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Challenges and opportunities in Quaternary palynology

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Science China Earth sciences 2024年第7期67卷 2148-2161页

作者： Qinghai XU Houyuan LU Zhuo ZHENG College of Geographical sciences Hebei Key Laboratory of Environmental Change and Ecological ConstructionHebei Normal UniversityShijiazhuang 050024China Key Laboratory of Cenozoic geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Earth sciences and Engineering Sun Yat-sen UniversityZhuhai 519082China

Quaternary palynology plays a pivotal role in investigating global climate change and various other research fields,serving as an essential tool for the quantitative analysis of paleoenvironment ***,due to the vast diversity of terrestrial ecosystems and intricate interactions between vegetation,climate,and human activities,further advancements are required in the following aspects within this discipline.(1)The accuracy of classification in pollen morphology and fossil pollen identification needs improvement,particularly at the species *** represents a significant challenge in present Quaternary ***-aided intelligent recognition holds promise as a solution for species identification based on more detail pollen morphology.(2)Most pollen-based vegetation and climate reconstructions overlook the significance of bare *** bare ground can lead to substantial inaccuracies when quantitatively reconstructing past vegetation and climate.(3)While pollen records provide reliable information on paleoclimate changes,current quantitative climate reconstruction models heavily rely on modern pollen datasets derived from present-day vegetation disturbed more or less by human *** introduces bias and uncertainties into paleoclimate reconstruction.(4)Although pollen can serve as an indicator of human activities,accurately quantifying the intensity of human influence remains *** accurate identification of crop pollen,reconstructing reliable land cover/use data,and integrating multidisciplinary data may enhance the identification and quantification of signals related to human activity in pollen records.

关键词： Quaternary palynology Paleoclimate Paleovegetation Human activity

Sustainable all-weather CO2 utilization by mimicking natural photosynthesis in a single material

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National Science Review 2024年第2期11卷 177-187页

作者： Xianjin Shi Yu Huang Ran Long Zhenyu Wang Liqin Wang Junji Cao Gangqiang Zhu Yujie Xiong State Key Laboratory of Loess and Quaternary geology(SKLLQG) Key Laboratory of Aerosol Chemistry and Physics Institute of Earth EnvironmentChinese Academy of Sciences Center of Excellence in Quaternary Science and Global Change Chinese Academy of Sciences University of Chinese academy of sciences Hefei National Research Center for Physical sciences at the Microscale School of Chemistry and Materials Science and National Synchrotron Radiation Laboratory University of Science and Technology of China institute of Atmospheric Physics Chinese Academy of Sciences School of Physics and Information Technology Shaanxi Normal University

Solar-driven CO2conversion into hydrocarbon fuels is a sustainable approach to synchronously alleviating the energy crisis and achieving net ***,the dependence of the conversion process on solar illumination hinders its practical application due to the intermittent availability of sunlight at night and on cloudy or rainy ***,we report a model material of Pt-loaded hexagonal tungsten trioxide（Pt/h-WO3） for decoupling light and dark reaction processes,demonstrating the sustainable CO2conversion under dark conditions for the first *** such a material system,hydrogen atoms can be produced by photocatalytic water splitting under solar illumination,stored together with electrons in the h-WO3through the transition of W6+to W5+and spontaneously released to trigger catalytic CO2reduction under dark ***,we demonstrate using natural light that CH4production can persist at night and on rainy days,proving the accomplishment of all-weather CO2conversion via a sustainable way.

关键词： sustainable CO2 utilization artificial photosynthesis all-weather application charge storage

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

Relationship between mitochondrial respiratory dysfunction of blood mononuclear cells and heart failure severity

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Journal of Geriatric Cardiology 2024年第1期21卷 130-134页

作者： Viacheslav A.Korepanov Tariel A.Atabekov Tatiana Yu.Rebrova Roman E.Batalov Sergey A.Afanasiev Cardiology Research institute Tomsk National Research Medical CenterRussian Academy of SciencesTomskRussia

Chronic heart failure(CHF)is a clinical syndrome manifested by reduced pumping ability of the heart,increased pressure in heart chambers in both physical activity and at *** symptoms of this syndrome are dyspnea,undue fatigability,peripheral edema,which follow structural and functional changes of the myocardium.[1]The growing incidence of CHF,especially among elderly people,is an urgent problem for medicine in the vast majority of industrialized *** instance,in russian Federation,CHF is diagnosed in about 7%of cardiovascular *** the same time,this indicator varies from 0.3%in young people(20-29 years old)to 70%in the older age group.[2,3].

