Abstract: A powder consisting of barium titanate powder, strontium titanate powder or a solid solution thereof, characterized in that (a) its average particle diameter is 0.07 to 0.5.mu., (b) its specific surface area measured is 20 m.sup.2 /g or less and does not exceed 2.5 times the specific surface area calculated from the average particle diameter on the assumption that the powder particles are spherical, (c) its crystallite diameter calculated from the half-width of the peak of the X-ray diffraction pattern for the powder is 0.05.mu. or more, and (d) its shape is substantially spherical. Said powder can be produced by reacting hydrous titanium oxide with barium hydroxide and/or strontium hydroxide at a temperature ranging from 60.degree. C. to less than 110.degree. C. in the presence of 120 to 2,000 moles of water per mole of titanium.

Abstract: A dielectric ceramic composition comprising 87.5 to 99.6 mole % of barium titanate as a first component, 0.2 to 7.0 mole % of copper oxide as a second component, 0.2 to 5.5 mole % of at least one member selected from the group consisting of lithium oxide, zinc oxide, cadmium oxide and iron oxide as a third component, and if necessary, at least one complex oxide selected from the group consisting of lead titanate, strontium titanate, calcium titanate, magnesium titanate, barium zirconate, calcium zirconate, strontium zirconate, lead zirconate, magnesium zirconate, lead stannate, calcium stannate, strontium stannate, barium stannate and magnesium stannate, as a fourth component in an amount of 0.3 to 40.0 moles per 100 moles of the sum of the first, second and third components; and a process for producing said dielectric ceramic composition.

Abstract: A tetraazaannulene cobalt complex compound having the general formula (I); ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 each independently is a hydrogen atom, a C.sub.1-8 alkoxy group or a C.sub.1-8 alkyl group but in case of one of R.sub.1, R.sub.2 and R.sub.3 being a hydrogen atom the other two groups are not hydrogen atoms at the same time, and when R.sub.1 is a methyl group R.sub.2 and R.sub.3 are not hydrogen atoms at the same time.

Abstract: A post-activation type dry image forming material comprising (I) a silver salt component reducible to free silver upon light exposure and including silver iodide; (II) a redox reactive composition capable of making a visual change by a redox reaction of said composition, said reaction being initiated by heating in the presence of free silver; (III) an oxidizing agent for free silver which has an oxidizing capacity for free silver but is rendered photosensitive by heating and which, upon light exposure after said heating, is suppressed with respect to the oxidizing capacity for free silver and capable of catalytically promoting the redox reaction of said composition; and (IV) a photoreactive oxidizing agent, upon light exposure, capable of returning the reduced oxidizing agent for free silver to the original state.

Abstract: A process for preparing a silver salt of an organic carboxylic acid comprising reacting an alkali metal salt of the organic carboxylic acid with a water-soluble silver salt, and wherein there is used as the reaction solvent a mixture consisting of at least one water-soluble or partially water-soluble C.sub.3 -C.sub.8 alcohol and water and having a mixing volume ratio of 1/5 to 5/1. The silver salt of the organic carboxylic acid prepared in high yield according to the process of the present invention is in uniformly finely divided form of high purity and suitable for use in photographic materials.

Abstract: A novel dry image forming material comprising (a) a non-photosensitive organic silver salt oxidizing agent, (b) a reducing agent for silver ions, (c) a photosensitive silver halide or a photosensitive silver halide-forming component capable of forming a photosensitive silver halide by the reaction thereof with said organic silver salt oxidizing agent, and (d) a substituted 3-pyrazolin-5-one. The dry image forming material has improved sensitivity and storage stability of the raw image forming material and can form thereon an excellent black tone image.

Abstract: A dry image forming material comprising:(a) an organic silver salt oxidizing agent;(b) a photosensitive silver compound or a component capable of forming a photosensitive silver compound by the reaction with the organic silver salt oxidizing agent (a);(c) a reducing agent for silver ion; and(d) at least one compound selected from the group consisting of .alpha.,.alpha.,.alpha.',.alpha.'-o-tetrabromoxylene, .alpha.,.alpha.,.alpha.',.alpha.'-m-tetrabromoxylene, .alpha.,.alpha.,.alpha.',.alpha.'-p-tetrabromoxylene, 1,2-diiodoethane and tribromoacetic acid.

Abstract: A heat developable photosensitive material comprising:(a) an organic silver salt oxidizing agent;(b) a halogen molecule or an organic haloamide compound;(c) a reducing agent for silver ion; and(d) a nitrogen-containing organic base whose pKa of the conjugate acid ranges from 0.5 to 10.0 and the nitrogen-containing organic base having, in its molecule, no acidic proton or a nitrogen-containing organic base whose pKa of its conjugate acid ranges from 0.5 to 10.0 and the nitrogen-containing organic base having, in its molecule, an acidic proton whose pKa is more than 12.

Abstract: A dry image forming material comprising:(a) a non-photosensitive organic silver salt oxidizing agent;(b) a reducing agent for silver ion; and(c) a compound of the formula, ##STR1## wherein R.sup.1 and R.sup.2 independently represent an aryl group or a substituted aryl group; and X represents a chlorine atom, a bromine atom or an iodine atom.

Abstract: A dry image forming material comprising (a) a non-photosensitive organic silver salt oxidizing agent, (b) a reducing agent for a silver ion and (c) a halogen molecule, which material is excellent in that a high sensitivity can be obtained and the occurrence of fog is extremely small. The sensitivity can be further improved by incorporation of a halogen ion source in addition to the halogen molecule. Furthermore, the dry image forming material can be improved, with respect to light stability of the raw image forming material and stabilities to heat and humidity, by incorporation of a nickel compound and/or a cobalt compound. In the dry image forming material of this invention, further incorporation of a carboxylic acid anhydride exerts a remarkable anti-fogging effect. The dry image forming material of this invention is non-photosensitive under normal lighting conditions and therefore, can be prepared, handled and stored in a light room.

Abstract: An N.sup.4 -acyl-1-.beta.-D-arabinofuranosylcytosine having the following formula ##SPC1##Wherein R is an aliphatic acyl group having 3 to 35 carbon atoms. The compounds of this invention are useful as a cancer chemotherapeutic agent for controlling tumors, e.g., in mice, an insecticide, and a fungicidal surface active agent.