نتایج جستجو برای: ytterbium
تعداد نتایج: 1316 فیلتر نتایج به سال:
An ytterbium-doped photonic bandgap fiber amplifier operating at the long wavelength edge of the ytterbium gain band is investigated for high power amplification. The spectral filtering effect of the photonic bandgap efficiently suppresses amplified spontaneous emission at the conventional ytterbium gain wavelengths and thus enables high power amplification at 1178 nm. A record output power of ...
The internal stresses of plasma-sprayed multilayer ytterbium disilicate environmental barrier coatings were measured using microfocused high-energy X-rays in a transmission geometry. Stresses were measured for as-sprayed and ex-situ heat-treated ytterbium disilicate topcoats at room temperature and during in-situ heating and cooling experiments. In-situ loading experiments were also performed o...
Pyrene-appended ytterbium complexes have been prepared using Ugi reactions to vary the chromophore-lanthanide separation. Formation of the ytterbium(iii) excited state is sensitised via both the singlet and triplet excited states of the chromophore. Energy transfer from the latter is relatively slow, and gives rise to oxygen-dependent luminescence.
We demonstrate an ultraviolet diode laser system for cooling of trapped ytterbium ions. The laser power and linewidth are comparable to those of previous systems based on resonant frequency doubling, but the system is simpler, more robust, and less expensive. We use the laser system to cool small numbers of ytterbium ions confined in a linear Paul trap. From the observed spectra, we deduce fina...
Two ytterbium(III) complexes comprising alkynylamidinate ligands, namely bis-(η5-cyclo-penta-dien-yl)(3-cyclo-propyl-N,N'-diiso-propyl-propynamidinato-κ2N,N')ytterbium(III), [Yb(C5H5)2(C12H19N2)] or Cp2Yb[( i Pr2N)2C-C≡C-c-C3H5] (1) and tris-(3-phenyl-N,N'-di-cyclo-hexyl-propynamidinato-κ2N,N')ytterbium(III), [Yb(C21H27N2)3] or Yb[(CyN)2C-C≡C-Ph]3 (Cy = cyclo-hex-yl) (2) have been synthesized a...
Although ytterbium was named by the Swiss chemist Jean de Marignac in 1878, his ‘element’ was subsequently split into two in 1905: ytterbium and lutetium. The atomic weight of the ‘new’ ytterbium was later published in 1907 — so when was ytterbium actually discovered? The story begins on 13 June 1726, more than 150 years before it first received its name. On that date an agreement was signed al...
A coprecipitation method with ytterbium hydroxide was studied for the determination of cadmium in water samples by graphite-furnace atomic absorption spectrometry. Up to 40 ng of cadmium in water samples was quantitatively coprecipitated with ytterbium hydroxide at pH 8.0-11.2. The concentration factor was 100 fold. The coprecipitated cadmium was sensitively determined without any influence of ...
Bulk yttrium oxysulfide phosphors were prepared using the polysulfide flux method. The morphology and structure was characterized using transmission electron microscopy and x-ray powdered diffraction. Visible emissions occurring near 530 and 550 nm and 660 670 nm consistent with the H11/2, S3/2 → I15/2 and F9/2 → I15/2 transitions, respectively, were observed under 808, 980, and 1560 nm excitat...
E and EC Department, PEC University of Technology Sector 12, Chandigarh, India __________________________________________________________________________________________ Abstract: In this paper we have discussed the importance of YDFA and obtained optimized Gain and maintained Noise Figure in single stage and double stage YDFA (Ytterbium Doped Fiber Amplifier) with the help of simulation models...
A ytterbium(III)-indapybox catalysed enantioselective decarboxylative addition reaction of β-ketoacids to isatins is described. The biologically important 3-hydroxy oxindoles were obtained in high yields and excellent enantioselectivities.
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