Abstract: Primary molecules are formed by sublimation in a sublimation chamber (2), they are then transferred at a transfer flow-rate to a decomposition head (10) at a higher temperature, and they are transformed therein into secondary molecules that are lighter in weight to form molecular beams (16). In accordance with the invention, the transfer flow-rate is adjusted by adjusting an effective vector flow-rate which is the vector flow-rate of a vector gas inserted into the sublimation chamber via a feed tube (26) and sucked out via a suction tube (30). The invention applies, in particular, to making III-V type semiconductor components by molecular beam epitaxy.

Abstract: The energization current of an indium phosphide or gallium arsenide double channel semiconductor laser is confined within a laser stripe by near and far current blocking arrangements. The near current blocking arrangements are formed by a blocking junction formed in two lateral channels delimiting the stripe. The far current blocking arrangements are formed by an iron-doped semi-insulative layer grown epitaxially before the lateral channels are etched. A particular application is to the fabrication of pump lasers used in optical amplifiers of optical fiber links.

Abstract: In a method of manufacturing a planar buried heterojunction laser, after etching to delimit a laser stripe in relief on a substrate, lateral layers to surround the stripe are formed by a non-selective growth method not only at the sides of the stripe but also above it to create a parasitic projection. This projection is then removed after separation from the substrate by selective attack of a lift-off stripe which was deposited for this purpose above the stripe prior to this etching. Passages are formed for the attack medium used for this purpose. The invention can be applied in particular to the manufacture of fiber optic transmission systems.

Abstract: A vacuum evaporation device incorporates a main treatment enclosure connected to an auxiliary chamber containing a material evaporation cell. The cell is fixed to a tight bellows displacement member able to displace the cell between a first advanced position towards a main enclosure and a second retracted position. A sealing valve provided with a slide is provided for the main enclosure from the auxiliary chamber, whereby the material of the evaporation cell can thus be changed without placing the main enclosure under atmosphere again. A fixed heating tube, connecting the main enclosure to the auxiliary chamber, has a first end engaged in the main enclosure and a second end issuing into the auxiliary chamber. The second end is provided with an end piece made from a thermally insulating material ensuring mechanical continuity and thermal insulation with the support part and able to bearingly receive the evaporation cell when the latter is in the advanced position.

Abstract: The present invention relates to novel isocyano derivatives of linear or cross-linked, natural or synthetic macromolecules, the derivatives being of the general formula P--O--Q--NC, wherein P is the macromolecular backbone, the oxygen atom is part of the hydroxy group, Q is a group --(CH.sub.2).sub.n --wherein n is an integer of at least 3 carbon atoms, and up to about 20 carbon atoms, or Q is an aralkyl group, to a process for preparing such derivatives and to a process of linking to same biologically active proteins and to the products thus obtained.

Abstract: Enzymes are convalently found to anionic or cationic hydrophilic polymeric carriers formed by essentially complete reaction of pendent anhydride groups of ethylene-maleic anhydride copolymer (EMA) with a diamine selected from the group consisting of hydrazine, P, P'-diaminodiphenylmethane and 1,6-diaminohexane to produce resins having pendent amine groups. The EMA-hydrazide and EMA- P,P'-diaminodiphenylmethane resins can be rendered cationic by reaction with N,N-dimethyl-1,3-propanediamine.

Abstract: Novel substituted polyamides of the general formula ##EQU1## wherein A and B, which may be identical or different, are the hydrocarbon backbone groups of the formula --(CH.sub.2).sub.n --, where n is an integer, R.sub.2 and R.sub.3 are the residues of an aldehyde R.sub.2 --CHO or of an isocyanide R.sub.3 --N.tbd.C, where R.sub.2 and R.sub.3 are aliphatic, aromatic or heterocyclic residues of the respective aldehyde or isocyanide, or where R.sub.3 is a chromophoric moiety. R.sub.2 and R.sub.3 can be substituted, and amongst the possible substituents there may be R.sub.3 designating --(CH.sub.2).sub.n --NHCO--CHR.sub.2 --N(CO)(R.sub.4)--X, where R.sub.4 is the residue of a monocarboxylic or dicarboxylic acid and X is the lysyl residue of a protein, which may be biologically active, or the residue of a low-molecular weight compound containing a primary amine moiety. Preferred polyamides are various types of nylons.