359 research outputs found

    Scientific Drilling

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    The South China Sea is not a mini-Atlantic: plate-edge rifting vs intra-plate rifting

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    © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Wang, P., Huang, C., Lin, J., Jian, Z., Sun, Z., & Zhao, M. The South China Sea is not a mini-Atlantic: plate-edge rifting vs intra-plate rifting. National Science Review, 6(5), (2019): 902-913, doi:10.1093/nsr/nwz135.The South China Sea, as ‘a non-volcanic passive margin basin’ in the Pacific, has often been considered as a small-scale analogue of the Atlantic. The recent ocean drilling in the northern South China Sea margin found, however, that the Iberian model of non-volcanic rifted margin from the Atlantic does not apply to the South China Sea. In this paper, we review a variety of rifted basins and propose to discriminate two types of rifting basins: plate-edge type such as the South China Sea and intra-plate type like the Atlantic. They not only differ from each other in structure, formation process, lifespan and geographic size, but also occur at different stages of the Wilson cycle. The intra-plate rifting occurred in the Mesozoic and gave rise to large oceans, whereas the plate-edge rifting took place mainly in the mid-Cenozoic, with three-quarters of the basins concentrated in the Western Pacific. As a member of the Western Pacific system of marginal seas, the South China Sea should be studied not in isolation on its origin and evolution, but in a systematic context to include also its neighboring counterparts.This work was supported by the National Natural Science Foundation of China as a part of the ‘South China Sea Deep’ Project (91128000)

    \u3cem\u3eIn Situ\u3c/em\u3e Activated Co\u3csub\u3e3–x\u3c/sub\u3eNi\u3csub\u3ex\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e as a Highly Active and Ultrastable Electrocatalyst for Hydrogen Generation

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    The spinel Co3O4 has emerged as a promising alternative to noble-metal-based electrocatalysts for electrochemical water electrolysis in alkaline medium. However, pure Co3O4, despite having high activity in anodic water oxidation, remains inactive toward the hydrogen evolution reaction (HER). Here, a Ni-doped Co3O4(Co3–xNixO4) prepared by a simple method exhibits favorable HER activity and stability (\u3e300 h, whether in 1 M KOH or the realistic 30 wt % KOH solution) after in situ electrochemical activation, outperforming almost all of the oxide-based electrocatalysts. More importantly, using the combination of in situ Raman spectroscopy and multiple high-resolution electron microscopy techniques, it is identified that the surface of Co3–xNixO4 crystals is reduced into intertwined CoyNi1–yO nanoparticles with highly exposed {110} reactive planes. Density functional theory calculations further prove that the Ni-doped CoO component in CoyNi1–yO plays a major role during the alkaline HER, because the introduction of Ni atoms into Co–O octahedra can optimize the electrical conductivity and tailor the adsorption/desorption free energies of Had and OHad intermediates

    Simulation of long eccentricity (400-kyr) cycle in ocean carbon reservoir during Miocene Climate Optimum: Weathering and nutrient response to orbital change

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    Deep-sea foraminiferal ÎŽ13C records contain abundant 400-kyr cycles indicating a link between eccentricity forcing and ocean carbon reservoir change. Here we simulate the oceanic ÎŽ13C maxima events forced by the Earth's orbital geometry during the Miocene Climate Optimum (MCO, 17-14 Ma) using a box model. The simulated results of both surface and deep water ÎŽ13C display co-varying 400-kyr cycle. Modulated by orbital parameters, weathering induced carbon input will change the burial ratio of carbonates to organic carbon and further result in periodic changes in the oceanic ÎŽ13C. The increase of riverine nutrient input, which is synchronous with riverine carbon input, often stimulates primary productivity and burial of organic carbon. Our results support that eccentricity maxima (minima) enhance (reduce) weathering intensity and nutrient supply, which lead to minima (maxima) of ÎŽ13C. The prominent 400-kyr cycle of ocean carbon reservoir is interpreted as likely caused by a long memory of carbon in the ocean.Wentao Ma, Jun Tian, Qianyu Li and Pinxian Wan

    South China Sea surface water evolution over the last 12 Myr: A south-north comparison from Ocean Drilling Program Sites 1143 and 1146

