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Cross section determination of^(27)Al(n,2n)^(26)Al reaction induced by 14-MeV neutrons uniting with D-T neutron activation and AMS techniques

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Nuclear Science and Techniques 2024年第6期35卷 78-89页

作者： Xian-Lin Yang Chang-Lin Lan Yu-Ting Wei Yi Zhang Gong Jiang Bo Xie Yu Liu Hong-Tao Shen Xiao-Jun Sun School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China moe Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China State key laboratory of Environmental geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Guangxi key laboratory of Nuclear Physics and Nuclear Technology Guangxi Normal UniversityGuilin 541004China

Aluminum is the primary structural material in nuclear engineering,and its cross section induced by 14-MeV neutrons is of great *** address the issue of insufficient accuracy for the^(27)Al(n,2n)^(26)Al reaction cross section,the activation method and accelerator mass spectrometry(AMS)technique were used to determine the^(27)Al(n,2n)^(26)Al cross section,which could be used as a D-T plasma ion temperature monitor in fusion *** the China Academy of Engineering Physics,neutron activation was performed using a K-400 neutron generator produced by the T(d,n)4He ***^(26)Al∕^(27)Al isotope ratios were measured using the newly installed GYIG 1 MV AMS at the Institute of geochemistry,Chinese Academy of *** neutron flux was monitored by measuring the activity of 92mNb produced by the 93Nb(n,2n)92mNb *** measured results were compared with available data in the experimental nuclear reaction database,and the measured values showed a reasonable degree of consistency with partially available literature *** newly acquired cross-sectional data at 12 neutron energy points through systematic measurements clarified the divergence,which has two different growth trends from the existing experimental *** obtained results are also compared with the corresponding evaluated database,and the newly calculated excitation functions with TALYS−1.95 and EMPIRE−3.2 codes,the agreement with CENDL−3.2,TENDL-2021 and EMPIRE−3.2 results are generally acceptable.A substantial improvement in the knowledge of the^(27)Al(n,2n)^(26)Al reaction excitation function was obtained in the present work,which will lay the foundation for the diagnosis of the fusion ion temperature,testing of the nuclear physics model,evaluation of nuclear data,etc.

关键词： 14-MeV neutron ^(27)Al(n,2n)^(26)Al Cross section AMS

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Revisiting the Mg isotopic systematics of siliciclastic components of sediments and sedimentary rocks:A new geochemical proxy of continental weathering in Earth's history

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Science China Earth Sciences 2024年第2期67卷 620-633页

作者： Tianzheng HUANG Bing SHEN Kangjun HUANG Meng NING Chao LI Jinzhuang XUE Yuanlin SUN Baoqi HUANG key laboratory of Orogenic Belt and Crustal Evolution MOESchool of Earth and Space SciencesPeking UniversityBeijing100871China State key laboratory of Continental Dynamics Shaanxi Key Laboratory of Early Life and EnvironmentsDepartment of GeologyNorthwest UniversityXi’an710069China Institute of Sedimentary Geology Chengdu University of TechnologyChengdu610059China key laboratory of Rhenium-Osmium Isotopic geochemistry Chinese Academy of Geological SciencesBeijing100037China

The Mg isotopic compositions of siliciclastic components(δ^(26)Mg_(sili))of sediments and sedimentary rocks have been commonly used to constrain the intensity of continental weathering,based on observations of,(1)an upward enrichment of26Mg in modern weathering profiles,(2)preferential uptake of26Mg in soil clays,and(3)general positive correlations between weathering intensities andδ^(26)Mg_(sili)***,not all weathering profiles display an upward increase ofδ^(26)Mg_(sili),and not all soil clays enrich in26Mg,complicating the interpretations ofδ^(26)Mg_(sili)data of sediments and sedimentary *** further explore the controls ofδ^(26)Mg_(sili)of sediments and sedimentary rocks,here we measuredδ^(26)Mg_(sili),mineralogical compositions and major element compositions of deep sea sediments from South China Sea(SCS)and carbonate rock samples from two late Paleozoic sections in South *** samples show decreasing trends of both normalized Mg concentration(Mgnorm)andδ^(26)Mg_(sili)values with the increase of weathering intensity,while SCS sediments samples do not show any correlation between Mgnormorδ^(26)Mg_(sili)values and weathering intensity.A three-stages weathering model is developed to explain the observed Mgnorm andδ^(26)Mg_(sili)*** the new model,weathering can be divided into three stages,(1)the preliminary weathering stage characterized by dissolution of primary minerals and formation of secondary clay minerals in saprolite,(2)the transitional stage with massive vermiculite and chlorite formation on the bottom of soil,and(3)the advanced stage showing dissolution of vermiculite and chlorite in the top of *** new model explains anδ^(26)Mg_(sili)increase and Mgnormdecrease with an increase weathering intensity in preliminary weathering stage and decrease of Mgnormandδ^(26)Mg_(sili)with increase weathering intensity in advanced weathering *** revised weathering model warrants the application of Mg isotope in the study of contin

