We investigate three types of amplification processes for light fields coupling to an atom near the end a one-dimensional semi-infinite waveguide. consider two setups where drive creates population inversion in bare or dressed basis three-level and one setup is due higher-order driven two-level atom. In all cases, waveguide acts as mirror light. find that this enhances ways compared same open F...

In recent years, there has been a decline in the efficiency of coal mining by traditional methods. On one hand, volume outside contour cut, which is economically impractical for open-pit mining, increasing. other when using underground geotechnology, cost production exceeds performing operations open this due to differences factors operation pit and mine. This circumstance determines use open-u...

The cofferdam method is generally applied in the construction of underwater pier foundation bridge engineering, and pouring bottom sealing concrete one important links cofferdam. can prevent water seepage balance main body cofferdam, its structural size quality have a great influence on above functions. Under condition large level difference, it difficult to determine reasonable thickness concr...