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[en] A first part discusses the content of the French law related to energy and climate (LREC) which actually reviews and corrects two major elements of the energy transition: the general objectives of the public policy (the climate objective in terms of carbon neutrality and with introduction of a factor 6, and the energy objectives which are updated), and aspects related with governance (reform of institutional tools such as the High Council for Climate and various agencies, and of formal tools such as programming and planning tools, and assessment tools. The second part comments other issues of the LREC: energy sources (development of renewable energy sources which are to be selected, located, and related to specialised activities, and the phasing out of fossil energies), and the choices of new vectors such as hydrogen. It also comments how the law addresses transition in the different usages of energy through a reduction of energy consumptions (building energy performance, optimisation of the CEE system), and an empowerment of energy consumers (legal framework for self-consumption, creation of a legal framework for communities of renewable energy)
[en] The effect of fluorination on various types of phyllosilicate minerals has been investigated. Two different fluorination techniques have been used: direct F2 gas and cold radio frequency plasma involving c-C4F8 or O2/CF4 mixtures. The modifications of the surface composition and properties have been followed mostly by x-ray photoelectron spectroscopy (XPS). Depending of the fluorination reagents, a reactive etching process involving M-F bonding occurs (direct F2 gas; O2-CF4 rf plasma) or a carbon fluoride deposition takes place (c-C4F8 rf plasma). In the case of F2-gas treated minerals, Si 2p XPS signal accounts for the presence of fluorinated Si environments.
[en] Highlights: • Structural filiation of stannates compounds. • 119Sn Mossbauer analysis of Sn-X chemical bonding (X = OH, O, F). • Nephelauxetic effect observed in the luminescence of Pr3+ doped stannate compounds. - Abstract: CaSn(OH)6, CaSnO3 and CaSnF6 compounds were elaborated from a “one-batch” synthesis route: the coprecipitation of the pure double hydroxide leads to pure double oxide or fluoride after annealing treatments under air or HF as anhydrous gas, respectively. Structural and morphological features of the three matrices were carefully investigated by X Ray Diffraction analysis and Scanning Electron Microscopy, respectively. In addition, the luminescent properties of the Pr-doped compounds were performed and compared. The nanometric size of the double hydroxide inhibits the luminescence. The interpretation of the emission spectra obtained for Pr-doped CaSnO3 and CaSnF6 compounds is based on the covalence/ionic balance of the M–O or M–F bonds.
[en] Highlights: → The magnesium and manganese borohydrides form a solid solution MgxMn(1-x)(BH4)2 (x = 0-0.8) which conserves the trigonal structure of Mn((BH4)2. → Coexistence of both trigonal and hexagonal borohydrides occurs within nominal composition ranging from xMg = 0.8-0.9. → The decomposition temperature of trigonal MgxMn(1-x)(BH4)2 (x = 0-0.8) does not vary significantly with magnesium content (433-453 K). → The desorbed gas contains mostly hydrogen and 3-7.5 mol.% of diborane B2H6. - Abstract: A solid solution of magnesium and manganese borohydrides was studied by in situ synchrotron radiation X-ray powder diffraction and infrared spectroscopy. A combination of thermogravimetry, mass and infrared spectroscopy, and atomic emission spectroscopy were applied to clarify the thermal gas desorption of pure Mn(BH4)2 and a solid solution of composition Mg0.5Mn0.5(BH4)2. MgxMn(1-x)(BH4)2 (x = 0-0.8) conserves the trigonal structure of Mn(BH4)2 at room temperature. Manganese is dissolved in the hexagonal structure of α-Mg(BH4)2, with the upper solubility limit not exceeding 10 mol.% at room temperature. There exists a two-phase region of trigonal and hexagonal borohydrides within the compositional range x = 0.8-0.9 at room temperature. Infrared spectra show splitting of various vibrational modes, indicating the presence of two cations in the trigonal MgxMn(1-x)(BH4)2 solid solutions, as well as the appearance of a second phase, hexagonal α-Mg(BH4)2, at higher magnesium contents. All vibrational frequencies are shifted to higher values with increasing magnesium content. The decomposition temperature of the trigonal MgxMn(1-x)(BH4)2 (x = 0-0.8) does not vary significantly as a function of the magnesium content (433-453 K). The desorbed gas contains mostly hydrogen and 3-7.5 mol.% diborane B2H6, as determined from analyses of the Mn(BH4)2 and Mg0.5Mn0.5(BH4)2 samples. An eutectic relation between α-Mg(BH4)2 and LiBH4 is observed. The solid solution MgxMn(1-x)(BH4)2 is a promising material for hydrogen storage as it decomposes at a similar temperature to Mn(BH4)2, i.e. at a much lower temperature than pure Mg(BH4)2 without significantly losing hydrogen weight capacity thanks to substitution of Mn by Mg up to 80 mol.%. The questions of diborane release and reversibility remain to be addressed.
[en] This annual world report on the economic system and strategies (RAMSES) first proposes a synthesis of 2014 in terms of international relationships. The first part addresses the emerging countries (Brazil, Russia, India, China, South Africa, Indonesia, Turkey, Iran, Saudi Arabia, and Mexico) and the redistribution of world balances (the question of the decline of the USA, Europe in front of emerging countries, Japan in front of China). The contributions of the second part discuss the stakes and challenges between established and emerging powers (energy powers, military powers, economic powers) and the associated issues (geopolitical balance, migrations, cooperation and competition, Internet governance). The contributions of the third part address various European and world issues: EU and Russia, the Ukrainian issue, the presence of China in Eastern Europe, religious and political conflict between Shiites and Sunnis, terrorism, the situation in the Middle-East, crisis in Africa, China in Africa, the end of populist regimes in Cuba, Venezuela and Argentina, the missed emergence of Thailand, the issue of a financial world regulation, the role of the new pope). A chronology, maps and figures are provided
[en] Silicon‐mediated fluoride abstraction is demonstrated as a means of generating the first fluorido‐cyanido transition metal complexes. This new synthetic approach is exemplified by the synthesis and characterization of the heteroleptic complexes, trans‐[MF(CN)] (M=Re, Os), obtained from their homoleptic [MF] parents. As shown by combined high‐field electron paramagnetic resonance spectroscopy and magnetization measurements, the partial substitution of fluoride by cyanide ligands leads to a marked increase in the magnetic anisotropy of trans‐[ReF(CN)] as compared to [ReF], reflecting the severe departure from an ideal octahedral (O point group) ligand field. This methodology paves the way toward the realization of new heteroleptic transition metal complexes that may be used as highly anisotropic building‐blocks for the design of high‐performance molecule‐based magnetic materials. (© 2020 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)