| 1. |
- An, W. W., et al.
(författare)
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Synthesis and surface characteristics of CeTbO3+delta induced by femtosecond laser irradiation
- 2007
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Ingår i: Applied Surface Science. - : Elsevier BV. - 1873-5584 .- 0169-4332. ; 253:8, s. 3884-3887
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Tidskriftsartikel (refereegranskat)abstract
- This work describes the use of focused, high-intensity light from a Ti: sapphire laser that generates femtosecond pulses to irradiate mixture of CeO2 and Tb4O7 under ambient conditions. The prepared samples were investigated by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). XRD and XPS measurement results demonstrated that solid solution CeTbO3+delta with cubic fluorite structure has been synthesized on the irradiated target surface. SEM micrographs showed that the ultra-short laser irradiation resulted in the formation of foamy structure and spherical particles with size varying from about 30 to 200 nm. The formation mechanism has been discussed in detail. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Biemont, E, et al.
(författare)
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Core-polarization effects and radiative lifetime measurements in PrIII
- 2001
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 64:2
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Tidskriftsartikel (refereegranskat)abstract
- New radiative lifetimes of eight levels in Pr III have been measured using the time-resolved laser-induced fluorescence method. A tunable frequency-doubled dye laser with 1-ns pulse duration was used to excite selectively doubly ionized praseodymium in a laser-produced plasma. The experimental results agree generally well with theoretical data, provided core-polarization effects are considered in the calculations in an adequate way.
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| 3. |
- Biemont, E, et al.
(författare)
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Experimental and theoretical energy levels, transition probabilities and radiative lifetimes in YbIII
- 2001
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 34:10, s. 1869-1876
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Tidskriftsartikel (refereegranskat)abstract
- The analysis of the spectrum of Yb rn has been extended allowing us to establish 11 new energy level values. In addition, radiative lifetimes of two excited states of Yb III have been measured for the first time using time-resolved laser-induced fluorescence following two-photon excitation. The good agreement between experimental results and semi-empirical calculations performed with the relativistic Hartree-Fock method including core-polarization effects allows the determination of transition probabilities for 15 lines.
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| 4. |
- Biemont, E, et al.
(författare)
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Measurement of radiative lifetimes and determination of transition probabilities of astrophysical interest in HoIII
- 2001
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 1365-2966 .- 0035-8711. ; 328:4, s. 1085-1090
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Tidskriftsartikel (refereegranskat)abstract
- Lifetimes of six levels belonging to the 4f(10)6p configuration of Ho III have been measured for the first time using the time-resolved laser-induced fluorescence method. They are compared with multiconfigurational pseudo-relativistic Hartree-Fock calculations. A very good agreement is found. Using the experimental lifetimes and theoretical branching fractions, a first set of transition probabilities of astrophysical interest has been obtained for this ion.
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| 5. |
- Biemont, E, et al.
(författare)
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Radiative lifetime measurements and transition probabilities of astrophysical interest in ErIII
- 2001
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 1365-2966 .- 0035-8711. ; 321:3, s. 481-486
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Tidskriftsartikel (refereegranskat)abstract
- Radiative lifetimes of seven excited states of Er iii have been measured using time-resolved laser-induced fluorescence following two-photon excitation. Relativistic Hartree-Fock calculations taking core-polarization effects into account are found to be in excellent agreement with the experimental results. A large set of new calculated transition probabilities is presented for many transitions of astrophysical interest. These results will be useful for investigating the composition of chemically peculiar stars.
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| 6. |
- Li, Z. S, et al.
(författare)
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Radiative lifetime measurements in TmIII with time-resolved laser spectroscopy and comparisons with HFR calculations
- 2001
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 34:8, s. 1349-1359
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Tidskriftsartikel (refereegranskat)abstract
- Natural radiative lifetimes of eight levels in Tm m were measured with the time-resolved laser-induced fluorescence (LIF) technique. Free doubly ionized thulium ions were obtained in a laser-produced plasma. Three even-parity levels were excited from the ground state with one-photon excitation, using a laser system generating pulses of 1 ns duration. Five odd-parity levels were excited from the ground state with two-photon excitation, where a picosecond laser system was employed. In both cases, the lifetimes were evaluated from transient LIF signals detected with a fast-detection system. The experimental lifetime results were compared with Hartree-Fock calculations including relativistic corrections. Good agreement was achieved for the 4f(12)6p levels while larger discrepancies are noted for some 4f(12)5d levels.
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| 7. |
- Lou, X. T., et al.
(författare)
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Sulfur dioxide measurements using an ultraviolet light-emitting diode in combination with gas correlation techniques
- 2009
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Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 94:4, s. 699-704
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Tidskriftsartikel (refereegranskat)abstract
- The important air pollutant sulfur dioxide has a strong structured absorption band in the ultraviolet (UV) region around 300 nm. Recently, light-emitting diodes (LEDs) with structureless emission in a band about 15-nm wide in the UV region have become available. We demonstrate that they can be ideal sources for gas absorption measurements combined with the gas correlation technique, where an absorption cell with an optically thick column of the gas under investigation is used for analysing the target gas contents in a path between the LED and the measurement device. A sensitivity of 0.4 ppm sulfur dioxide was obtained with a 19-cm optical path length and 60-s integration time. Particularly compact and cost-effective monitors especially for industrial emissions can be envisaged.
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| 8. |
- Somesfalean, Gabriel, et al.
(författare)
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All-diode-laser ultraviolet absorption spectroscopy for sulfur dioxide detection
- 2005
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Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 80:8, s. 1021-1025
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Tidskriftsartikel (refereegranskat)abstract
- Ultraviolet radiation around 302 nm was produced by sum-frequency generation in beta-barium borate employing a blue and a near-infrared diode laser. The diode-laser-based spectrometer has a mode-hop-free tuning range of 50 GHz and was used for high-resolution spectroscopic detection of sulfur dioxide. Differential measurements of several gas concentrations, at low pressure as well as at ambient atmospheric pressure, were demonstrated. The detection limit in the first implementation of the instrument was about 20 ppm m at atmospheric pressure, essentially limited by interference fringes. Methods for greatly improving this limit are suggested.
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| 9. |
- Zhang, Z. G, et al.
(författare)
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Lifetime measurements in Gd II and Gd III using time-resolved laser spectroscopy
- 2001
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Ingår i: European Physical Journal D. Atomic, Molecular, Optical and Plasma Physics. - : Springer Science and Business Media LLC. - 1434-6060. ; 13:3, s. 301-304
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Tidskriftsartikel (refereegranskat)abstract
- Natural radiative lifetimes of 20 levels (energy range between 20 000 35 000 cm(-1)) in Cd II and 5 levels (energy range between 43 000-49 000 cm(-1)) in Gd III have been measured using time-resolved laser-induced fluorescence III a laser-produced plasma.
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| 10. |
- Zhang, Z. G, et al.
(författare)
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Natural radiative lifetimes in Ce II
- 2001
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Ingår i: Physica Scripta. Topical Issues. - 0281-1847. ; 63:2, s. 122-127
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Tidskriftsartikel (refereegranskat)abstract
- New radiative lifetimes of 18 levels (energy range between 30 000 cm(-1)) and 39 000 cm(-1), in Ce II have been measured using the time-resolved laser-induced fluorescence method. A tunable frequency-doubled dye laser with I ns pulse duration was used to excite selectively singly ionized cerium in a laser-produced plasma The experimental results are compared with theoretical data and the agreement is found to be very good.
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