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Microstructures,Deformation Mechanisms and Seismic Properties of Synkinematic Migmatite from Southeastern Tibet:Insights from the Migmatitic Core of the Ailao Shan-Red River Shear Zone,Western Yunnan,China

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Journal of earth Science 2024年第4期35卷 1149-1169页

作者： Weiwei Ma Bo Zhang Fulong Cai Baoyou Huang Lei Zhang Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking UniversityBeijing100871China institute of Tibetan Plateau research Chinese Academy of SciencesBeijing100085China

Seismic anisotropy originating within the continental crust is commonly used to determine the deformation and kinematic flow within active orogens and is attributed to regionally oriented mica or hornblende ***,naturally deformed rocks usually contain compositional layers(e.g.,parallel compositional banding).It is necessary to understand how both varying mineral contents and differing intensities of compositional layering influence the seismic properties of the deep *** this study,we analyzed the seismic response of migmatitic amphibolite with compositional banding *** present the microstructures,fabrics,calculated seismic velocities,and seismic anisotropies of mylonitic amphibolite from a horizontal shear layer preserved within the Ailao Shan-Red River shear zone,southwestern Yunnan,*** investigated sample is characterized by pronounced centimeter-scale compositional *** microstructures and fabrics suggest that migmatitic amphibolite rocks within deep crust may delineate regions of deformation-assisted,channelized,reactive,porous melt *** origin of compositional banding in the studied migmatitic amphibolite is attributed primarily to partial melting together with some horizontal shearing *** microfabrics and structures investigated in this study are considered to be typical for the base of active horizontal shear layers in the deep crust of southeastern *** responses are modeled by using crystal preferred orientations for minerals of the migmatitic amphibolite by applying the Voigt-Reuss-Hill homogenization *** P-wave and S-wave velocities are largely consistent in the various layers of the ***,seismic anisotropies of P-wave(AV_(p))and S-wave(AVs)are higher in the melanosomes(AV_(p)=5.6%,AV_(s)=6.83%)than those in the leucosomes and the whole rock(AV_(p)=4.2%–4.6%,AV_(s)=3.1%–3.2%).In addition,there is pronounced,S-wave splitting oblique to the foliation plane in the migm

关键词： deformation-assisted melt flow seismic anisotropy microstructure compositional banding migmatite deep crust southeastern Tibet

Norian(Late Triassic) conodonts from the Raohe area， Heilongjiang， Northeastern China

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Journal of earth Science 2024年

作者： Xianlang Wu Paul B.Wignall Xulong Lai Yan Chen Jinling Yuan Guiyue Luo Haishui Jiang State Key Laboratory of Biogeology and environmental Geology， school of earth sciences， China University of Geosciences school of earth and Environment， University of Leeds Hubei institute of Geosciences

The Raohe area of Heilongjiang Province， Northeast China belongs to the Nadanhada Terrane， which was in low latitudes of Panthalassa during the Triassic. The composition of the Late Triassic conodont fauna， derived from limestone lenses interpreted to be formed on seamounts， provides important new information on the pelagic biota in this ocean. New conodont samples collected from sections at Minzhu， Minnan and Chigangbei belong to three Norian conodont zones. In ascending order， they are: Mockina postera Zone， Mockina bidentata Zone and Parvigondolella andrusovi Zone. The Norian conodont fauna in the Raohe area has distinct attributes: there are a lot of cosmopolitan species (e.g. Mockina postera， Mockina bidentata， Parvigondolella andrusovi) which enable good global correlation; endemic conodont species are also present， (e.g. Mockina sakurae， Mockina shamiseni， Norigondolella nadanhadaensis) indicating that Panthalassa Ocean conodont populations also contains unique taxa; and some conodonts belong to taxa with much shorter ranges in surrounding epeiric seas (e.g. Carnepigondolella pseudoechinata， Neocavitella cavitata and Epigondolella vialovi). The presence of the latter “relicts” indicates that the seamounts were persistently suitable habitats for many millions of years in the Late Triassic.

