Chemical Properties of Superfine Pulverized Coal Particles. Part 4. Sulfur Speciation by X-ray Absorption Near-Edge Structure Spectroscopy

2020 ◽  
Vol 34 (11) ◽  
pp. 13686-13697
Author(s):  
Jiaxun Liu ◽  
Xiuchao Yang ◽  
Yuanzhen Jiang ◽  
Hai Zhang ◽  
Xue Jiang ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Pulverized Coal ◽  
Edge Structure ◽  
X Ray ◽  
Coal Particles ◽  
Sulfur Speciation ◽  
X Ray Absorption

Electronic structures of CdSe nanocrystals — An X-ray absorption near-edge structure (XANES) investigation

2007 ◽  
Vol 85 (10) ◽  
pp. 756-760 ◽  
Author(s):  
Jigang Zhou ◽  
Xingtai Zhou ◽  
Xuhui Sun ◽  
Michael Murphy ◽  
Franziskus Heigl ◽  
...  
Keyword(s):  
Electronic Structures ◽  
Quantum Confinement Effect ◽  
Chemical Properties ◽  
Trioctylphosphine Oxide ◽  
Cdse Nanocrystals ◽  
Edge Structure ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Capping Ligands ◽  
X Ray Absorption

CdSe nanocrystals (NCs), capped with trioctylphosphine oxide and 1-octadecanamine, have been synthesized with colloidal methods. Both UV–vis absorption and photoluminescence spectra show that the prepared nanostructures exhibit a quantum confinement effect. X-ray absorption near–edge structure (XANES) at Se K-edge recorded in fluorescence yield mode have been carried out on these NCs, with different size and capping ligands to gain insight into how their electronic structures are affected by the NC size and chemical properties of the ligands. The results indicate that XANES are sensitive to both the NC size and the nature of the capping ligands. The whiteline intensity in XANES spectra can be related to the photoluminescence properties of these NCs.Key words: CdSe nanocrystals, capping ligands, X-ray absorption near-edge structure, UV–vis spectroscopy, photoluminescence.

scholarly journals Sulfur speciation in heavy petroleums: Information from X-ray absorption near-edge structure

1991 ◽  
Vol 55 (3) ◽  
pp. 801-814 ◽  
Author(s):  
Geoffrey S. Waldo ◽  
Robert M.K. Carlson ◽  
J.Michael Moldowan ◽  
Kenneth E. Peters ◽  
James E. Penner-hahn
Keyword(s):  
Edge Structure ◽  
X Ray ◽  
Sulfur Speciation ◽  
X Ray Absorption

Comparative Study of Iron and Sulfur Speciation Transformation of Pyrite and Marcasite by Extreme Thermophilic Archaea Acidianus manzaensis

2015 ◽  
Vol 1130 ◽  
pp. 342-346
Author(s):  
Hong Chang Liu ◽  
Jin Lan Xia ◽  
Zhen Yuan Nie ◽  
Hong Rui Zhu ◽  
Yi Dong Zhao ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
Sulfur Species ◽  
Edge Structure ◽  
X Ray ◽  
Mineral Structure ◽  
Sulfur Speciation ◽  
Acidianus Manzaensis ◽  
X Ray Absorption ◽  
Lower Oxidation ◽  
Thermophilic Archaea

Differential utilization of isomers pyrite and marcasite by Acidianus manzaensis were comparatively studied, besides the iron and sulfur speciation transformation of the minerals was also investigated based on synchrotron radiation X-ray absorption near edge structure (XANES) spectroscopy. The results showed that the biooxidation of pyrite was faster than marcasite. The bioleached surface of both pyrite and marcasite are serious corroded, and the Fe (III)-containing species as well as jarosite were gradually produced, and more elemental sulfur species were formed on the marcasite surface than that for pyrite. It demonstrates the mineral structure does affect the biooxidation of pyrite and marcasite, and the more precipitated elemental sulfur might be one of the reasons leading to lower oxidation rate of marcasite by A. manzaensis.

