Abstract: A solution for forming a superconductive thin film prepared by dissolving a mol of a compound selected from group A consisting of alkoxides and alkoxyalkoxides of a rare earth metal element; b mol of a compound selected from group B consisting of alkoxides and alkoxyalkoxides of Ba, Sr and Ca; and c mol of a compound selected from group C consisting of alkoxides and alkoxyalkoxides of Cu in e liter of a compound selected from group E, a solvent selected from alcohols together with d mol of a compound selected from group D for inhibiting hydrolysis action such as an amine, a ketone and a glycol, such that the following relationships:0.1.times.(a+b+c).ltoreq.d.ltoreq.3.times.(a+b+c)and0.01.ltoreq.[(a+b+c)/e].ltoreq.3can be satisfied.

Abstract: A solution for forming a superconductive thin film prepared by dissolving a mol of a compound selected from group A consisting of alkoxides and alkoxyalkoxides of a rare earth metal element; b mol of a compound selected from group B consisting of alkoxides and alkoxyalkoxides of Ba, Sr and Ca; and c mol of a compound selected from group C consisting of alkoxides and alkoxyalkoxides of Cu in e liter of a compound selected from group E, a solvent selected from alcohols together with d mol of a compound selected from group D having hydrolysis inhibitory action such as an amine, a ketone and a glycol, such that the following relationships:0.1.times.(a+b+c).gtoreq.d.gtoreq.3.times.(a+b+c)and0.1.gtoreq.[(a+b+c)/e].gtoreq.emay be satisfied.

Abstract: Means are provided for determining the TOD (total oxygen demand) of combustible materials contained in water, principally, sea water.Test water containing halides of alkali metals or alkaline earth metals, such as sea water, is burned in an oxygen-containing inert gas flowing through a combustion tube which contains a catalyst and which is heated to a combustion supporting temperature. The amount of oxygen consumed is measured.Inside the said combustion tube, down the gas stream from the catalyst, is provided a decomposing agent which consists of a hydroxide or carbonate of an alkali metal, or a hydroxide, oxide or carbonate of an alkaline earth metal, or of any mixture of them, thereby to decompose into sodium chloride and oxygen the sodium hypochlorite which was formed from the combustion of the test water.