Abstract: An acoustic device comprises a sound generating unit having a vibration diaphragm, the acoustic device is provided with a sound outlet, the sound waves at a front side of the vibration diaphragm radiates to the outside through the sound outlet; and an enclosed closed cavity formed at a rear side of the vibration diaphragm, the closed cavity is divided into first and second closed cavities by a partition part, and at least a portion of the partition part flexibly deforms, the first closed cavity is adjacent to the vibration diaphragm, the second closed cavity is far away from the vibration diaphragm, the volume of the second closed cavity is larger than that of the first closed cavity; the second closed cavity encloses the sound waves into the second closed cavity; at least a part of an electronic apparatus housing is used for forming the first and/or the second closed cavity.

Abstract: Method and apparatus for recycling fine ash particles for a multiphase chemical reactor (MCR), wherein coal is partially oxidized in the MCR to produce an exit gas stream in which fine ash particles are entrained, and wherein the MCR comprises a high temperature region with a temperature at or above a fusion temperature of the fine ash particles, wherein substantially all of the fine ash particles from the exit gas stream are returned to the high temperature region, to achieve improved carbon conversion and reduction in fly ash quantity.