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molybdenite Re-Os,titanite and garnet U-Pb dating of the magushan skarn Cu-mo deposit,Xuancheng district,middle-Lower Yangtze River metallogenic Belt

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Geoscience Frontiers 2021年第3期12卷 399-415页

作者： Yue Li Feng Yuan simon m.Jowitt Fangyue Wang Xiangling Li Yufeng Deng Yunyue Wang Taofa Zhou School of Resources and Environmental Engineering Hefei University of TechnologyHefei 23009China Anhui Province Engineering Research Center for mineral Resources and mine Environments Hefei University of TechnologyHefei 23009China Department of Geoscience University of Nevada Las Vegas4505 S.Maryland Pkwy.NV 89154-4010USA

The magushan skarn Cu-mo deposit is a representative example of the skarn mineralization occurring within the Xuancheng ore district of the middle-Lower Yangtze River metallogenic Belt of eastern *** precise age of an ore deposit is important for understanding the timing of mineralization relative to other geological events in a region and to fully place the formation of a mineral deposit within the geological context of other processes that occur within the study ***,we present new molybdenite Re-Os and titanite and andradite garnet U-Pb ages for the magushan deposit and use these data to outline possible approaches for identifying genetic relationships in geologically complex *** spatial and paragenetic relationships between the intrusions,alteration,and mineralization within the study area indicates that the formation of the magushan deposit is genetically associated with the porphyritic ***,this is not always the case,as some areas contain complexly zoned plutons with multiple phases of intrusion or mineralization may be distal from or may not have any clear spatial relationship to a *** means that it may not be possible to determine whether the mineralization formed as a result of single or multiple magmatic/hydrothermal *** such,the approaches presented in this study provide an approach that allows the identification of any geochronological relationships between mineralization and intrusive events in areas more complex than the study *** published zircon U-Pb data for the mineralization-related porphyritic granodiorite in this area yielded an age of 134.2±1.2 ma(mSWD=1.4)whereas the Re-Os dating of molybdenite from the study area yielded an isochron age of 137.7±2.5 ma(mSWD=0.43).The timing of the mineralizing event in the study area was further examined by the dating of magmatic accessory titanite and skarn-related andradite garnet,yielding U-Pb ages of 136.3±2.5 ma(mSWD=3.2)and 135.9±2.7 ma(mSWD=2.

关键词： magushan skarn deposit molybdenite Re-Os dating Titanite U-Pb dating Garnet U-Pb dating Xuancheng ore district middle-Lower Yangtze River metallogenic Belt

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Tritrophic interactions between parasitoids and cereal aphids are mediated by nitrogen fertilizer

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Insect Science 2015年第6期22卷 813-820页

作者： muhammad A. Aqueel Abu-bakar m. Raza Rashad m. Balal muhammad A. Shahid Irfan mustafa muhammad m. Javaid simon R. Leather Division of Biology Imperial College London Silwood Park Campus Ascot SL5 7PY UK University College of Agriculture Department of Biological Sciences University of Sargodha Pakistan Department of Crop and Environment Sciences Harper Adams UniversityShropshire TFIO 8NB UK

Host plant nutritional quality can directly and indirectly affect the third trophic levels. The aphid-parasitoid relationship provides an ideal system to investigate tritrophic interactions （as the parasitoids are completely dependent for their development upon their hosts） and assess the bottom up forces operating at different concentrations of nitrogen applications. The effects of varying nitrogen fertilizer on the performance of Aphidius colemani （V.） reared on Sitobion avenae （E） and Aphidius rhopalosiphi （D.） reared on Rhopalosiphum padi （L.） were measured. Parasitism and percent emergence ofparasitoids were positively affected by nitrogen fertilizer treatments while developmental duration （egg, larval, and pupal stages） was not affected by increasing nitrogen inputs. In males and females of both parasitoid species, adult longevity increased with the increasing nitrogen fertilizer. Hind tibia length and mummy weight of both parasitoid species increased with nitrogen fertilizer concentrations, as a result of larger aphids. This study showed that nitrogen application to the soil can have important consequences for aboveground multitrophic interactions.

关键词： cereal aphid parasitoids nitrogen fertilization tritrophic interactions

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The generation and evolution of the Archean continental crust:The granitoid story in southeastern Brazil

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Geoscience Frontiers 2022年第4期13卷 144-164页

作者： Rodrigo S.marimon Chris J.Hawkesworth Elton L.Dantas Rudolph A.J.Trouw Wilson Teixeira Peter C.Hackspacher Allen Fetter Ciro A.Ávila Silvia Volante Atlas V.Corrêa Neto Everton m.Bongiolo Rodrigo Vinagre maurício simon Depto.de Geologia IGEOUniversidade Federal do Rio de JaneiroUFRJRio de JaneiroRJBrazil School of Earth Sciences University of BristolBristolUnited Kingdom Instituto de Geociências Universidade de BrasíliaUnBBrasíliaDFBrazil Instituto de Geociências Universidade de São PauloUSPSão PauloSPBrazil Instituto de Geociências e Ciências Exatas Universidade Estadual PaulistaRio ClaroSPBrazil Institute of Geology Mineralogy and GeophysicsRuhr-Universität BochumUniversitätsstraße 15044801 BochumGermany ISOTOPIA Lab School of EarthAtmosphere and EnvironmentMonash UniversityWellington RdClaytonVIC 3800Australia Programa de Pós-Graduação em Geociências IGUniversidade Federal do Rio Grande do SulUFRGSPorto AlegreRSBrazil