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    Planktonic foraminifera (PF) from Ocean Drilling Program (ODP) Sites 1143 and 1146 in the southern and northern South China Sea (SCS), respectively, were quantitatively analyzed in order to reconstruct the sea-surface environment over the last 12 Myr. The observed decrease in deep-dwelling PF species after ∌10 Ma at both sites is interpreted to reflect a depression of the upper water thermocline, corresponding to the closure of the Indonesian Seaway around 11-9 Ma. This upper water column structure implies the intensification of equatorial Pacific warm currents and the initial formation of the western Pacific "warm pool" (WPWP) during the early Late Miocene. The consistent pattern of south-north thermocline evolution and the synchronous disappearance of Globoquadrina dehiscens (9.8 Ma) at both Sites 1143 and 1146 together imply that the entire SCS was likely under the influence of the newly developed WPWP at ∌10 Ma. After ∌8 Ma, sea-surface temperatures and thermocline variations evolved differently between the southern and northern SCS. The total deep-dwelling PF fauna at Site 1143 decreased gradually in abundance from 6.6 to 2 Ma, indicating a deepening of the thermocline in the southern SCS. In contrast, deep-dwelling PF species increased in abundance from 3.1 to 2 Ma at Site 1146, reflecting a shoaling of the thermocline in the northern SCS. This south-north contrast reflects two major environmental regimes: (1) the southern SCS, which has mainly been under the influence of the WPWP since the late Late Miocene, and (2) the northern SCS, where effects of the east Asian winter monsoon have prevailed, especially since the Late Pliocene. Estimate of past sea-surface temperatures (SSTs) at Site 1143 suggests a relatively stable and warm environment in the southern SCS since about 2.5 Ma, with an increased influence of warm subsurface waters after the mid-Pleistocene transition (1.2-0.9 Ma). In the northern SCS, however, a gradual decrease in winter SST recorded at Site 1146 over the last 4 Myr records east Asian monsoon evolution, especially the enhancement of the east Asian winter monsoon between 3.1 and 2 Ma. Copyright 2004 by the American Geophysical Union.Baohua Li, Jiliang Wang, Baoqi Huang, Qianyu Li, Zhimin Jian, Quanhong Zhao, Xin Su and Pinxian Wan

    Resource: A multi‐species multi‐timepoint transcriptome database and webpage for the pineal gland and retina

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    The website and database https://snengs.nichd.nih.gov provides RNA sequencing data from multi-species analysis of the pineal glands from zebrafish (Danio rerio), chicken (White Leghorn), rat (Rattus novegicus), mouse (Mus musculus), rhesus macaque (Macaca mulatta), and human (Homo sapiens); in most cases, retinal data are also included along with results of the analysis of a mixture of RNA from tissues. Studies cover day and night conditions; in addition, a time series over multiple hours, a developmental time series and pharmacological experiments on rats are included. The data have been uniformly re-processed using the latest methods and assemblies to allow for comparisons between experiments and to reduce processing differences. The website presents search functionality, graphical representations, Excel tables, and track hubs of all data for detailed visualization in the UCSC Genome Browser. As more data are collected from investigators and improved genomes become available in the future, the website will be updated. This database is in the public domain and elements can be reproduced by citing the URL and this report. This effort makes the results of 21st century transcriptome profiling widely available in a user-friendly format that is expected to broadly influence pineal research.Fil: Chang, Eric. National Instituto of Child Health & Human Development; Estados UnidosFil: Fu, Cong. National Instituto of Child Health & Human Development; Estados UnidosFil: Coon, Steven L.. National Instituto of Child Health & Human Development; Estados UnidosFil: Alon, Shahar. No especifĂ­ca;Fil: Bozinoski, Marjan. No especifĂ­ca;Fil: Breymaier, Matthew. National Instituto of Child Health & Human Development; Estados UnidosFil: Bustos, Diego Martin. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias MĂ©dicas. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Clokie, Samuel J.. National Instituto of Child Health & Human Development; Estados UnidosFil: Gothilf, Yoav. No especifĂ­ca;Fil: Esnault, Caroline. National Instituto of Child Health & Human Development; Estados UnidosFil: Iuvone, P. Michael. Emory University School of Medicine; Estados UnidosFil: Mason, Christopher E.. No especifĂ­ca;Fil: Ochocinska, Margaret J.. National Instituto of Child Health & Human Development; Estados UnidosFil: Tovin, Adi. No especifĂ­ca;Fil: Wang, Charles. Loma Linda University; Estados UnidosFil: Xu, Pinxian. No especifĂ­ca;Fil: Zhu, Jinhang. No especifĂ­ca;Fil: Dale, Ryan. National Instituto of Child Health & Human Development; Estados UnidosFil: Klein, David C.. National Instituto of Child Health & Human Development; Estados Unido
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