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Divergent responses of runoff to climate change in the upper basins of the Third Pole dominated by westerlies and monsoon

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Science China Earth Sciences 2024年第8期67卷 2592-2614页

作者： Qikai sun Fengge SU He sun State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100101China

The diverse climates,distribution of snow and glaciers,and geographic locations directly affect the runoff response to climate change in the upper basins of the Third *** present,a comprehensive analysis of runoff variations and their distinct responses to climate change in the westerlies-and monsoon-dominated upper basins is still *** study comprehensively analyzed annual runoff variations in westerlies-dominated basins(the upper basins of the Aksu(UAKS),Syr Darya(USRD),yarkant(UyK),Hotan(UHT),Amu Darya(UAMD),and Indus(UI))and monsoon-dominated basins(the upper basins of the yangtze(UyA),yellow(UyE),Lancang(ULC),Nujiang(UNJ),and yarlung Zangbo(UyZ))of the Third Pole from 1961 *** multi-source meteorological data and large-scale circulation factors,this study investigated the divergent responses of runoff in the upper basins to climate change,and explored the large-scale circulation mechanisms underlying runoff variations in these upper *** results showed that:(1)The annual runoff in the majority of upper basins(except for the UyE and UyZ)exhibited an increasing trend,and the annual runoff in the UAKS,UyK,and UI showed a significant increasing trend from1961 to *** annual runoff in the upper basins of the Third Pole changed abruptly from decreasing to increasing between the 1980s and 2000s,with the exception of the UyE.(2)The runoff in the monsoon-dominated upper basins has been controlled primarily by changes in precipitation over the past 55 *** contrast,the runoff in the westerlies-dominated upper basins exhibited three distinct long-term responses to climate change:temperature-dominated(UyK and UHT),precipitation-dominated(USRD and UAMD),and the combined influence of precipitation and temperature(UAKS and UI).Since the 1960s,the sensitivity of runoff to warm season temperature changes in the most westerlies-dominated upper basins has decreased,while the response of runoff to precipitation changes has intensified.(3)The stud

关键词： Upper basins of the Third Pole Climate change Westerlies and monsoon Runoff variations Large-scale circulation factors

New perspectives on deep carbon cycling

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Science China Earth Sciences 2024年第8期67卷 2411-2422页

作者： Weidong sun Center of Deep Sea Research Key Laboratory of Ocean Observation and ForecastingInstitute of OceanologyChinese Academy of SciencesQingdao 266071China Laoshan Laboratory Qingdao 266237China University of Chinese Academy of Sciences Beijing 100049China

The proto-atmosphere serves as a crucial starting point for the carbon *** based on atmospheric data from Mars and Venus suggest that Earth's proto-atmosphere contained>110 bar of CO_(2)and>2.6 bar of *** protoatmosphere had over 1000 bar of water vapor during the magma ocean stage,assuming the proto-ocean had a volume of two oceans of *** this stage both water and carbon dioxide were in a supercritical state at the magma-atmosphere *** serpentinization reactions occurred due to rock-water interaction,producing abundant ***,nitrogen is reduced to ammonia,and carbon dioxide to methane,forming carbonate *** proto-atmosphere dominated by methane,ammonia,and hydrogen formed a significant amount of amino acids through *** process is essential not only to the origin of life,but also to the early carbon-nitrogen cycle on *** the Hadean eon,a large amount of CO_(2)was sequestered as carbonate and organic ***,it mainly entered the deep mantle through mantle overturn or *** the mantle transition zone,carbonate undergoes“Redox freezing”,where carbonate is reduced to diamond through oxidation of ferrous iron in the *** the lower mantle,Fe^(2+)undergoes disproportionation reactions,forming Fe^(3+)and metallic *** these,Fe^(3+)mainly resides in bridgmanite,thereby increasing the oxygen fugacity of the lower mantle,while metallic iron falls to the Earth's *** distribution of carbon in the mantle is crucial for deep carbon *** density curves of diamond and mantle peridotite melt intersect at the bottom of the mantle transition zone(about 660 km).This density crossover leads to the accumulation of diamond during the magma ocean *** materials such as subducting slabs enter the lower mantle,compensatory upwelling of lower mantle material *** enters the upper mantle,decomposes,releasing Fe^(3+)ions and oxidizes diamond

关键词： Carbon cycling Proto-atmosphere Amino acids Subduction initiation Passive margin subduction Atmospheric carbon dioxide

The precipitation and effect of topologically close-packed phases in Ni-based single crystal superalloys

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Journal of Materials Science & Technology 2024年第6期173卷 149-169页

作者： Jinguo Li Jingxia sun Jinlai Liu Xiaofeng sun Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The precipitation of topologically close-packed(TCP)phases is the result of microstructure instabilities of Ni-based *** review seeks to comprehensively collate all the available information on TCP phases in SX superalloys based on the latest ***,the thermodynamics and kinetics of the TCP phase precipitation are ***,the morphology,composition and orientation of TCP phases and their sequential transformation are summarized in ***,the factors affecting the precipitation of these phases are sorted ***,the proposed damage mechanisms of TCP phases are ***,several control and prediction methods of the TCP phase precipitation are reviewed,so the alloy designer can better balance the relationship between microstructure stabilities and properties of the superalloy.

