The earliest generation of stars, far from being a mere novelty, transformed the universe from darkness to light. The first atoms to form after the Big Bang filled the universe with atomic hydrogen and a few light elements. As gravity pulled gas clouds together, the first stars ignited and their radiation turned the surrounding atoms into ions. By looking at gas between us and distant galaxies, we know that this ionization eventually pervaded all space, so that few hydrogen atoms remain today between galaxies. Knowing exactly when and how it did so is a primary goal of cosmologists, because this would tell us when the early stars formed and in what kinds of galaxies. Although this ionization is beginning to be understood by using theoretical models and computer simulations, a new generation of telescopes is being built that will map atomic hydrogen throughout the universe.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1126/science.1125644 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Revealing Crucial Influences of Boron Support on Regulating Geometric and Electronic Structures of 3D Catalyst for Hydrogen Evolution and Oxygen Reduction Reactions.
Nano Lett
January 2025
Institute of Future Technology, Southwest Jiaotong University, Chengdu 610031, China.
Building insights into the structure-performance relationship of catalysts has been emphasized recently. However, it remains a challenge due to catalysts' various and complex structures, especially the easily overlooked influence of the support material. Here, we reveal the crucial influences of boron introduction on synthesizing 3D carbon nanotube monoliths with embedded multistate Co metals, i.
View Article and Find Full Text PDFInfluence of zinc oxide nanoparticles on the carbon accumulation on silver exposed to carbon dioxide hydrogenation reaction conditions.
Nanoscale
January 2025
Center for Energy and Environmental Sciences, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen, Switzerland.
The strong influence of surface adsorbates on the morphology of a catalyst is exemplified by studying a silver surface with and without deposited zinc oxide nanoparticles upon exposure to reaction gases used for carbon dioxide hydrogenation. Ambient pressure X-ray photoelectron spectroscopy and scanning tunneling microscopy measurements indicate accumulation of carbon deposits on the catalyst surface at 200 °C. While oxygen-free carbon species observed on pure silver show a strong interaction and decorate the atomic steps on the catalyst surface, this decoration is not observed for the oxygen-containing species observed on the silver surface with additional zinc oxide nanoparticles.
View Article and Find Full Text PDFNuclear power plant waste heat opens a window of next-generation desalination hybridization: a SOAR-based review.
Water Sci Technol
January 2025
Department of Production Engineering and Mechanical Design, Faculty of Engineering, Tanta University 31527, Egypt; Faculty of Engineering, Pharos University in Alexandria 21648, Alexandria, Egypt.
This review examines the potential for utilizing nuclear power plant (NPP) waste heat in hybrid desalination systems, focusing on Reverse Osmosis-Low-Temperature Evaporation (RO-LTE) driven by renewable energy sources and atomic waste heat. By employing a SOAR (Strengths, Opportunities, Aspirations, Results) analysis, the study evaluates the integration of NPP waste heat into various desalination technologies, emphasizing the environmental benefits and energy efficiency improvements. Fundamental aspirations include advancements in material science and heat exchanger designs, which enhance heat transfer and evaporation processes.
View Article and Find Full Text PDFBilayer nanographene reveals halide permeation through a benzene hole.
Nature
January 2025
Institut für Organische Chemie, Universität Würzburg, Würzburg, Germany.
Graphene is a single-layered sp-hybridized carbon allotrope, which is impermeable to all atomic entities other than hydrogen. The introduction of defects allows selective gas permeation; efforts have been made to control the size of these defects for higher selectivity. Permeation of entities other than gases, such as ions, is of fundamental scientific interest because of its potential application in desalination, detection and purification.
View Article and Find Full Text PDFCyclodehydrogenation of molecular nanographene precursors catalyzed by atomic hydrogen.
Nat Commun
January 2025
Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, PL 30-348, Krakow, Poland.
Atomically precise synthesis of graphene nanostructures on semiconductors and insulators has been a formidable challenge. In particular, the metallic substrates needed to catalyze cyclodehydrogenative planarization reactions limit subsequent applications that exploit the electronic and/or magnetic structure of graphene derivatives. Here, we introduce a protocol in which an on-surface reaction is initiated and carried out regardless of the substrate type.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!