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AbstractDendronic antennae systems containing pyrene units as energy donors and a styrylpyridinium derivative as energy acceptor show efficient energy transfer from the green‐emitting pyrene excimer to the red‐emitting acceptor. For the third dendron generation the effective screening of the pyrene units on the acceptor provides thin films showing bright red emission. Single‐layer light‐emitting diodes prepared by properly balancing the dendrons and donor units concentration in polyvinylcarbazole show electroluminescence from the blue, green and red components of the monomeric donor, the donor excimer and the acceptor when excitons are generated in the polymer and subsequently transferred to the molecules by resonant energy transfer.

This paper addresses the current knowledge on climate change impacts on mass movement activity in mountain environments by illustrating characteristic cases of debris flows, rock slope failures and landslides from the French, Italian, and Swiss Alps. It is expected that events are likely to occur less frequently during summer, whereas the anticipated increase of rainfall in spring and fall could likely alter debris-flow activity during the shoulder seasons (March, April, November, and December). The magnitude of debris flows could become larger due to larger amounts of sediment delivered to the channels and as a result of the predicted increase in heavy precipitation events. At the same time, however, debris-flow volumes in high-mountain areas will depend chiefly on the stability and/or movement rates of permafrost bodies, and destabilized rock glaciers could lead to debris flows without historic precedents in the future. The frequency of rock slope failures is likely to increase, as excessively warm air temperatures, glacier shrinkage, as well as permafrost warming and thawing will affect and reduce rock slope stability in the direction that adversely affects rock slope stability. Changes in landslide activity in the French and Western Italian Alps will likely depend on differences in elevation. Above 1500 m asl, the projected decrease in snow season duration in future winters and springs will likely affect the frequency, number and seasonality of landslide reactivations. In Piemonte, for instance, 21st century landslides have been demonstrated to occur more frequently in early spring and to be triggered by moderate rainfalls, but also to occur in smaller numbers. On the contrary, and in line with recent observations, events in autumn, characterized by a large spatial density of landslide occurrences might become more scarce in the Piemonte region.

A method for carrying out molecular dynamics simulations in which the potential energy U of the molecular system is constrained at its initial value is developed and thoroughly tested. The constraint is not introduced within the framework of the Lagrange multipliers technique, rather it is fulfilled in a natural way by carrying out the simulations in terms of suitable sets of delocalized coordinates. Such coordinates are defined by an appropriate tuning of the Baker, Kessi, and Delley internal delocalized nonredundant coordinates technique [J. Chem. Phys. 105, 192 (1996)]. The proposed method requires multiple evaluations of energy and gradients in each step of the molecular dynamics simulation, so that constant U simulations suffer some overhead compared to ordinary simulations. But the particular formulation of the delocalized coordinates and of the equations of motion greatly simplifies all the various steps required by the Baker’s technique, thus allowing for the efficient implementation of the method itself. The technique is reliable and allows for very high accuracy in the potential energy conservation during the whole simulation. Moreover, it proved to be free of drift troubles which can occur when standard constraint methods are straightforwardly implemented without the application of appropriate correcting techniques.

Grape production is highly responsive to weather conditions and therefore very sensitive to climate change. To evaluate how viticulture in the traditional Italian wine region Emilia-Romagna could be affected by climate change, several bioclimatic indices describing the suitability for grapevine production were calculated for two future periods (2011–2040 and 2071–2100) using CORDEX (Coordinated Regional Climate Downscaling Experiment) high-resolution climate simulations under two Representative Concentration Pathways (RCP) scenarios—RCP 4.5 and RCP 8.5. The projections for both of the RCP scenarios showed that most of the Emilia-Romagna region will remain suitable for grape production during the period 2011–2040. By the end of the twenty-first century, the suitability to produce grapes in Emilia-Romagna could be threatened to a greater or smaller extent, depending on the scenario. During the period 2071–2100, the entire Emilia-Romagna region will be too hot for grape production under the RCP 8.5 scenario. Under the RCP 4.5 scenario, changes will be milder, suggesting that the Emilia-Romagna region could still be suitable for grape cultivation by the end of the twenty-first century but would likely require certain adjustments.

Decomposition of five amino acids, alanine, serine, cysteine, aspartic acid, and asparagine, under irradiation with soft X rays (magnesium Kalpha X-ray source) in ultra-high vacuum was studied by means of X-ray photoelectron spectrometry (XPS) and mass spectrometry. A comparative analysis of changes in XPS line shapes, stoichiometry and residual gas composition indicates that the molecules decompose by several pathways. Dehydration, decarboxylation, decarbonylation, deamination and desulfurization of pristine molecules accompanied by desorption of H2, H2O, CO2, NH3 and H2S are observed with rates depending on the specific amino acid. NEXAFS spectra of cysteine at the carbon, oxygen and nitrogen K-shell and sulfur L2,3 edges complement the XPS and mass spectrometry data and show that the exposure of the sample to an intense soft X-ray synchrotron beam results in the formation of C-C and C-N double and triple bonds. Qualitatively, the amino acids studied can be arranged in the following ascending order of radiation stability: serine

The scaling of thin film photovoltaics to a commercially viable size relies on the series connection of multiple small cells into modules. These interconnections are typically formed by three patterning steps, each of which have an impact on the series resistance and consequently on the total module performance. Here, we implement the transmission line method for the complete analysis of the P2 patterning step of the photoactive layer in organic photovoltaic modules. Devices are investigated with a sample design that allows for a comparative study of the P2 connection on the solar cell performance. We compare subtractive mechanical scribing to a newly developed additive pre-patterning method for the P2 step. Aerosol Jet printed pre-patterning lines of low surface energy and conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) modified with a fluorosurfactant repel the subsequently spray coated photoactive layer. Furthermore, the influence of MoO3 in the P2 pattern is elucidated, displaying a substantial increase in series resistance and decrease in device performance.

AbstractThe synthesis and determination of the structure of a Förster resonance energy transfer probe intended for the detection of specific nucleic acid sequences are described here. The probe is based on the hybridization of oligonucleotide modified quantum dots with a fluorescently labeled nucleic acid sample resulting in changes of the fluorescence emission due to the energy transfer effect. The stoichiometry distribution of oligonucleotides conjugated to quantum dots was determined by capillary electrophoresis separation. The results indicate that one to four molecules of oligonucleotide are conjugated to the surface of a single nanoparticle. This conclusion is confirmed by the course of the dependence of Förster resonance energy transfer efficiency on the concentration of fluorescently labeled complementary single‐stranded nucleic acid, showing saturation. While the energy transfer efficiency of the probe hybridized with complementary nucleic acid strands was 30%, negligible efficiency was observed with a noncomplementary strand.