, for example, gas exchange. However, little is known selleck compound about the effects of low blue light itself on gas exchange. The aims of the present study were (i) to characterize stomatal behaviour in Festuca arundinacea leaves through leaf gas exchange measurements in response to a sudden reduction in blue light, and (ii) to test the putative role of Ci on blue light gas exchange responses. An infrared gas analyser selleck (IRGA) was used with light transmission filters to study stomatal conductance (gs), transpiration (Tr), assimilation

(A), and intercellular concentration of CO2 (Ci) responses to blueless PAR (1.80 mu mol m(-2) s(-1)). The results were compared with those obtained under a neutral filter supplying a similar photosynthetic efficiency to the blueless PAR filter. It was shown that the reduction of blue light triggered a drastic and instantaneous decrease of gs by 43.2% and of Tr by 40.0%, but a gradual stomatal reopening began 20 min after the start of the low blue light treatment, thus leading to new steady-states. This new stomatal equilibrium was supposed to be related to Ci. The results were confirmed in more developed plants although they exhibited delayed and less marked responses. It is concluded that stomatal responses to blue light could play a key role in photomorphogenetic mechanisms through PP2 in vitro their effect on transpiration.”
“We demonstrate experimentally the existence of triple twins in Ni-Mn-Ga

magnetic shape memory single crystals with a modulated five-layered martensite structure using optical observations and x-ray diffraction. Subsequently, we investigate the response of the crystals with triple-twin segments to compressive loading up to several MPa. Such loading typically resulted in an abrupt rearrangement of the twin microstructure to a configuration with many fine twins (1-10 mu m in size) ending at a twin boundary. This type of twin microstructure exhibited recoverable deformation with up to 0.3% macroscopic strain and an estimated 2.5% local strain, while the recoverable strain was much smaller for other studied microstructure configurations. The results indicate that by the creation of a suitable twin microstructure, the originally pseudoplastic or magnetoplastic material can be made rubberlike elastic or magnetoelastic with the macroscopic recoverable strain comparable to 2.5%. (C) 2011 American Institute of Physics. [doi:10.1063/1.