Abstract: A positive electrode mixture layer for a lithium-ion secondary battery suitable for producing a lithium-ion secondary battery with high rate characteristics at an ordinary temperature and low temperatures and low internal resistance (DCR) at low temperatures, characterized by including a positive electrode active material, a binder, and a conductive additive, in which the conductive additive includes carbon black, a carbon nanotube (1) having an average fiber diameter of 80 to 400 nm, and a carbon nanotube (2) having an average fiber diameter of 0.4 to 3.0 nm, the content rates of the carbon black, the carbon nanotube (1), and the carbon nanotube (2) in the conductive additive are 40 to 80% by mass, 10 to 50% by mass, and 1 to 30% by mass, respectively, and the content rate of the conductive additive in the positive electrode mixed layer is 0.1 to 5.0% by mass.

Abstract: A head includes a face portion, a sole portion, and an internal weight portion provided on an inner surface of the sole portion and located apart from the face portion. The internal weight portion includes a base portion, and a protruding portion protruding from the base portion toward a face side and located apart from the inner surface of the sole portion. The protruding portion is positioned on the face side with respect to the head center of gravity. A thickness of a toe-side part of the protruding portion and/or a thickness of a heel-side part of the protruding portion is greater than a thickness of a middle part of the protruding portion. Alternatively, a middle part of the protruding portion in a toe-heel direction is absent. The internal weight portion may be formed integrally with the sole portion, or may be a different member from the sole portion.

Abstract: A lithium ion battery lifetime prediction method executes, by a computer, acquiring training data including cycle measurement data and lifetime data of a battery, learning a lifetime prediction model using the training data with respect to one or more cycle numbers at which a prediction is made, to acquire a set of learned lifetime prediction models corresponding to the cycle numbers at which the prediction is made, respectively, successively acquiring cycle measurement data for prediction of a battery that is a prediction target, up to the cycle numbers at which the prediction is made, respectively, and inputting the cycle measurement data for prediction acquired up to the cycle numbers at which the prediction is made, to the learned lifetime prediction models of the corresponding cycle numbers at which the prediction is made, and acquiring a probability distribution of a lifetime at the cycle numbers at which the prediction is made, respectively, as an output.

Abstract: A golf club head includes a weight object and a weight object receiving portion that is provided on an outer surface of the head and in which at least a part of the weight object is housed. The weight object or the weight object receiving portion includes a shape change mechanism that enables the weight object or the weight object receiving portion to change a shape of itself. The weight object receiving portion includes: a rotational force applying part that applies a rotational force on the weight object as a reaction generated when the weight object is pressed by the shape change; and a rotation prevention part that is located at a position abutting against the weight object when the rotational force is applied and that stops the weight object from being rotated by the rotational force and prevents rotation of the weight object.

Abstract: A golf club head includes: a head body that includes a cavity; a weight that is detachably attached to the cavity; and a cover that is openably and closably attached to the head body and that covers at least a part of the cavity when the cover is in a closed state. The weight is attached to the cavity in a state where the weight is slidingly movable in the cavity. In the closed state, the cover applies a pressing force to the weight. The weight may be fixed to the cavity by a static frictional force increased by the pressing force. The cavity may form a slide groove.

Abstract: A golf club head includes: a head body that includes a cavity; a weight that is detachably attached to the cavity; and a cover that is openably and closably attached to the head body and that covers at least a part of the cavity when the cover is in a closed state. The weight is attached to the cavity in a state where the weight is slidingly movable in the cavity. In the closed state, the cover applies a pressing force to the weight. The weight may be fixed to the cavity by a static frictional force increased by the pressing force. The cavity may form a slide groove.

