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Photon-recoil imaging: Expanding the view of nonlinear x-ray physics 期刊论文
Science, 2020
作者:  U. Eichmann;  H. Rottke;  S. Meise;  J.-E. Rubensson;  J. Söderström;  M. Agåker;  C. Såthe;  M. Meyer;  T. M. Baumann;  R. Boll;  A. De Fanis;  P. Grychtol;  M. Ilchen;  T. Mazza;  J. Montano;  V. Music;  Y. Ovcharenko;  D. E. Rivas;  S. Serkez;  R. Wagner;  S. Eisebitt
收藏  |  浏览/下载:7/0  |  提交时间:2020/09/30
Intense x-rays can be (slightly) exciting 期刊论文
Science, 2020
作者:  Thomas Pfeifer
收藏  |  浏览/下载:4/0  |  提交时间:2020/09/30
Lucky strike 期刊论文
Science, 2020
作者:  Joshua Sokol
收藏  |  浏览/下载:4/0  |  提交时间:2020/08/18
Identification of chondritic krypton and xenon in Yellowstone gases and the timing of terrestrial volatile accretion 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (25) : 13997-14004
作者:  Broadley, Michael W.;  Barry, Peter H.;  Bekaert, David V.;  Byrne, David J.;  Caracausi, Antonio;  Ballentine, Christopher J.;  Marty, Bernard
收藏  |  浏览/下载:9/0  |  提交时间:2020/06/16
origin of Earth'  s volatiles  accretion  mantle plume  noble gases  Yellowstone  
NEON is seeding the next revolution in ecology 期刊论文
FRONTIERS IN ECOLOGY AND THE ENVIRONMENT, 2020, 18 (1) : 3-3
作者:  Balch, Jennifer K.;  Nagy, R. Chelsea;  Halpern, Benjamin S.
收藏  |  浏览/下载:5/0  |  提交时间:2020/07/02
Limits on gas impermeability of graphene 期刊论文
NATURE, 2020, 579 (7798) : 229-+
作者:  Pagano, Justin K.;  Xie, Jing;  Erickson, Karla A.;  Cope, Stephen K.;  Scott, Brian L.;  Wu, Ruilian;  Waterman, Rory;  Morris, David E.;  Yang, Ping;  Gagliardi, Laura;  Kiplinger, Jaqueline L.
收藏  |  浏览/下载:27/0  |  提交时间:2020/07/03

Despite being only one-atom thick, defect-free graphene is considered to be completely impermeable to all gases and liquids(1-10). This conclusion is based on theory(3-8) and supported by experiments(1,9,10) that could not detect gas permeation through micrometre-size membranes within a detection limit of 10(5) to 10(6) atoms per second. Here, using small monocrystalline containers tightly sealed with graphene, we show that defect-free graphene is impermeable with an accuracy of eight to nine orders of magnitude higher than in the previous experiments. We are capable of discerning (but did not observe) permeation of just a few helium atoms per hour, and this detection limit is also valid for all other gases tested (neon, nitrogen, oxygen, argon, krypton and xenon), except for hydrogen. Hydrogen shows noticeable permeation, even though its molecule is larger than helium and should experience a higher energy barrier. This puzzling observation is attributed to a two-stage process that involves dissociation of molecular hydrogen at catalytically active graphene ripples, followed by adsorbed atoms flipping to the other side of the graphene sheet with a relatively low activation energy of about 1.0 electronvolt, a value close to that previously reported for proton transport(11,12). Our work provides a key reference for the impermeability of two-dimensional materials and is important from a fundamental perspective and for their potential applications.