关键词： Ni-based superalloys Topologically close packed(TCP)phases Precipitation Microstructure stability Properties

Fossil Equidae in the Linxia Basin with Biostratigraphic and Paleozoogeographic Significance

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 1-9页

作者： sun Boyang Key Laboratory of Vertebrate Evolution and Human Origins of the Chinese Academy of Sciences Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China

The Linxia Basin is characterized by an abundance of Cenozoic sediments,that contain exceptionally rich fossil *** are abundant in the Linxia Basin,the fossil record of equids in this region including 16 species that represent 10 *** comparison to other classic late Cenozoic areas in China,the Linxia Basin stands out,because the fauna and chronological data accompanying Linxia equids render them remarkably useful for *** anchitheriines in the region,such as Anchitherium and Sinohippus,represent early equids that appeared in the late stages of the middle and late Miocene,*** the equines,most species of Chinese hipparions have been identified in the Linxia Basin and some species of the genera Hipparion and Hippotherium have FAD records for ***,Equus eisenmannae is one of the earliest known species of Equus in the Old World and is well-represented at the Longdan *** species with precise geohistorical distributions can serve as standards for high-resolution chronological units within this *** at the eastern margin of the Tibetan Plateau and subject to considerable uplift,the Linxia Basin has served as a biogeographic transition area for equids throughout the late Cenozoic.

关键词： Equidae Cenozoic biostratigraphy paleozoogeography Linxia Basin

Achieving simultaneously high conversion and high selectivity for light olefins directly producing from syngas

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Science China Chemistry 2024年第3期67卷 753-754页

作者： yuhan sun Shanxi Research Institute Huairou Research LaboratoryTaiyuan 030032China Institute of Carbon Neutrality ShanghaiTech UniversityShanghai 201210China

The activity and selectivity are two primary indexes of a successful catalyst for chemical reactions. However,achieving a high activity and a high selectivity simultaneously is a long-standing challenge in catalysis, the socalled activity-selectivity trade-off. In the article recently published in Science, a research team led by Prof.

关键词： selectivity simultaneous catalysis

ONE-PARAMETER FINITE DIFFERENCE METHODS AND THEIR ACCELERATED SCHEMES FOR SPACE-FRACTIONAL SINE-GORDON EQUATIONS WITH DISTRIBUTED DELAy

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Journal of Computational Mathematics 2024年第3期42卷 705-734页

作者： Tao sun Chengjian Zhang Haiwei sun School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and TechnologyWuhan 430074China Department of Mathematics University of MacaoMacaoChina

This paper deals with numerical methods for solving one-dimensional(1D)and twodimensional(2D)initial-boundary value problems(IBVPs)of space-fractional sine-Gordon equations(SGEs)with distributed *** 1D problems,we construct a kind of oneparameter finite difference(OPFD)*** is shown that,under a suitable condition,the proposed method is convergent with second order accuracy both in time and *** implementation,the preconditioned conjugate gradient(PCG)method with the Strang circulant preconditioner is carried out to improve the computational efficiency of the OPFD *** 2D problems,we develop another kind of OPFD *** such a method,two classes of accelerated schemes are suggested,one is alternative direction implicit(ADI)scheme and the other is ADI-PCG *** particular,we prove that ADI scheme can arrive at second-order accuracy in time and *** some numerical experiments,the computational effectiveness and accuracy of the methods are further ***,for the suggested methods,a numerical comparison in computational efficiency is presented.

关键词： Fractional sine-Gordon equation with distributed delay One-parameter finite difference methods Convergence analysis ADI scheme PCG method

Impact of effective stress on permeability for carbonate fractured-vuggy rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 942-960页

作者： Ke sun Huiqing Liu Juliana y.Leung Jing Wang yabin Feng Renjie Liu Zhijiang Kang yun Zhang State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China School of Mining&Petroleum Engineering University of AlbertaEdmontonT6G 1H9Canada SINOPEC Petroleum Exploration and Production Research Institute Beijing100083China