Abstract: A state of a golf club head placed such that a shaft axis line is vertical to a horizontal plane and a normal line is parallel to a first perpendicular plane on which the shaft axis line lies is defined as a 0-degree state. A direction parallel to the first perpendicular plane and parallel to the horizontal plane is defined as a projection direction. A projected area of the head projected in the projection direction when the head is rotated by ?°about the shaft axis line toward a back side from the 0-degree state is denoted by WA?. WA? is divided by the shaft axis line into a first region (having an area denoted by Af?) and a second region (having an area denoted by Ab?), and a difference (Af?-Ab?) is denoted by S?. S90 is -4500 (mm2) or less. S15 is 4700 (mm2) or less.

Abstract: A head includes a face portion, a sole portion, and an internal weight portion provided on an inner surface of the sole portion and located apart from the face portion. The internal weight portion includes a base portion, and a protruding portion protruding from the base portion toward a face side and located apart from the inner surface of the sole portion. The protruding portion is positioned on the face side with respect to the head center of gravity. A thickness of a toe-side part of the protruding portion and/or a thickness of a heel-side part of the protruding portion is greater than a thickness of a middle part of the protruding portion. Alternatively, a middle part of the protruding portion in a toe-heel direction is absent. The internal weight portion may be formed integrally with the sole portion, or may be a different member from the sole portion.

Abstract: An object of the present invention is to provide a composite material usable as a negative electrode material of a lithium-ion secondary battery. A composite material of the present invention includes: a carbonaceous material; and a metal oxide layer coating a surface of the carbonaceous material, in which the metal oxide layer coats the surface of the carbonaceous material, forming a sea-island structure in which the metal oxide layer is scattered in islands, and a coating rate of the carbonaceous material with the metal oxide layer is 20% or more and 80% or less. A composite material of the present invention includes: a carbonaceous material; and a metal oxide layer and amorphous carbon layer coating the surface of the carbonaceous material, in which the metal oxide layer is scattered in islands on the surface of the carbonaceous material.

Abstract: A head includes a body member that has an opening, and a face member that includes a striking face and closes the opening. The face member includes a face portion that forms the striking face, and a peripheral portion that extends from a peripheral edge of the face portion toward a back side. The peripheral portion of the face member is welded to the body member. A weld bead that juts from the inner surface of the head is formed at a boundary position between the peripheral portion and the body member. A wall thickness at a face-side end point of the weld bead is greater than a wall thickness at a body-side end point of the weld bead. The peripheral portion has a length of less than or equal to 6 mm.

Abstract: A head includes a face portion, a crown portion, a sole portion, and a hosel portion. The crown portion includes a protruding portion on a crown outer surface. The protruding portion does not form any part of an outer contour line of the head in a front view of the head as viewed from a face side. The protruding portion forms an outer contour line of the head in a heel projection figure in which the head that is placed on a ground plane such that a shaft axis line is perpendicular to the ground plane and a face angle is 0° is viewed from a heel side along the ground plane. In this head, aerodynamic drag and lifting force at position 9 can be increased. In this head, air resistance at position 6 can be suppressed.

Abstract: A golf club includes a head, a shaft, and a grip. The head has a center-of-gravity depth of greater than or equal to 23.5 mm. The head has a center-of-gravity distance of less than or equal to 39 mm. The shaft has a forward flex of greater than or equal to 110 mm. When f1 denotes the forward flex of the shaft and f2 denotes a backward flex of the shaft, f2/f1 may be greater than or equal to 0.8 and less than or equal to 0.9. The head may have a volume of greater than or equal to 380 cc. The shaft may have a weight of less than or equal to 50 g.

Abstract: A golf club head includes: a head body that includes a cavity; a weight that is detachably attached to the cavity; and a cover that is openably and closably attached to the head body and that covers at least a part of the cavity when the cover is in a closed state. The weight is attached to the cavity in a state where the weight is slidingly movable in the cavity. In the closed state, the cover applies a pressing force to the weight. The weight may be fixed to the cavity by a static frictional force increased by the pressing force. The cavity may form a slide groove.

