Abstract: An opto-electronic converter comprises a mesoscopic resonant cavity constituted by a quantum wire made of a material that is a conductor or a semiconductor and situated between two electron mirrors of nanometer size, the said wire being interrupted over a gap having a width of a few tens of .ANG., into which gap a photosensitive material is inserted, tabs being provided at the ends of said cavity to pass an electrical current.

Abstract: An electrochemical secondary cell using lithium and a liquid organic electrolyte, the cell being of the cylindrical or prismatic type, wherein its separator comprises a microporous film of polyolefin next to the lithium anode and a film of cross-linked polymer that swells in the electrolyte and which applies pressure against the electrodes. The cross-linked polymer may be an ion conducting polymer including a polyether with two terminal amine functions.

Abstract: A method of manufacturing a component of the tape or filament kind out of a material based on a superconducting oxide having a high critical temperature, wherein said material is formed while it is in the vitreous state,the method being characterized by the fact that the material is subsequently crystallized:in a first step under a magnetic field and at a temperature T.sub.l lying between the vitreous transition temperature T.sub.g and the crystallization temperature T.sub.x, during which step isolated microcrystallites of submicroscopic size develop and their c axes orient themselves parallel to one another because of said applied magnetic field; andin a second step at a temperature T.sub.2 close to the crystallization temperature, in which the existing nuclei grow while retaining the texture imparted to them during said first step.

Abstract: An activatable lithium/bromine trifluoride electrochemical cell comprising an anode of lithium or lithium alloy, a positive current collector based on carbon black, and an electrolyte based on bromine trifluoride, wherein the quantity of bromine trifluoride is not less than 200 ml per dm.sup.2 of anode area, and that means are provided for causing the electrolyte to circulate through said cell at a linear speed of not less than 0.5 cm/second. Discharge yield is doubled [curve B] compared with a prior art cell [curve A].

Abstract: A rechargeable electrochemical cell comprising a cathode, an anode based on a carbon-containing material capable of intercalating lithium ions, and an electrolyte constituted by a cross-linked polymer incorporating a lithium salt and a dipolar aprotic solvent. At least the surface of the carbon-containing material is less crystallized than graphite so as to be impermeable to said solvent, while allowing the lithium to diffuse.

Abstract: A process for obtaining precursors for high critical temperature superconductor ceramics by precipitating salts which are insoluble in water comprises the following stages: A starting solution of soluble salts is prepared in which the cations are in the stoichiometric proportions of the required superconductor phase. A first full precipitation is carried out of a first series of cations at a first value of pH. The first precipitates obtained is filtered out and washed and the filtrate is retained. The pH of the filtrate is changed to a second value and the residual cations are precipitated. The second precipitate is filtered. The first and second precipitates are homogenized. The product obtained is dried, calcined, and ground.

Abstract: A lithium and bromine trifluoride electrochemical cell designed to be discharged after being activated and stored, the cell comprising an anode made of lithium or lithium alloy and a positive current collector made of carbon black, and containing at least one compound that is soluble in bromide trifluoride, and is capable of stabilizing the passivation layer of said anode and of blocking corrosion of said anode during storage, the compound being selected from sulfonates and being at a concentration lying in the range 10.sup.-2 moles per liter to 1 mole per liter. After the cell of the invention has been stored, it restores a large fraction of its initial capacity (curve C).

Abstract: A method of fabricating preforms for making optical fibers by drawing, in which a silica deposit, including a doping agent, is formed in successive layers inside a silica-based tube (1) from a chemical vapor containing a gaseous compound of silicon, oxygen, and a gaseous compound of an element for doping the silica, with the composite tube then being subjected to collapsing so as to cause the empty axial zone (3), the tube hollow, to disappear. The silica of the initial tube is then eliminated, by removal, after which a recharge of silica (5) is made around the remaining cylinder (4) by plasma torch deposition from a gas comprising oxygen and a halogen derivative of silica.