Shirley factor

Naturally, the localization of the formation region of the interaction integrals in the vicinity of the nucleus brings relativity into play. As the atomic treatment of the interactions is carried out at a relativistic level, and rescaling of the matrix elements is done non-relativistically, a comparison of near-nucleus relativistic wavefunctions with non-relativistic ones enables the investigator to account for relativity in a fashion reminding of the Shirley-factor technique. This technique, however, does not comprise direct relativistic effects on chemical binding [6]. Fully relativistic SW variants exist (e.g., see [7] and refs, cited therein) but semirelativistic (SR) prescriptions (e.g., see /8/) do not only direct the computational effort towards the most essential effects but, moreover, provide a clearer and denser idea of the subject under consideration. 

Values of the relativity factor S (Z) for Z = 1-96 have been compiled by Shirley [1] and others [2, 3]. For example, S (Z) = 1.32 for iron (Z = 26), 2.48 for tin (i = 50), and 19.4 for neptunium (Z = 93). The problem of relativistic corrections does not arise in Mossbauer effect studies, where one compares compounds of the same Mossbauer nuclide, because the relativity factor S (Z) is constant for all compounds of a given Mossbauer nuclide. 

The resulting data were then treated by use of standard XPS methods. An asymmetric background correction using the Shirley function (described in detail by Castle and Salvi 16)), was used for all spectra, and peaks were fit by using a mixed Gaussian-Lorenzian distribution. Quantitation was performed with the equation (A/Sj) + EA/S, where A, is the peak area and 5/ is the atomic sensitivity factor for the element i being determined 17). Atomic sensitivity factors are empirical constants determined on standards of the elements 18). This yields an atom percentage (atom %) for each element at the surface of the material. 

Gallo-Penn, A. M., Shirley, P. S., Andrews, J. L., Tinlin, S., Webster, S., Cameron, C., Hough, C., Notley, C., Lillicrap, D., Kaleko, M. and Connelly, S. (2001). Systemic delivery of an adenoviral vector encoding canine factor VIII results in short-term phenotypic correction, inhibitor development, and biphasic liver toxicity in hemophilia A dogs. Blood 97, 107-113. 

The electronic structure of nanopowders was explored by method of X-ray photoelectron spectroscopy (XPS) by electronic spectrometer ES-2404 with PHOIBOS-IOO SPECS energy analyzer (E MgK(x-1253.6 eV, P-200 W, P=210 7 Pa). The spectrometer is equipped with an ion gun IQE-11/35 and a flood gun FG 15/40 for sample charge neutralization. The spectra of W4f7/2-level were factorized into component couples with parameters AEp (4f5/2 - 4f7/2) =2.1 eV, I4B/2/ Ln/2 = 0.77. The spectra of Ols-level were factorized into separate components. The factorization was carried out by Gauss-Newton method. The areas of components were determined after subtraction of background by Shirley method [1]. 

Singh M, Shirley B, Bajwa K, Samra E, Hora M, O Hagan D (2001) Controlled release of recombinant insulin-like growth factor from a novel formulation of polylactide-co-gly-colide microparticles. J Control Release 70 21-28... 

X-ray photoelectron spectroscopy (XPS) measurements were performed using a SSX-100 model 206 Surface Science Instrument Spectrometer operated at 10 kV, 12 mA with a monochromatized A1 Ka radiation (1486.6 eV). The catalysts were pressed into the samples holders of 6 mm and then introduced into the preparation chamber of the spectrometer. The Cu, Mosd, Co2p, Niap and Ou lines were recorded for each sample. All binding energies were referenced to the Cu level at 284.8 eV. Surface composition was determined from the peak intensities and the Scofield sensitivity factors provided by the instrument software. For spectrum deconvolution, a Shirley baseline was used and peaks were considered Gaussian/ Lorentzian ratio of 85/15. 

Reduction treatments in the XPS preparation chamber consisted of heating at 773K for 1 h of the calcined precursors, first under vacuum, to remove most of the contaminants adsorbed on the samples ( H2O, CO2, etc), and then under 10 torr of H2 for another horn at the appropriate temperatures in the range 300K-773K. The spectra were directly recorded and stored in a HP- Vectra 386 computer on line with the spectrometer where they were submitted to background subtraction (Shirley base line) and Factor Analysis to calculate % of Ce in the reduced samples as will be described elsewher[14]. 

Rees WH. Physical factors determining the comfort performance of textiles. In Third Shirley international seminar textiles for coin/brt 1971, Manchester. 

XPS measurements were carried out on an AXIS NOVA photoelectron spectrometer (Kratos Analytical, Manchester, UK). The surface atomic concentration was determined firom peak areas using sensitivity factors. Spectrum background was subtracted according to Shirley. The XPS peaks of the Ti species were analyzed by spectra deconvolution software (CasaXPS-Vision 2, Kratos Analytical, UK). 

Because of relativistic effects which arise from the high kinetic energy of the electrons very close to the nucleus (especially in heavy elements), the non-relativistic wave functions i/ta and should be multiplied by a factor S (Z) [Shirley (1964)]. 

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