[en] A detailed spectroscopic study of various Yb³⁺:CaF₂ crystals with dopant concentrations ranging from 0.03 to 2 at% Yb³⁺ has been performed. By using site-selective laser excitation, the low-temperature (7 K) excitation and emission spectra recorded in the case of the lower doped samples (0.03% and 0.05%) are found to be dominated by three types of sites with excited state fluorescence lifetimes of about 2, 8 and 10 ms. Confronted with crystal field calculations, these sites have been identified as Yb³⁺ ions in trigonal (C_3v), tetragonal (C_4v) and cubic environments, respectively. At higher dopant concentrations (>0.1 at%), evidence is found of a third kind of site, whose contribution increases up to be dominant as dopant concentration is increased above about 1 at%Yb³⁺ and which gives rise to the lasing center which has been recently discovered and operated

[en] This publication contains a set of articles proposed by researchers and political, economic and industrial actors involved in or concerned by the development of smart grids and their different aspects: emergence of a more social engineering, the situation of the French smart grid sector, the example of a start-up (GridPocket), the roles of start-ups and small companies, the importance of smart grid for territories, the commitment of the French State, France as a leader of smart grids at the European scale, the support of the Commission for the Regulation of Energy (CRE) to the development of smart grids, the digitalisation of the electric transport grid, the challenges of energy transition, smart grids as a new challenge for the electric power sector, industrial challenges for the development of smart grids, a new definition of energy efficiency, the development of energy storage in smart grids, smart building in a smart city, supporting digital transition in territories, the role of institutional investors, new risks associated with the complexity of smart grids

[en] This report treats of the link between climate change and sea level. It was written in complement to volume 4 of the Jouzel's mission report 'Regionalized scenarios. France's climate in the 21. Century' published in August 2014. It updates volume 3 of this report already devoted to the sea level issue and published in February 2012. It aims at taking stocks of the knowledge about past and future sea level changes at the world and French coast scales, and about the main physical impacts of sea level rise (marine submersion, coastal erosion, saline influx into coastal aquifers and impacts on coastal and harbour infrastructures). However, the socio-economic impact and related risks management are not approached. It is based on the IPCC expertise and on results of works carried out by the French scientific community

[en] The coastline of France faces a range of highly specific challenges, in terms of demographics, urbanisation, socio-economic activities and the environment. The attractiveness of coastlines, and the ever-growing trend for soil sealing, is making these territories increasingly vulnerable to the impacts of climate change. The main impacts of climate change are rising temperatures, changing rainfall and cyclone patterns, the acidification of water and rising sea levels - an impact that is addressed in detail in this work. Data gathered since the early 20. century reveal a significant trend, namely that sea levels rose substantially and quickly during the last century, at a rate five times faster than in previous millennia. In statistical terms, the average sea level rose by 1.7 ± 0.2 mm per year between 1901 and 2010, and by 3.2 ± 0.4 mm per year between 1993 in 2014. All current climate models predict that average global sea levels will rise at a rate faster than that observed between 1971 and 2010 during the 21. century. This means that, in addition to the 20 cm rise in sea levels observed in the last 150 years, the sea is expected to rise by a further 26 to 82 cm by the end of this century. The exact rise will depend on the success of efforts to reduce greenhouse gas emissions. Although the rise in average sea levels in the last 150 years may seem insignificant when compared with the height of waves and tides, the IPCC's summary report (2014) suggests that an average rise in sea levels of 0.5 m would, without suitable adaptation and protection measures, result in flooding occurring between 10 and 100 times more often. This report presents: 1 - The main impacts of climate change on the coastline 2 - Climate change and sea level: from the planet to the French coastline 3 - Adaptation - from crisis management to planning: 'Waves and flooding' warnings; Cost of coastal natural disasters and the insurance mechanism; Regulating territories exposed to coastal flooding risks; A national coastal erosion anticipation strategy; Experimental relocation of activities and property: towards spatial reconfiguration of territories threatened by coastal risks; Scientific knowledge, today and tomorrow; The LiCCo project and the perspectives of elected officials on both sides of the Channel