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Localization and delocalization of light in photonic moire lattices 期刊论文
NATURE, 2020, 577 (7788) : 42-+
作者:  Wang, Peng;  Zheng, Yuanlin;  Chen, Xianfeng;  Huang, Changming;  Kartashov, Yaroslav V.;  Torner, Lluis;  Konotop, Vladimir V.;  Ye, Fangwei
收藏  |  浏览/下载:11/0  |  提交时间:2020/07/03

Moire lattices consist of two superimposed identical periodic structures with a relative rotation angle. Moire lattices have several applications in everyday life, including artistic design, the textile industry, architecture, image processing, metrology and interferometry. For scientific studies, they have been produced using coupled graphene-hexagonal boron nitride monolayers(1,2), graphene-graphene layers(3,4) and graphene quasicrystals on a silicon carbide surface(5). The recent surge of interest in moire lattices arises from the possibility of exploring many salient physical phenomena in such systems  examples include commensurable-incommensurable transitions and topological defects(2), the emergence of insulating states owing to band flattening(3,6), unconventional superconductivity(4) controlled by the rotation angle(7,8), the quantum Hall effect(9), the realization of non-Abelian gauge potentials(10) and the appearance of quasicrystals at special rotation angles(11). A fundamental question that remains unexplored concerns the evolution of waves in the potentials defined by moire lattices. Here we experimentally create two-dimensional photonic moire lattices, which-unlike their material counterparts-have readily controllable parameters and symmetry, allowing us to explore transitions between structures with fundamentally different geometries (periodic, general aperiodic and quasicrystal). We observe localization of light in deterministic linear lattices that is based on flatband physics(6), in contrast to previous schemes based on light diffusion in optical quasicrystals(12), where disorder is required(13) for the onset of Anderson localization(14) (that is, wave localization in random media). Using commensurable and incommensurable moire patterns, we experimentally demonstrate the twodimensional localization-delocalization transition of light. Moire lattices may feature an almost arbitrary geometry that is consistent with the crystallographic symmetry groups of the sublattices, and therefore afford a powerful tool for controlling the properties of light patterns and exploring the physics of periodic-aperiodic phase transitions and two-dimensional wavepacket phenomena relevant to several areas of science, including optics, acoustics, condensed matter and atomic physics.


  
Recycling and metabolic flexibility dictate life in the lower oceanic crust 期刊论文
NATURE, 2020, 579 (7798) : 250-+
作者:  Zhou, Peng;  Yang, Xing-Lou;  Wang, Xian-Guang;  Hu, Ben;  Zhang, Lei;  Zhang, Wei;  Si, Hao-Rui;  Zhu, Yan;  Li, Bei;  Huang, Chao-Lin;  Chen, Hui-Dong;  Chen, Jing;  Luo, Yun;  Guo, Hua;  Jiang, Ren-Di;  Liu, Mei-Qin;  Chen, Ying;  Shen, Xu-Rui;  Wang, Xi;  Zheng, Xiao-Shuang;  Zhao, Kai;  Chen, Quan-Jiao;  Deng, Fei;  Liu, Lin-Lin;  Yan, Bing;  Zhan, Fa-Xian;  Wang, Yan-Yi;  Xiao, Geng-Fu;  Shi, Zheng-Li
收藏  |  浏览/下载:37/0  |  提交时间:2020/05/13

The lithified lower oceanic crust is one of Earth'  s last biological frontiers as it is difficult to access. It is challenging for microbiota that live in marine subsurface sediments or igneous basement to obtain sufficient carbon resources and energy to support growth(1-3) or to meet basal power requirements(4) during periods of resource scarcity. Here we show how limited and unpredictable sources of carbon and energy dictate survival strategies used by low-biomass microbial communities that live 10-750 m below the seafloor at Atlantis Bank, Indian Ocean, where Earth'  s lower crust is exposed at the seafloor. Assays of enzyme activities, lipid biomarkers, marker genes and microscopy indicate heterogeneously distributed and viable biomass with ultralow cell densities (fewer than 2,000 cells per cm(3)). Expression of genes involved in unexpected heterotrophic processes includes those with a role in the degradation of polyaromatic hydrocarbons, use of polyhydroxyalkanoates as carbon-storage molecules and recycling of amino acids to produce compounds that can participate in redox reactions and energy production. Our study provides insights into how microorganisms in the plutonic crust are able to survive within fractures or porous substrates by coupling sources of energy to organic and inorganic carbon resources that are probably delivered through the circulation of subseafloor fluids or seawater.