关键词： severity instance pumping

The response of Martian photoelectron boundary to the 2018 global dust storm

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Science China Earth sciences 2024年第9期67卷 2772-2782页

作者： Yuqi WANG Jun CUI Yong WEI Zhaopeng WU Kai FAN Zhaojin RONG Fei HE Yutian CAO Jiawei GAO 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 Planetary Environmental and Astrobiological Research Laboratory(PEARL) School of Atmospheric SciencesSun Yat-sen UniversityZhuhai 519082China Center for Excellence in Comparative Planetology Chinese Academy of SciencesHefei 230026China

Extensive research efforts have revealed that the Martian dust storms can perturb the upper atmospheric condition and as a consequence,enhance plasma density and photoelectron flux in the ***,previous observational studies of the Martian dust storm impacts have been restricted to regions below 400 km,which limits our understanding of the Martian dust storm effects in the upper ionosphere and ***,based on the suprathermal electron measurements made by the Solar Wind Electron Analyzer onboard the Mars Atmosphere and Volatile Evolution,we identify with an automatic procedure the occurrences of all photoelectron boundary(PEB)crossings at solar zenith angle below 120°(with a dust-free median altitude of about 600 km).Using the dayside PEB as a proxy of the upper ionospheric and magnetospheric condition,we analyze the variations of the PEB altitude during the 2018 global dust storm(GDS)of Mars Year 34(MY34)and compare them with the period in MY33 when there was no global dust *** conclude that the column dust optical depth(CDOD)emerges as one of the main driving factors for PEB altitude variations during the *** analysis implies that the GDS can affect the Martian upper atmosphere and ionosphere over considerable distances and extended time scales.

关键词： Martian global dust storm Martian photoelectron boundary Upper ionosphere

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Method to measure tree-ring width,density,elemental composition,and stable carbon and oxygen isotopes using one sample

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Journal of Forestry Research 2024年第3期35卷 167-174页

作者： Chenxi Xu Yaru Zhao Wenling An Qingyu Zhao Yucheng Liu Masaki Sano Takeshi Nakatsuka Key Laboratory of Cenozoic geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029People's Republic of China CAS Center for Excellence in Life and Paleoenvironment Beijing 100044People's Republic of China College of Earth sciences University of Chinese Academy of SciencesBeijing 100049People's Republic of China Graduate School of Environment Studies Nagoya UniversityNagoya 4648601Japan

Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pretreat-ment has been needed for each ***,we developed a method by which each proxy can be measured in the same ***,the sample is polished for ring width *** obtaining the ring width data,the sample is cut to form a 1-mm-thick wood *** sample is then mounted in a vertical sample holder,and gradually scanned by an X-ray ***,the count rates of the fluorescent photons of elements(for chemical characteriza-tion)and a radiographic grayscale image(for wood density)are obtained,*** density and the element content are ***,cellulose is isolated from the 1-mm wood plate by removal of lignin,and *** producing this cellulose plate,cellulose subsamples are separated by knife under the microscope for inter-annual and intra-annual stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)*** on this method,RW,density,elemental composition,δ^(13)C,and δ^(18)O can be measured from the same sample,which reduces sample amount and treatment time,and is helpful for multi-proxy comparison and combination research.

关键词： Tree-ring width Tree-ring density Tree-ring elemental composition Tree-ring stable carbon and oxygenisotopes

Polymetamorphism of the ultrahigh-temperature granulites in the Rauer Group,East Antarctica:new evidence from zircon SHRIMP U-Pb ages

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Advances in Polar Science 2024年第2期35卷 192-205页

作者： TONG Laixi LIU Zhao LI Chao LU Junsheng YANG Wenqiang WANG Yanbin State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi’an 710069China institute of geology Chinese Academy of Geological SciencesBejing 100037China

