Search results for " Spectra"

showing 10 items of 709 documents

EBIT diagnostics using X-ray spectra of highly ionized Ne

2003

We have carried out a detailed analysis of highly ionized neon spectra collected at the NIST EBIT using an NTD germanium X-ray microcalorimeter developed at the Harvard-Smithsonian Center for Astrophysics [Nucl. Instr. and Meth. A 444 (2000) 156]. Our attention was focused especially on the Ne IX He-like triplet to check electron density diagnostics through the intercombination/forbidden line ratio. We have investigated possible effects of the ion dynamics on the plasma emission line intensities, looking at the dependence of the count-rate and the charge state distribution on the electron beam energy and current. The temperature and spatial distribution of the neon ions, and hence the overl…

X-ray spectraNuclear and High Energy PhysicsElectron densityEBITChemistrySurfaces Coatings and Filmchemistry.chemical_elementFizikai tudományokSurfaces and InterfacesPlasmaIonNeonSettore FIS/05 - Astronomia E AstrofisicaTermészettudományokIonizationAstrophysical plasmaPhysics::Atomic PhysicsEmission spectrumAtomic physicsIonization of atomForbidden mechanismInstrumentationExcitation
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The Vibrational Stretching States of the Pyramidal Molecules: Application to the Arsine and Stibine.

2002

XY3 Molecules[ PHYS.QPHY ] Physics [physics]/Quantum Physics [quant-ph]Vibrational SpectraLie Algebra[PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph]
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Study of optical absorbance and MR relaxation of Fricke xylenol orange gel dosimeters

2017

Abstract Studies on the optical absorbance spectra of Fricke xylenol orange gel dosimeters were performed, in the wavelength range from 300 nm to 800 nm, in order to highlight some particular characteristics that can affect the achievable precision. The spectra are different mainly due to the different types of xylenol orange that was used and to a lower extent due to the different gelling agents (agarose or gelatine). The characteristic of variation of absorbance spectra versus dose, however, are similar in the various cases and can explain some peculiarities, as apparent effects of dose threshold. Changes of spectral shapes appear over the time after irradiation. Magnetic resonance measur…

Xylenol orangeSettore ING-IND/20 - Misure E Strumentazione NucleariAnalytical chemistry01 natural sciencesSpectral line030218 nuclear medicine & medical imagingIon03 medical and health scienceschemistry.chemical_compound0302 clinical medicineFricke gel dosimeter; MR measurement; Optical absorbance spectra; Radiation; Instrumentation0103 physical sciencesmedicineIrradiationFricke gel dosimeterInstrumentationSettore CHIM/02 - Chimica FisicaRadiationDosimeter010308 nuclear & particles physicsSettore FIS/01 - Fisica SperimentaleRelaxation (NMR)MR measurementSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)chemistryFerricAgarosesense organsOptical absorbance spectramedicine.drugRadiation Measurements
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Analyse et Estimations Spectrales des Processus alpha-Stables non-Stationnaires

2006

In this work a new spectral representation of a symmetric alpha-stable processes is introduced. It is based on a covariation pseudo-additivity and Morse-Transue's integral with respect to a bimesure built by using pseudo-additivity property. This representation, specific to S$\alpha$S processes, is analogous to the covariance of second order processes. On the other hand, it generalizes the representation established for stochastic integrals with respect to symmetric alpha-stable process of independent increments. We provide a classification of non-stationary harmonizable processes; this classification is based on the bimesure structure. In particular, we defined and investigated periodicall…

[ MATH ] Mathematics [math]Densité spectraleSpectral estimation[MATH] Mathematics [math]Estimation spectraleLepage Seriesnon-parametrique StatistiquesPeriodically covariated processesSéries de LepageSpectral AnalysisSpectral densityStrong mixing.Statistiques non paramétriquesMélange fortCovariationProcessus \alpha-stables[MATH]Mathematics [math]Mélange fort.Processus périodiquement covariés\alpha-stable ProcessesAnalyse spectrale
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Frequency composition of traction and tillage forces on a mole plough

