Abstract: An acoustic metasurface structure is configured to absorb sounds. The acoustic metasurface structure comprises a main body, an externally-connecting configuration and an inner configuration. The externally-connecting configuration and the inner configuration are respectively formed inside the main body. An externally-connecting tube of the externally-connecting configuration is in fluid communication with an external environment and an externally-connecting cavity of the externally-connecting configuration. An inner tube of the inner configuration is in fluid communication with the externally-connecting cavity and an inner cavity of the inner configuration. With the externally-connecting configuration and the inner configuration forming a series-type structure in the main body, the acoustic metasurface structure increases an acoustic impedance.

Abstract: A water circulating apparatus and method for using in a built swimming pool or a swimming pool during building. The apparatus includes: a container disposed in the swimming pool and the container has a water outlet and a water inlet respectively on a front end and a rear end, the water outlet and inlet are under the water level in the swimming pool, and a water circulation actuating mechanism provided on the front end of the container for pushing and lifting water from the front end of the container and controlling flow rate of water to flow out from the water outlet to the other end of the swimming pool, and to cause the water in the rear end of the swimming pool to flow into the container from the water inlet, and to flow toward the water outlet through the container, thus effecting water circulation in the swimming pool.