Abstract: Provided is a bulk GaN crystal in which the degree of curvature of the c-plane is reduced. The bulk GaN crystal includes a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, and the main surface is a specific main surface A that satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.

Abstract: Provided is a bulk GaN crystal in which the degree of curvature of the c-plane is reduced. The bulk GaN crystal includes a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, and the main surface is a specific main surface A that satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.

Abstract: A vehicle is provided with an exhaust gas recirculation system and an automatic transmission which shifts in accordance with a plurality of shift patterns including a shift pattern in which upshift occurs at relatively low vehicle speeds and a shift pattern in which upshift occurs at relatively high vehicle speeds. The exhaust gas recirculation system includes an exhaust gas recirculation control mechanism which reduces the amount of exhaust gas to be returned to the combustion chamber when the former shift pattern is selected.