What are the hinged(?) structures in front of the F-4 Phantom's intakes?
From Wikipedia:


  A splitter plate is a component in some jet aircraft, used to control the airflow into the engine. Where the engine air intake is mounted partway back along the fuselage or under the wing, the splitter plate diverts the boundary layer away from the engine intake. It is a form of boundary layer control. 




From Youtube: an F4