Abstract: A turbulence-enhanced liquid-solid friction nano power generation device is provided, including multiple power generation cores connected in parallel. Each of the power generation cores includes an outer tube, a friction liquid, external friction electrodes, internal turbulators and internal friction electrodes. When the power generation cores undergo a swing motion, the friction liquid inside the outer tube rubs against an inner wall of the outer tube and an outer membrane of each of the internal turbulators to generate charges; and the charges are transferred based on the external friction electrodes and the internal friction electrodes, and an alternating current is generated and is led out through an external wire.

Abstract: The present disclosure relates to systems and methods for reducing noise in an imaging system. The methods may include determining an imaging sequence for imaging a subject. When imaging the subject based at least on the imaging sequence, the imaging system may generate a first noise. The methods may further include obtaining, based on the imaging sequence, noise reduction data from a database. And the method may also include causing a generation device to produce a second noise based on the noise reduction data. The second noise may be configured to interfere with the first noise to reduce the first noise.

Abstract: The present disclosure relates to power transformers and medical devices having the same. A power transformer may include a first magnet comprising a first magnetic core and a first winding and a second magnet comprising a second magnetic core and a second winding wound around a side wall of the second magnetic core. The first magnetic core may include an annular body, and the first winding may be wound around a side wall of the annular body. The second magnetic core may include a groove extending from an end surface of the second magnetic core. The first magnet and the second magnet may be contactless. At least part of the annular body may be embedded in the groove. The first winding and the second winding may be at least partially overlapped along an axial direction of the second magnetic core.

Abstract: The present disclosure relates to systems and methods for reducing noise in an imaging system. The methods may include determining an imaging sequence for imaging a subject. When imaging the subject based at least on the imaging sequence, the imaging system may generate a first noise. The methods may further include obtaining, based on the imaging sequence, noise reduction data from a database. And the method may also include causing a generation device to produce a second noise based on the noise reduction data. The second noise may be configured to interfere with the first noise to reduce the first noise.