Abstract: Disclosed herein is a method for producing aromatic polyether which has a less coloring and high transparency and can be used for various purposes without limitation. The method comprises polymerizing (1) a substantially equimolar mixture of a dihydric phenol compound and a dihalogenobenzenoid compound and/or (2) a halophenol, in an organic solvent having high polarity, in the presence of at least one compound selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, and alkali metal hydroxides in an amount providing at least equivalent atoms of alkali metal to the phenolic hydroxyl groups, and in the presence of oxalic acid or an alkali metal salt thereof in an amount of 0.01 to 0.5% in terms of oxalic acid with respect to the weight of aromatic polyether to be obtained.

Abstract: A positive-tone photosensitive resin composition for forming a thick film which is suitably used for photofabrication such as manufacture of circuit boards, a photosensitive resin film, and a method of forming a bump using the same. The photosensitive resin composition comprising (A) a novolac resin with a weight average molecular weight of 2,000-30,000, (B) a polyvinyl lower alkyl ether, (C) a polyphenol derivative compound with a molecular weight of 200-1,000, and (D) a compound containing a naphthoquinonediazido group.

Abstract: The invention is to provide the methods for producing highly water-absorbable and water-retainable hydrogels having a large particle diameter together with a sufficient gel strength. The method is characterized by use of a specific dispersing agent in the water-in-oil type inverse phase suspension polymerization of an .alpha.,.beta.-unsaturated carboxylic acid and/or its alkali metal salt. Due to the high water-absorbability and water-retainability, along with the superior gel strength and the stable gel structure, the hydrogels of the invention enlarge the conventional range of usages.

Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a substrate, a stacked body, a semiconductor pillar, a charge storage film, and a drive circuit. The stacked body is provided on the substrate. The stacked body includes a plurality of insulating films alternately stacked with a plurality of electrode films. A through-hole is made in the stacked body to align in a stacking direction. The semiconductor pillar is buried in an interior of the through-hole. The charge storage film is provided between the electrode film and the semiconductor pillar. The drive circuit supplies a potential to the electrode film. The diameter of the through-hole differs by a position in the stacking direction. The drive circuit supplies a potential to reduce a potential difference with the semiconductor pillar as a diameter of the through-hole piercing the electrode film decreases.