Abstract: A mesoporous catalyst for purifying lean burn NOx emission including a mesoporous material, which substantially has pores with a diameter of 2 to 50 nm and a specific surface area of 100 to 1,400 m2/g, selected from the group consisting of mesoporous silica and mesoporous alumina, and 0.01 to 20 mass % of a catalyst carried on the mesoporous material with an average particle size of 1 to 20 nm containing platinum and/or iridium is provided.

Abstract: A mesoporous catalyst for purifying lean burn NOx emission including a mesoporous material, which substantially has pores with a diameter of 2 to 50 nm and a specific surface area of 100 to 1,400 m2/g, selected from the group consisting of mesoporous silica and mesoporous alumina, and 0.01 to 20 mass % of a catalyst carried on the mesoporous material with an average particle size of 1 to 20 nm containing platinum and/or iridium is provided.

Abstract: In order to produce a new substance having a diamond crystal structure, the following steps are taken in order. First, a graphite-like substance is prepared which contains boron (B), carbon (C) and nitrogen (N) as main elements. Then, the graphite-like substance is mixed with a metal powder to produce a mixture. Then, a pressure is applied to the mixture to produce a molded body, and then an explosion pressure is applied to the molded body.

Abstract: There are disclosed a modified oriented polyacetal product, the surface of said product being coated partly or entirely with a phenolic compound-polyacetal composite layer, the application thereof and a process for preparing the same.

Abstract: There are disclosed a modified oriented polyacetal product, the surface of said product being coated partly or entirely with a phenolic compound-polyacetal composite layer, the application thereof and a process for preparing the same.

Abstract: There are disclosed a polyacetal composition comprising(A) 70-97% by weight of a polyacetal and(B) 30-3% by weight of a transparent polyamide elastomer represented by the general formula ##STR1## in which PA and G represent the groups specified as in the body of the text;said polyamide elastomer exhibiting a relative viscosity of at least 1.5 in m-cresol at 30.degree. C. and at a polymer concentration of 0.5 g/dl anda 1-mm thick sheet of the polyamide elastomer having a haze of not more than 75%, and streched and oriented polyacetal material using it.

Abstract: A polyacetal copolymer of continuous length is disclosed. The copolymer has an apparent density of 1.20 to 1.46 g/cm.sup.3, and a tensile modulus (X) of 19 GPA or more and a density change percentage (Y) of 85% or more. The relationship between the density change percentage (Y) and the tensile modulus (X) is defined by the following relationship:when 19.ltoreq.X.ltoreq.30, then Y.gtoreq.127.7-1.42X, and when X>30, Y.gtoreq.85.A method for producing this copolymer includes permitting a polymeric material in continuous length to pass through a pressurizing fluid and applying a substantially uniform pressure therearound. A drawing stress is applied to the material while heating it at a temperature not above its softening point, thus subjecting the material to high stretching.