Abstract: A sensor of the present invention includes, in order, a first conductor layer which is made of a direct transition type semiconductor and generates an electromagnetic wave; a non-conductor layer; a second conductor layer; and a third electrode, in which a first electrode is provided on a part of a first surface of the first conductor layer opposite to the non-conductor layer side, and a second electrode is provided on the other part of the first surface. Thus, the present invention can provide a sensor which identifies and detects a substance.

Abstract: A micro electron gun that is capable of extracting electrons from a semiconductor utilizing a quantum size effect and that can be mounted individually for each of pixels is disclosed, as well as a picture display apparatus using such electron guns which is high in quantum efficiency, of high brightness and thin, as well as methods of manufacture thereof. Conduction electrons from a n-type semiconductor substrate (2) are accelerated under an electric field through a layer or layers (4) of quantum size effect micro particles (3) formed on surfaces of the n-type semiconductor substrate (2) and passed therethrough without undergoing phonon scattering, so that they when arriving at an electrode (5) may possess an amount of energy not less than the work function of the electrode (5) and are thus allowed to spring out into a vacuum.

Abstract: A micro electron gun that is capable of extracting electrons from a semiconductor utilizing a quantum size effect and that can be mounted individually for each of pixels is disclosed, as well as a picture display apparatus using such electron guns which is high in quantum efficiency, of high brightness and thin, as well as methods of manufacture thereof. Conduction electrons from a n-type semiconductor substrate (2) are accelerated under an electric field through a layer or layers (4) of quantum size effect micro particles (3) formed on surfaces of the n-type semiconductor substrate (2) and passed therethrough without undergoing phonon scattering, so that they when arriving at an electrode (5) may possess an amount of energy not less than the work function of the electrode (5) and are thus allowed to spring out into a vacuum.

Abstract: A micro electron gun that is capable of extracting electrons from a semiconductor utilizing a quantum size effect and that can be mounted individually for each of pixels is disclosed, as well as a picture display apparatus using such electron guns which is high in quantum efficiency, of high brightness and thin, as well as methods of manufacture thereof. Conduction electrons from a n-type semiconductor substrate (2) are accelerated under an electric field through a layer or layers (4) of quantum size effect micro particles (3) formed on surfaces of the n-type semiconductor substrate (2) and passed therethrough without undergoing phonon scattering, so that they when arriving at an electrode (5) may possess an amount of energy not less than the work function of the electrode (5) and are thus allowed to spring out into a vacuum.

Abstract: A micro electron gun that is capable of extracting electrons from a semiconductor utilizing a quantum size effect and that can be mounted individually for each of pixels is disclosed, as well as a picture display apparatus using such electron guns which is high in quantum efficiency, of high brightness and thin, as well as methods of manufacture thereof. Conduction electrons from a n-type semiconductor substrate (2) are accelerated under an electric field through a layer or layers (4) of quantum size effect micro particles (3) formed on surfaces of the n-type semiconductor substrate (2) and passed therethrough without undergoing phonon scattering, so that they when arriving at an electrode (5) may possess an amount of energy not less than the work function of the electrode (5) and are thus allowed to spring out into a vacuum.

Abstract: A process for producing NH.sub.3 and SO.sub.2 from ammonium sulfate, which comprises(i) reacting ammonium sulfate with a metal oxide or hydroxide at a temperature of not more than 200.degree. C. to form NH.sub.3, water and a metal sulfate and recovering NH.sub.3,(ii) decomposing the metal sulfate in the presence of a reducing agent to form a metal oxide and SO.sub.2 and recovering SO.sub.2, and(iii) recycling the metal oxide to step (i) as such or after it is converted to a metal hydroxide.