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In-situ analysis and genetic investigation of Li-bearing minerals in McDermitt clay-type lithium deposit,Nevada,USA

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Acta Geochimica 2024年第3期43卷 478-488页

作者： Yi Cui Hanjie Wen Zhengbing Zhou Kunyue Ling Lin Xu Shirong Liu Fei Xu school of earth sciences East China University of TechnologyNanchang 330013China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China school of earth sciences and Resources Chang’an UniversityXi’an 710054China College of earth and Planetary sciences University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China State Key Laboratory of environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for *** McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted by a clay-rich sequence of smectite-dominated intervals and illite-dominated intervals,***,the occurrence of Li and the genesis of Li-bearing minerals within smectite-dominated intervals have not been thoroughly investigated in previous ***,we studied the mineralogy,the in-situ Li distribution,and the bonding environments of Li within the smectite intervals using a combination of instru-mental techniques including scanning electron microscope,transmission electron microscope,time-of-flight secondary ion mass spectrometry,and nuclear magnetic *** results indicate that the smectite exhibits low crystallinity characteristics of lacustrine clay authigenesis and is com-monly found tofill the interstices among volcanic minerals or envelop them;Li is mainly hosted by Mg-smectite rather than the volcanic *** the tuffaceous sediment samples,the volcanic glass has undergone a transformation,resulting in its complete disappearance and alteration into clay *** to the octahedral sites of Mg-smectite bounded in Li,it is referred to be *** interpret that the hectorite’s precipitation occurs in a high saline-alkaline water environment,a result of McDermitt *** conclusion can be supported by the coexistence of spherulitic calcite and ***,this study confirms hectorite as the main Li-bearing mineral and increases the understanding of the genetic model of hectorite formation in intracontinental caldera basins.

关键词： McDermitt caldera Lithium occurrence Tuffaceous sediments Mineralogy Hectorite neoformation

Numerical evaluations on the fluid production in the in-situ conversion of continental shale oil reservoirs

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Petroleum Science 2024年第04期21卷 2485-2501页

作者： Zhao-Bin Zhang Maryelin Josefina Brice?o Montilla Shou-Ding Li Xiao Li Jian-Peng Xing Yan-Zhi Hu Key Laboratory of Shale Gas and Geoengineering Institute of Geology and Geophysics Chinese Academy of Sciences institute of earth sciences Chinese Academy of Sciences College of earth and Planetary sciences University of Chinese Academy of Sciences institute of Energy Peking University

In-situ conversion presents a promising technique for exploiting continental oil shale formations,characterized by highly fractured organic-rich rock. A 3D in-situ conversion model, which incorporates a discrete fracture network, is developed using a self-developed thermal-flow-chemical(TFC) *** of the model elucidates the in-situ conversion process in three stages and defines the transformation of fluids into three distinct outcomes according to their end stages. The findings indicate that kerogen decomposition increases fluid pressure, activating fractures and subsequently enhancing permeability. A comprehensive analysis of activated fracture permeability and heating power reveals four distinct production modes, highlighting that increasing heating power correlates with higher cumulative fluid production. Activated fractures, with heightened permeability, facilitate the mobility of heavy oil toward production wells but hinder its cracking, thereby limiting light hydrocarbon ***, energy efficiency research demonstrates the feasibility of the in-situ conversion in terms of energy utilization, especially when considering the surplus energy from high-fluctuation energy sources such as wind and solar power to provide heating.

关键词： In-situ conversion Continental shale oil Natural fracture network TFC model

VSAN:A new visualization method for super-large-scale academic networks

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Frontiers of Computer Science 2024年第1期18卷 119-137页

作者： Qi LI Xingli WANG Luoyi FU Xinde CAO Xinbing WANG Jing ZHANG Chenghu ZHOU Department of Electronic Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Computer Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China school of environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China school of oceanography Shanghai Jiao Tong UniversityShanghai 200240China institute of Geographic sciences and Natural Resources research Chinese Academy of SciencesBeijing 100101China

