K edge absorption spectra

Comparison of As K edge absorption spectra for tailings and reference compounds of known oxidation states shows that arsenate (As5+) is the dominant... 

Similarly, comparison of the Mo K edge absorption spectra for tailings and reference compounds of known oxidation states (Fig. 2), shows that Mo6+ is the dominant form of molybdenum in the mine tailings. The characteristic pre-edge feature in the near edge spectra indicates that Mo in the tailings occurs mostly as a molybdate. 

For Se (Fig. 3), comparison of the Se K edge absorption spectra for tailings relative to reference compounds of known oxidation states shows that selenite (Se4+) was the dominant form of selenium in the mine tailings, along with a considerable amount of reduced Se species (selenide S°).These analyses are... 

Waychunas, G. A., Apted, M. J. Brown Jr, G. E. (1983) X-ray K-edge absorption spectra of Fe minerals and model compounds I. Near-edge structure. Phys. 

Fig. 12. Copper K-edge absorption spectra of CuCl and CuCl2. From Doniach et al. (80).

Figure S. The Br K-edge absorption spectra of Br at aqueous solution surfaces by the TR-XAFS method. / total-conversion-electron current and / the gas ionization current of X-ray intensity monitor.

Sulfur tolerances of Cu- and H-mordenite zeolite catalysts prepared by ion-exchange were examined in a fixed-bed flow-reactor system. Rates of reduction of NO over HM or CuHM with C2H4 and CuNZA with C3H6 are decreased by SO2 included in the feed gas stream. Surface areas and sulfur contents of the deactivated catalysts, their TGA and TPSR patterns and observations by XPS and Raman suggest the formation of a sulfur species on the catalyst surface in the form of sulfate (SO/ ) which causes the loss of NO removal activity of the catalysts. Data from Cu K-edge absorption spectra suggest sulfur electrostatically interacts with Cu ions on the catalyst surface. 

The application of the XANES method to metallic elements is even more demonstrative. Greaves et al. have collected K-edge absorption spectra for f.c.c. Cu and a-Mn. The two spectra show four strong peaks in the first 60 eV of fine structure. But, although both metals have close-packed structures of similar size atoms, the positions and amplitude of the peaks are different (Table 8). 

Fig. 24. K-edge absorption spectra probe the local density of states at selected atomic sites. The gallium K-edge and manganese Kedge of MnjGaC shown give the respective local densities of states. In the lower part the local density of states at the Mn and Cu sites of Mn3CuN are measured by manganese and copper Kedges...

Figure 3. A compaheon fin K-edge absorption spectra of spiiwjh PS II preparations poised in the and S2...

J. Wong, F. Lytle, R. Messmer, D. Maylotte, K-edge absorption spectra of selected vanadium compounds. Phys. Rev. B 30, 5596-5610 (1984)... 

Figure 7. Iron K-edge absorption spectra of (A) model complexes and (B) iron proteins.

Fig. 16 P K-edge XANES spectra for CoP and C00.80V0.20P- The inset highlights the absorption edges, located by their inflection points (vertical dashed lines). Reprinted with permission from [60]. Copyright Elsevier...

Fjo. 8. Oxidation state versus energy positions of various absorption features in the V K edge XANES spectra of various vanadium oxides. From Wong era/. (3/2). 

Figure 7. Ground-state wave function of plastocyanin. A HOMO wave function contour for plastocyanin (28). B HOMO wave function contour for the thiolate copper complex tet b (34/ C Copper L-edge (38) and sulfur K-edge (34) spectra as probes of metal-ligand covalency. D Absorption, single-crystal polarized absorption, and low-temperature MCD spectra of plastocyanin. The absorption spectrum has been Gaussian resolved into its component bands as in reference 33.

Br K-edge absorption measurements in transmission mode were performed using a 1 cm or a S mm thick cell at BL-6B and -lOB of the Photon Factory (National Laboratory for High Energy Physics, Tsukuba). The spectra were taken at the concentrations of 0.1 and 0.05 mol dm at room temperature. The concentration dependence of the spectra was not observed at this concentration range. 

All data were collected in the transmission mode using gas-filled ionization chambers to measure the X-ray intensity before (Iq) and after (I) the sample. For the Pt samples, the Pt Lm-edge absorption spectra (Eq 11560 eV) were collected using N2 in both ion chambers. For Pd samples, the Pd K-edge spectra (E 24350 eV)... 

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