XANES

XANES X-ray adsorption nearedge spectroscopy [178a] Same as NEXAFS Same as NEXAFS... 

Kongingsberger D C and Prins R (ed) 988 X-Ray Absorption Principies, Appiications, Techniques of EXAFS, SEXAFS and XANES (New York Wiley)... 

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.

XANES, and in a-C H films the sp sp ratio can be measured directly using nmr spectroscopy [71]. 

Based on the equation presented in the problem statement, the mi.xture of butane, cyclohe.xane, ethyl ether and liquid petroleum gas is evaluated in terms of the combined TLV as follows ... 

Fluoro uracil mercury Tegafur Formaldehyde Biperiden Bronopol Cortivazol Edetate disodium Glaziovine Hexetidine Meptazinol Metampicillin sodium Methylol riboflavin Nifurfoline Nifurtoinol Noxytiolin Oxymetazoline HCI Phenindamine tartrate Pipebuzone Thihexinol Timonacic sodium Triclobisonium chloride T romethamine Tyloxapol Formamide Cimetide Primidone Protriptyline Razo xane Spiperone Formic acid Bupivacaine... 

Figure 4. Contributions to XMCD. a. thin line C ( thick line C broken line. Left panel XANES right panel EXAFS...

Mn02) [56], The XANES spectra at the Ni K-edge indicates that, unlike the ABS alloys, there is very little interaction between hydrogen and Ni but rather strong interactions with Ti, V, and Zr. The hydrogen is presumably located in tetrahedra that contain large fractions of these three elements, whereas the Ni-rich sites are probably empty. Thus the function of Ni in AB2 alloys may be primarily to serve as a catalyst for the electrochemical hydriding reactions. 

XAFS (EXAFS and XANES) methods X-ray diffraction method Biological investigations Flydrolysis of [OrganotinllV)]" Cations Interactions of [OrganotinllV)]" with Biological Molecules... 

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... 

XANES method gives useful information of effective electron occupation (oxidation state) of the studied element. 

Some structural data obtained by these methods are also discussed in the following sections. The XANES spectra of organotin(lV) are usually not so informative. The advantages and disadvantages of EXAFS as a structural probe are discussed... 

Nagy, L. Theoretical Background ofEXAFS and XANES Spectroscopies. Application in Inorganic and in Bioinorganic Chemistry. Novel Results in Chemistry, Akademiai Kiado, Budapest, 1999 p. 63. 

Abstract Molecular spectroscopy is one of the most important means to characterize the various species in solid, hquid and gaseous elemental sulfur. In this chapter the vibrational, UV-Vis and mass spectra of sulfur molecules with between 2 and 20 atoms are critically reviewed together with the spectra of liquid sulfur and of solid allotropes including polymeric and high-pressure phases. In particular, low temperature Raman spectroscopy is a suitable technique to identify single species in mixtures. In mass spectra cluster cations with up to 56 atoms have been observed but fragmentation processes cause serious difficulties. The UV-Vis spectra of S4 are reassigned. The modern XANES spectroscopy has just started to be applied to sulfur allotropes and other sulfur compounds. 

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