As a carrier of knowledge,papers have been a popular choice since ancient times for documenting everything from major historical events to breakthroughs in science and *** the booming development of science and technology,the number of papers has been growing *** like the fact that Internet of Things(IoT)allows the world to be connected in a flatter way,how will the network formed by massive academic papers look like?Most existing visualization methods can only handle up to hundreds of thousands of node size,which is much smaller than that of academic networks which are usually composed of millions or even more *** this paper,we are thus motivated to break this scale limit and design a new visualization method particularly for super-large-scale academic networks(VSAN).Nodes can represent papers or authors while the edges means the relation(e.g.,citation,coauthorship)between *** order to comprehensively improve the visualization effect,three levels of optimization are taken into account in the whole design of VSAN in a progressive manner,i.e.,bearing scale,loading speed,and effect of layout *** main contributions are two folded:(1)We design an equivalent segmentation layout method that goes beyond the limit encountered by state-of-the-arts,thus ensuring the possibility of visually revealing the correlations of larger-scale academic entities.(2)We further propose a hierarchical slice loading approach that enables users to observe the visualized graphs of the academic network at both macroscopic and microscopic levels,with the ability to quickly zoom between different *** addition,we propose a“jumping between nebula graphs”method that connects the static pages of many academic graphs and helps users to form a more systematic and comprehensive understanding of various academic *** our methods to three academic paper citation datasets in the AceMap database confirms the visualization scalability of VSAN in t

关键词： academic networks large graph visualization graph layout graph loading

Fire resistance evaluation through synthetic fire tests and generative adversarial networks

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 587-614页

作者： Aybike Özyüksel Çiftçioğlu M.Z.Naser Department of Civil Engineering Manisa Celal Bayar University45140Türkiye school of Civil&environmental Engineering and earth sciences(SCEEES) Clemson UniversityClemsonSC 29631USA Artificial Intelligence research institute for Science and Engineering(AIRISE) Clemson UniversityClemsonSC 29631USA

This paper introduces a machine learning approach to address the challenge of limited data resulting from costly and time-consuming fire experiments by enlarging small fire test data sets and predicting the fire resistance of reinforced concrete *** approach begins by creating deep learning models,namely generative adversarial networks and variational autoencoders,to learn the spatial distribution of real fire *** then use these models to generate synthetic tabular samples that closely resemble realistic fire resistance values for reinforced concrete *** generated data are employed to train state-of-the-art machine learning techniques,including Extreme Gradient Boost,Light Gradient Boosting Machine,Categorical Boosting Algorithm,Support Vector Regression,Random Forest,Decision Tree,Multiple Linear Regression,Polynomial Regression,Support Vector Machine,Kernel Support Vector Machine,Naive Bayes,and K-Nearest Neighbors,which can predict the fire resistance of the columns through regression and *** learning analyses achieved highly accurate predictions of fire resistance values,outperforming traditional models that relied solely on limited experimental *** study highlights the potential for using machine learning and deep learning analyses to revolutionize the field of structural engineering by improving the accuracy and efficiency of fire resistance evaluations while reducing the reliance on costly and time-consuming experiments.

关键词： deep learning fire resistance generative adversarial networks machine learning

Extreme value theory applied to the auroral electrojet indices

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earth and Planetary Physics 2024年第2期8卷 375-381页

作者： Si Chen Hong Yuan Yong Wei Guang Yang FengZheng Yu Aerospace Information research institute Chinese Academy of SciencesBeijing 100094China Key Laboratory of earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of earth and Planetary sciences University of Chinese Academy of SciencesBeijing 100049China

The study of extreme weather and space events has gained paramount importance in modern society owing to rapid advances in high *** and describing exceptional occurrences plays a crucial role in making decisive assessments of their potential impact on technical,economic,and social aspects in various *** research focuses on analyzing the hourly values of the auroral electrojet(AE)geomagnetic index from 1957 to 2019 by using the peak over threshold method in extreme value *** fitting the generalized Pareto distribution to extreme AE values,shape parameter indices were derived,revealing negative values that establish an upper bound for this time ***,it became evident that the AE values had reached a plateau,suggesting that extreme events exceeding the established upper limit are *** a result,although the need for diligent precautions to mitigate the consequences of such extreme events persists,surpassing the upper limit of AE values becomes increasingly *** is also possible to observe an aurora in the middle-and low-latitude regions during the maximum period of the AE index.

