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国际研究称二叠纪乙烷排放量至少占全球化石源乙烷的4% 快报文章
气候变化快报,2024年第18期
作者:  董利苹
Microsoft Word(14Kb)  |  收藏  |  浏览/下载:404/0  |  提交时间:2024/09/19
Space-based Observations  Tropospheric  Ethane Map Emissions from Fossil Fuel Extraction  
UNECE发布新版《可持续发展目标统计路线图》 快报文章
资源环境快报,2022年第04期
作者:  牛艺博
Microsoft Word(21Kb)  |  收藏  |  浏览/下载:768/0  |  提交时间:2022/03/01
UNECE  Sustainable Development  Statistics  Road Map  
研究绘制21世纪森林碳通量的全球地图 快报文章
气候变化快报,2021年第3期
作者:  裴惠娟
Microsoft Word(13Kb)  |  收藏  |  浏览/下载:529/0  |  提交时间:2021/02/05
Forest  Carbon Fluxes  Map  
科学家提出改进印度洋环境观测系统的路线图 快报文章
地球科学快报,2021年第2期
作者:  王立伟
Microsoft Word(17Kb)  |  收藏  |  浏览/下载:474/3  |  提交时间:2021/01/25
IndOOS  Road Map  
英国海洋科学促进海洋生产力与可持续海洋路线图摘要 快报文章
资源环境快报,2020年第17期
作者:  薛明媚,吴秀平
Microsoft Word(13Kb)  |  收藏  |  浏览/下载:381/1  |  提交时间:2020/09/15
UK  Marine Science  Road Map  
Contribution of Changes in Synoptic-Scale Circulation Patterns to the Past Summer Precipitation Regime Shift in Eastern China 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (12)
作者:  Zhou, Baiquan;  Zhai, Panmao;  Chen, Yang
收藏  |  浏览/下载:24/0  |  提交时间:2020/05/25
circulation pattern  dynamic and thermodynamic contributions  southern flood-northern drought  self-organizing map  
Physics-Informed Deep Neural Networks for Learning Parameters and Constitutive Relationships in Subsurface Flow Problems 期刊论文
WATER RESOURCES RESEARCH, 2020, 56 (5)
作者:  Tartakovsky, A. M.;  Marrero, C. Ortiz;  Perdikaris, Paris;  Tartakovsky, G. D.;  Barajas-Solano, D.
收藏  |  浏览/下载:30/0  |  提交时间:2020/07/02
deep neural networks  physics-informed machine learning  parameter estimation  learning constitutive relationships  unsaturated flow  MAP  
A map of object space in primate inferotemporal cortex 期刊论文
NATURE, 2020, 583 (7814) : 103-+
作者:  Wu, Huihui;  Li, Bosheng;  Iwakawa, Hiro-oki;  Pan, Yajie;  Tang, Xianli;  Ling-hu, Qianyan;  Liu, Yuelin;  Sheng, Shixin;  Feng, Li;  Zhang, Hong;  Zhang, Xinyan;  Tang, Zhonghua;  Xia, Xinli;  Zhai, Jixian;  Guo, Hongwei
收藏  |  浏览/下载:69/0  |  提交时间:2020/07/03

Primate inferotemporal cortex contains a coarse map of object space consisting of four networks, identified using functional imaging, electrophysiology and deep networks.


The inferotemporal (IT) cortex is responsible for object recognition, but it is unclear how the representation of visual objects is organized in this part of the brain. Areas that are selective for categories such as faces, bodies, and scenes have been found(1-5), but large parts of IT cortex lack any known specialization, raising the question of what general principle governs IT organization. Here we used functional MRI, microstimulation, electrophysiology, and deep networks to investigate the organization of macaque IT cortex. We built a low-dimensional object space to describe general objects using a feedforward deep neural network trained on object classification(6). Responses of IT cells to a large set of objects revealed that single IT cells project incoming objects onto specific axes of this space. Anatomically, cells were clustered into four networks according to the first two components of their preferred axes, forming a map of object space. This map was repeated across three hierarchical stages of increasing view invariance, and cells that comprised these maps collectively harboured sufficient coding capacity to approximately reconstruct objects. These results provide a unified picture of IT organization in which category-selective regions are part of a coarse map of object space whose dimensions can be extracted from a deep network.


