排序方式: 共有29条查询结果,搜索用时 15 毫秒
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The paper describes past and present efforts in modeling of laser-induced plasma and overviews plasma diagnostics carried out by pump-probe techniques. Besides general information on existing plasma models, the emphasis is given to models relevant to spectrochemical analysis, i.e. models of radiating plasma. Special attention is paid to collisional-radiative (CR) and collisional-dominated (CD) plasma models where radiative processes play an important role. Also, calibration-free (CF) models are considered which may endow with the possibility for standardless spectroscopic analysis. In the diagnostic part, only methods based on the use of additional diagnostic tools (auxiliary lasers, optics, and probes) are described omitting those based on plasma own radiation. A short review is provided on image-based diagnostics (shadowgraphy, schlieren, and interferometry), absorption and fluorescence, Langmuir probe, and less frequently used cavity ringdown and Thomson scattering methods. 相似文献
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Laser induced breakdown spectroscopy as a tool for discrimination of glass for forensic applications 总被引:1,自引:0,他引:1
Rodriguez-Celis EM Gornushkin IB Heitmann UM Almirall JR Smith BW Winefordner JD Omenetto N 《Analytical and bioanalytical chemistry》2008,391(5):1961-1968
Materials analysis and characterization can provide important information as evidence in legal proceedings. The potential
of laser induced breakdown spectroscopy (LIBS) for the discrimination of glass fragments for forensic applications is presented
here. The proposed method is based on the fact that glass materials can be characterized by their unique spectral fingerprint.
Taking advantage of the multielement detection capability and minimal to no sample preparation of LIBS, we compared glass
spectra from car windows using linear and rank correlation methods. Linear correlation combined with the use of a spectral
mask, which eliminates some high-intensity emission lines from the major elements present in glass, provides effective identification
and discrimination at a 95% confidence level. 相似文献
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I.B. Gornushkin U. Panne J.D. Winefordner 《Spectrochimica Acta Part B: Atomic Spectroscopy》2009,64(10):1040
The purpose of this work is to improve the performance of a linear correlation method used for material identification in laser induced breakdown spectroscopy. The improved correlation procedure is proposed based on the selection and use of only essential spectral information and ignoring empty spectral fragments. The method is tested on glass samples of forensic interest. The 100% identification capability of the new method is demonstrated in contrast to the traditional approach where the identification rate falls below 100% for many samples. 相似文献
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Y. M. Antipov V. A. Batarin V. A. Bessubov N. P. Budanov Y. P. Gorin Y. A. Gornushkin S. P. Denisov S. V. Klimenko I. V. Kotov P. A. Kulinich A. A. Lebedev G. V. Micelmacher A. G. Olshevski F. Palombo A. I. Petrukhin R. V. Pirtzkhalava S. A. Polovnikov V. N. Roinishvili J. Sedlak D. A. Stoyanova V. I. Travkin 《Zeitschrift fur Physik C Particles and Fields》1985,27(1):21-25
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Marek Hoehse David Mory Stefan Florek Friederike Weritz Igor Gornushkin Ulrich Panne 《Spectrochimica Acta Part B: Atomic Spectroscopy》2009,64(11-12):1219-1227
Raman and laser-induced breakdown spectroscopy is integrated into a single system for molecular and elemental microanalyses. Both analyses are performed on the same ~ 0.002 mm2 sample spot allowing the assessment of sample heterogeneity on a micrometric scale through mapping and scanning. The core of the spectrometer system is a novel high resolution dual arm Echelle spectrograph utilized for both techniques. In contrast to scanning Raman spectroscopy systems, the Echelle–Raman spectrograph provides a high resolution spectrum in a broad spectral range of 200–6000 cm? 1 without moving the dispersive element. The system displays comparable or better sensitivity and spectral resolution in comparison to a state-of-the-art scanning Raman microscope and allows short analysis times for both Raman and laser induced breakdown spectroscopy. The laser-induced breakdown spectroscopy performance of the system is characterized by ppm detection limits, high spectral resolving power (15,000), and broad spectral range (290–945 nm). The capability of the system is demonstrated with the mapping of heterogeneous mineral samples and layer by layer analysis of pigments revealing the advantages of combining the techniques in a single unified set-up. 相似文献
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 52, No. 3, pp. 363–368, March, 1990. 相似文献
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This paper communicates modifications to our new calibration method based on linear correlation, described in detail in a former paper [Spectrochim. Acta 56B, 1159], which extend its applicability. The presented, generalized linear correlation method (GLCM) can be applied in any spectroscopic method for quantitation, and also when multielemental, trace solutions are analyzed and the analysis is not complete. Applications of the method to UV-Vis spectrophotometry and inductively coupled plasma mass spectrometry (ICP-MS) are also presented. The method showed a good, typically 1-5%, accuracy in all applications. 相似文献
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E. Tognoni G. Cristoforetti S. Legnaioli V. Palleschi A. Salvetti M. Mueller U. Panne I. Gornushkin 《Spectrochimica Acta Part B: Atomic Spectroscopy》2007,62(12):1287-1302
Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) has been proposed several years ago as an approach for quantitative analysis of Laser-Induced Breakdown Spectroscopy spectra. Recently developed refinement of the spectral processing method is described in the present work. Accurate quantitative results have been demonstrated for several metallic alloys. However, the degree of accuracy that can be achieved with Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of generic samples still needs to be thoroughly investigated. The authors have undertaken a systematic study of errors and biasing factors affecting the calculation in the Calibration-Free Laser-Induced Breakdown Spectroscopy spectra processing. These factors may be classified in three main groups: 1) experimental aberrations (intensity fluctuations and inaccuracy in the correction for spectral efficiency of a detection system), 2) inaccuracy in theoretical parameters used for calculations (Stark broadening coefficients and partition functions) and 3) plasma non-ideality (departure from thermal equilibrium, spatial and temporal inhomogeneities, optical thickness, etc.). In this study, the effects of experimental aberrations and accuracy of spectral data were investigated, assuming that the analytical plasma is ideal. Departure of the plasma conditions from ideality will be the object of future work. The current study was based on numerical simulation. Two kinds of metallic alloys, iron-based and aluminum-based, were studied. The relative weight of the error contributions was found to depend on the sample composition. For the here-investigated samples, the experimental aberrations contribute to the overall uncertainty on the quantitative results more than theoretical parameters. The described simulation method can be applied to the Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of any other kind of sample. 相似文献