Edge structures

The corresponding Kohn-Sham wave functions (Fig. 16b) show that the metallic edge states I and II are localized entirely on the molybdenum edge with sulfur dimers, whereas edge state III is associated with the fully covered sulfur edge (not shown). 

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Figure 8.33 Formation of an absorption edge and pre-edge structure in X-ray absorption...

Yes, in the near-edge structure of edge profiles information... 

EXAFS is part of the field of X-ray absorption spectroscopy (XAS), in which a number of acronyms abound. An X-ray absorption spectrum contains EXAFS data as well as the X-ray absorption near-edge structure, XANES (alternatively called the near-edge X-ray absorption fine structure, NEXAFS). The combination of XANES (NEXAFS) and EXAFS is commonly referred to as X-ray absorption fine structure, or XAFS. In applications of EXAFS to surface science, the acronym SEXAFS, for surface-EXAFS, is used. The principles and analysis of EXAFS and SEXAFS are the same. See the article following this one for a discussion of SEXAFS and NEXAFS. 

Figure 2 Molybdenum K-edge X-ray absorption spectrum, ln(i /i ) versus X-ray energy (eV), for molybdenum metal foil (25- jjn thick), obtained by transmission at 77 K with synchrotron radiation. The energy-dependent constructive and destructive interference of outgoing and backscattered photoelectrons at molybdenum produces the EXAFS peaks and valleys, respectively. The preedge and edge structures marked here are known together as X-ray absorption near edge structure, XANES and EXAFS are provided in a new compilation of literature entitled X-rsy Absorption Fine Structure (S.S. Hasain, ed.) Ellis Norwood, New York, 1991.

EXAFS and Near Edge Structure III. Proceeding of an International Conference. (K. O. Hodgson, B. Hedman, and J. E. Penner-Hahn, eds.) Springer, Berlin, 1984. 

Near-edge structures superimposed on the general atomic edge profile are caused by transitions of inner-shell electrons of a particular atom to the lowest unoccupied... 

The space shuttle and other aerospace vehicles use carbon-carbon extensively in nose cap, leading edges, structural panels, and other components. 

The X-ray absorption fine structure (XAFS) methods (EXAFS and X-ray absorption near-edge structure (XANES)) are suitable techniques for determination of the local structure of metal complexes. Of these methods, the former provides structural information relating to the radial distribution of atom pairs in systems studied the number of neighboring atoms (coordination number) around a central atom in the first, second, and sometimes third coordination spheres the... 

X-ray absorption near edge structure (XANES) spectroscopy is a non-destructive and sensitive probe of the coordination number and geometry as well as of the effective charge of a chosen atom within a molecule and therefore also of the formal oxidation number. Recently, there have been a number of XANES studies at the sulfur K-edge demonstrating the sensitivity of... 

Various nonpremixed edge structures for symmetric cases (From Daou, R., Daou, ]., and Dold, J., Combust. Theory Model., 8,683,2004. With permission) (a) trihrachial, (b) cotton-bud shape, and (c) monobrachial structures and for asymmetric cases [19] (d) tribrachial and (e) bibrachial structures. 

Tribrachial edge structure exhibiting flow redirection effect. (From Ruetsch, G.R., Vervisch, L., and Lihan, A., Phys. Fluids, 7,1447,1995.)... 

Evidence for the first reason was demonstrated in X-ray photoelectron spectroscopy (XPS) or X-Ray Absorption Near Edge Structure (XANES) studies, as well as by many voltammetric studies. ... 

If a vacant site is occupied by another Nb atom, such that it is a dimer, new catalysts may be designed. The Nb dimer catalyst(2) was prepared by reaction of [Nb(ri -C5H5)H-p-(T, Ti -CsH4)]2 with a Si02 at 313 K, followed by treatment with 02 at 773 K. A proposed structure(2) was characterized by EXAFS, x-ray absorption near-edge structure(XANES), FT-IR, UV-vis, and XPS, which shows Nb-Nb (coordination number 0.9) and Nb-Si(2.3)... 

XANES X-ray absorption near edge structure spectroscopy... 

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