关键词： Clay mineral Chemical weathering CIA Soil Weathering model

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快速干湿气候振荡与中国古代大规模社会动荡

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Science Bulletin 2024年第3期69卷 314-318页

作者：孟先强张灿李根程鉴如蔡洁刘一兰霍利倪振宇张恩楼 State key laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 21008China Department of Earth Science University of CaliforniaSanta Barbara CA 93106USA Ministry of Education key laboratory of surficial geochemistry School of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China

Climate conditions have long been acknowledged as a pivotal factor shaping regional productivity and influencing available resources,consequently playing an important role in driving social changes throughout human history[1–3].In ancient East Asia,the Chinese agrarian civilization emerged around 4000 years ago in northern China,the region termed the“Central Plains”.This region faced recurrent episodes of large-scale social unrest,profoundly impacting the societal structure and dynastic cycles[4].These episodes were marked by extended civil peasant uprisings and/or incursions from northern nomadic tribes,often spanning decades to centuries[5].Both the agrarian societies in the Central Plains and the husbandry-based nomadic tribes in the vast northern grasslands,characterized by semi-arid and semi-humid climates,were notably sensitive to climate variations[6].

关键词： husbandry driving profound

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High-Pressure Behavior of Ferromagnesite(Mg_(0.81)Fe_(0.19))CO_(3)by Synchrotron X-Ray Diffraction and Raman Spectroscopy up to 53 GPa

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Journal of Earth Science 2024年第2期35卷 525-535页

作者： Lin Liang Guibin Zhang Shengxuan Huang Jingjing Niu Dongzhou Zhang Jingui Xu Wen Liang Shan Qin key laboratory of Orogenic Belts and Crustal Evolution MOEand School of Earth and Space SciencesPeking UniversityBeijing100871China CAS Center of Excellence in Tibetan Plateau Earth Sciences and key laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing100101China Hawai’i Institute of Geophysics and Planetology School of Ocean and Earth Science and TechnologyUniversity of Hawai’i at ManoaHawai’i96822USA key laboratory of High Temperature and High Pressure Study of the Earth’s Interior Institute of GeochemistryChinese Academy of SciencesGuiyang550081China

Ferromagnesite(Mg,Fe)CO_(3)with 20 mol%iron is a potential host mineral for carbon transport and storage in the Earth *** high-pressure behavior of synthetic ferromagnesite(Mg_(0.81)Fe_(0.19))CO_(3)up to 53 GPa was investigated by synchrotron X-ray diffraction(XRD)and Raman *** iron bearing carbonate underwent spin transition at around 44–46 GPa accompanied by a volume collapse of 1.8%,which also demonstrated a variation in the dνi/dP slope of the Raman *** pressure-volume data was fitted by a third-order Birch-Murnaghan equation of state(BM-EoS)for the high spin *** best-fit K_(0)=108(1)GPa and K_(0)'=4.2(1).Combining the dνi/dP and the K_(0),the mode Grüneisen parameters of each vibrational mode(T,L,ν4 andν1)were *** effects of iron concentration on the Mg_(1−x)Fe_(x)CO_(3)system related to high-pressure compressibility and vibrational properties are *** results expand the knowledge of the physical properties of carbonates and provide insights to the potential deep carbon host.

关键词： ferromagnesite synchrotron XRD Raman spectroscopy high pressure geochemistry mineral

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Transcriptomics and physiological analyses reveal that sulfur alleviates mercury toxicity in rice(Oryza sativa L.)

