We have performed two-photon ultraviolet direct frequency comb spectroscopy on the 1S-3S transition in atomic hydrogen to illuminate the so-called proton radius puzzle and to demonstrate the potential of this method. The proton radius puzzle is a significant discrepancy between data obtained with muonic hydrogen and regular atomic hydrogen that could not be explained within the framework of quantum electrodynamics. By combining our result [ = 2,922,743,278,665.79(72) kilohertz] with a previous measurement of the 1S-2S transition frequency, we obtained new values for the Rydberg constant [ = 10,973,731.568226(38) per meter] and the proton charge radius [ = 0.8482(38) femtometers]. This result favors the muonic value over the world-average data as presented by the most recent published CODATA 2014 adjustment.
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http://dx.doi.org/10.1126/science.abc7776 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
College of Energy, Soochow Institute for Energy and Materials Innovations, Light Industry Institute of Electrochemical Power Sources, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou, Jiangsu 215006, China.
The solid-electrolyte interphase (SEI) strongly determines the stability and reversibility of aqueous Zn-ion batteries (AZIBs). In traditional electrolytes, the nonuniform SEI layer induced by severe parasitic reactions, such as the hydrogen evolution reaction (HER), will exacerbate the side reactions on Zn anodes, thus leading to low zinc utilization ratios (ZURs). Herein, we propose to use methoxy ethylamine (MOEA) as a nucleophilic additive, which has a stronger nucleophilic characteristic than water, with the advantage of an abundance of nucleophilic atoms.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Chemistry, Clemson University, 211 S. Palmetto Blvd, Clemson, SC, 29634, USA.
Minimizing the oxidation of lipids remains one of the most important challenges to extend the shelf-life of food products and reduce food waste. While most consumer products contain antioxidants, the most efficient strategy is to incorporate combinations of two or more compounds, boosting the total antioxidant capacity. Unfortunately, the reasons for observing synergistic / antagonistic / additive effects in food samples are still unclear, and it is common to observe very different responses even for similar mixtures.
View Article and Find Full Text PDFStructure
January 2025
Department of Computational Chemistry, Lund University, Chemical Centre, P.O. Box 124, 221 00 Lund, Sweden; European Spallation Source ESS ERIC, P.O. Box 176, 221 00 Lund, Sweden. Electronic address:
Lysozyme is a model system for crystallographers. In this issue of Structure, Ramos et al. report atomic resolution neutron structures of lysozyme, which unambiguously show the protonation states and hydrogen-bonding networks of the active site.
View Article and Find Full Text PDFSci Total Environ
January 2025
University of Tokyo, Japan.
Over the last 20 years, we have dramatically improved hydrometeorological data including isotopes, but are we making the most of this data? Stable isotopes of oxygen and hydrogen in the water molecule (stable water isotopes - SWI) are well known tracers of the global hydrological cycle producing critical climate science. Despite this, stable water isotopes are not explicitly included in influential climate reports (e.g.
View Article and Find Full Text PDFACS Nano
January 2025
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215006, China.
Low-temperature direct ammonia fuel cell (DAFC) stands out as a more secure technology than the hydrogen fuel cell system, while there is still a lack of elegant bottom-up synthesis procedures for efficient ammonia oxidation reaction (AOR) electrocatalysts. The widely accepted d-band center, even with consideration of the d-band width, usually fails to describe variations in AOR reactivity in many practical conditions, and a more accurate activity descriptor is necessary for a less empirical synthesis path. Herein, the upper d-band edge, ε, derived from the d-band model, is identified as an effective descriptor for accurately establishing the descriptor-activity relationship.
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