Abstract: A metal atom cluster-embedded magnetic iron oxide nanoparticle (MION) is disclosed. The metal atom cluster is embedded in an iron oxide crystal matrix and has a content of 0.1% to 15%. A method for preparing the MION includes: dissolving a metal precursor of iron oxide, an organic acid, and an organic amine in an organic solvent to form a uniform reaction system; heating the reaction system to 150° C. to 350° C. in an inert gas atmosphere; adding a metal atom cluster precursor; and heating to perform a reflux reaction until the metal atom cluster precursor is completely decomposed. The MION shows improved magnetic properties due to the embedding of the metal atom cluster, and the iron oxide fully ensures the stability of properties of the nanoparticles. The nanoparticles are especially applicable to biomedical detection and therapy and other fields.

Abstract: Embodiments of this application disclose an ODU and a transmit power control method for an ODU. The ODU includes a controller, a radio frequency processor, a waveguide channel, an antenna, a wave-absorbing block, a detector, and a motor controller. The controller is configured to obtain target transmit power, first transmit power, and a to-be-transmitted first radio frequency signal, and generate a control signal based on a difference between the target transmit power and the first transmit power. The radio frequency processor is configured to: perform frequency conversion on the first radio frequency signal to obtain the second radio frequency signal, and transmit the second radio frequency signal, where the second radio frequency signal is transmitted to the antenna through the waveguide channel. The wave-absorbing block has one end located in the waveguide channel and the other end connected to the motor controller.

Abstract: The present disclosure discloses a local oscillator feedthrough signal correction apparatus, including a microprocessor control unit, a first digital-to-analog converter, a second digital-to-analog converter, a mixer, a local oscillator, a signal output line, a signal splitter, and a detector tube. The signal splitter is disposed in the signal output line, and the first digital-to-analog converter and the second digital-to-analog converter are configured to provide the mixer with quadrature direct current components VI and VQ used for local oscillator feedthrough signal correction. The mixer outputs a local oscillator feedthrough signal to the signal output line. The signal splitter obtains the local oscillator feedthrough signal by means of splitting, and the detector tube detects the local oscillator feedthrough signal.

Abstract: Embodiments of this application disclose an ODU and a transmit power control method for an ODU. The ODU includes a controller, a radio frequency processor, a waveguide channel, an antenna, a wave-absorbing block, a detector, and a motor controller. The controller is configured to obtain target transmit power, first transmit power, and a to-be-transmitted first radio frequency signal, and generate a control signal based on a difference between the target transmit power and the first transmit power. The radio frequency processor is configured to: perform frequency conversion on the first radio frequency signal to obtain the second radio frequency signal, and transmit the second radio frequency signal, where the second radio frequency signal is transmitted to the antenna through the waveguide channel. The wave-absorbing block has one end located in the waveguide channel and the other end connected to the motor controller.

Abstract: The present disclosure discloses a local oscillator feedthrough signal correction apparatus, including a microprocessor control unit, a first digital-to-analog converter, a second digital-to-analog converter, a mixer, a local oscillator, a signal output line, a signal splitter, and a detector tube. The signal splitter is disposed in the signal output line, and the first digital-to-analog converter and the second digital-to-analog converter are configured to provide the mixer with quadrature direct current components VI and VQ used for local oscillator feedthrough signal correction. The mixer outputs a local oscillator feedthrough signal to the signal output line. The signal splitter obtains the local oscillator feedthrough signal by means of splitting, and the detector tube detects the local oscillator feedthrough signal.

Abstract: Disclosed are a method for enhancing contrast of magnetic resonance imaging and a method for treating tumor.