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Pyrite morphology and episodic euxinia of the Ediacaran Doushantuo Formation in South China

Science China Earth Sciences 2017年第1期60卷 102-113页

作者： YE YunTao wu chaodong ZHAI LiNa AN ZhengZe Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education School of Earth and Space Sciences Peking University Beijing 100871 China Institute of Oil & Gas Peking University Beijing 100871 China No. 103 Geological Team Guizhou Bureau of Geology and Mineral Exploration and Development Tongren 554300 China

The Ediacaran Doushantuo Formation with well-preserved fossil record in South China provides a rare window for our understanding of biological evolution,global carbon cycle,and oceanic redox *** negativeδ^(13)C anomalies(i.e.,the Shuram excursion)in Ediacaran successions worldwide fundamentally challenge the traditional models of isotopic mass ***,conflicting opinions of both oxic and anoxic conditions have been proposed for the deep waters during this ***,we present a detailed study of pyrite morphology and carbonate carbon isotope data documented from drill core samples at Songtao County,northeastern *** aggregates are the dominant pyrite form in black shale and they can transfer to euhedral crystals through continuous growth of the constituent microcrystals.A positive correlation between microcrystal sizes(d)and framboid diameters(D)is observed,while the different D/d ratios of framboids in argillaceous dolostone and black shale reflect different substrate *** microprobe analyses reveal no consistent compositional patterns between framboidal and euhedral *** size distributions of the investigated drill core,in combination with previously published redox data from the intra-shelf Jiulongwan section,shelf margin Zhongling section,and lower slope wuhe section,suggest that three episodes of marine euxinia have been established throughout the deposition of the Doushantuo *** time lag between the uppermost euxinic interval and the Shuram excursion may arise from the depression of sulfate reduction maintained by other oxidants.

关键词： Ediacaran Doushantuo Formation Framboidal pyrite Carbon isotope Ocean anoxia Yangtze Platform

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Age and Provenance of Loess deposits on the Northern Flank of Tianshan Mountain

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Acta Geologica Sinica(English Edition) 2009年第3期83卷 648-654页

作者： YUAN Qingdong ZHANG Zhicheng wu chaodong GUO Zhaojie Key Laboratory of Orogenic Belts and Crustal Evolution （Peking University） Ministry of Education Beijing 100871 China

The distribution, optically stimulated luminescence dating and granulometric properties suggest that the loess on the northern flank of Tian Shan should be divided into two types. One which is like mantle and is named type A, is located on the windward slopes and dated to about 54.5±5.73 Ka. The other, called type B, lies flatly on the terraces of the rivers or low hills and penetrated 30.8±2.05 Ka ago. Here we study the origin and the age of two types of loess, and a model of loess formation is proposed. The dust was entrained from the Gobi Desert located to the north of Tian Shan by the monsoon from Mongolia, obstructed by the high mountains and deposited on the windward slopes of the mountains. The rivers and flows then transported the aeolian loess to low terraces and piedmont alluvial plains.

关键词： loess optically stimulated luminescence dating granulometric properties North Tianshan

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Seismic Imaging of the Sedimentary System of the Upper Cretaceous Nenjiang Formation in the Northern Songliao Basin

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Journal of Earth Science 2019年第4期30卷 788-798页

作者： wuling Mo chaodong wu Nan Su Shun Zhang Mingzhen Wang School of Earth and Space Sciences Peking UniversityBeijing 100871China PetroChina Exploration and Development Research Institute Langfang 257000China Exploration and Development Research Institute of Daqing Oilfield Co. Ltd. Daqing 163712China

This paper studied seismic imaging of the sedimentary system of the Nenjiang Formation in the Northern Songliao Basin based on seismic sedimentology. An accurate and detailed depiction and explanation is provided for underground geological bodies within a relative geological period using the stratal slice technology,based on three-order sequence correlations of well logging and seismic data for the purpose of obtaining high-resolution pictures of the sedimentary system. Research results have revealed that the sedimentary system of the Upper Cretaceous Nenjiang Formation in the Northern Songliao Basin includes meandering streams,anastomosing streams,lake deltas,and sediment gravity flow channels. Based on seismic imaging analysis,the genesis and seismic geomorphology of the sedimentary system of the Nenjiang Formation are explored in order to understand the spatial distribution of typical sedimentary bodies and the evolution of streams in the Nenjiang Formation. According to the research results,the sedimentation of the Nenjiang Formation was subject to the delta system in the east and northeast of the formation. The provenance in the northeastern part played a dominant role during the deposition of the Nenjiang Formation for some time;after the earlier maximum flooding in the second and third members of the Nenjiang Formation,the northeastern system began to decline and was gradually replaced by the eastern system. Stratal slices have revealed that a well-developed gravity flow channel system was developed in the first member of the Nenjiang Formation,and massive slip blocks occurred in the second and third members of the formation. The research results indicated that the large gravity flow channel system in the first member of the Nenjiang Formation was formed by streams that emptied directly into the lake;and the slip blocks in the second and third members were the results of gravity sliding of sediments along steep slopes at the delta front.