Extraction of local coordination structure in a low-concentration uranyl system by XANES

2016 ◽  
Vol 23 (3) ◽  
pp. 758-768 ◽  
Author(s):  
Linjuan Zhang ◽  
Jing Zhou ◽  
Jianyong Zhang ◽  
Jing Su ◽  
Shuo Zhang ◽  
...  
Keyword(s):  
Structural Information ◽  
Chemical Properties ◽  
Edge Structure ◽  
X Ray ◽  
Low Concentration ◽  
Simplified Approach ◽  
Bond Lengths ◽  
Uranyl Carbonate ◽  
X Ray Absorption ◽  
Xanes Analysis

Obtaining structural information of uranyl species at an atomic/molecular scale is a critical step to control and predict their physical and chemical properties. To obtain such information, experimental and theoreticalL3-edge X-ray absorption near-edge structure (XANES) spectra of uranium were studied systematically for uranyl complexes. It was demonstrated that the bond lengths (R) in the uranyl species and relative energy positions (ΔE) of the XANES were determined as follows: ΔE1= 168.3/R(U—Oax)2− 38.5 (for the axial plane) and ΔE2= 428.4/R(U—Oeq)2− 37.1 (for the equatorial plane). These formulae could be used to directly extract the distances between the uranium absorber and oxygen ligand atoms in the axial and equatorial planes of uranyl ions based on the UL3-edge XANES experimental data. In addition, the relative weights were estimated for each configuration derived from the water molecule and nitrate ligand based on the obtained average equatorial coordination bond lengths in a series of uranyl nitrate complexes with progressively varied nitrate concentrations. Results obtained from XANES analysis were identical to that from extended X-ray absorption fine-structure (EXAFS) analysis. XANES analysis is applicable to ubiquitous uranyl–ligand complexes, such as the uranyl–carbonate complex. Most importantly, the XANES research method could be extended to low-concentration uranyl systems, as indicated by the results of the uranyl–amidoximate complex (∼40 p.p.m. uranium). Quantitative XANES analysis, a reliable and straightforward method, provides a simplified approach applied to the structural chemistry of actinides.

X-ray absorption near-edge structure (XANES) spectroscopy identifies differential sulfur speciation in corneal tissue

2013 ◽  
Vol 405 (21) ◽  
pp. 6613-6620 ◽  
Author(s):  
Giulia Veronesi ◽  
Elena Koudouna ◽  
Marine Cotte ◽  
Francis L. Martin ◽  
Andrew J. Quantock
Keyword(s):  
Xanes Spectroscopy ◽  
Corneal Tissue ◽  
Edge Structure ◽  
X Ray ◽  
Sulfur Speciation ◽  
X Ray Absorption

Oxidative Degradation Monitoring of Natural Rubber Using S K-Edge X-Ray Absorption near-Edge Spectroscopy (XANES)

2012 ◽  
Vol 620 ◽  
pp. 440-445 ◽  
Author(s):  
Wirach Taweepreda ◽  
Wanwisa Limphirat ◽  
Prayoon Songsiriritthigul
Keyword(s):  
Natural Rubber ◽  
Oxidative Degradation ◽  
Chemical Properties ◽  
Oxidative Process ◽  
Tetramethylthiuram Disulfide ◽  
Edge Structure ◽  
X Ray ◽  
Degradation Monitoring ◽  
Zinc Diethyldithiocarbamate ◽  
X Ray Absorption

In this work, we present the results of sulfur crosslinking and degradation in natural rubber (NR) studied by X-ray absorption near-edge structure spectroscopy (XANES). Sulfur K-edge XANES spectra has been collected and analyzed to provide the geometry and electronic environment of sulfur crosslinks during vulcanization and degradation processes by ozone aging. We found that reversion took place before the onset of oxidative process at the sulfur bridge. Parallel to the oxidative process, the production of cyclic sulfanes took places. This physico-chemical properties which were calculated from S K-edge XANES spectra were correlated with the mechanical of NR films by varying accelerator type. The accelerator zinc diethyldithiocarbamate (ZDEC) gave highest film strength when compared with other accelerators: N-cyclohexylbenzothiazole sulfenamide (CBS), 2,2' dibenzothiazyl disulfide (MBTS), and tetramethylthiuram disulfide (TMTD).

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