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A dual temperature- and light-responsive C2H2/C2H4 separation switch in a diarylethene metal-organic framework (MOF) is presented. At 195 K and 100 kPa this MOF shows ultrahigh C2H2/C2H4 selectivity of 47.1, which is almost 21.4 times larger than the corresponding value of 2.2 at 293 K and 100 kPa, or 15.7 times larger than the value of 3.0 for the material under UV at 195 K and 100 kPa. The origin of this unique control in C2H2/C2H4 selectivity, as unveiled by density functional calculations, is due to a guest discriminatory gate-opening effect from the diarylethene unit. [ABSTRACT FROM AUTHOR]

Inverted metamorphic multi-junction solar cells have reached efficiencies close to 46%. These solar cells contain very high-quality materials that exhibit strong luminescent coupling between the junctions. The presence of luminescent coupling has a significant impact on the behavior of multi-junction solar cells affecting the optimal design of these devices. Because of the importance of studying devices under real operating conditions, the temperature dependence of the luminescent coupling is analyzed over a range of 25-120°C. Luminescent coupling analysis results show a reduction of the luminescent coupling current as a function of temperature in two tandem components of an inverted metamorphic triple junction solar cell such as GaInP/GaAs and GaAs/GaInAs solar cells. This reduction is quantified and examined by means of luminescent coupling analysis and modeling, electroluminescence measurements and optical modeling at the device and subcell level. The results of the models are verified and discussed. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Changes in annual and seasonal temperatures were studied from 18 stations, distributed all over the Basilicata region (southern Italy), for the 1951-2010 period. The analysis is based on high-quality and homogenous daily minimum and maximum temperatures. Both minimum ( Tmin) and maximum ( Tmax) temperatures increase, especially after 1971. Seasonal results show upward trends in Tmin in winter, spring and summer, whereas they show downward trends in Tmin in autumn, especially in the last normal 1981-2010. Tmax also shows upward trends in spring and summer, whereas it tends to decrease during winter and autumn. The intra-annual extreme temperature range (ETR) index also shows a general positive trend, especially during spring. Eleven indices were used to assess the changes in both the cold and warm tails of the daily temperature distribution. The presence of trends was assessed by means of the Mann-Kendall test. The results reveal a general upward tendency on warm days (TX90), warm nights (TN90) and tropical nights (T20) especially because of an increase in temperature after 1971. This datum is fully confirmed in summer which is the season mainly responsible for this trend. The annual occurrence of summer days (SU) and very warm days (TX99) is weakly increasing. The majority of cold extremes, i.e. very cold nights (TN1), cold days (TX10), cold nights (TN10), frost days (FD) and ice days (ID) showed negative trends, thus confirming the overall warming trend in the Basilicata region. This negative trend could stem from the strong increase of Tmin during winter, spring and summer. [ABSTRACT FROM AUTHOR]

ABSTRACT Variability is a very important inherent characteristic of climate and it varies on all timescales. It is also considered an important factor regarding changes of extreme events. On the basis of daily temperature records at 63 stations in the eastern and central Tibetan Plateau during 1960-2008, we examine changes of temperature mean, variability and extremes for the region, and study correlations between multiscale temperature variability and various extreme temperature events. Results show that considering the entire study region, a significantly decreasing trend is observed for intra-annual temperature variability ( StdD), whereas a significantly increasing trend is observed for interannual temperature variability ( IVT). Further relationships between multiscale temperature variability and temperature extremes over the past 49 years show that IVT is positively correlated with cold/warm nights ( TN10/ TN90) and warm days ( TX90), whereas StdD is positively correlated with cold extremes ( TN10/ TX10) and negatively correlated with warm extremes ( TN90/ TX90). Nevertheless, annual mean temperature also plays an important role in the relationships between temperature variability and temperature extremes, for correlations between IVT and cold temperature extremes in two warming periods are quite different. Stations with different temperature trends for mean, variability and extremes in the two warming periods are categorized in the study region, and these temperature characteristics in each category are also affected by local effects, such as elevation, topography and urbanization. However, in strong warming periods, the change of mean temperature still has a dominant effect on extreme temperature events. [ABSTRACT FROM AUTHOR]