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Journal of Environmental Sciences 2024年第1期135卷 10-25页

作者： Yingmei Huang Jicai Yi Xiaomin Li Fangbai Li National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and ManagementInstitute of Eco-Environmental and Soil SciencesGuangdong Academy of SciencesGuangzhou 510650China Guangzhou Institute of geochemistry Chinese Academy of SciencesGuangzhou 510640China University of Chinese Academy of Sciences Beijing 100049China College of Life Sciences South China Agricultural UniversityGuangzhou 510642China SCNU Environmental Research Institute Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety&MOE Key Laboratory of Theoretical Chemistry of EnvironmentSouth China Normal UniversityGuangzhou 510006China

Mercury(Hg)is one of the most dangerous contaminants and has sparked global concern since it poses a health risk to humans when consumed through ***(S)is a crucial component for plant growth,and S may reduce Hg accumulation in rice ***,the detailed effects of S and the mechanisms underlying S-mediated responses in Hg-stressed rice plants remain ***,to investigate the effects of S addition on rice growth,Hg accumulation,physiological indexes,and gene expression profiles,rice seedlings were hydroponically treated with Hg(20μmol/L Hg Cl_(2))and Hg plus elemental sulfur(100 mg/L).S application significantly reduced Hg accumulation in Hg-stressed rice roots and alleviated the inhibitory effects of Hg on rice growth.S addition significantly reduced Hg-induced reactive oxygen species generation,membrane lipid peroxidation levels,and activities of antioxidant enzymes while increasing glutathione content in *** analysis of roots identified 3,411,2,730,and 581 differentially expressed genes in the control(CK)***,CK ***+S,and Hg ***+S datasets,*** pathway of S-mediated biological metabolism fell into six groups:biosynthesis and metabolism,expression regulation,transport,stimulus response,oxidation reduction,and cell wall *** majority of biological process-related genes were upregulated under Hg stress compared with CK treatment,but downregulated in the Hg+S *** results provide transcriptomic and physiological evidence that S may be critical for plant Hg stress resistance and will help to develop strategies for reduction or phytoremediation of Hg contamination.

关键词： Sulfur Mercury Transcriptomics Detoxification

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快速干湿气候振荡与中国古代大规模社会动荡（英文）

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Science Bulletin 2024年第3期 314-318页

作者：孟先强张灿李根程鉴如蔡洁刘一兰霍利倪振宇张恩楼 State key laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Department of Earth Science University of California Ministry of Education key laboratory of surficial geochemistry School of Earth Sciences and Engineering Nanjing University

Climate conditions have long been acknowledged as a pivotal factor shaping regional productivity and influencing available resources,consequently playing an important role in driving social changes throughout human history [1-3].In ancient East Asia,the Chinese agrarian civilization emerged around 4000 years ago in northern China,the region termed the"Central Plains".This region faced recurrent episodes of large-scale social unrest,profoundly impacting the societal structure and dynastic cycles [4].These episodes were marked by extended civil peasant uprisings and/or incursions from northern nomadic tribes,often spanning decades to centuries [5].Both the agrarian societies in the Central Plains and the husbandry-based nomadic tribes in the vast northern grasslands,characterized by semi-arid and semi-humid climates,were notably sensitive to climate variations [6].

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A Deep Mantle Source for the Late Neoarchean Metamorphosed Basalts in Eastern Hebei,North China Craton:Insights from Whole-Rock geochemistry and Sm-Nd Isotopes,and Zircon U-Pb-Hf Isotopes

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Journal of Earth Science 2024年第1期35卷 29-40页

作者： Zhuang Li Chunjing Wei Chuan Yang Xi Zhang College of Geosciences China University of PetroleumBeijing 102249China moe key laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking UniversityBeijing 100871China China Transport Telecommunications and Information Center Beijing 100011China

The basalts within the greenstone belt worldwide serve as an ideal target to decipher the nature of Archean mantle sources and further to extend the understanding of the early stages of Earth's *** provide important insights into the issues,we carried out a detailed investigation of whole-rock geochemistry and Sm-Nd isotopes,and zircon U-Pb-Hf isotopes for the Late Neoarchean metamorphosed basalts in eastern Hebei,North China Craton.U-Pb isotopic dating using the LA-ICPMS on zircons reveals that the basalts in eastern Hebei erupted at ca.2.48-2.51 Ga and subsequently experienced multiple regional metamorphic events at 2477 and 1798 Ma,*** metamorphosed basalts are featured by low SiO_(2),MgO,K_(2)O+Na_(2)O,and high Fe O contents,endowed with the subalkaline and high-Fe tholeiitic *** radiogenic initial Nd and Hf isotope values and correlations among V,Ni and Cr contents strongly imply that the basalts experienced significant clinopyroxene and olivine fractionation and minor crustal contamination during magma *** are also characterized by the relatively low total REE contents and exhibit significant depletions to moderate enrichments in the LREE contents,indicating the derivation from a deep mantle source in an Archean proto-mantle plume setting.

