Abstract: A noise reducing structure includes a first resonance tube that extends in a first direction, that takes in from a sound absorbing opening portion a sound wave that is generated from a noise source, and that causes the sound wave to resonate to reduce leakage to outside; and a second resonance tube that extends in a second direction differing from the first direction, and that, along with the first resonance tube, causes the sound wave that is generated from the noise source to resonate to reduce the leakage to the outside.

Abstract: A noise reducing structure includes an internal structural body that includes a noise source; an exterior body that includes an inner side surface facing the internal structural body and that covers an outer side of the internal structural body; a space portion that is surrounded by an erected wall, the internal structural body, and the inner side surface, the erected wall being erected so as to, from one of the internal structural body and the inner side surface towards the other of the internal structural body and the inner side surface, be connected to the other of the internal structural body and the inner side surface; and a sound absorbing opening portion that is connected to the space portion and that is formed at a portion near the noise source.

Abstract: A noise reducing structure includes an internal structural body that includes a noise source; an exterior body that includes an inner side surface facing the internal structural body and that covers an outer side of the internal structural body; a space portion that is surrounded by an erected wall, the internal structural body, and the inner side surface, the erected wall being erected so as to, from one of the internal structural body and the inner side surface towards the other of the internal structural body and the inner side surface, be connected to the other of the internal structural body and the inner side surface; and a sound absorbing opening portion that is connected to the space portion and that is formed at a portion near the noise source.

Abstract: A noise reducing structure includes a first resonance tube that extends in a first direction, that takes in from a sound absorbing opening portion a sound wave that is generated from a noise source, and that causes the sound wave to resonate to reduce leakage to outside; and a second resonance tube that extends in a second direction differing from the first direction, and that, along with the first resonance tube, causes the sound wave that is generated from the noise source to resonate to reduce the leakage to the outside.

Abstract: It is aimed at providing an oxynitride powder, which is suitable for usage as a phosphor, is free from coloration due to contamination of impurities, and mainly includes a fine ?-sialon powder. An oxynitride powder is produced by applying a heat treatment in a reducing and nitriding atmosphere, to a precursor compound including at least constituent elements M, Si, Al, and O (where M is one element or mixed two or more elements selected from Li, Mg, Ca, Sr, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), thereby decreasing an oxygen content and increasing a nitrogen content of the precursor.

Abstract: It is aimed at providing an oxynitride powder, which is suitable for usage as a phosphor, is free from coloration due to contamination of impurities, and mainly includes a fine ?-sialon powder. An oxynitride powder is produced by applying a heat treatment in a reducing and nitriding atmosphere, to a precursor compound including at least constituent elements M, Si, Al, and O (where M is one element or mixed two or more elements selected from Li, Mg, Ca, Sr, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), thereby decreasing an oxygen content and increasing a nitrogen content of the precursor.