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Due to the generally delocalized nature of molecular valence orbitals, valence-shell spectroscopies do not usually allow to specifically target a selected atom in a molecule. However, in X-ray electron spectroscopy, the photoelectron momentum is large and the recoil angular momentum transferred to the molecule is larger when the photoelectron is ejected from a light atom compared with a heavy one. This confers an extreme sensitivity of the rotational excitation to the ionization site. Here we show that, indeed, the use of high-energy photons to photoionize valence-shell electrons of hydrogen chloride offers an unexpected way to decrypt the atomic composition of the molecular orbitals due to the rotational dependence of the photoionization profiles. The analysis of the site-specific rotational envelopes allows us to disentangle the effects of the two main mechanisms of rotational excitation, based on angular momentum exchange between the molecule and either the incoming photon or the emitted electron.
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http://dx.doi.org/10.1038/ncomms4816 | DOI Listing |
J Phys Chem A
September 2025
Univ. Rennes, CNRS, IPR (Institut de Physique de Rennes), UMR 6251, Rennes F-35000, France.
We present the first dataset of collisional (de)-excitation rate coefficients of HCN induced by CO, one of the main perturbing gases in cometary atmospheres. The dataset spans the temperature range of 5-50 K. It includes both state-to-state rate coefficients involving the lowest ten and nine rotational levels of HCN and CO, respectively, and the so-called "thermalized" rate coefficients over the rotational population of CO at each kinetic temperature.
View Article and Find Full Text PDFAnn Biomed Eng
September 2025
Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 11, 10115, Berlin, Germany.
The functional interaction of regulatory mechanisms that manage total centre of mass (CoM) energy, frontal plane whole-body angular momentum and mediolateral margin of stability (MoS) during hole negotiation gait was investigated. Joint kinematics, leg posture, total CoM energy, frontal plane whole-body angular momentum, mediolateral MoS and muscle activation patterns of seven bilateral lower leg muscles were assessed in 18 participants. During hole negotiation, we found an increase in the peak-to-peak range of total CoM energy and frontal plane whole-body angular momentum during the preparation, hole and recovery steps, and a decrease in mediolateral MoS at touch-down during the preparation and hole steps compared to level walking, providing evidence of an increased challenge in stability control.
View Article and Find Full Text PDFNat Commun
September 2025
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Berlin, Germany.
Light-induced magnetisation switching is one of the most intriguing and promising areas where an ultrafast phenomenon can be utilised in technological applications. So far, experiment and theory have considered the origin of all-optical helicity-independent magnetisation switching (AO-HIS) in individual magnetic films only as a microscopically local, thermally-driven process of angular momentum transfer between different subsystems. Here, we demonstrate that this local picture is insufficient and that AO-HIS must also be regarded as a spatially inhomogeneous process along the depth within a few-nanometre thin magnetic layer.
View Article and Find Full Text PDFACS Nano
September 2025
Instituto de Ciencia de Materiales de Barcelona. ICMAB-CSIC. Campus Universitario UAB, Bellaterra 08193, Spain.
In this work, we investigate how the crystallographic growth direction influences spin current transmission in antiferromagnetic (AF) NiO thin films. By manipulating epitaxial growth, we explored the spin transport characteristics in LaSrMnO/NiO/Pt heterostructures grown on top of (001)- and (111)-oriented SrTiO substrates, varying the NiO barrier thickness (t). Spin currents were generated via spin pumping (SP), and detection was done by the inverse spin Hall effect (ISHE).
View Article and Find Full Text PDFJ Sports Sci
September 2025
Faculty of Sport Culture, Nippon Sport Science University, Tokyo, Japan.
In the discus throw, the release velocity is crucial for determining optimal performance, with the angular momentum about the vertical axis playing a significant role. Nonetheless, the underlying mechanism remains unclear. The purpose of the present study was to investigate the rotational mechanics of standing discus throw using an inclined board placed under the right foot.
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