关键词： auroral electrojet indices extreme value theory extreme events

Health risks and sources of trace elements and black carbon in PM_(2.5)from 2019 to 2021 in Beijing

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Journal of environmental sciences 2024年第8期142卷 69-82页

作者： Chenjie Hua Wei Ma Feixue Zheng Yusheng Zhang Jiali Xie Li Ma Boying Song Chao Yan Hongyan Li Zhen Liu Qian Liu Markku Kulmala Yongchun Liu Aerosol and Haze Laboratory Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China institute for Atmospheric and earth System research Faculty of ScienceUniversity of HelsinkiHelsinki 00014Finland school of Environment and Safety Taiyuan University of Science and TechnologyTaiyuan 030024China State Key Laboratory of environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

A comprehensive health risk assessment of PM_(2.5)is meaningful to understand the current status and directions regarding further improving air quality from the perspective of human *** this study,we evaluated the health risks of PM_(2.5)as well as highly toxic inorganic components,including heavy metals(HMs)and black carbon(BC)based on longterm observations in Beijing from 2019 to *** results showed that the relative risks of chronic obstructive pulmonary disease,lung cancer,acute lower respiratory tract infection,ischemic heart disease,and stroke decreased by 4.07%-9.30%in 2020 and 2.12%-6.70%in2021 compared with ***,they were still at high levels ranging from 1.26 to 1.77,in particular,stroke showed the highest value in *** had the highest hazard quotient(HQ,from 2.18 to 2.56)for adults from 2019 to 2021,while Ni,Cr,Pb,As,and BC showed high carcinogenic risks(CR>1.0×10^(-6))for *** HQ values of Mn and As and the CR values of Pb and As showed constant or slight upwards trends during our observations,which is in contrast to the downward trends of other HMs and PM_(2.5).Mn,Cr,and BC are crucial toxicants in PM_(2.5).A significant shrink of southern region sourcesof HMs and BCshrank suggests the increased importance of local ***,dust,and biomass burning are the major contributors to the non-carcinogenic risks,while traffic emissions and industry are the dominant contributors to the carcinogenic risks in Beijing.

关键词： PM_(2.5) Heavy metals Black carbon Health risk Source apportionment

An Overview on the Composition and Age of Upper Crust of Proto-Tethyan Lajishan Intra-oceanic Arc,NE Tibet Plateau

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 285-302页

作者： FU Changlei HE Xiaohu YAN Zhen Jonathan CAITCHISON XIAO Wenjiao WANG Bingzhang LI Wufu LI Yusen SinoProbe Laboratory Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China Key Laboratory of the Northern Qinghai–Tibet Plateau Geological Processes and Mineral Resources Qinghai Geological Survey InstituteXining 810012China Department of Geology School of Earth SciencesYunnan UniversityKunming 650091China school of earth and environmental sciences University of QueenslandBrisbane 4072Australia Xinjiang institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China school of earth Science and Resources China University of GeosciencesBeijing 100083China

Identification and anatomy of oceanic arcs within ancient orogenic belt are significant for better understanding the tectonic framework and closure process of paleo-ocean *** article summarizes the geological,geochemical,and geochronological characteristics of upper crust of Proto-Tethyan Lajishan intra-oceanic arc and provides new data to constrain the subduction evolution of the South Qilian *** intra-oceanic arc volcanic rocks,including intermediate-mafic lava,breccia,tuff,and minor felsic rocks,are distributed along southern part of the Lajishan ophiolite *** and isotopic compositions indicate that the intermediate-mafic lava were originated from depleted mantle contaminated by sediment melts or hydrous fluids,whereas the felsic rocks were likely generated by partial melting of juvenile mafic crust in intra-oceanic arc *** from felsic rocks yield consistent and concordant ages ranging from 506 to 523 Ma,suggesting these volcanic rocks represent the relicts of upper crust of the Cambrian intra-oceanic *** with the Cambrian forearc ophiolite and accretionary complex,we suggest that the Cambrian intra-oceanic arc in the Lajishan ophiolite belt is belonging to the intra-oceanic arc system which was generated by south-directed subduction in the South Qilian Ocean at a relatively short interval between approximately 530 and 480 Ma.

关键词： volcanic rocks intra-oceanic arc U-Pb age Lajishan ophiolite belt South Qilian Ocean Proto-Tethyan realm