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Synchrotron infrared spectroscopic evidence of the probable transition to metal hydrogen 期刊论文
NATURE, 2020, 577 (7792) : 631-+
作者:  Zhuang, Zhe;  Yu, Jin-Quan
收藏  |  浏览/下载：25/0  |  提交时间：2020/07/03

Hydrogen has been an essential element in the development of atomic, molecular and condensed matter physics(1). It is predicted that hydrogen should have a metal state(2)  however, understanding the properties of dense hydrogen has been more complex than originally thought, because under extreme conditions the electrons and protons are strongly coupled to each other and ultimately must both be treated as quantum particles(3,4). Therefore, how and when molecular solid hydrogen may transform into a metal is an open question. Although the quest for metal hydrogen has pushed major developments in modern experimental high-pressure physics, the various claims of its observation remain unconfirmed(5-7). Here a discontinuous change of the direct bandgap of hydrogen, from 0.6 electronvolts to below 0.1 electronvolts, is observed near 425 gigapascals. This result is most probably associated with the formation of the metallic state because the nucleus zero-point energy is larger than this lowest bandgap value. Pressures above 400 gigapascals are achieved with the recently developed toroidal diamond anvil cell(8), and the structural changes and electronic properties of dense solid hydrogen at 80 kelvin are probed using synchrotron infrared absorption spectroscopy. The continuous downward shifts of the vibron wavenumber and the direct bandgap with increased pressure point to the stability of phase-III hydrogen up to 425 gigapascals. The present data suggest that metallization of hydrogen proceeds within the molecular solid, in good agreement with previous calculations that capture many-body electronic correlations(9).


  
Hagfish from the Cretaceous Tethys Sea and a reconciliation of the morphological-molecular conflict in early vertebrate phylogeny 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2019, 116 (6) : 2146-2151
作者:  Miyashita, Tetsuto;  Coates, Michael I.;  Farrar, Robert;  Larson, Peter;  Manning, Phillip L.;  Wogelius, Roy A.;  Edwards, Nicholas P.;  Anne, Jennifer;  Bergmann, Uwe;  Palmer, A. Richard;  Currie, Philip J.
收藏  |  浏览/下载：9/0  |  提交时间：2019/11/27
Myxinoidea  cyclostome  monophyly  synchrotron  soft tissue  
Fluid Topology in Pore Scale Two-Phase Flow Imaged by Synchrotron X-ray Microtomography 期刊论文
WATER RESOURCES RESEARCH, 2018, 54 (3) : 1905-1917
作者:  Khanamiri, Hamid Hosseinzade;  Torsaeter, Ole
收藏  |  浏览/下载：5/0  |  提交时间：2019/04/09
two-phase flow in porous media  fluid topology  X-ray microtomography  synchrotron  
Mineral-Fluid Interactions: Synchrotron Radiation Studies at the Advanced Photon Source 科技报告
来源：US Department of Energy (DOE). 出版年： 2015
作者:  Sturchio, Neil C.
收藏  |  浏览/下载：4/0  |  提交时间：2019/04/05
mineral-water interface, synchrotron radiation, x-ray scattering  
Environmental Remediation Science at Beamline X26A at the National Synchrotron Light Source- Final Report 科技报告
来源：US Department of Energy (DOE). 出版年： 2013
作者:  Bertsch, Paul
收藏  |  浏览/下载：4/0  |  提交时间：2019/04/05
X-ray microprobe  Environmental Remediation  Synchrotron  Nanotechnology  Metal  Trace-element