关键词： zircon U-Pb-Hf isotopes geochemistry Late Neoarchean basaltic magmatism North China Craton Archean proto-mantle plume

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Geochronology and geochemistry of the Xingxingxia Triassic A-type Granites in Central Tianshan,NW China:Petrogenesis and Tectonic Implications

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 337-351页

作者： HUANG Zengbao LI Xiyao ZHAO Hao LU Qing Geological Survey of Gansu Province Lanzhou 735000China key laboratory of Submarine Geosciences and Prospecting Techniques MOE and College of Marine GeosciencesOcean University of ChinaQingdaoShandong 266100China Research Institute of Petroleum Exploration and Development Shengli OilfieldSINOPECDongyingShandong 257000China

The Triassic granitoids in Central Tianshan play a key role in determining the petrogenesis and tectonic evolution on the southern margin of the Central Asian orogenic *** this study,we present SHRIMP zircon U-Pb ages,Hf isotopic and geochemical data on the Xingxingxia biotite granite,amazonite granite and granitic pegmatite in Central Tianshan,NW *** U-Pb dating yielded formation ages of 242 Ma for the biotite granite and 240 Ma for the amazonite *** granitoid rocks have high K_(2)O with low MgO and CaO *** are enriched in Nb,Ta,Hf and Y,while being depleted in Ba and Sr,showing flat HREE patterns and negative Eu *** have typical A-type granite geochemical signatures with high Ga/A_(1)(8–13)and TFeO/(TFeO+MgO)ratios,showing an A_(2) affinity for biotite granite and an A_(1) affinity for amazonite granite and granitic *** ε_(Hf)(t)values of the granitoids are 0.45–2.66,with Hf model ages of 0.99–1.17 *** suggests that these A-type granites originated from partial melting of the lower *** propose that Xingxingxia Triassic A-type granites formed under lithospheric extension from post-orogenic to anorogenic intraplate settings and NE-trending regional strike-slip fault-controlled magma emplacement in the upper crust.

关键词： Triassic A-type granite Xingxingxia Central Tianshan Central Asian orogenic belt

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Oxidation and Mineralization of Mn^2＋ Ions Mediated by Pseudomonasputida： Insights from an Experimental Study

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Acta Geologica Sinica(English Edition) 2017年第4期91卷 1276-1285页

作者： CHEN Xiaoy LU Xiancai LIU Huan LI Juan XIANG Wanli ZHANG Rui LU Jianjun moe key laboratory of surficial geochemistry School of Earth Sciences and Engineering Nanjing University Nanjing Jiangsu 210093 China

The formation of manganese oxides in nature is commonly mediated by microorganisms. In this study, the mineralization of biogenic manganese oxidation mediated by Pseudomanas putida has been experimentally investigated by employing various characterization techniques, including SEM, FESEM, TEM, XRD, and STXM-NEXAFS. The results indicate that Mn^2＋ ions can be oxidized into Mn （IV） minerals （birnessite and pyrolusite） and Mn（III） minerals （hausmannite and feitknechtite）, successively. The primary products （birnessite and pyrolusite） further transformed into hausmannite and feitknechtite under Mn^2＋ ion-enriched conditions. However, birnessite and pyrolusite are the end- products of the continuous microbial oxidation processes. These biogenic Mn oxides are poorly crystallized, which provides them with a high potential for usage in environmental restoration of contaminated soils and waters contaminated with heavy metals. The approaches employed in this study will also enrich genesis research of biological oxidation of Mn（II） species in nature.

关键词： Pseudomanasputida Mn^2+ microbial oxidation biomineralization

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Uranium comminution age responds to erosion rate semiquantitatively

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Acta Geochimica 2017年第3期36卷 426-428页

作者： Le Li Laifeng Li Gaojun Li moe key laboratory of surficial geochemistry Department of Earth Sciences Nanjing University 163 Xianlindadao Nanjing 210023 China

Here we present(^(234)U/^(238)U)data from river sediments collected on the Tibetan ***(^(234)U/^(238)U)ratios of a specific grain size fraction show good correlation with erosion rates,which were determined by in-situ–produced cosmogenic *** correlation has previously been observed in a wide range of geomorphic settings,suggesting that(^(234)U/^(238)U)ratios of fluvial sediments have great potential to quantify erosion rates.

关键词： Uranium isotope Catchment erosion rate Tibetan Plateau Surface process

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