Abstract: A production process which comprises a preform formation step of forming a fiber preform made of silicon carbide short fibers having heat resistance of 1000° C. or greater; a sol-gel preparation step of preparing a sol-gel solution containing a heat resistant compound having heat resistance of 1000° C. or greater; an impregnation-drying-calcination step of impregnating the fiber preform with the sol-gel solution, followed by drying and calcining; and a crystallization step of crystallizing the fiber preform after impregnation, drying and calcination.

Abstract: There is disclosed a lobe mixer comprising: a cylindrical partition wall 22 which partitions a high-speed inner flow from a low-speed outer flow; a lobe portion 24 which is disposed on a downstream side of the partition wall and whose transverse sectional shape is a waveform shape and is enlarged on the downstream side; and a connecting reinforcement member 26 which is disposed between lobe side walls 24a extending in a radial direction of the lobe portion to connect the adjacent lobe side walls to each other. The connecting reinforcement member 26 is a thin member disposed along a flow line of a fluid which flows between the lobe side walls.

Abstract: The porous sound-absorbing material manufactured is light and has excellent heat resistance to be applicable to the exhaust nozzle etc. of a jet engine, can effectively absorb noise as that from a jet engine, over a wide range of frequencies, is free from variations in porosity, and provides stable performance characteristics. An essential feature thereof is the formation of a skeleton of the material, with aggregates containing voids. Thus, a porous sound-absorbing material having a skeleton of aggregates with first voids is described, wherein diameters of first voids of the aggregates are 50 ?m to 100 ?m, approximately, and diameters of second voids between the aggregates are 100 ?m to 600 ?m.

Abstract: An optically active poly(N-?-methylbenzylmaleimide) represented by the following formula (1): wherein n is a number within a range of from 2 to 10,000, and symbol * represents optically active carbon, and having a specific rotation ([?]43525) of at least +30°.

Abstract: A lobe mixer (22) used in jet engines, is provided with diameter expansion portions (22a) in which the diameters gradually increase in the downstream direction, in which adjacent diameter expansion portions have different diameters from each other, and which guide the core gasses that flow along the inner sides of the adjacent diameter expansion portions, peripherally outwards at different angles. Thus, the gasses are mixed without the thrust of the jet engine being reduced, and the noise of the jet is reduced.

Abstract: An optically active poly(N-&agr;-methylbenzylmaleimide) represented by the following formula (1): wherein n is a number within a range of from 2 to 10,000, and symbol * represents optically active carbon, and having a specific rotation ([&agr;]43525) of at least +30°.

Abstract: An optically active poly(N-&agr;-methylbenzylmaleimide) represented by the following formula (1): 1

Abstract: A lobe mixer (22) used in jet engines, is provided with diameter expansion portions (22a) in which the diameters gradually increase in the downstream direction, in which adjacent diameter expansion portions have different diameters from each other, and which guide the core gasses that flow along the inner sides of the adjacent diameter expansion portions, peripherally outwards at different angles. Thus, the gasses are mixed without the thrust of the jet engine being reduced, and the noise of the jet is reduced.

Abstract: The porous sound-absorbing material manufactured is light and has excellent heat resistance to be applicable to the exhaust nozzle etc. of a jet engine, can effectively absorb noise as that from a jet engine, over a wide range of frequencies, is free from variations in porosity, and provides stable performance characteristics. An essential feature thereof is the formation of a skeleton of the material, with aggregates 5 containing voids 6.

Abstract: An optically active poly(N-&agr;-methylbenzylmaleimide) represented by the following formula (1): 1

Abstract: There is disclosed a lobe mixer comprising: a cylindrical partition wall 22 which partitions a high-speed inner flow from a low-speed outer flow; a lobe portion 24 which is disposed on a downstream side of the partition wall and whose transverse sectional shape is a waveform shape and is enlarged on the downstream side; and a connecting reinforcement member 26 which is disposed between lobe side walls 24a extending in a radial direction of the lobe portion to connect the adjacent lobe side walls to each other. The connecting reinforcement member 26 is a thin member disposed along a flow line of a fluid which flows between the lobe side walls.

Abstract: An optically active poly(N-&agr;-methylbenzylmaleimide) represented by the following formula (1): wherein n is a number within a range of from 2 to 10,000, and symbol * represents optically active carbon, and having a specific rotation ([&agr;]43525) of at least +30°.

Abstract: An optically active poly(N-&agr;-methylbenzylmaleimide) represented by the following formula (1): 1

Abstract: A polymer obtained by polymerizing a fumaric acid derivative represented by the following general formula (1): ##STR1## in which R.sup.1 represents an alkyl group having 1-6 carbon atoms and A denotes a radical of ##STR2## in which R.sup.2 and R.sup.3 represent each an alkyl group having 1-4 carbon atoms and may be identical with or different from each other, R.sup.4 denotes an alkyl group having 1-6 carbon atoms or a benzyl group and m and n denote each an integer of 1-6.