The Rauer Group is located on the eastern margin of the early Paleozoic Prydz Belt in East Antarctica,and the typical ultrahigh-temperature(UHT,>900℃)granulites outcrop on Mather ***,the timing of UHT metamorphism and P–T path of the UHT granulites have long been debated,which is critical to understanding the tectonic nature and evolution history of the Prydz ***,both a sapphirine-bearing UHT metapelitic granulite and a garnet-bearing UHT mafic granulite are selected for zircon SHRIMP U-Pb age *** results show that metamorphic zircon mantles yield weighted mean^(206)Pb/^(238)U ages of 918±29 Ma and 901±29 Ma for the metapelitic and mafic granulites,respectively,while zircon rims and newly grown zircons yield weighted mean^(206)Pb/^(238)U ages of 523±9 Ma and 532±11 Ma,*** new zircon age data suggest that the UHT granulites may have experienced polymetamorphism,in which pre-peak prograde stage occurred in the early Neoproterozoic Grenvillian orogenesis(1000–900 Ma),whereas the UHT metamorphism occurred in the late Neoproterozoic to early Paleozoic Pan-African orogenesis(580–460 Ma).This implies that P–T path of the UHT granulites should consist of two separate high-grade metamorphic events including the Grenvillian and Pan-African events,which are supposed to be related to assembly of Rodinia and Gondwana supercontinents respectively,and hence the overprinting UHT metamorphic event may actually reflect an important intracontinental reworking.

关键词： ultrahigh-temperature granulites zircon SHRIMP U-Pb ages polymetamorphism Rauer Group East Antarctica

Features of sampling stream sediments of large river valleys under cryolithogenesis conditions in the Balygychan-Sugoy trough,North-East of Russia

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Acta Geochimica 2024年第4期43卷 638-660页

作者： Artem S.Makshakov Raisa G.Kravtsova A.P.Vinogradov institute of Geochemistry Siberian Branch of the Russian Academy of SciencesFavorskiy Str 1AIrkutskRussia 664033

Comprehensive research has been implemented to raise the efficiency of the geochemical survey of stream sediments(SSs)that formed under the cryolithogenesis *** authors analysed the composition,structure and specific features of the formation of exogenous anomalous geochemical fields(AGFs)identified through SSs of large river valleys of IV *** our case,these were the valleys of Maly Ken,Ken and Tap *** rivers are located in the central and southern parts of the Balygychan-Sugoy trough enclosed in the Magadan region,North-East of *** authors proposed a new technique to sample loose alluvium of SSs in the large river valleys along the *** profiles were located across the *** AGFs of Au,Ag,Pb,Zn,Sn,Bi,Mo and W were *** between elements have been *** elements are the main indicator elements of Au-Ag,Ag-Pb,Sn-Ag,Mo-W and Sn-W mineralization occurring on the sites under *** results obtained were compared with the results of geochemical surveys of *** is concluded that the AGFs recognized along the profiles reflect the composition and structure of eroded and drained ore zones,uncover completely and precisely the pattern of element distribution in loose sediments of large water *** alluvium fraction<0.25 mm seems to be most significant in a practical sense,as it concentrated numerous ore *** of this fraction in the river valleys of IV order does not cause any difficulty,for this kind of material is *** developed technique of alluvium sampling within large river valleys is efficient in searching for diverse mineralization at all stages of prognostic *** is applicable for geochemical survey of SSs performed at different scales both in the North-East of Russia,as well as other regions with similar climatic conditions,where the SSs are formed under the cryolithogenesis conditions.

关键词： Stream sediments Large river valleys Geochemical fields Mineralization Indicator elements Geochemical survey

Major methods of seismic anisotropy

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Earthquake Research Advances 2024年第3期4卷 82-91页

作者： Xinai Zhao Jing Wu State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China College of Earth and Planetary sciences University of Chinese Academy of SciencesBeijing100049China

Seismic anisotropy reveals that seismic wave velocity, amplitude, and other physical properties show variations in different directions, which can be divided into lattice-preferred orientation(LPO) and shape-preferred orientation(SPO) according to its physical mechanisms. The main methods for studying seismic anisotropy include shearwave splitting analysis, P-wave travel time inversion and surface-wave tomography, etc. There are some differences and correlations among these methods. Seismic anisotropy is an important way to reveal the dynamic processes of crust-mantle evolution, and it is significant for monitoring crustal stress changes and improve seismic exploration studies. With the help of long-term observation, the application of machine learning techniques and combining inversion based on multiple phases would become potential developments in seismic anisotropy studies. This may improve the understanding of complex seismic anisotropic models, such as multiple layers anisotropy with an oblique axis of symmetry.

关键词： Seismic anisotropy Shear-wave splitting P-wave travel time inversion Surface-wave tomography