To gain insight into the flow mechanisms and stress sensitivity for fractured-vuggy reservoirs,several core models with different structural characteristics were designed and fabricated to investigate the impact of effective stress on permeability for carbonate fractured-vuggy rocks(CFVR).It shows that the permeability performance curves under different pore and confining pressures(*** stress conditions)for the fractured core models and the vuggy core models have similar change *** ranges of permeability variation are significantly wider at high pore pressures,indicating that permeability reduction is the most significant during the early stage of development for fractured-vuggy *** each obtained effective stress coefficient for permeability(ESCP)varies with the changes in confining pressure and pore pressure,the effective stresses for permeability of four representative CFVR show obvious nonlinear characteristics,and the variation ranges of ESCP are all between 0 and ***,a comprehensive ESCP mathematical model considering triple media,including matrix pores,fractures,and dissolved vugs,was *** is proved theoretically that the ESCP of CFVR generally varies between 0 and ***,the regression results showed that the power model ranked highest among the four empirical models mainly applied in stress sensitivity characterization,followed by the logarithmic model,exponential model,and binomial *** concept of“permeability decline rate”was introduced to better evaluate the stress sensitivity performance for CFVR,in which the one-fracture rock is the strongest,followed by the fracture-vug rock and two-horizontalfracture rock;the through-hole rock is the *** general,this study provides a theoretical basis to guide the design of development and adjustment programs for carbonate fractured-vuggy reservoirs.

关键词： Effective stress Permeability Carbonate fractured-vuggy rocks Structure characteristics Stress sensitivity

Dominant woody plant species recognition with a hierarchical model based on multimodal geospatial data for subtropical forests

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Journal of Forestry Research 2024年第3期35卷 111-130页

作者： Xin Chen yujun sun State Forestry&Grassland Administration Key Laboratory of Forest Resources&Environmental Management Beijing Forestry UniversityBeijing 100083People's Republic of China

Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable ***,the potential of GEE for forest resource management has not been fully *** extract dominant woody plant species,GEE combined Sen-tinel-1(S1)and Sentinel-2(S2)data with the addition of the National Forest Resources Inventory(NFRI)and topographic data,resulting in a 10 m resolution multimodal geospatial dataset for subtropical forests in southeast *** and texture features,red-edge bands,and vegetation indices of S1 and S2 data were computed.A hierarchical model obtained information on forest distribution and area and the dominant woody plant *** results suggest that combining data sources from the S1 winter and S2 yearly ranges enhances accuracy in forest distribution and area extraction compared to using either data source ***,for dominant woody species recognition,using S1 winter and S2 data across all four seasons was *** terrain factors and removing spatial correlation from NFRI sample points further improved the recognition *** optimal forest extraction achieved an overall accuracy(OA)of 97.4%and a maplevel image classification efficacy(MICE)of 96.7%.OA and MICE were 83.6%and 80.7%for dominant species extraction,*** high accuracy and efficacy values indicate that the hierarchical recognition model based on multimodal remote sensing data performed extremely well for extracting information about dominant woody plant *** the results using the GEE application allows for an intuitive display of forest and species distribution,offering significant convenience for forest resource monitoring.

关键词： Google Earth Engine Sentinel Forest resource inventory data Dominant woody plant species Subtropics Model performance

Complex adaptive system theory,agent-based modeling,and simulation in dominant technology formation

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Journal of Systems Engineering and Electronics 2024年第1期35卷 130-153页

作者： ZHANG Ruihan sun Bing Glorious sun School of Business and Management Donghua UniversityShanghai 200051China School of Economics and Management Harbin Engineering UniversityHarbin 150001China

Dominant technology formation is the key for the hightech industry to“cross the chasm”and gain an established foothold in the market(and hence disrupt the regime).Therefore,a stimulus-response model is proposed to investigate the dominant technology by exploring its formation process and ***,based on complex adaptive system theory and the basic stimulus-response model,we use a combination of agent-based modeling and system dynamics modeling to capture the interactions between dominant technology and the socio-technical *** results indicate the following:(i)The dynamic interaction is“stimulus-reaction-selection”,which promotes the dominant technology’s formation.(ii)The dominant technology’s formation can be described as a dynamic process in which the adaptation intensity of technology standards increases continuously until it becomes the leading technology under the dual action of internal and external mechanisms.(iii)The dominant technology’s formation in the high-tech industry is influenced by learning ability,the number of adopting users and ***,a“critical scale”of learning ability exists to promote the formation of leading technology:a large number of adopting users can promote the dominant technology’s formation by influencing the adaptive response of technology standards to the socio-technical landscape and the choice of technology standards by the socio-technical *** is a minimum threshold and a maximum threshold for the role of adaptability in the dominant technology’s formation.(iv)The socio-technical landscape can promote the leading technology’s shaping in the high-tech industry,and different elements have different *** study promotes research on the formation mechanism of dominant technology in the high-tech industry,presents new perspectives and methods for researchers,and provides essential enlightenment for managers to formulate technology strategies.

关键词： complex adaptive system theory agent-based modeling and simulation dominant technology socio-technical landscape adaptation-choice