Abstract: A piston allowing a lubrication layer of a resin coating with a low friction coefficient to be tightly adhered to a skirt portion of a piston for an internal combustion engine, with low friction, superior wear resistance, and superior anti-seizing properties and that can reduce wear of a cylinder inner wall even if the lubrication layer is peeled off or abraded, is provided. Metal or ceramic fine particles having an average particle diameter of 20 ?m to 400 ?m are injected with compressed air or compressed nitrogen as a mixture fluid onto the skirt portion of the piston, made of an aluminum alloy and produced by a method such as casting or forging, at an injection speed of 80 m/s or more or an injection pressure of 0.2 MPa or more to be collided with the skirt portion, thereby uniformly making a microstructure of a piston base material fine-grained in a depth range of 1 ?m to 15 ?m from a surface of the skirt portion and forming a modified layer with an activated surface.

Abstract: The connection structure between unit cells connects a plurality of batteries B1 and B2 in series with bottomed cylindrical battery cases 2 and 5 which function as electrode terminals on one side, sealing plates 3 which close the opening portions of the battery cases 2 and 5 which function as electrode terminals on another side, and the first ring 1a with a flange is conductively connected at a bottom portion of a battery case 2 of one battery B1, the second ring 1b with a flange is conductively connected at an upper portion of the sealing plate 3 of another battery B2, and the first ring 1a and the second ring 1b are fitted.

Abstract: A piston allowing a lubrication layer of a resin coating with a low friction coefficient to be tightly adhered to a skirt portion of a piston for an internal combustion engine, with low friction, superior wear resistance, and superior anti-seizing properties and that can reduce wear of a cylinder inner wall even if the lubrication layer is peeled off or abraded, is provided. Metal or ceramic fine particles having an average particle diameter of 20 ?m to 400 ?m are injected with compressed air or compressed nitrogen as a mixture fluid onto the skirt portion of the piston, made of an aluminum alloy and produced by a method such as casting or forging, at an injection speed of 80 m/s or more or an injection pressure of 0.2 MPa or more to be collided with the skirt portion, thereby uniformly making a microstructure of a piston base material fine-grained in a depth range of 1 ?m to 15 ?m from a surface of the skirt portion and forming a modified layer with an activated surface.

Abstract: The connection structure between unit cells connects a plurality of batteries B1 and B2 in series with bottomed cylindrical battery cases 2 and 5 which function as electrode terminals on one side, sealing plates 3 which close the opening portions of the battery cases 2 and 5 which function as electrode terminals on another side, and the first ring 1a with a flange is conductively connected at a bottom portion of a battery case 2 of one battery B1, the second ring 1b with a flange is conductively connected at an upper portion of the sealing plate 3 of another battery B2, and the first ring 1a and the second ring 1b are fitted.