1,920 research outputs found
The Diagnostic Value of Computer-assisted Post-processing Technique of CT Colonography for Patients with Colorectal Cancer.
No full text
Cw ion lasers pumped by electron beams
No full textWe have obtained cw laser radiation from singly ionized Hg, I, Cd, Se, and As by exciting He metal-vapor mixtures with a dc electron beam. The beam is generated by glow discharge electron guns located apart from the active medium. This is the first time that cw ion laser action has been obtained using electron beam excitation
CW laser action in atomic fluorine
No full textWe have obtained CW laser action on four transitions in the doublet system of atomic fluorine for the first time. All previously reported laser action was on a pulsed basis only. CW laser radiation was obtained when F2 or AgF was used as a fluorine donor in an electron beam pumped helium plasma. A multiline output power of 200 mW was obtained
Transcatheter arterial embolization of acute upper gastrointestinal tract bleeding with N-butyl-2-cyanoacrylate.
No full textCW silver ion laser with electron beam excitation
No full textA CW laser power of 140 mW was obtained in the 840.39 nm transition of Ag II by electron beam excitation. This electron beam excited metal vapor ion laser is capable of operating using metals with high vaporization temperatures and is of interest for generation of CW coherent radiation in the 220-260 nm spectral region
1-W cw Zn ion laser
No full textWe have obtained 1.2W of cw laser power on the 4911.6- and 4924.0-Å transitions of Zn II by exciting a He-Zn gas mixture with a dc glow discharge electron beam. In addition, 0.25-W output power has been obtained on the 6149.9-Å line of Hg+ using the same excitation scheme. The combination of electron beam ionization of rare gas atoms and subsequent charge transfer excitation to metal ion levels is shown to have the potential of significantly increasing the efficiency of ion lasers. cw multiwatt visible and ultraviolet ion lasers operating at efficiencies > 10-3 appear feasible using this excitation scheme
Stabilization as a CW approximation
No full textAbstractThis paper describes a peculiar property of the category of S-modules constructed by the author, Kriz, Mandell, and May: the full subcategory of suspension spectra (all of which are S-modules) forms a precise copy of the category of topological spaces. Consequently, the “classical” homotopy category of S-modules with morphisms the actual homotopy classes of maps contains a copy of unstable homotopy theory. Stabilization and stable homotopy are induced by CW approximation as S-modules. One consequence is that CW complexes whose suspension spectra are CW S-modules must be contractible
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