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Metallic glasses that harden under strain 期刊论文
NATURE, 2020, 578 (7796) : 521-522
作者:  Keller, Andreas J.;  Roth, Morgane M.;  Scanziani, Massimo
收藏  |  浏览/下载:10/0  |  提交时间:2020/07/03

A process that reduces the risk of metallic glasses failing under stress.


Metallic glasses are much stronger than conventional metals, but form certain instabilities under stress that lead to fracture. A process known as rejuvenation has been shown to solve this problem.


  
THE SUPER-COOL MATERIALS THAT SEND HEAT TO SPACE 期刊论文
NATURE, 2020, 577 (7788) : 18-20
作者:  Lim, XiaoZhi
收藏  |  浏览/下载:0/0  |  提交时间:2020/07/03
Accurate compound-specific C-14 dating of archaeological pottery vessels 期刊论文
NATURE, 2020, 580 (7804) : 506-+
作者:  Yin, Yafei;  Lu, J. Yuyang;  Zhang, Xuechun;  Shao, Wen;  Xu, Yanhui;  Li, Pan;  Hong, Yantao;  Cui, Li;  Shan, Ge;  Tian, Bin;  Zhang, Qiangfeng Cliff;  Shen, Xiaohua
收藏  |  浏览/下载:20/0  |  提交时间:2020/05/13

Pottery is one of the most commonly recovered artefacts from archaeological sites. Despite more than a century of relative dating based on typology and seriation(1), accurate dating of pottery using the radiocarbon dating method has proven extremely challenging owing to the limited survival of organic temper and unreliability of visible residues(2-4). Here we report a method to directly date archaeological pottery based on accelerator mass spectrometry analysis of C-14 in absorbed food residues using palmitic (C-16:0) and stearic (C-18:0) fatty acids purified by preparative gas chromatography(5-8). We present accurate compound-specific radiocarbon determinations of lipids extracted from pottery vessels, which were rigorously evaluated by comparison with dendrochronological dates(9,10) and inclusion in site and regional chronologies that contained previously determined radiocarbon dates on other materials(11-15). Notably, the compound-specific dates from each of the C-16:0 and C-18:0 fatty acids in pottery vessels provide an internal quality control of the results(6) and are entirely compatible with dates for other commonly dated materials. Accurate radiocarbon dating of pottery vessels can reveal: (1) the period of use of pottery  (2) the antiquity of organic residues, including when specific foodstuffs were exploited  (3) the chronology of sites in the absence of traditionally datable materials  and (4) direct verification of pottery typochronologies. Here we used the method to date the exploitation of dairy and carcass products in Neolithic vessels from Britain, Anatolia, central and western Europe, and Saharan Africa.


Using lipid residues absorbed in potsherds, the ages of pottery from various archaeological sites are determined and validated using sites for which the dates are well known from other methods.


  
Boundaries transformed in pure metals 期刊论文
NATURE, 2020, 579 (7799) : 350-351
作者:  Ledford, Heidi
收藏  |  浏览/下载:2/0  |  提交时间:2020/07/03

Interfaces between the tiny crystal grains that make up solid copper have been shown to change from one ordered phase to another, independently of the phase adopted by the crystals, opening up prospects for materials development.


Polymorphs of grain boundaries in copper visualized and modelled.


  
GENE THERAPY SHOWS PROMISE FOR THIEF OF SIGHT 期刊论文
NATURE, 2020, 579 (7797) : 11-11
作者:  Fabbiano, Giuseppina
收藏  |  浏览/下载:0/0  |  提交时间:2020/07/03
Redox-switchable carboranes for uranium capture and release 期刊论文
NATURE, 2020, 577 (7792) : 652-+
作者:  Marques, Joao C.;  Li, Meng;  Schaak, Diane;  Robson, Drew N.;  Li, Jennifer M.
收藏  |  浏览/下载:31/0  |  提交时间:2020/07/03

The uranyl ion (UO22+  U(vi) oxidation state) is the most common form of uranium found in terrestrial and aquatic environments and is a central component in nuclear fuel processing and waste remediation efforts. Uranyl capture from either seawater or nuclear waste has been well studied and typically relies on extremely strong chelating/binding affinities to UO22+ using chelating polymers(1,2), porous inorganic(3-5) or carbon-based(6,7) materials, as well as homogeneous(8) compounds. By contrast, the controlled release of uranyl after capture is less established and can be difficult, expensive or destructive to the initial material(2,9). Here we show how harnessing the redox-switchable chelating and donating properties of an ortho-substituted closo-carborane (1,2-(Ph2PO)(2)-1,2-C2B10H10) cluster molecule can lead to the controlled chemical or electrochemical capture and release of UO22+ in monophasic (organic) or biphasic (organic/aqueous) model solvent systems. This is achieved by taking advantage of the increase in the ligand bite angle when the closo-carborane is reduced to the nido-carborane, resulting in C-C bond rupture and cage opening. The use of electrochemical methods for uranyl capture and release may complement existing sorbent and processing systems.


Redox-switchable chelation is demonstrated for a carborane cluster molecule, leading to controlled chemical or electrochemical capture and release of uranyl in monophasic or biphasic model solvent systems.


  
Versatile strategy for making 2D materials 期刊论文
NATURE, 2020, 577 (7791) : 477-478
作者:  Leong, Wei Sun
收藏  |  浏览/下载:1/0  |  提交时间:2020/07/03
Nanostructured alloys light the way to silicon-based photonics 期刊论文
NATURE, 2020, 580 (7802) : 188-189
作者:  Phillips-Cremins, Jennifer;  Landhuis, Esther
收藏  |  浏览/下载:4/0  |  提交时间:2020/07/03

Silicon used for electronics has a cubic crystal lattice, which makes the material unsuitable for photonics applications. A method for producing germanium and silicon-germanium alloys that have hexagonal lattices offers a solution.


  
Pervasive human-driven decline of life on Earth points to the need for transformative change 期刊论文
SCIENCE, 2019, 366 (6471) : 1327-+
作者:  Diaz, Sandra;  Settele, Josef;  Brondizio, Eduardo S.;  Ngo, Hien T.;  Agard, John;  Arneth, Almut;  Balvanera, Patricia;  Brauman, Kate A.;  Butchart, Stuart H. M.;  Chan, Kai M. A.;  Garibaldi, Lucas A.;  Ichii, Kazuhito;  Liu, Jianguo;  Subramanian, Suneetha M.;  Midgley, Guy F.;  Miloslavich, Patricia;  Molnar, Zsolt;  Obura, David;  Pfaff, Alexander;  Polasky, Stephen;  Purvis, Andy;  Razzaque, Jona;  Reyers, Belinda;  Chowdhury, Rinku Roy;  Shin, Yunne-Jai;  Visseren-Hamakers, Ingrid;  Willis, Katherine J.;  Zayas, Cynthia N.
收藏  |  浏览/下载:20/0  |  提交时间:2020/02/17
Order emerging from disorder 期刊论文
SCIENCE, 2019, 366 (6465) : 573-574
作者:  Dragoe, Nita;  Berardan, David
收藏  |  浏览/下载:3/0  |  提交时间:2020/02/17