  
Molecular basis of beta-arrestin coupling to formoterol-bound beta(1)-adrenoceptor 期刊论文
NATURE, 2020
作者:  Pulliainen, Jouni;  Luojus, Kari;  Derksen, Chris;  Mudryk, Lawrence;  Lemmetyinen, Juha;  Salminen, Miia;  Ikonen, Jaakko;  Takala, Matias;  Cohen, Juval;  Smolander, Tuomo;  Norberg, Johannes
收藏  |  浏览/下载:37/0  |  提交时间:2020/07/03

The beta(1)-adrenoceptor (beta(1)AR) is a G-protein-coupled receptor (GPCR) that couples(1)to the heterotrimeric G protein G(s). G-protein-mediated signalling is terminated by phosphorylation of the C terminus of the receptor by GPCR kinases (GRKs) and by coupling of beta-arrestin 1 (beta arr1, also known as arrestin 2), which displaces G(s)and induces signalling through the MAP kinase pathway(2). The ability of synthetic agonists to induce signalling preferentially through either G proteins or arrestins-known as biased agonism(3)-is important in drug development, because the therapeutic effect may arise from only one signalling cascade, whereas the other pathway may mediate undesirable side effects(4). To understand the molecular basis for arrestin coupling, here we determined the cryo-electron microscopy structure of the beta(1)AR-beta arr1 complex in lipid nanodiscs bound to the biased agonist formoterol(5), and the crystal structure of formoterol-bound beta(1)AR coupled to the G-protein-mimetic nanobody(6)Nb80. beta arr1 couples to beta(1)AR in a manner distinct to that(7)of G(s)coupling to beta(2)AR-the finger loop of beta arr1 occupies a narrower cleft on the intracellular surface, and is closer to transmembrane helix H7 of the receptor when compared with the C-terminal alpha 5 helix of G(s). The conformation of the finger loop in beta arr1 is different from that adopted by the finger loop of visual arrestin when it couples to rhodopsin(8). beta(1)AR coupled to beta arr1 shows considerable differences in structure compared with beta(1)AR coupled to Nb80, including an inward movement of extracellular loop 3 and the cytoplasmic ends of H5 and H6. We observe weakened interactions between formoterol and two serine residues in H5 at the orthosteric binding site of beta(1)AR, and find that formoterol has a lower affinity for the beta(1)AR-beta arr1 complex than for the beta(1)AR-G(s)complex. The structural differences between these complexes of beta(1)AR provide a foundation for the design of small molecules that could bias signalling in the beta-adrenoceptors.


A cryo-electron microscopy structure of the beta 1-adrenoceptor coupled to beta-arrestin 1 and activated by the biased agonist formoterol, as well as the crystal structure of a related formoterol-bound adrenoreceptor, provide insights into biased signalling in these systems.


  
Mapping the twist-angle disorder and Landau levels in magic-angle graphene 期刊论文
NATURE, 2020, 581 (7806) : 47-+
作者:  Luck, Katja;  39;Amata, Cassandra
收藏  |  浏览/下载:20/0  |  提交时间:2020/07/03

The recently discovered flat electronic bands and strongly correlated and superconducting phases in magic-angle twisted bilayer graphene (MATBG)(1,2) crucially depend on the interlayer twist angle, theta. Although control of the global theta with a precision of about 0.1 degrees has been demonstrated(1-7), little information is available on the distribution of the local twist angles. Here we use a nanoscale on-tip scanning superconducting quantum interference device (SQUID-on-tip)(8) to obtain tomographic images of the Landau levels in the quantum Hall state(9) and to map the local theta variations in hexagonal boron nitride (hBN)-encapsulated MATBG devices with relative precision better than 0.002 degrees and a spatial resolution of a few moire periods. We find a correlation between the degree of theta disorder and the quality of the MATBG transport characteristics and show that even state-of-the-art devices-which exhibit correlated states, Landau fans and superconductivity-display considerable local variation in theta of up to 0.1 degrees, exhibiting substantial gradients and networks of jumps, and may contain areas with no local MATBG behaviour. We observe that the correlated states in MATBG are particularly fragile with respect to the twist-angle disorder. We also show that the gradients of theta generate large gate-tunable in-plane electric fields, unscreened even in the metallic regions, which profoundly alter the quantum Hall state by forming edge channels in the bulk of the sample and may affect the phase diagram of the correlated and superconducting states. We thus establish the importance of theta disorder as an unconventional type of disorder enabling the use of twist-angle gradients for bandstructure engineering, for realization of correlated phenomena and for gate-tunable built-in planar electric fields for device applications.


SQUID-on-tip tomographic imaging of Landau levels in magic-angle graphene provides nanoscale maps of local twist-angle disorder and shows that its properties are fundamentally different from common types of disorder.