Observation and Control of Laser-Enabled Auger Decay

Single photon laser enabled Auger decay (spLEAD) has been redicted theoretically [Phys. Rev. Lett. 111, 083004 (2013)] and here we report its first experimental observation in neon. Using coherent, bichromatic free-electron laser pulses, we have detected the process and coherently controlled the angular distribution of the emitted electrons by varying the phase difference between the two laser fields. Since spLEAD is highly sensitive to electron correlation, this is a promising method for probing both correlation and ultrafast hole migration in more complex systems.Comment: 5 pages, 3 figure

Attosecond electronic recollision as field detector

We demonstrate the complete reconstruction of the electric field of visible-infrared pulses with energy as low as a few tens of nanojoules. The technique allows for the reconstruction of the instantaneous electric field vector direction and magnitude, thus giving access to the characterisation of pulses with an arbitrary time-dependent polarisation state. The technique combines extreme ultraviolet interferometry with the generation of isolated attosecond pulses.Comment: 5 figure

Highly Efficient Near-IR Photoluminescence of Er3+ Immobilized in Mesoporous SBA-15

SiO2 mesoporous molecular sieve SBA-15 with the incorporation of erbium ions is studied as a novel type of nanoscopic composite photoluminescent material in this paper. To enhance the photoluminescence efficiency, two schemes have been used for the incorporation of Er3+ where (1) Er3+ is ligated with bis-(perfluoromethylsulfonyl)-aminate (PMS) forming Er(PMS)x-SBA-15 and (2) Yb3+ is codoped with Er3+ forming Yb-Er-SBA-15. As high as 11.17 × 10−21cm2 of fluorescent cross section at 1534 nm and 88 nm of “effective bandwidth” have been gained. It is a 29.3% boost in fluorescent cross section compared to what has been obtained in conventional silica. The upconversion coefficient in Yb-Er-SBA-15 is relatively small compared to that in other ordinary glass hosts. The increased fluorescent cross section and lowered upconversion coefficient could benefit for the high-gain optical amplifier. Finally, the Judd–Ofelt theory has also been used for the analyses of the optical spectra of Er(PMS)x-SBA-15

Canola no Cerrado: performance de híbridos para incorporação no sistema de cultivo sob irrigação.

A cultura da canola possui grande importância mundial, ocupando a terceira posição da oleaginosa mais produzida, antecedida pela soja e palma de óleo. O Brasil ainda não consolidou a produção dessa espécie, sendo necessários mais estudos para promover sua tropicalização, principalmente em regiões com temperaturas mais altas. Nesse contexto, o trabalho teve como objetivo avaliar os componentes fenológicos e produtivos de canola sob irrigação visando sua tropicalização. O experimento foi conduzido em área experimental da Embrapa Cerrados, Planaltina, DF, situada a 15°35?30?? S e 47°42?30?? W, a 1.007 m altitude. Utilizou‑se o delineamento experimental de blocos ao acaso, com 16 genótipos de canola e quatro repetições. O híbrido Diamond foi o mais precoce com ciclo próximo aos 100 dias, de forma geral, a maioria dos híbridos foi agrupada como precoce. Os híbridos Diamond, ALHT B4, Hyola 50, Hyola 433 e a população F2 originária da Hyola 50, apresentaram destaque com números de sementes por síliqua superiores a 25, contudo, os demais genótipos apresentaram número de grãos superiores a 20 grãos por síliqua. Os híbridos de canola apresentam redução no seu ciclo quando cultivados no Cerrado. A produtividade de grãos da canola sob irrigação é superior à média nacional em 2019 (1.371 kg ha‑1), demonstrando o alto potencial do seu cultivo no Cerrado

The AVuPUR project (Assessing the Vulnerabiliy of Peri-Urbans Rivers): experimental set up, modelling strategy and first results

International audienceLe projet AVuPUR a pour objectif de progresser sur la compréhension et la modélisation des flux d'eau dans les bassins versants péri-urbains. Il s'agit plus particulièrement de fournir des outils permettant de quantifier l'impact d'objets anthropiques tels que zones urbaines, routes, fossés sur les régimes hydrologiques des cours d'eau dans ces bassins. Cet article présente la stratégie expérimentale et de collecte de données mise en ½uvre dans le projet et les pistes proposées pour l'amélioration des outils de modélisation existants et le développement d'outils novateurs. Enfin, nous présentons comment ces outils seront utilisés pour simuler et quantifier l'impact des modifications d'occupation des sols et/ou du climat sur les régimes hydrologiques des bassins étudiés. / The aim of the AVuPUR project is to enhance our understanding and modelling capacity of water fluxes within suburban watersheds. In particular, the objective is to deliver tools allowing to quantify the impact of anthropogenic elements such as urban areas, roads, ditches on the hydrological regime of suburban rivers. This paper presents the observation and data collection strategy set up by the project, and the directions for improving existing modelling tools or proposing innovative ones. Finally, we present how these tools will be used to simulate and quantify the impact of land use and climate changes on the hydrological regimes of the studied catchments