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Anisotropy in the density of unoccupied states can be detected in the fine structure of ionization edges in angle-resolved EELS. It is shown that in a crystal an interference term occurs in the inelastic signal, and how it relates to electron channeling and site selection. The combination of orientation and site selection induces subtle variations in the ELNES. It is shown how this technique can be used to analyze local anisotropy related to the point group of the target atom. A second example shows how to extract non-dipole transitions at small scattering angles.
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http://dx.doi.org/10.1016/s0304-3991(00)00125-x | DOI Listing |
J Synchrotron Radiat
September 2025
School of Physics, University of Melbourne, Parkville, Victoria 3010, Australia.
Serial femtosecond X-ray crystallography (SFX) captures the structure and dynamics of biological macromolecules at high spatial and temporal resolutions. The ultrashort pulse produced by an X-ray free-electron laser (XFEL) `outruns' much of the radiation damage that impairs conventional crystallography. However, the rapid onset of `electronic damage' due to ionization limits this benefit.
View Article and Find Full Text PDFMed Phys
August 2025
Division of Radiation Oncology, National Cancer Centre Singapore, Singapore, Singapore.
Background: Dose-driven continuous scanning (DDCS) is a type of beam delivery in Hitachi pencil beam scanning (PBS) particle therapy system. Particle beam is irradiated continuously between spots to achieve a higher effective dose rate and a shorter beam delivery time. The beam is only turned off at break spots, the end of a treatment layer and during spill change.
View Article and Find Full Text PDFCureus
July 2025
Central Laboratory of Parasitology and Mycology, Ibn Sina University Hospital, Rabat, MAR.
Geotrichosis is a rare opportunistic mycosis caused by emerging yeasts rarely associated with fungemia. We report a case of invasive ()infection in a neutropenic patient. A 71-year-old man with rectosigmoid cancer undergoing chemotherapy was admitted to the emergency department with septic shock.
View Article and Find Full Text PDFJ Chem Phys
June 2025
Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, USA.
Orbital relaxation of the core region is a primary source of error in the computation of core ionization and core excitation energies. Recently, Transition-Potential Coupled Cluster (TP-CC) methods have been used to explicitly treat orbital relaxation using non-variational molecular orbitals determined by reoccupation of orbitals optimized for a fractional core occupation. The amount of fractional occupation is governed by parameter λ, and recommended values for accurate TP-CCSD and XTP-CCSD computations of carbon, nitrogen, oxygen, and fluorine K edges were previously determined.
View Article and Find Full Text PDFEarth Planets Space
May 2025
Department of Physics, University of Oslo, Postboks 1048, 0316 Oslo, Norway.
Abstract: The SS-520-3 sounding rocket was launched on November 4th, 2021 as part of the Grand Challenge Initiative - Cusp from Ny-Ålesund, Svalbard. The rocket was launched into the cusp ionosphere during the main phase of a geomagnetic storm. In this study we utilize two low energy particle analyzers as well as a multi-needle Langmuir probe and an impedance probe as part of the rocket payload.
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