Abstract: A method of making a plain bearing sliding layer for use in internal combustion engines, comprising the immersion of a metal substrate in a chemical solution containing copper, tin and lead salts to which is added one of the compounds represented by the following three exemplary structures: ##STR1## where X is one of the chemical elements selected from sulphur and nitrogen, --C represents one carbon atom, and radicals R.sub.1 and R.sub.2 represent the allowed variations, from a single hydrogen atom up to the typical structures of inorganic compounds or aliphatic, aromatic or cyclic chain organic radicals. The chemical solution is subjected to an electric current with a density and potential controlled as a function of time, thereby effecting the selective electrodeposition of the solution elements on the substrate so as to form successive and alternate layers of softer material and harder material.

Abstract: Gas-diffusion electrodes (GDE's) suitable for use with a solid polymer electrolyte (s.p.e.), particularly in s.p.e. fuel cells, which GDE's provide unusually highly efficient use of noble or precious electrocatalytic metals, are obtained by starting with a GDE which is essentially fully fabricated except for electrocatalytic metal treatment and s.p.e. treatment, e.g. a carbon GDE having a gas-permeable hydrophobic face and a particulate carbon-containing catalytic face. This untreated GDE is treated bya. impregnating an s.p.e. solutuion into the catalytic face until the solution penetrates part way into the cross-section of the GDE, especially into the carbon particulate or other support material, but not as far as the hydrophobic, gas permeable face,b. inserting the thus-treated GDE and a counterelectrode into a plating bath containing, for example, M.sup.+, M.sup.++, and/or M.sup.+++ ions, where M is a metal of Group VIII or I-B of the Periodic Table, andc.