The Archean Eon was a time of geodynamic *** evidence of these transitions come from igneous/metaigneous rocks,which dominate cratonic segments *** data for granitoids from an Archean basement inlier related to the Southern S?o Francisco Craton(SSFC),are integrated with geochronological,isotopic and geochemical data on Archean granitoids from the *** rocks are divided into three main geochemical groups with different ages:(1)TTG(3.02–2.77 Ga);(2)mediumto high-K granitoids(2.85–2.72 Ga);and(3)A-type granites(2.7–2.6 Ga).The juvenile to chondritic(Hf-Nd isotopes)TTG were divided into two sub-groups,TTG 1(low-HREE)and 2(high-HREE),derived from partial melting of metamafic rocks similar to those from adjacent greenstone *** compositional diversity within the TTG is attributed to different pressures during partial melting,supported by a positive correlation of Dy/Yb and Sr/Zr,and batch melting *** proposed TTG sources are geochemically similar to basaltic rocks from modern island-arcs,indicating the presence of subduction processes concomitant with TTG ***~2.85 Ga to 2.70 Ga,the dominant rocks were K-rich *** are modeled as crustal melts of TTG,during regional metamorphism indicative of crustal *** compositional diversity is linked to:(i)differences in source composition;(ii)distinct melt fractions during partial melting;and(iii)different residual mineralogies reflecting varying P–T ***-collisional(~2.7–2.6 Ga)A-type granites reflect rifting in that they were closely followed by extension-related dyke swarms,and they are interpreted as differentiation or partial melting products of magmas derived from subduction-modified *** sequence of granitoid emplacement indicates subduction-related magmatism was followed by crustal thickening,regional metamorphism and crustal melting,and post-collisional extension,similar to that seen in younger Wilson *** is compelling evide

关键词： Granitoid petrogenesis Archean geodynamics Crustal evolution TTGs A-types Batch melting calculations

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On-the-fly active learning of interpretable Bayesian force fields for atomistic rare events

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npj Computational materials 2020年第1期6卷 1502-1512页

作者： Jonathan Vandermause Steven B.Torrisi simon Batzner Yu Xie Lixin Sun Alexie m.Kolpak Boris Kozinsky Department of Physics Harvard UniversityCambridgeMA 02138USA John A.Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeMA 02138USA Center for Computational Engineering Massachusetts Institute of TechnologyCambridgeMA 02139USA Department of mechanical Engineering Massachusetts Institute of TechnologyCambridgeMA 02139USA Bosch Research CambridgeMA 02139USA

machine learned force fields typically require manual construction of training sets consisting of thousands of first principles calculations,which can result in low training efficiency and unpredictable errors when applied to structures not represented in the training set of the *** severely limits the practical application of these models in systems with dynamics governed by important rare events,such as chemical reactions and *** present an adaptive Bayesian inference method for automating the training of interpretable,low-dimensional,and multi-element interatomic force fields using structures drawn on the fly from molecular dynamics *** an active learning framework,the internal uncertainty of a Gaussian process regression model is used to decide whether to accept the model prediction or to perform a first principles calculation to augment the training set of the *** method is applied to a range of single-and multi-element systems and shown to achieve a favorable balance of accuracy and computational efficiency,while requiring a minimal amount of ab initio training *** provide a fully opensource implementation of our method,as well as a procedure to map trained models to computationally efficient tabulated force fields.

关键词： fields element typically

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Alignment between galaxies and large-scale structure

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Chinese Journal of Astronomy and Astrophysics 2009年第1期9卷 41-58页

作者： A. Faltenbacher Cheng Li simon D. m. White Yi-Peng Jing Shu-De mao Jie Wang max-Planck-Institute for Astrophysics Karl-Schwarzschild-Str. 1 D-85741 Garching Germany mPA/SHAO Joint Center for Astrophysical Cosmology at Shanghai Astronomical Observatory Shanghai 200030 China Jodrell Bank Centre for Astrophysl＇cs Alan Turing Building The University of Manchester Manchester M13 9PL UK Department of Physics Institute of Computational Cosmology University of Durham Science Laboratories South Road Durham DH1 3LE UK

Based on the Sloan Digital Sky Survey DR6 （SDSS） and the ＇millennium Simulation （mS）, we investigate the alignment between galaxies and large-scale structure. For this purpose, we develop two new statistical tools, namely the alignment correlation function and the cos（20）-statistic. The former is a two-dimensional extension of the traditional two-point correlation function and the latter is related to the ellipticity correlation function used for cosmic shear measurements. Both are based on the cross correlation between a sample of galaxies with orientations and a reference sample which represents the large-scale structure. We apply the new statistics to the SDSS galaxy catalog. The alignment correlation function reveals an overabundance of reference galaxies along the major axes of red, luminous （L 〉～L＊） galaxies out to projected separations of 60 h-lmpc. The signal increases with central galaxy luminosity. No alignment signal is detected for blue galaxies. The cos（2θ）-statistic yields very similar results. Starting from a mS semi-analytic galaxy catalog, we assign an orientation to each red, luminous and central galaxy, based on that of the central region of the host halo （with size similar to that of the stellar galaxy）. As an alternative, we use the orientation of the host halo itself. We find a mean projected misalignment between a halo and its central region of -25°. The misalignment decreases slightly with increasing luminosity of the central galaxy. Using the orientations and luminosities of the semi-analytic galaxies, we repeat our alignment analysis on mock surveys of the mS. Agreement with the SDSS results is good if the central orientations are used. Predictions using the halo orientations as proxies for cen- tral galaxy orientations overestimate the observed alignment by more than a factor of 2. Finally, the large volume of the mS allows us to generate a two-dimensional map of the alignment correlation function, which shows the reference galaxy distrib

关键词： dark matter halos clustering-galaxies large-scale structure of Universe- cosmology theory -dark matter

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