Abstract: Provided is a turbo fan engine (TF) provided with a power transmission device that switches main shafts (MSs) connected to a starter generator (SG) so as to perform power transmission, between at startup and after the startup. The TF includes a first MS and a second MS. The power transmission device includes a first shaft, an intermediate shaft, and a second shaft that are coaxially disposed, and a clutch. The first shaft is connected to the first MS through bevel gears, the intermediate shaft is disposed outside of the first shaft and is connected to the SG through bevel gears, and the second shaft is disposed outside of the intermediate shaft and is connected to the second MS through bevel gears.

Abstract: Provided is a turbo fan engine (TF) provided with a power transmission device that switches main shafts (MSs) connected to a starter generator (SG) so as to perform power transmission, between at startup and after the startup. The TF includes a first MS and a second MS. The power transmission device includes a first shaft, an intermediate shaft, and a second shaft that are coaxially disposed, and a clutch. The first shaft is connected to the first MS through bevel gears, the intermediate shaft is disposed outside of the first shaft and is connected to the SG through bevel gears, and the second shaft is disposed outside of the intermediate shaft and is connected to the second MS through bevel gears.

Abstract: Hall device is provided by enabling stable provision of a quantum well compound semiconductor stacked structure. It has first and second compound semiconductor layers composed of Sb and at least two of five elements of Al, Ga, In, As and P, and an active layer composed of InxGa1-xAsySb1-y (0.8?x?1.0, 0.8?y?1.0), which are stacked. Compared with the active layer, the first and second compound semiconductor layers each have a wider band gap, and a resistance value five times or more greater. The lattice constant differences between the active layer and the first and second compound semiconductor layers are each designed in a range of 0.0-1.2%, and the thickness of the active layer is designed in a range of 30-100 nm.

Abstract: Hall device is provided by enabling stable provision of a quantum well compound semiconductor stacked structure. It has first and second compound semiconductor layers composed of Sb and at least two of five elements of Al, Ga, In, As and P, and an active layer composed of InxGa1-x,AsySb1-y (0.8?x?1.0, 0.8 <y?1.0), which are stacked. Compared with the active layer, the first and second compound semiconductor layers each have a wider band gap, and a resistance value five times or more greater. The lattice constant differences between the active layer and the first and second compound semiconductor layers are each designed in a range of 0.0-1.2%, and the thickness of the active layer is designed in a range of 30-100 nm.