66 research outputs found
Unexpected luminescence of Cr5+ and Cr3+ ions in ZrSiO4 zircon crystals
Luminescence, decay-times and EPR spectroscopy of Cr-doped ZrSiO4 show the presence of both Cr3+ and Cr5+ active centers, which can be connected with Zr4+ and Si4+ adjacent two-cation replacement. Cr5+ emission occurs within a similar spectral range as for Cr4+ and hence confusion is possible
IR Bismuth active centers in optical fibers: Combined excitation-emission spectroscopy
3D excitation-emission luminescence spectra of Bi-doped optical fibers of
various compositions were measured in a wide wavelength range 450-1700 nm. Such
luminescence spectra were obtained for Bi-doped pure silica and germania
fibers, and for Bi-doped Al- or P-codoped silica fibers (at room and liquid
nitrogen temperatures). The energy level schemes of IR bismuth active centers
in pure silica and germania core fibers were derived from spectra obtained. The
energy level schemes similarity of bismuth active centers in these two types of
fibers was revealed.Comment: 12pages, 7 figures, 5 table
METHOD FOR THE BEST SOLUTIONS SEARCH IN MULTIOBJECTIVE DECISION PROBLEMS
This paper describes a method for con structing a decision rule providing the isolation of the most preferable soluti ons in multiobjective decision problems. The method is based on the iterative procedure for constructing decision rules. Criteria of meaning-fulness and consistency of received information are formulated. The results are given of applying the method to solution of the most preferable alternatives searc
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