关键词： seismic sedimentology stratal slice sedimentary system Nenjiang Formation Songliao Basin

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Referential significance of sulfur isotopes and separation of S species in black shales of Southwest China

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Chinese Science Bulletin 1999年第17期44卷 1612-1616页

作者： chaodong wu Fangang Zeng Jiajin Lei Rui Zhao Peking Univ Dept Geol Beijing 100871 Peoples R China Chinese Acad Sci Inst Geol Beijing 100029 Peoples R China

The states of S species in black shales are very complex, such as organic sulfur, pyrite sulfur and sulphate sulfur. The mineral microtexture, sulfur content and sulfur isotope can indicate the formation conditions and diagenetic processes of the black shales. The S species are separated perfectly and the relation between the content, mineral microtexture and

关键词： S species sulfur isotope black shales anoxic environment.

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Geochemistry of Platinum Group and Rare Earth Elements of the Polymetallic Layer in the Lower Cambrian,Weng'an,Guizhou Province

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Acta Geologica Sinica(English Edition) 2009年第3期83卷 618-627页

作者： FU Yong wu chaodong GUAN Ping QU Wenjun CHEN Jiafu Key Laboratory of Orogenic Belts and Crustal Evolution MOE Peking University Beijing 100871 China National Research Center of Geoanalysis Beijing 100037 China

The black shales of the Lower Cambrian Niutitang Formation in Weng＇an, on the Yangtze platform of south China, contain voluminous polymetallic sulfide deposits. A comprehensive geochemical investigation of trace, rare earth, and platinum group elements （PGE） has been undertaken in order to discuss its ore genesis and correlation with the tectono-depositional setting. The ore-bearing layers enrich molybdenum （Mo）, nickel （Ni）, vanadium （V）, lead （Pb）, strontium （Sr）, barium （Ba）, uranium （U）, arsenic （As）, and rare earth elements （REE） in abundance. High uranium/ thorium （U/Th） ratios （U/Th〉I） indicated that mineralization was mainly influenced by the hydrothermal process. The 8U value was above 1.9, showing a reducing sedimentary condition. The REE patterns showed high enrichment in light rare earth elements （LREE）（heavy rare earth elements （HREE）（LREE/HREE=5-17）, slightly negative europium （Eu） and cerium （Ce） anomalies （δEu=0.81- 0.93）, and positive Ce anomalies （δCe=0.76-1.12）. PGE abundance was characterized by the PGE-type distribution patterns, enriching platinum （Pt）, palladium （Pd）, ruthenium （Ru） and osmium （Os）. The Pt/Pd ratio was 0.8, which is close to the ratios of seawater and ultramafic rocks. All of these geochemical features suggest that the mineralization was triggered by hydrothermal activity in an extensional setting in the context of break-up of the Rodinian supercontinent.

关键词： geochemistry polymetallic layer hydrothermal activity Lower Cambrian

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基于EN 15595标准的防滑系统极低黏着试验研究

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电力机车与城轨车辆 2024年第1期47卷 96-101,134页

作者：吴朝东王晓勇阳靖黎丹重载快捷大功率电力机车全国重点实验室中车株洲电力机车有限公司湖南株洲412001

针对TSI认证对于轨道车辆防滑系统的要求,文章阐述了EN 15595标准对防滑系统极低黏着试验工况的技术要求、试验程序和试验方法,根据标准要求开展了车辆防滑系统极低黏着试验和仿真试验,对试验数据和防滑系统功能进行理论分析,并基于试... 详细信息

