Using ultrafast laser excitation and time-correlated single-photon counting techniques, we have measured the collisional mixing rates between the rubidium 5(2)P fine-structure levels in the presence of (4)He gas. A nonlinear dependence of the mixing rate with (4)He density is observed. We find Rb fine-structure transfer is primarily due to binary collisions at (4)He densities of < or = 10(19) cm(-3), while at greater densities, three-body collisions become significant. We determine a three-body collisional transfer rate coefficient (5(2)P(3/2) --> 5(2)P(1/2)) of 1.25(9)x10(-32) cm(6)/s at 22 degrees C.
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http://dx.doi.org/10.1364/OL.35.002146 | DOI Listing |
Acc Chem Res
January 2025
The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford OX1 3QR, U.K.
ConspectusThe discovery of reversible hydrogenation using metal-free phosphoborate species in 2006 marked the official advent of frustrated Lewis pair (FLP) chemistry. This breakthrough revolutionized homogeneous catalysis approaches and paved the way for innovative catalytic strategies. The unique reactivity of FLPs is attributed to the Lewis base (LB) and Lewis acid (LA) sites either in spatial separation or in equilibrium, which actively react with molecules.
View Article and Find Full Text PDFAnal Chem
January 2025
Shandong Provincial Key Laboratory of Tumor Imaging Equipment Development and Integrated Diagnosis and Treatment Technology, Linyi University, Linyi 276000, China.
Drug-induced liver injury (DILI) has emerged as an urgent clinical challenge. It is characterized by mitochondrial dysfunction in liver cells, which leads to abnormal changes in HO levels within the mitochondria. Super-resolution imaging allows for the observation of the fine structure of mitochondria at the nanometer scale, potentially enabling the detection of mitochondrial HO levels during DILI at the subcellular organelle level.
View Article and Find Full Text PDFPNAS Nexus
January 2025
The Harrison M. Randall Laboratory of Physics, University of Michigan, Ann Arbor, MI 48109-1040, USA.
The direct, ultrafast excitation of polar phonons with electromagnetic radiation is a potent strategy for controlling the properties of a wide range of materials, particularly in the context of influencing their magnetic behavior. Here, we show that, contrary to common perception, the origin of phonon-induced magnetic activity does not stem from the Maxwellian fields resulting from the motion of the ions themselves or the effect their motion exerts on the electron subsystem. Through the mechanism of electron-phonon coupling, a coherent state of circularly polarized phonons generates substantial non-Maxwellian fields that disrupt time-reversal symmetry, effectively emulating the behavior of authentic magnetic fields.
View Article and Find Full Text PDFNat Commun
January 2025
Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, PR China.
The H-evolution kinetics play a pivotal role in governing the photocatalytic hydrogen-evolution process. However, achieving precise regulation of the H-adsorption and H-desorption equilibrium (H/H) still remains a great challenge. Herein, we propose a fine-tuning d-p hybridization strategy to precisely optimize the H/H kinetics in a Ni-B modified CdS photocatalyst (Ni-B/CdS).
View Article and Find Full Text PDFSe Pu
January 2025
Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
Lipids are indispensable components of living organisms and play pivotal roles in cell-membrane fluidity, energy provision, and neurotransmitter transmission and transport. Lipids can act as potential biomarkers of diseases given their abilities to indicate cell-growth status. For example, the lipid-metabolism processes of cancer cells are distinct from those of normal cells owing to their rapid proliferation and adaptation to ever-changing biological environments.
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