Single-Valued DMBE Potential Energy Surface for HSO: A Distributed n-Body Polynomial Approach

An accurate single-valued double many-body expansion (DMBE) potential energy surface is reported for the ground electronic state of HSO based on novel MR CISD ab initio energies suitably corrected for the complete one-electron basis set/complete CI limit. To improve the accuracy of the fit, we have suggested a n-body distributed polynomial approach which implies using individual multinomial developments at the various stationary points. For simplicity, only the three most relevant such points have been considered: two minima (HSO, HOS) and the saddle point connecting them

A useful form of the recurrence relation between relativistic atomic matrix elements of radial powers

Recently obtained recurrence formulae for relativistic hydrogenic radial matrix elements are cast in a simpler and perhaps more useful form. This is achieved with the help of a new relation between the $r^a$ and the $\beta r^b$ terms ($\beta$ is a $4\times 4$ Dirac matrix and $a, b$ are constants) in the atomic matrix elements.Comment: 7 pages, no figure

Electromagnetic behaviour and thermal stability of a conduction-cooled, no-insulated 2G-HTS coil at intermediate temperatures

The electromagnetic and thermal properties of a double pancake coil made of second generation high temperature superconductor, 2G-HTS, have been studied. The coil was wound with no-insulation between turns (NI coil) and was later impregnated with epoxy resin and glued to a copper support plate. The coil was thermally anchored to the cryocooler cold finger and cooled by conduction. After several thermal cycles no degradation of its superconducting properties was observed. The coil was operated under high vacuum and high currents (up to 400 A in steady conditions) at different temperatures in the range between 5 K and 77 K, with special focus on the analysis above 30 K. The charge and discharge characteristics, and the experimentally measured and numerically estimated critical currents, have been studied. The different loss contributions during current ramp and the thermal contact conductance between different parts of the double pancake coil have been measured. The implications of these two factors on the thermal stability and the behaviour of the whole cryogenic system are discussed

Solar ultraviolet radiation is necessary to enhance grapevine fruit ripening transcriptional and phenolic responses

Background: Ultraviolet (UV) radiation modulates secondary metabolism in the skin of Vitis vinifera L. berries, which affects the final composition of both grapes and wines. The expression of several phenylpropanoid biosynthesis-related genes is regulated by UV radiation in grape berries. However, the complete portion of transcriptome and ripening processes influenced by solar UV radiation in grapes remains unknown.Results: Whole genome arrays were used to identify the berry skin transcriptome modulated by the UV radiation received naturally in a mid-altitude Tempranillo vineyard. UV radiation-blocking and transmitting filters were used to generate the experimental conditions. The expression of 121 genes was significantly altered by solar UV radiation. Functional enrichment analysis of altered transcripts mainly pointed out that secondary metabolism-related transcripts were induced by UV radiation including VvFLS1, VvGT5 and VvGT6 flavonol biosynthetic genes and monoterpenoid biosynthetic genes. Berry skin phenolic composition was also analysed to search for correlation with gene expression changes and UV-increased flavonols accumulation was the most evident impact. Among regulatory genes, novel UV radiation-responsive transcription factors including VvMYB24 and three bHLH, together with known grapevine UV-responsive genes such as VvMYBF1, were identified. A transcriptomic meta-analysis revealed that genes up-regulated by UV radiation in the berry skin were also enriched in homologs of Arabidopsis UVR8 UV-B photoreceptor-dependent UV-B -responsive genes. Indeed, a search of the grapevine reference genomic sequence identified UV-B signalling pathway homologs and among them, VvHY5-1, VvHY5-2 and VvRUP were up-regulated by UV radiation in the berry skin.Conclusions: Results suggest that the UV-B radiation-specific signalling pathway is activated in the skin of grapes grown at mid-altitudes. The biosynthesis and accumulation of secondary metabolites, which are appreciated in winemaking and potentially confer cross-tolerance, were almost specifically triggered. This draws attention to viticultural practices that increase solar UV radiation on vineyards as they may improve grape features. © 2014 Carbonell-Bejerano et al.; licensee BioMed Central Ltd

Recurrence relation for relativistic atomic matrix elements

Recurrence formulae for arbitrary hydrogenic radial matrix elements are obtained in the Dirac form of relativistic quantum mechanics. Our approach is inspired on the relativistic extension of the second hypervirial method that has been succesfully employed to deduce an analogous relationship in non relativistic quantum mechanics. We obtain first the relativistic extension of the second hypervirial and then the relativistic recurrence relation. Furthermore, we use such relation to deduce relativistic versions of the Pasternack-Sternheimer rule and of the virial theorem.Comment: 10 pages, no figure

Angular emission properties of a layer of rare-earth based nanophosphors embedded in one-dimensional photonic crystal coatings

The angular properties of light emitted from rare-earth based nanophosphors embedded in optical resonators built in one-dimensional photonic crystal coatings are herein investigated. Strong directional dependence of the photoluminescence spectra is found. Abrupt angular variations of the enhancement caused by the photonic structure and the extraction power are observed, in good agreement with calculated polar emission patterns. Our results confirm that the optical cavity favors the extraction of different wavelengths at different angles and that integration of nanophosphors within photonic crystals provides control over the directional emission properties that could be put into practice in phosphorescent displays.Ministerio de Ciencia e Innovación MAT2008- 02166, CSD2007-00007Junta de Andalucía FQM3579, FQM524