Abstract: In a method for the manufacture of an encased high critical temperature superconducting wire by the "powder in tube" method, prior to the introduction of a compressed rod of superconducting material into a silver tube, the rod is heat treated so that grains of unwanted phase are reabsorbed. The tube can be drawn more easily, and strands can be produced with a regular geometry and no defects. The wire is constituted by 15 .mu.m to 20 .mu.m thick filaments (30) with a form factor of more than 60.

Abstract: A method of making a high critical temperature superconductive fiber by fiber drawing a material of the family Bi.sub.x Pb.sub.y Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.z where 1.9.ltoreq. x+y.ltoreq. 2.3. In the method a preform is made, fiber drawing is performed, and the resulting fiber is annealed in air, wherein said preform is constituted by a block of vitreous material having the formula Bi.sub.x P.sub.y Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.z where: 1.9.ltoreq. x+y.ltoreq. 2.3 and a tube surrounding said block and made of a vitreous material having the formula Bi.sub.x' Sr.sub.2 Ca.sub.1 Cu.sub.2 O.sub.z' with 1.5.ltoreq. x'.ltoreq. 2.2.

Abstract: The device for discharging electrochemical cells (20, 21) into a load (Rc) is of the type comprising switching means (25, 26), each cooperating with one of the electrochemical cells (20, 21), these switching means (25, 26) being controlled sequentially by a generator (23) providing N pulse trains (SC1, SC2) offset relative to one another, each electrochemical cell (20, 21) being connected to the load (Rc) for the duration of a pulse, through the switching means (25, 25) with which the cell cooperates. According to the invention, it is characterized in that the pulses of each train (SC1, SC2) have an interval of overlap with the pulses of another train (SC1, SC2), such that the load (Rc) is constantly supplied by at least one of the N electro-chemical cells (20, 21), the overlap interval being very much smaller than the duration of each of said pulses.

Abstract: An X-ray generator comprises an anode (4) and a cathode (10) disposed in an enclosure (2) under low helium pressure and powered by an electric pulse generator (20) providing sufficient voltage in order to generate runaway electrons. The emission face of the cathode is a section of an emission plate (10) constituted by a carbon felt whose fibers have a privileged orientation perpendicular to said face in order to encourage the emission of electrons from said face. The invention is particularly applicable to pre-ionizing the discharge chamber of a gas laser.

Abstract: The inventive means includes a supply vessel (10) having a bottom opening (14), feed means (15 to 17) for supplying the vessel (10) with solid silicon and means (11 to 13) for heating the vessel, said vessel being placed above the crucible (1) containing the melt (8) so that the molten silicon in the vessel (10) flows out through the bottom opening (14) into the crucible (1) when the level (h) of the molten silicon in the supply vessel reaches a maximum value (20) and the replenishing flow stops when the level (h) has fallen to a minimum value (22). An application involving the deposition of a layer of polycrystalline silicon onto a carbon tape is described.

Abstract: An optical fiber telecommunication device comprises an interconnecting volume and N stations connected to this volume by pairs of transmit and receive optical fibers. Each station comprises a tunable optical frequency laser coupled to the transmit fiber and a heterodyne receiver system coupled to the receive fiber. It is provided with a tunable frequency laser local oscillator. The volume is disposed in a central office comprising a clock to determine different timing periods assigned to the N stations. The carrier frequency of the laser for each station is initially adjusted to a first frequency reserved for modulating ringing signals in the respective channels. The central office comprises a processor connected to the interconnecting volume to receive the ringing signals and designate a carrier frequency for each call request. This frequency is transmitted through the interconnecting volume to the calling station and the called station on a second reserved frequency.

Abstract: A device for depositing a layer of polycrystalline silicon on a carbon tape comprises a bath of molten silicon through which the carbon tape is drawn vertically. Two semicircular channels are supported vertically in the vicinity of the edges of the tape with their concave side towards the tape. The channels are partially immersed in the bath so as to raise the level of its surface by capillary action. The device is applicable to the manufacture of solar cells.

Abstract: Along an axis (2) of an optical cavity there are: a mirror (3) having a W-shaped cross section to give inner and outer conical reflecting surfaces (4, 6) which are oppositely inclined, a plane mirror (8) having an axial opening and facing the W-shaped mirror (3), a convex mirror (16) receiving the oscillating radiation from the W-shaped mirror (3) via the opening in the plane mirror (8), and a mirror (17) disposed between the plane mirror (8) and the convex mirror (16), said mirror (17) having an aperture and being inclined to the axis so as to extract laser energy from the oscillator.

Abstract: The process includes an electrochemical reduction, under carbon dioxide atmosphere, of benzyl type ArCH.sub.2 X or ArCH(CH.sub.3)X halogenides.According to the invention, the process consists of operating in the presence of a catalyst containing at least one organometallic complex derived from a transition metal combined with a bidentate or tetradentate coordinate.

Abstract: The amplifier has a fluid active medium and contained in housing (1). The medium is excited by electric discharge in a resistance (4) constituted by a conductive layer deposited on an insulating support.Application to iodine lasers.

Abstract: A vitreous material suitable for coating a semiconductor component comprises, by weight:30% to 40% zinc oxide ZnO,15% to 30% lead oxide PbO,20% to 40% boron oxide B.sub.2 O.sub.3,5% to 20% silicon dioxide SiO.sub.2,2% to 10% aluminum titanate Al.sub.2 TiO.sub.5, and0% to 5% bismuth oxide Bi.sub.2 O.sub.3.

Abstract: A laser amplification system comprises in series on the emission axis of a laser oscillator a germanium plate inclined at the Brewster angle, a Fresnel parallelepiped, a laser amplifier and a reflecting mirror, as well as a Fresnel parallelepiped and a laser amplifier aligned on the reflection axis of the plate. The system is intended for application in the study of plasmas.

Abstract: This invention concerns a device for maintaining a separation between two electric conductors. A dielectric spacer comprises, in the vicinity of at least one conductor, a portion having high permittivity. Application to the increase in the voltages which coaxial electric power conveying cables can withstand.

Abstract: Low density polyethylene with a very small proportion of low molecular weight polyethylene (e.g. such as can be extracted by washing by ethanol) is used as an insulation material for high voltage power cable.

Abstract: The invention relates to a sodium-sulphur electric cell. It comprises a cathode tank containing sulphur, a solid electrolyte tube being disposed in this tank and containing sodium, said cathode tank being lined with a continuous strip of felt or fabric, more particularly of graphite wound in a spiral one of whose ends is in contact with the wall of the cathode tank, at least one of the turns of said spiral having a plurality of holes, the other end of the strip being in contact with either the electrolyte tube or a conductive grid surrounding the tube and disposed at a predetermined distance from that tube. The invention is implemented in electric vehicles.

Abstract: Concentric closed tubes define an outer steam vessel with the inner tube constituted by a selective membrane consisting of a metallic oxide having a first doping to effect passage of oxygen ions through the membrane to the interior of the inner tube acting as an oxygen collector and having a second doping to effect return conduction of electrons through said membrane to increase heating of the steam. A vacuum pump is applied to the interior of the inner tube to provide a pressure differential to facilitate oxygen passage through the membrane.

Abstract: Power laser chain. Two amplifying elements are separated by a linear polarizer placed between two polarization transformers such as a quarter wave plate or a Fresnel parallelepiped, this preventing auto-oscillators in the amplifying chain, it being possible to repeat that sequence several times in the chain.