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全球湿地复湿可有效减少温室气体排放 快报文章
气候变化快报,2022年第16期
作者:  陈竹君 刘莉娜
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Rewetting wetland  CO2  Water table  GHG exchange  
地核和地幔之间的原始3He交换 快报文章
地球科学快报,2022年第07期
作者:  王晓晨
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Earth's Core  Earth's Mantle  Helium-3 Exchange  
WMO批准通过加强国际旨在强化全球观测与地球系统数据交换的行动的重大举措 快报文章
地球科学快报,2021年第21期
作者:  刘燕飞
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Keywords: Earth System  Data exchange  Global Basic Observing Network  
Exchange Dynamics of Typical Emerging and Legacy Persistent Organic Pollutants at the Air-Water Interface Over a Strongly Human-Influenced Large River Estuary 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (13)
作者:  Guo, Tianfeng;  Li, Yuanyuan;  Lin, Tian;  Wu, Zilan;  Jiang, Yuqing;  Guo, Zhigang
收藏  |  浏览/下载:23/0  |  提交时间:2020/08/18
BDE-209  PCB  air-water gas exchange  transport pathway  source-sink fate  
Unequal raw material exchange between and within countries: Galicia (NW Spain) as a core-periphery economy 期刊论文
ECOLOGICAL ECONOMICS, 2020, 172
作者:  Pinero, Pablo;  Perez-Neira, David;  Infante-Amate, Juan;  Chas-Amil, Maria L.;  Doldan-Garcia, Xoan R.
收藏  |  浏览/下载:27/0  |  提交时间:2020/07/02
Unequal exchange  Material footprint  Material flow accounting  Value added  World system theory  Multi-Regional Input-Output  
Ecological macroeconomics in the open economy: Sustainability, unequal exchange and policy coordination in a center-periphery model 期刊论文
ECOLOGICAL ECONOMICS, 2020, 172
作者:  Althouse, Jeffrey;  Guarini, Giulio;  Gabriel Porcile, Jose
收藏  |  浏览/下载:23/0  |  提交时间:2020/07/02
Ecological macroeconomics  Green growth  Ecologically unequal exchange  Balance of payments constraint  Environmental policy coordination  Center-periphery model  
Global reconstruction reduces the uncertainty of oceanic nitrous oxide emissions and reveals a vigorous seasonal cycle 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (22) : 11954-11960
作者:  Yang, Simon;  Chang, Bonnie X.;  Warner, Mark J.;  Weber, Thomas S.;  Bourbonnais, Annie M.;  Santoro, Alyson E.;  Kock, Annette;  Sonnerup, Rolf E.;  Bullister, John L.;  Wilson, Samuel T.;  Bianchi, Daniele
收藏  |  浏览/下载:35/0  |  提交时间:2020/05/20
nitrous oxide  air-sea gas exchange  seasonal variability  nitrogen cycle  greenhouse gases  
FACT caught in the act of manipulating the nucleosome 期刊论文
NATURE, 2020, 577 (7790) : 426-+
作者:  Shen, Helen
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The organization of genomic DNA into nucleosomes profoundly affects all DNA-related processes in eukaryotes. The histone chaperone known as '  facilitates chromatin transcription'  (FACT(1)) (consisting of subunits SPT16 and SSRP1) promotes both disassembly and reassembly of nucleosomes during gene transcription, DNA replication and DNA repair(2). However, the mechanism by which FACT causes these opposing outcomes is unknown. Here we report two cryo-electron-microscopic structures of human FACT in complex with partially assembled subnucleosomes, with supporting biochemical and hydrogen-deuterium exchange data. We find that FACT is engaged in extensive interactions with nucleosomal DNA and all histone variants. The large DNA-binding surface on FACT appears to be protected by the carboxy-terminal domains of both of its subunits, and this inhibition is released by interaction with H2A-H2B, allowing FACT-H2A-H2B to dock onto a complex containing DNA and histones H3 and H4 (ref. (3)). SPT16 binds nucleosomal DNA and tethers H2A-H2B through its carboxy-terminal domain by acting as a placeholder for DNA. SSRP1 also contributes to DNA binding, and can assume two conformations, depending on whether a second H2A-H2B dimer is present. Our data suggest a compelling mechanism for how FACT maintains chromatin integrity during polymerase passage, by facilitating removal of the H2A-H2B dimer, stabilizing intermediate subnucleosomal states and promoting nucleosome reassembly. Our findings reconcile discrepancies regarding the many roles of FACT and underscore the dynamic interactions between histone chaperones and nucleosomes.


  
Inverse Cascade Evidenced by Information Entropy of Passive Scalars in Submerged Canopy Flows 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (9)
作者:  Ghannam, Khaled;  Poggi, Davide;  Bou-Zeid, Elie;  Katul, Gabriel G.
收藏  |  浏览/下载:20/0  |  提交时间:2020/05/13
canopy turbulence  land-atmosphere exchange  scalar mixing  inverse cascade  
Entanglement-based secure quantum cryptography over 1,120 kilometres 期刊论文
NATURE, 2020
作者:  Paldi, Flora;  Alver, Bonnie;  Robertson, Daniel;  Schalbetter, Stephanie A.;  Kerr, Alastair;  Kelly, David A.;  Baxter, Jonathan;  Neale, Matthew J.;  Marston, Adele L.
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An efficient entanglement-based quantum key distribution is sent from the Micius satellite to two ground observatories 1,120 kilometres apart to establish secure quantum cryptography for the exchange ofquantum keys.


Quantum key distribution (QKD)(1-3)is a theoretically secure way of sharing secret keys between remote users. It has been demonstrated in a laboratory over a coiled optical fibre up to 404 kilometres long(4-7). In the field, point-to-point QKD has been achieved from a satellite to a ground station up to 1,200 kilometres away(8-10). However, real-world QKD-based cryptography targets physically separated users on the Earth, for which the maximum distance has been about 100 kilometres(11,12). The use of trusted relays can extend these distances from across a typical metropolitan area(13-16)to intercity(17)and even intercontinental distances(18). However, relays pose security risks, which can be avoided by using entanglement-based QKD, which has inherent source-independent security(19,20). Long-distance entanglement distribution can be realized using quantum repeaters(21), but the related technology is still immature for practical implementations(22). The obvious alternative for extending the range of quantum communication without compromising its security is satellite-based QKD, but so far satellite-based entanglement distribution has not been efficient(23)enough to support QKD. Here we demonstrate entanglement-based QKD between two ground stations separated by 1,120 kilometres at a finite secret-key rate of 0.12 bits per second, without the need for trusted relays. Entangled photon pairs were distributed via two bidirectional downlinks from the Micius satellite to two ground observatories in Delingha and Nanshan in China. The development of a high-efficiency telescope and follow-up optics crucially improved the link efficiency. The generated keys are secure for realistic devices, because our ground receivers were carefully designed to guarantee fair sampling and immunity to all known side channels(24,25). Our method not only increases the secure distance on the ground tenfold but also increases the practical security of QKD to an unprecedented level.