Abstract: Disclosed are a display apparatus and a method for controlling screen projections from multiple devices to a same screen. The display apparatus includes: a display and at least one processor configured to execute instructions to cause the display apparatus to: establish a connection with a first projection device; receive projection contents; control the display to show a top-level application of a user interface displayed, in a case that the projection content is vertical media resource; determine whether the top-level application supports split screen display; when the top-level application supports split screen display, the top-level application is displayed in a first window and the projection contents are displayed in a second window; when the top-level application does not support split screen display, the top level application after proportional reduction is displayed in either of the two windows, and the projection content are displayed in the other window of the two windows.

Abstract: An all metal, microwave-pumped, waveguide CO.sub.2 laser includes a waveguide providing a vacuum envelope containing the CO.sub.2 gas having a longitudinal ridge extending at least partially across the width of the waveguide and extending along a length of the waveguide and a ceiling facing the ridge. The ridge and ceiling have horizontal surfaces facing one another which together function as an optical waveguide of the laser and define a longitudinal optically active region therebetween which, in the preferred embodiment, opens out into remaining portions of the waveguide along either side of said ridge. A pair of reflecting mirrors are located at each end of said optically active region and an antenna or ramped waveguide couples a microwave source into the waveguide.

Abstract: An in-phase coupled strip linear CO.sub.2 waveguide laser includes an upper aluminum plate and an aluminum waveguide bed including parallel ridges, each in the range of about 2 to about 5 mm wide, at a gap of about 0.5 to 2 mm from the upper plate. The slots are about 2 mm deep to prevent discharge therein and about 1 mm wide. The width of the slots is selected to permit coupling between the discharge channels formed between each ridge and the upper plate while separating the discharge beams in each channel. Discharge in each channel is in-phase coupled in the fundamental mode to produce a single lobe far field with a simple Fabry-Perot resonator.