针对TSI认证对于轨道车辆防滑系统的要求,文章阐述了EN 15595标准对防滑系统极低黏着试验工况的技术要求、试验程序和试验方法,根据标准要求开展了车辆防滑系统极低黏着试验和仿真试验,对试验数据和防滑系统功能进行理论分析,并基于试验和仿真分析结果提出防滑系统试验相关建议。

关键词：防滑系统极低黏着车辆试验仿真试验

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Metformin and metabolic diseases： a focus on hepatic aspects

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Frontiers of Medicine 2015年第2期9卷 173-186页

作者： Juan Zheng Shih-Lung Woo Xiang Hu Rachel Botchlett Lulu Chen Yuqing Huo chaodong wu Department of Nutrition and Food Science Texas A &M University College Station TX 77843 USA Department of Endocrinology Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430022 China Drug Discovery Center Key Laboratory of Chemical Genomics Peking University Shenzhen Graduate School Shenzhen 518055 China

Metformin has been widely used as a diabetes （T2D）. As a drug that primarily targets first-line anti-diabetic medicine for the treatment ot type Z the liver, metformin suppresses hepatic glucose production （HGP）, serving as the main mechanism by which metformin improves hyperglycemia of T2D. BiochemicaUy, metformin suppresses gluconeogenesis and stimulates glycolysis. Metformin also inhibits glycogenolysis, which is a pathway that critically contributes to elevated HGP. While generating beneficial effects on hyperglycemia, metformin also improves insulin resistance and corrects dyslipidemia in patients with T2D. These beneficial effects of metformin implicate a role for metformin in managing non-alcoholic fatty liver disease. As supported by the results from both human and animal studies, metformin improves hepatic steatosis and suppresses liver inflammation. Mechanistically, the beneficial effects of metformin on hepatic aspects are mediated through both adenosine monophosphate-activated protein kinase （AMPK）-dependent and AMPK-independent pathways. In addition, metformin is generally safe and may also benefit patients with other chronic liver diseases.

关键词： metformin diabetes hepatic steatosis inflammatory response insulin resistance

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Hippocampal overexpression of TREM2 ameliorates high fat diet induced cognitive impairment and modulates phenotypic polarization of the microglia

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Genes & Diseases 2022年第2期9卷 401-414页

作者： Min wu Maolin Liao Rongfeng Huang Chunxiu Chen Tian Tian Hongying Wang Jiayu Li Jibin Li Yuxiang Sun chaodong wu Qifu Li Xiaoqiu Xiao Department of Endocrinology The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016PR China The Chongqing Key Laboratory of Translational Medicine in Major Metabolic Diseases The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016PR China Department of Nutrition and Food Hygiene School of Public Health and ManagementChongqing Medical UniversityChongqing 400016PR China Department of Neurology Affiliated Hospital of Guizhou Medical UniversityGuiyangGuizhou 550004PR China Department of Nutrition and Food Science Texas A&M UniversityCollege StationTX 77843USA

Type 2 diabetes mellitus(T2DM)and Alzheimer's disease(AD)share several common pathophysiological *** variants of triggering receptor expressed on myeloid cells 2(TREM2)increase the risk of developing AD,suggesting the involvement of TREM2 and innate immunity in AD *** is still unknown whether TREM2 is related to cognitive impairment in ***,we investigated the effects of the hippocampal overexpression of TREM2 on cognitive in long-term high-fat diet(HFD)-fed *** C57BL/6J mice were maintained on HFD for 50 ***2 was overexpressed in the hippocampus 36 weeks after HFD feeding using adeno-associated virus vector(AAV)-mediated gene *** results showed that the HFD feeding induced rapid and persistent weight gain,glucose intolerance and significant impairments in learning and *** with AAV-con,AAV-TREM2 significantly ameliorated cognitive impairment without altering body weight and glucose homeostasis in HFD *** overexpression of TREM2 upregulated the synaptic proteins spinophilin,PSD95 and synaptophysin,suggesting the improvement in synaptic *** complexity and spine density in the CA1 region were rescued after TREM2 ***,TREM2 markedly increased the number of iba-1/Arg-1-positive microglia in the hippocampus,suppressed neuroinflammation and microglial *** sum,hippocampal TREM2 plays an important role in improving HFD-induced cognitive dysfunction and promoting microglial polarization towards the M2 anti-inflammatory *** study also suggests that TREM2 might be a novel target for the intervention of obesity/diabetes-associated cognitive decline.

