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Ancient diamonds show Earth was primed for life's explosion at least 2.7 billion years ago 新闻
来源平台:EurekAlert. 发布日期:2021
作者:  admin
收藏  |  浏览/下载:15/0  |  提交时间:2021/07/26
Ancient diamonds show Earth was primed for life's explosion at least 2.7 billion years ago 新闻
来源平台:EurekAlert. 发布日期:2021
作者:  admin
收藏  |  浏览/下载:1/0  |  提交时间:2021/07/26
Driving in the snow is a team effort for AI sensors 新闻
来源平台:EurekAlert. 发布日期:2021
作者:  admin
收藏  |  浏览/下载:10/0  |  提交时间:2021/06/07
Solar wind from the center of the Earth 新闻
来源平台:EurekAlert. 发布日期:2021
作者:  admin
收藏  |  浏览/下载:2/0  |  提交时间:2021/05/21
The pioneering technology that is uncovering the mysteries of the 'Kraken' 新闻
来源平台:EurekAlert. 发布日期:2021
作者:  admin
收藏  |  浏览/下载:1/0  |  提交时间:2021/04/29
The pioneering technology that is uncovering the mysteries of the 'Kraken' 新闻
来源平台:EurekAlert. 发布日期:2021
作者:  admin
收藏  |  浏览/下载:40/0  |  提交时间:2021/04/29
Study: Women want more info on reproductive care restrictions from religious hospitals 新闻
来源平台:EurekAlert. 发布日期:2020
作者:  admin
收藏  |  浏览/下载:0/0  |  提交时间:2020/10/12
In the line of fire 新闻
来源平台:EurekAlert. 发布日期:2020
作者:  admin
收藏  |  浏览/下载:4/0  |  提交时间:2020/09/14
Mice are shrinking, but are climate change and cities to blame? 新闻
来源平台:EurekAlert. 发布日期:2020
作者:  admin
收藏  |  浏览/下载:7/0  |  提交时间:2020/06/02
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.