Abstract: A spiral magnetic fluid composite sealing structure of a roller bit comprising a cone leg and a roller, wherein the roller and the cone leg are in rotatable connection in a fitting manner through a roller inner hole and a cone leg shaft journal, a sealing groove is formed in an opening end of the roller inner hole, and a spiral magnetic fluid sealing assembly is arranged in the sealing groove. Through the arrangement of the spiral magnetic fluid sealing assembly, a spiral sand discharging effect is realized, compared with a passive sealing mode, the sealing performance is greatly improved by active sand discharging mode, and the service life of sealing is significantly prolonged; a slurry sealing effect of magnetic fluid seals is realized, resulting the sealing gap is tightly sealed under the magnetic action; in addition, the automatic compensation function of magnetic fluid can also be realized.

Abstract: A noise reduction method and a noise reduction apparatus are provided. The noise reduction method is applied to a keyboard of an integrated terminal device, and the noise reduction method includes: obtaining a first voice source and a second voice source, where the first voice source is a fidelity voice source, the second voice source is an audio signal that includes the first voice source and a noise signal, and the noise signal comes from noise generated by vibration of the keyboard, and/or the noise signal comes from noise of an environment in which the integrated terminal device is located; determining the noise signal based on the first voice source and the second voice source. Based on the technical solutions in this application, the noise signal generated by the integrated terminal device can be offset, so that noise reduction processing is implemented and user experience is improved.