Abstract: A joining structure is provided which includes a first resin member and a second resin member having respective joining portions that are joined together by friction welding. The joining structure further includes a projecting wall that is opposed to the joining portions of the first and second resin members with a spacing therebetween. In the joining structure, at least one notch is formed in a surface of the projecting wall that faces the joining portions of the first and second resin members.

Abstract: A joining structure is provided which includes a first resin member and a second resin member having respective joining portions that are joined together by friction welding. The joining structure further includes a projecting wall that is opposed to the joining portions of the first and second resin members with a spacing therebetween. In the joining structure, at least one notch is formed in a surface of the projecting wall that faces the joining portions of the first and second resin members.

Abstract: A thin film of a perovskite-type transparent potassium niobate formed on an amorphous substrate. The thin film of a perovskite-type potassium niobate has excellent transparency, can be (110) oriented, and can be used for optical devices, such as an optical waveguide, a second harmonic generating device, and an optical switching device.

Abstract: A thin film of a perovskite-type transparent potassium niobate formed on an amorphous substrate. The thin film of a perovskite-type potassium niobate has excellent transparency, can be (110) oriented, and can be used for optical devices, such as an optical waveguide, a second harmonic generating device, and an optical switching device. The amorphous substrate is a glass substrate or a composite amorphous substrate comprising an amorphous layer which contains at least one element selected from the group consisting of alkaline earth metal elements, rare earth elements, Bi, Pb, Nb, Co, Ni, and W.

Abstract: A glass-ceramic magnetic disk substrate which is prepared by forming, then heat treating, and then polishing a crystallizable glass composition comprising, expressed in terms of weight percent on the oxide basis: from 20 to 45% SiO.sub.2 ; from 25 to 45% Al.sub.2 O.sub.3 ; from 10 to 25% B.sub.2 O.sub.3 ; from 2 to 12% MgO; from 0.5 to 8% TiO.sub.2 ; from 0.5 to 5% P.sub.2 O.sub.5 ; from 0 to 2% Li.sub.2 O; from 0 to 2% Na.sub.2 O; from 0 to 3% K.sub.2 O; wherein, the total of the contents of Li.sub.2 O, Na.sub.2 O and K.sub.2 O is from 0 to 5%; and wherein the magnetic disk substrate comprises a main crystalline phase consisting of at least one member selected from the group consisting of mullite and aluminum borate crystals. The glass composition can easily be formed and the disk substrate can easily be polished, has excellent mechanical strength, surface flatness, surface smoothness, chemical durability, and heat resistance, and shows no deterioration of magnetic film characteristics by alkali migration.

Abstract: Popcorn polymer growth on the inner surface of an olefin production apparatus is inhibited by treating a popcorn polymer with an efficient amount of a popcorn polymer growth inhibitor while the operation of the apparatus is suspended and olefins are removed from the apparatus.

Abstract: The formation of popcorn polymer on the inner surface of an olefin production apparatus is inhibited by treating the surface with a surface treating agent comprising an organic acid and/or salts thereof and at least one member selected from the group consisting of a corrosion-resistant agent, a reducing agent and a penetrant, and balance being water.