1997

International audience

[ MATH ] Mathematics [math]stationnary spectral processes Fourier[PHYS]Physics [physics][ PHYS ] Physics [physics][ STAT ] Statistics [stat][SPI] Engineering Sciences [physics][MATH] Mathematics [math][STAT] Statistics [stat][PHYS] Physics [physics][STAT]Statistics [stat][SPI]Engineering Sciences [physics][ SPI ] Engineering Sciences [physics][MATH]Mathematics [math]ComputingMilieux_MISCELLANEOUS
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$PT$-symmetry and Schrödinger operators. The double well case

2016

International audience; We study a class of $PT$-symmetric semiclassical Schrodinger operators, which are perturbations of a selfadjoint one. Here, we treat the case where the unperturbed operator has a double-well potential. In the simple well case, two of the authors have proved in [6] that, when the potential is analytic, the eigenvalues stay real for a perturbation of size $O(1)$. We show here, in the double-well case, that the eigenvalues stay real only for exponentially small perturbations, then bifurcate into the complex domain when the perturbation increases and we get precise asymptotic expansions. The proof uses complex WKB-analysis, leading to a fairly explicit quantization condi…

[ MATH.MATH-SP ] Mathematics [math]/Spectral Theory [math.SP]MSC: 35P20 81Q12 81Q20 35Q40Complex WKB analysis[ MATH.MATH-MP ] Mathematics [math]/Mathematical Physics [math-ph]EigenvaluesMathematics::Spectral TheoryPT-symmetryMathematics - Spectral Theory[MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph]35P20 35Q40 81Q12 81Q20Quantization conditonSchrödinger operatorsMathematical Physics[MATH.MATH-SP]Mathematics [math]/Spectral Theory [math.SP]
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On the high resolution spectroscopy and intramolecular potential function of SO2

2009

Abstract Two weak stretching bands, ν 1  + 3 ν 3 and 3 ν 1  +  ν 3 , of the sulfur dioxide molecule have been recorded at high resolution and analyzed for the first time with using a Fourier transform Bruker IFS-120 HR interferometer. About 1000 transitions with J max .  = 51, K a max . = 16 , and 900 transitions with J max .  = 53, K a max . = 16 have been assigned to the bands ν 1  + 3 ν 3 and 3 ν 1  +  ν 3 , respectively. Analysis of the recorded spectra was made using the model of isolated vibrational states. Parameters obtained from the fit reproduce the initial experimental ro-vibrational energies with the rms deviation of 0.0006 and 0.0012 cm −1 for the bands, 3 ν 1  +  ν 3 and ν 1  …

[ PHYS.QPHY ] Physics [physics]/Quantum Physics [quant-ph]Analytical chemistryHigh resolution02 engineering and technology01 natural sciencesSpectral linesymbols.namesakeNuclear magnetic resonance[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph]High-resolution spectra0103 physical sciencesMoleculePhysical and Theoretical ChemistrySpectroscopySpectroscopyPhysics010304 chemical physicsPotential functionFunction (mathematics)Spectroscopic parameters021001 nanoscience & nanotechnologyAtomic and Molecular Physics and OpticsInterferometryFourier transformSulfur dioxideIntramolecular forcesymbols0210 nano-technology
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Symmetrized Local States and Effective Dipole Moment within a Rovibrational Cartesian Picture.

1997

[ PHYS.QPHY ] Physics [physics]/Quantum Physics [quant-ph]Rovibrational Spectra. Algebraic Approach[PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph]Rovibrational Spectra. Algebraic Approach.
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Algebraic Approach to Vibrational Spectra of Stibine Molecule

2002

International audience

[ PHYS.QPHY ] Physics [physics]/Quantum Physics [quant-ph]Vibrational SpectraLie AlgebraComputingMilieux_MISCELLANEOUS[PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph]
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U(p+1) : Application aux états moléculaires très excités.

2004

International audience

[ PHYS.QPHY ] Physics [physics]/Quantum Physics [quant-ph]Vibrational SpectraLie AlgebraComputingMilieux_MISCELLANEOUS[PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph]
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