Abstract: The utility model discloses an airbag-type earplug comfortable to wear and offering sound insulation and noise reduction, which comprises a support part and an airbag part, a through ventilation channel is arranged in the middle of the support part, the airbag part is arranged outside the support part, and the whole airbag part is in the shape of a frustum, that is, an internal cavity of the airbag part gradually expands outward from one end to the other. This utility model can adaptively adjust to the size of different individuals' ear canals, providing a better fit and addressing the issues of sound leakage and ear swelling associated with traditional silicone and foam earplugs. Furthermore, a metal filter allows for the adjustment of micropore sizes from 1 ?m to 40 ?m according to different scenarios, overcoming the limitation of common foam filters on the market that cannot be washed.

Abstract: The present application discloses a dredging system for a pre-paved gravel foundation bed surface in open sea deep water, including a dredging mechanism, which includes a dredging suction head, a power component and a dredging pipeline, wherein the dredging suction head is connected with the dredging pipeline; the dredging pipeline is communicated with the power component; the dredging suction head includes at least one ridge surface suction port and at least one furrow suction port; the openings of all the furrow suction ports are lower than those of all the ridge surface suction ports; a lifting mechanism, which is connected with the dredging suction head and is used for lifting the dredging suction head to the gravel foundation bed surface; a moving mechanism, which is connected with the lifting mechanism and is used for driving the dredging suction head to move within a dredging range of the gravel foundation bed surface.

Abstract: The present application discloses a dredging system for a pre-paved gravel foundation bed surface in open sea deep water, including a dredging mechanism, which includes a dredging suction head, a power component and a dredging pipeline, wherein the dredging suction head is connected with the dredging pipeline; the dredging pipeline is communicated with the power component; the dredging suction head includes at least one ridge surface suction port and at least one furrow suction port; the openings of all the furrow suction ports are lower than those of all the ridge surface suction ports; a lifting mechanism, which is connected with the dredging suction head and is used for lifting the dredging suction head to the gravel foundation bed surface; a moving mechanism, which is connected with the lifting mechanism and is used for driving the dredging suction head to move within a dredging range of the gravel foundation bed surface.