Two photon absorption laser induced fluorescence (TALIF) measurements of neutral hydrogen and its isotopes are typically calibrated by performing TALIF measurements on krypton with the same diagnostic system and using the known ratio of the absorption cross sections [K. Niemi et al., J. Phys. D 34, 2330 (2001)]. Here we present the measurements of a new calibration method based on a ground state xenon scheme for which the fluorescent emission wavelength is nearly identical to that of hydrogen, thereby eliminating chromatic effects in the collection optics and simplifying detector calibration. We determine that the ratio of the TALIF cross sections of xenon and hydrogen is 0.024 ± 0.001.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1063/1.4955489 | DOI Listing |
Proc Natl Acad Sci U S A
February 2025
Department of Earth System Sciences, Center for Earth System Research and Sustainability, University of Hamburg, Hamburg 20146, Germany.
As an essential micronutrient, phosphorus plays a key role in oceanic biogeochemistry, with its cycling intimately connected to the global carbon cycle and climate change. Authigenic carbonate fluorapatite (CFA) has been suggested to represent a significant phosphorus sink in the deep ocean, but its formation mechanisms in oceanic low-productivity settings remain poorly constrained. Applying X-ray absorption near edge structure, transmission electron microscopy, and laser ablation inductively coupled plasma mass spectrometer analyses, we report a unique mineral assemblage where CFA crystals coat phillipsite in abyssal sediments of the East Mariana Basin and the Philippine Sea.
View Article and Find Full Text PDFNanoscale
January 2025
Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China.
Lowering the population inversion threshold is key to leveraging quantum dots (QDs) for nanoscale lasing and laser miniaturization. However, optical realization of population inversion in QDs has an inherent limitation: the number of excited electrons per QD is bound by the absorbed photons. Here we show that one can break this population limit and realize near-zero threshold inversion plasmonic doping.
View Article and Find Full Text PDFJ Biomed Opt
January 2025
The Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States.
Significance: Laparoscopic surgery presents challenges in localizing oncological margins due to poor contrast between healthy and malignant tissues. Optical properties can uniquely identify various tissue types and disease states with high sensitivity and specificity, making it a promising tool for surgical guidance. Although spatial frequency domain imaging (SFDI) effectively measures quantitative optical properties, its deployment in laparoscopy is challenging due to the constrained imaging environment.
View Article and Find Full Text PDFJ Food Sci Technol
January 2025
CIFF, National Centre for Biological Sciences, Bellary Road, Bengaluru, 560030 India.
The kinetics, oil migration pattern and the role of frying media during immersion frying of '', a dairy dessert, at the microstructural level were studied using confocal laser scanning microscopy (CLSM). After 6 min of frying, the depth of oil migration in increased from 0 to 3.16 mm in clarified butter (locally called '') and 3.
View Article and Find Full Text PDFACS Phys Chem Au
January 2025
Department of Medical Applied Chemistry, Chung Shan Medical University, Taichung 402, Taiwan.
Novel coumarin-triphenyliminophosphorane (TPIPP) fluorophores, synthesized via a nonhydrolytic Staudinger reaction, exhibit remarkable redox-responsive optical properties. Upon chemical and electrochemical oxidation, these compounds display a hypsochromic shift in absorption from 430 to 350 nm, accompanied by up to 11-fold fluorescence enhancement under 405 nm excitation. The fluorescence switching occurs at an electrochemical oxidation potential of approximately +2.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!