Abstract: A golf club includes a head; a shaft having a tip end and a butt end; a grip; and a weight member that is located in a butt end region having a distance from a butt end of the grip of less than or equal to 100 mm. The grip and the weight member constitute a grip-weight portion. The shaft, the grip, and the weight member constitute a shaft-grip-weight portion. The shaft has a weight of less than or equal to 40 g. The shaft has a shaft torque of less than or equal to 7.0°. The grip-weight portion has a weight of greater than or equal to 40 g. A ratio W1/W3 of a weight W1 of the butt end region to a weight W3 of the shaft-grip-weight portion is greater than or equal to 0.40.

Abstract: A golf club includes a head; a shaft having a tip end and a butt end; and a grip. The golf club has a length of greater than or equal to 45.0 inches. The head has a weight of greater than or equal to 195 g. The golf club has a club moment about a rotation center of less than or equal to 22.74 (kg·cm), the rotation center being a point 100 mm away from a butt end of the grip. The shaft may have a weight of less than or equal to 40 g. The golf club has a weight of greater than or equal to 280 g. A butt end region having a distance from the butt end of the grip of 100 mm or less may have a weight of greater than or equal to 27 g. This golf club can exhibit an on-plane effect.

Abstract: A golf club 2 includes a head 4, a shaft 6, and a grip 8. The club 2 has a forward club flex of greater than or equal to 170 mm. The forward club flex is measured for a golf club in the completed state. The weight of the head is denoted by Wh, and the weight of the club is denoted by Wc. Wh/Wc is greater than or equal to 0.72. With the golf club 2, a force acting on the player's body during a swing can be reduced. The golf club 2 can stabilize swing.

Abstract: A golf club includes a head; a shaft having a tip end and a butt end; a grip; and a weight member that is located in a butt end region having a distance from a butt end of the grip of less than or equal to 100 mm. The grip and the weight member constitute a grip-weight portion. The shaft, the grip, and the weight member constitute a shaft-grip-weight portion. The shaft has a weight Ws of less than or equal to 40 g. The shaft has a flex point ratio of less than or equal to 50%. The grip-weight portion has a weight W2 of greater than or equal to 40 g. A ratio W1/W3 of a weight W1 of the butt end region to a weight W3 of the shaft-grip-weight portion is greater than or equal to 0.40.

Abstract: A golf club includes a head; a shaft having a tip end and a butt end; a grip; and a weight member that is located in a butt end region having a distance from a butt end of the grip of 100 mm or less. The grip and the weight member constitute a grip-weight portion. The shaft, the grip, and the weight member constitute a shaft-grip-weight portion. The golf club has a weight of less than 295 g. The head has a weight of greater than or equal 195 g. The grip-weight portion has a weight of greater than or equal to 40 g. The head has a gravity center distance of greater than or equal to 44.5 mm. A ratio W1/W3 of a weight W1 (g) of the butt end region to a weight W3 (g) of the shaft-grip-weight portion is greater than or equal to 0.40.

Abstract: A golf club includes a head; a shaft; a grip; and a weight member that is located in a butt end region. The grip and the weight member constitute a grip-weight portion. The shaft, the grip, and the weight member constitute a shaft-grip-weight portion. The head has a weight of greater than or equal to 195 g. The grip-weight portion has a weight of greater than or equal to 40 g. The shaft has a weight of less than or equal to 40 g. The golf club has a weight of greater than or equal to 275 g and less than or equal to 300 g. W1/W3 is greater than or equal to 0.40, where W1 represents a weight (g) of the butt end region, and W3 represents a weight (g) of the shaft-grip-weight portion.

Abstract: A golf club includes a head; a shaft; a grip; and a weight member that is located in a butt end region. The grip and the weight member constitute a grip-weight portion. The shaft, the grip, and the weight member constitute a shaft-grip-weight portion. The golf club has a length of greater than or equal to 45.0 inches. The golf club has a weight of less than 295 g. The head has a weight of greater than or equal to 195 g. The grip-weight portion has a weight of greater than or equal to 40 g. W1/W3 is greater than or equal to 0.40, where W1 represents a weight (g) of the butt end region, and W3 represents a weight (g) of the shaft-grip-weight portion.