  
A lysosomal switch triggers proteostasis renewal in the immortal C. elegans germ lineage (vol 551, pg 629, 2017) 期刊论文
NATURE, 2020, 580 (7802) : E5-E5
作者:  Lu, Zhihao;  Zou, Jianling;  Li, Shuang;  Topper, Michael J.;  Tao, Yong;  Zhang, Hao;  Jiao, Xi;  Xie, Wenbing;  Kong, Xiangqian;  Vaz, Michelle;  Li, Huili;  Cai, Yi;  Xia, Limin;  Huang, Peng;  Rodgers, Kristen;  Lee, Beverly;  Riemer, Joanne B.;  Day, Chi-Ping;  Yen, Ray-Whay Chiu;  Cui, Ying;  Wang, Yujiao;  Wang, Yanni;  Zhang, Weiqiang;  Easwaran, Hariharan;  Hulbert, Alicia;  Kim, KiBem;  Juergens, Rosalyn A.;  Yang, Stephen C.;  Battafarano, Richard J.;  Bush, Errol L.;  Broderick, Stephen R.;  Cattaneo, Stephen M.;  Brahmer, Julie R.;  Rudin, Charles M.;  Wrangle, John;  Mei, Yuping;  Kim, Young J.;  Zhang, Bin;  Wang, Ken Kang-Hsin;  Forde, Patrick M.;  Margolick, Joseph B.;  Nelkin, Barry D.;  Zahnow, Cynthia A.;  Pardoll, Drew M.;  Housseau, Franck;  Baylin, Stephen B.;  Shen, Lin;  Brock, Malcolm V.
收藏  |  浏览/下载:26/0  |  提交时间:2020/07/03
Nightside condensation of iron in an ultrahot giant exoplanet 期刊论文
NATURE, 2020, 580 (7805) : 597-+
作者:  Lu, Zhihao;  Zou, Jianling;  Li, Shuang;  Topper, Michael J.;  Tao, Yong;  Zhang, Hao;  Jiao, Xi;  Xie, Wenbing;  Kong, Xiangqian;  Vaz, Michelle;  Li, Huili;  Cai, Yi;  Xia, Limin;  Huang, Peng;  Rodgers, Kristen;  Lee, Beverly;  Riemer, Joanne B.;  Day, Chi-Ping;  Yen, Ray-Whay Chiu;  Cui, Ying;  Wang, Yujiao;  Wang, Yanni;  Zhang, Weiqiang;  Easwaran, Hariharan;  Hulbert, Alicia;  Kim, KiBem;  Juergens, Rosalyn A.;  Yang, Stephen C.;  Battafarano, Richard J.;  Bush, Errol L.;  Broderick, Stephen R.;  Cattaneo, Stephen M.;  Brahmer, Julie R.;  Rudin, Charles M.;  Wrangle, John;  Mei, Yuping;  Kim, Young J.;  Zhang, Bin;  Wang, Ken Kang-Hsin;  Forde, Patrick M.;  Margolick, Joseph B.;  Nelkin, Barry D.;  Zahnow, Cynthia A.;  Pardoll, Drew M.;  Housseau, Franck;  Baylin, Stephen B.;  Shen, Lin;  Brock, Malcolm V.
收藏  |  浏览/下载:57/0  |  提交时间:2020/07/03

Ultrahot giant exoplanets receive thousands of times Earth'  s insolation(1,2). Their high-temperature atmospheres (greater than 2,000 kelvin) are ideal laboratories for studying extreme planetary climates and chemistry(3-5). Daysides are predicted to be cloud-free, dominated by atomic species(6) and much hotter than nightsides(5,7,8). Atoms are expected to recombine into molecules over the nightside(9), resulting in different day and night chemistries. Although metallic elements and a large temperature contrast have been observed(10-14), no chemical gradient has been measured across the surface of such an exoplanet. Different atmospheric chemistry between the day-to-night ('  evening'  ) and night-to-day ('  morning'  ) terminators could, however, be revealed as an asymmetric absorption signature during transit(4,7,15). Here we report the detection of an asymmetric atmospheric signature in the ultrahot exoplanet WASP-76b. We spectrally and temporally resolve this signature using a combination of high-dispersion spectroscopy with a large photon-collecting area. The absorption signal, attributed to neutral iron, is blueshifted by -11 +/- 0.7 kilometres per second on the trailing limb, which can be explained by a combination of planetary rotation and wind blowing from the hot dayside(16). In contrast, no signal arises from the nightside close to the morning terminator, showing that atomic iron is not absorbing starlight there. We conclude that iron must therefore condense during its journey across the nightside.


Absorption lines of iron in the dayside atmosphere of an ultrahot giant exoplanet disappear after travelling across the nightside, showing that the iron has condensed during its travel.


  
Reply to: Why fossil fuel producer subsidies matter 期刊论文
NATURE, 2020, 578 (7793) : E5-E7
作者:  Wang, Peng;  Zheng, Yuanlin;  Chen, Xianfeng;  Huang, Changming;  Kartashov, Yaroslav V.;  Torner, Lluis;  Konotop, Vladimir V.;  Ye, Fangwei
收藏  |  浏览/下载:24/0  |  提交时间:2020/05/13
A self-activating orphan receptor 期刊论文
NATURE, 2020, 579 (7797) : 35-35
作者:  Wang, Lin;  Wu, Juehui;  Li, Jun;  Yang, Hua;  Tang, Tianqi;  Liang, Haijiao;  Zuo, Mianyong;  Wang, Jie;  Liu, Haipeng;  Liu, Feng;  Chen, Jianxia;  Liu, Zhonghua;  Wang, Yang;  Peng, Cheng;  Wu, Xiangyang;  Zheng, Ruijuan;  Huang, Xiaochen;  Ran, Yajun;  Rao, Zihe;  Ge, Baoxue
收藏  |  浏览/下载:10/0  |  提交时间:2020/07/03

The first 3D structure of a full-length G-protein-coupled receptor whose natural activator is unknown has been determined, providing insights into an unusual mode of activation and a basis for discovering therapeutics.


  
China takes centre stage in global biodiversity push 期刊论文
NATURE, 2020, 578 (7795) : 345-346
作者:  Wang, Lin;  Wu, Juehui;  Li, Jun;  Yang, Hua;  Tang, Tianqi;  Liang, Haijiao;  Zuo, Mianyong;  Wang, Jie;  Liu, Haipeng;  Liu, Feng;  Chen, Jianxia;  Liu, Zhonghua;  Wang, Yang;  Peng, Cheng;  Wu, Xiangyang;  Zheng, Ruijuan;  Huang, Xiaochen;  Ran, Yajun;  Rao, Zihe;  Ge, Baoxue
收藏  |  浏览/下载:15/0  |  提交时间:2020/07/03

A major United Nations summit could see China push for ambitious targets and spotlights the country'  s own conservation efforts.


A major United Nations summit could see China push for ambitious targets and spotlights the country'  s own conservation efforts.