Abstract: A numerical control apparatus provides for manual shift operation involving feed shafts of a machine tool in terms of a work coordinate system easily and readily understood by an operator. The numerical control apparatus includes a manual shift amount input unit for receiving an amount of manual shift involving linear feed shafts as operator-input data in terms of a work coordinate system defined on the work revolved or rotated by a rotary feed shaft. The numerical control apparatus further includes a manual shift amount cumulative storage for cumulatively storing the received amount of manual shift in terms of a work coordinate system. Also included is a cumulative shift amount coordinate converter for converting the cumulative amount of shift from the work coordinate system data to data in terms of machine coordinate system defined on the machine tool.

Abstract: A process for preparing an organic silicon compound is here disclosed which comprises the step of reacting a halogenated hydrocarbon selected from the group consisting ##STR1## wherein each of X.sup.1 to X.sup.16 is selected from the group consisting of hydrogen, an alkyl group, alkenyl group, phenyl group, naphthyl group, alkoxy group, acyl group, alkylamino group and dialkylamino group having 1 to 20 carbon atoms which are unsubstituted or substituted and a halogen atom; and each of at least one of X.sup.1 to X.sup.4, at least one of X.sup.8 to X.sup.10 and at least one of X.sup.11 to X.sup.16 is a halogen atom,with a silane selected from the group consisting of SiH.sub.4, Si.sub.2 H.sub.6 and Si.sub.3 H.sub.8.

Abstract: A process for producing silanes represented by the general formula SI.sub.n H.sub.2n+2 wherein n is 1 or 2, which comprises (a) preparing a silicon-magnesium alloy containing at least one element selected from the goup consisting of Li, Na, K, Ca, Ba, Ti, Zr, Nb, Cr, Mo, Mn, Fe, Co, Ni, Pd, Cu, Ag, Zn, Cd, Al, Sn, Pb, Bi, Se, S and C as a third component element; (b) reacting the alloy containing the third component element with an acid in an ammonia solvent; and (c) thus, varying the ratio of Si.sub.2 H.sub.6 formed to SiH.sub.4 formed.

Abstract: A process for disproportionating silanes, which comprises contacting a silane having at least one Si--H bond represented by the general formulaR.sub.l H.sub.m SiX.sub.4-(l+m)wherein R represents an alkyl or aryl group, X represents a halogen atom or an alkoxy group, l is 0, 1 or 2, and m is 1, 2 or 3 and l+m is 1, 2 or 3, and when l is 2, R's may be identical or different, and when l+m is 1 or 2, X's may be identical or different, with a reaction product of a strong acid-type cation exchange resin with an amine and disproportionating the silane.

Abstract: A process for producing silicon hydrides represented by the general formula Si.sub.n H.sub.2n+2 wherein n is a positive integer of 1 to 6, which comprises reacting a silicon-containing alloy with an aqueous solution of an acid in the presence of at least one inert organic solvent having a boiling range of from -60.degree. C. to 250.degree. C.