Angle-resolved soft X-ray emission and absorption spectra in the BK and NK regions of hexagonal BN were measured using polarized synchrotron radiation. The take-off/incident-angle-dependence on the spectral features in both X-ray emission and absorption is clearly observed. The configuration of the sigma and pi orbitals, which were calculated using discrete variational (DV)-Xalpha molecular orbital calculations, explains the angle-resolved soft X-ray emission and absorption spectra. The relative peak intensity of the 394-eV peak in the NK X-ray emission provides useful information about the BN layer ordering.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/s1386-1425(02)00442-0 | DOI Listing |
Sci Rep
January 2025
Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea.
Distinguishing between Parkinson's disease (PD) and essential tremor (ET) can be challenging sometimes. Although positron emission tomography can confirm PD diagnosis, its application is limited by high cost and exposure to radioactive isotopes. Patients with PD exhibit loss of the dorsal nigral hyperintensity on brain magnetic resonance imaging (MRI).
View Article and Find Full Text PDFBest Pract Res Clin Endocrinol Metab
December 2024
Department of Nuclear Medicine, Post Graduate Institute of Medical Education and Research, Sector 12, Chandigarh 160012, India. Electronic address:
Primary hyperparathyroidism is the main cause of hypercalcemia, resulting predominantly from parathyroid adenomas followed by hyperplasia. Diagnosis relies on clinical and biochemical parameters. Accurate pre-operative localization is mandatory for better surgical outcome.
View Article and Find Full Text PDFTalanta
January 2025
Instituto de Historia (IH-CCHS), CSIC, C/ Albasanz 26-28, 28037, Madrid, Spain. Electronic address:
Analysis of glass-based artworks is important for authentication purposes. In recent years, there have been rapid advancements and improvements in the characterization of glass objects using different analytical approaches. The present study presents an interdisciplinary and multi-analytical authentication approach that provides useful tools and markers to unmask possible imitations, counterfeiting, and forgeries in Cultural Heritage glass beads by comparing the composition of historical and modern glass beads.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
School of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Reaction Engineering, Laboratory of New Energy & New Function Materials, Yanan University, Yan'an 716000, China.
Elemental analysis, infrared spectroscopy, and X-ray single crystal diffraction indicated that a novel metal-organic framework (Tb-MOF) designated as 0.5n[Hbpy]·[Tb(dpa)(HO)]·4nHO was synthesized successfully, (where Hdpa = 5-(3, 4-dicarboxy- phenoxy) isophenic acid, bpy = protonated 4,4'-bipyridine). Tb-MOF adopts a 3D network structure based on Tb ions and the (dpa) ligand through µ: η, η, η, η binding modes.
View Article and Find Full Text PDFJ Org Chem
January 2025
Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149 Münster, Germany.
Xanthine nucleosides play a significant role in the expansion of the four-letter genetic code. Herein, 7-functionalized 8-aza-7-deazaxanthine ribo- and 2'-deoxyribonucleosides are described. 2-Amino-6-alkoxy nucleosides were converted to halogenated 8-aza-7-deazaxanthine nucleosides by deamination followed by hydroxy/alkoxy substitution.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!