关键词： Diabetes Microglial polarization Neurodegeneration Neuroinflammation Obesity TREM2

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New insights into multiple provenances evolution of the Jurassic from heavy minerals characteristics in southern Junggar Basin, NW China

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Petroleum Exploration and Development 2019年第1期46卷 67-81页

作者： ZHOU Tianqi wu chaodong YUAN Bo SHI Zhongkui WANG Jialin ZHU Wen ZHOU Yanxi JIANG Xi ZHAO Jinyong WANG Jun MA Jian Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education School of Earth and Space Sciences Peking University Institute of Oil and Gas Peking University Geophysics Department in Exploration and Development Institution of Xinjiang Oilfield Company Institute of Remote Sensing and Geographical Information System School of Earth and Space Sciences Peking University Petroleum Exploration and Production Research Institute Sinopec Department of Xinjiang Exploration Project Management Sinopec Shengli Oilfield Company

The method of random forest was used to classify the heavy mineral assemblages of 2 418 Jurassic samples in the southern Junggar Basin, and determine the distribution of the heavy mineral assemblages from the same provenance systems. Based on the analysis of heavy minerals assemblages, ZTR index, sedimentary characteristics, U-Pb zircon ages, whole-rock geochemical and paleocurrent direction analysis, the study reveals that five important provenances were providing sediments to the southern Junggar Basin in the Jurassic period: The North Tianshan(NTS), Central Tianshan(CTS), Bogda Mountains, Zhayier Mountains and Kalamaili Mountains. During the Early Jurassic, NTS-CTS, Kalamaili Mountains and Zhayier Mountains are primary provenances, Bogda Mountains started to uplift and supply clastic materials in the Middle Jurassic. There are three sedimentary area in the Jurassic of southern Junggar Basin: the western part, the central part and the eastern part. In the western part, the clastic materials of the Early Jurassic was mainly from NTS blocks and Zhayier Mountains, and the sediments were dominantly derived from the Zhayier Mountains during the Middle–Late Jurassic. In the central part, the main provenance of the Early Jurassic switched from NTS to CTS. In the Xishanyao Formation, the main source went back to NTS again. The NTS was the primary provenance during the sedimentary periods of Toutunhe Formation and Qigu Formation. In the eastern part, the contribution of CTS and Kalamaili Mountains were considered as major provenances in the Early Jurassic-Xishanyao Formation, small proportion of sediments were from NTS. The Bogda mountains uplifted and started to provide sediments to the Junggar Basin in the sedimentary period of Xishanyao Formation, and became the major source during the Toutunhe Formation period, with small amount of sediments from CTS. The provenance from CTS was hindered during the sedimentary period of Qigu Formation owing to the uplifting of the Bogd

关键词： southern Junggar Basin Jurassic source to sink system provenance heavy minerals assemblages random forest

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100MPa压力下温度和水对干酪根结构状态影响的实验研究

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岩石学报 2005年第1期21卷 245-250页

作者：曾贻善吴朝东北京大学地质系北京100871

为了实验验证变质沉积物中的碳质物拉曼光谱地质温度计的可用性,利用冷封口式高温高压水热系统将焊封金管内的干酪根于100MPa压力和温度(250-700℃)、有水和无水条件下处理24小时,激光拉曼探针(LRM)分析表明,实验所得碳质物的一级和二... 详细信息

为了实验验证变质沉积物中的碳质物拉曼光谱地质温度计的可用性,利用冷封口式高温高压水热系统将焊封金管内的干酪根于100MPa压力和温度(250-700℃)、有水和无水条件下处理24小时,激光拉曼探针(LRM)分析表明,实验所得碳质物的一级和二级拉曼谱特征(拉曼峰的存在、峰的位置、宽度、高度和面积)随温度系统地变化,所得碳质物的D/O比值随温度升高而减小,但在D/O比-温度关系图上-500℃处有一拐点(极小)。实验条件下处理的干酪根的显微富利叶变换红外谱(micro-FTIR)分析表明,脂族C-H和芳族C-H吸收峰的相对强度在500℃左右急剧变化以及在700℃的实验产物中仍存在含氢的功能团。高温高压条件下,水的存在不利于碳质物的石墨化(有序化)。

关键词：干酪根结构状态拉曼谱学红外谱学高温高压实验

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