Abstract: An active laser medium for emitting a light beam by laser effect includes an X—F2-doped crystal, wherein X is a chemical element from the alkaline-earth family and F is fluorine. The crystal is doped with trivalent ions including: a first category of optically active dopant ions, in which each dopant ion is an ion of a first rare earth; and a second category of optically inactive dopant ions, referred to as buffer ions, in which each dopant ion is an ion of a rare earth different from the first rare earth. The second category of dopant ions has at least ions of a second rare earth and ions of a third rare earth, different from one another. The invention provides an active laser medium that can be used to obtain both a desired emission spectrum shape and a high thermal conductivity.

Abstract: A sacrificial positive active material for a lithium-ion electrochemical element which is a compound of formula (Li2O)x (MnO2)y(MnO)z(MOa)t in which: x+y+z+t=1; 1?x?y?0; 0.97?x?0.6; y?0.45; x ?0.17; y?0; y+z>0; t?0; 1?a<3. M is selected from the group consisting of Fe, Co, Ni, B, Al, Ti, Si, V, Mo, Zr and a mixture thereof.

Abstract: An active laser medium for emitting a light beam by laser effect includes an X—F2-doped crystal, wherein X is a chemical element from the alkaline-earth family and F is fluorine. The crystal is doped with trivalent ions including: a first category of optically active dopant ions, in which each dopant ion is an ion of a first rare earth; and a second category of optically inactive dopant ions, referred to as buffer ions, in which each dopant ion is an ion of a rare earth different from the first rare earth. The second category of dopant ions has at least ions of a second rare earth and ions of a third rare earth, different from one another. The invention provides an active laser medium that can be used to obtain both a desired emission spectrum shape and a high thermal conductivity.

Abstract: A sacrificial positive active material for a lithium-ion electrochemical element which is a compound of formula (Li2O)x (MnO2)y(MnO)z(MOa)t in which: x+y+z+t=1; 1?x?y?0; 0.97?x?0.6; y?0.45; x ?0.17; y?0; y+z>0; t?0; 1?a<3. M is selected from the group consisting of Fe, Co, Ni, B, Al, Ti, Si, V, Mo, Zr and a mixture thereof.

Abstract: This field-effect superconductor transistor (2) comprises a source electrode (4) and a drain electrode (6), connected by a superconducting channel (12), the channel (12) and the source (4) and drain (6) electrodes being arranged on a substrate (16), and a gate electrode (8) covering the channel (12). A layer (14) of semiconductor material is arranged between the channel (12) and the gate electrode (8), to control over the critical current of the superconducting channel (12) between a minimum value Ic_min and a maximum value Ic_max, by controlling the surface roughness of said channel (12), said surface roughness being controlled by combining the proximity effect between the superconducting channel (12) and the layer (14) of semiconductor material with the field effect in the layer (14) of semiconductor material by polarising the gate electrode (8).