Abstract: The product of this invention can be applied as a column packing for high performance liquid chromatography. This material is further useful as a catalyst carrier, as a sorbent for selective concentrating diluted compounds for analytical purposes, and for immobilizing enzymes and the like. The invention discloses a process for producing silicic acid xerogel matrix with a volume of pores up to 4.0 cm.sup.3 g.sup.-1 or even more, which process consists in that the starting soft and elastic silica hydrogel is subjected to combined effect of successive hardening in concentrated solutions of strong inorganic or organic acids, such as, for example, sulphuric acid, hydrochloric, phosphoric, nitric or trichloroacetic acids at ambient or elevated temperatures followed by acting in water-miscible solvents, such as, for example, in alcohols or ketones, and finally, by acting in water-immiscible solvents, such as, for example, in benzene, toluene, C.sub.5 to C.sub.12 hydrocarbons or carbon tetrachloride.

Abstract: A method is provided for fabricating substantially vertically aligned patterns of material on the opposed surfaces of a transparent substrate by employing a single external mask.

Abstract: A process of preparing spherical microparticles having size of from 0.5 to 1000 .mu.m and designed as chromatographic column charge, catalyst vehicle and absorption filling, or the like, by polymerizing a monomeric or polymeric substance in a macromolecular dispersing medium, the polymer forming said medium being different from that arising in polymerization process.

Abstract: A method and an apparatus are described for indicating and/or recording electrical quantities, the desired and actual values being converted into pulses whose repetition frequencies are proportional to the actual and desired quantities. The difference between the two pulse frequencies controls a stepping motor, whose shaft drives the indicating or recording element.