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Reliability of Relative Paleointensity Recorded in Chinese Loess-Paleosol Sediments

Acta Geologica Sinica(English Edition) 2012年第5期86卷 1276-1288页

作者： YANG Tianshui LI Haiyan WU Huaichun YANG Zhenyu zhang shihong HYODO Masayuki State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesBeijing 100083China School of the Earth Sciences and Resources China University of GeosciencesBeijing 100083China School of Ocean Sciences and Resources China University of GeosciencesBeijing 100083China Institute of Geomechanics Chinese Academy of Geological SciencesBeijing 100081China Research Center for Inland Seas Kobe UniversityKobe 657-8501Japan

A detailed paleomagnetic and rock-magnetic investigation spanning loess L7 to paleosol S8 has been carried out at the Baoji and Xifeng sections. Results of anisotropy of magnetic susceptibility confirm that the studied loess-paleosol sediments retain primary sedimentary fabrics. Stepwise thermal demagnetization shows that two well-defined magnetization components can be isolated from both loess and paleosol specimens. A low-temperature component, isolated between 100°C and 200°C, is consistent with the present geomagnetic field direction, and a high-temperature component, isolated between 200-300°C and 620-680°C, includes clearly normal and reversed polarities. Isothermal remanent magnetization and thermomagnetic analyses indicate that characteristic remanent magnetization is mainly carried by magnetite and hematite. The Day plot, together with the stratigraphic variations of rock-magnetic parameters, shows that the uniformity of magnetic mineralogy and grain size fulfills the criteria for relative paleointensity （RPI） studies. RPI records have been constructed using natural remanent magnetization （NRM） intensity after thermal demagnetization at 300°C normalized by low-frequency magnetic susceptibility （NRM 300 /χ）. The results show that the RPI record from the Baoji section, where pedogenesis is quite weak, is compatible with the stacked PISO-1500 paleointensity record, suggesting that it might reflect the paleointensity variation of the geomagnetic field. The RPI record from the Xifeng section, where pedogenesis is rather strong, indicates a clear dissimilarity with the stacked PISO-1500 paleointensity record, implying that it does not reflect the paleointensity variation of the geomagnetic field. Our new results show that the NRM 300 /χ from the strongly pedogenetic paleosols does not completely eliminate the pedogenetic （climatic） influence, so it might be unsuitable for a reliable paleointensity study.

关键词： Chinese loess pedogenesis relative paleointensity rock magnetism geomagnetic field

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Environmental magnetic comparisons between distal and proximal sediments of Huangqihai Lake,Inner Mongolia,China

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Science China Earth Sciences 2012年第9期55卷 1494-1503页

作者： DONG Jin WANG Yong zhang shihong CHI ZhenQing YAO PeiYi ZHAO ZhiLi Institute of Geology Chinese Academy of Geological Sciences Beijing 100037China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesBeijing 100083China

Spatial variations in lake sediments are a product of their depositional *** better correlate synchronous strata in Huangqihai Lake,two sections were excavated from the lake-center and the *** study involved detailed lithology,mineralogy,and rock magnetic *** results show that the frequency-dependent susceptibility,which is related to the content of super-paramagnetic minerals,is relatively easy to contrast between the two ***,mass susceptibility and saturation isothermal remanence,which are related to the content of total magnetic minerals,are difficult to contrast.A possible reason for this difference is that small-particle super-paramagnetic minerals are formed mainly during pedogenic processes,which correlates well with climate change and avoids the effects of local factors when corrections are made at the whole-lake *** sections can be divided into three stages,which appear to be well correlated with previous results obtained through other environmental proxies.

关键词：湖泊沉积物环境磁学黄旗海内蒙古频率磁化率远端中国磁性矿物

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DP-GH4169合金在热变形中片层状δ相的球化行为及动力学模型

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稀有金属材料与工程 2023年第11期52卷 3778-3784页

作者：张海燕程明胡如夫张士宏赵忠宁波工程学院机械与汽车工程学院浙江宁波315336 中国科学院金属研究所辽宁沈阳110016

通过OM、TEM和热模拟压缩实验等分析测试方法,对DP-GH4169合金在热变形过程中片层状δ相的球化行为及动力学模型进行了研究。结果表明:片层状δ相的溶解行为主要为Nb原子由δ/γ相界到达基体γ的长程扩散控制;在热变形过程中,溶解对于... 详细信息

通过OM、TEM和热模拟压缩实验等分析测试方法,对DP-GH4169合金在热变形过程中片层状δ相的球化行为及动力学模型进行了研究。结果表明:片层状δ相的溶解行为主要为Nb原子由δ/γ相界到达基体γ的长程扩散控制;在热变形过程中,溶解对于片层状δ相的球化行为影响较小,片层状δ相的临界球化应变εc取决于变形温度和应变速率;在热模拟压缩实验范围内,片层状δ相的临界球化应变εc为0.04~0.10,且随着变形温度升高和应变速率降低而减小;热变形中片层状δ相的球化体积分数与热变形参数之间满足Avrami方程。

关键词： GH4169合金热变形片层状δ相球化动力学模型

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Magnetic records of Core MD77-181 in the Bay of Bengal and their paleoenvironmental implications

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Chinese Science Bulletin 2006年第15期51卷 1884-1893页

作者： LI Haiyan zhang shihong FANG Nianqiao WANG Hongqiang State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China

高分辨率的环境磁性的大小在孟加拉的海湾在 CoreMD77-181 上被执行，包括磁性的危险性，非滞后的残余的磁化，所有样品的等温的残余的磁化，和磁性的危险性的温度依赖和代表性的样品的磁性的磁滞现象参数。结果建议那(1 ) 磁性的矿物... 详细信息

高分辨率的环境磁性的大小在孟加拉的海湾在 CoreMD77-181 上被执行，包括磁性的危险性，非滞后的残余的磁化，所有样品的等温的残余的磁化，和磁性的危险性的温度依赖和代表性的样品的磁性的磁滞现象参数。结果建议那(1 ) 磁性的矿物质集合上面 9.82 m 沉积(相应于最后 160 ka ) 被伪单人赛领域磁铁矿统治，与在冰川的时期的更丰富的粗糙的谷物比在间冰期的时期；(2 ) 最高沉积的 6.50 m (相应于最后 70 ka ) 在磁性的矿物质的谷物尺寸显示出重要时间的变化，可能反映在印度夏天季风的变化和诺思大西洋(Heinrich 事件) 的快速的冷事件之间的电视连接；(3 ) 在 9.82 m 下面的沉积被顺磁的矿物质(可能包括的黄铁矿) 统治，建议减少的成岩作用。核心 MD77-181 的磁性的记录在阿拉伯的海比得上在孟加拉，和 ODP Hole722B 的海湾的核心 MD77-180 的那些。这研究建议在 160 kasignificantly 改变了的 ~ 的苍白的海洋学的事件北印度洋的氧化还原作用状态，从在到 oxic 的事件前的减少的环境或在事件以后的 suboxic 环境。

关键词：磁记录岩化作用北印度洋古环境 MD77-181

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New paleomagnetic results from the Yangzhuang Formation of the Jixian System,North China,and tectonic implications

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Chinese Science Bulletin 2005年第14期50卷 1483-1489页

作者： WU Huaichun zhang shihong LI Zheng-Xiang LI Haiyan DONG Jin State Key Laboratory of Geological Processes and Mineral Resources & Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education China University of Geosciences Beijing 100083 China Tectonics Special Research Centre School of Earth and Geographical Sciences The University of Western Australia Crawley WA 6009 Australia

A paleomagnetic study was carried out on the Yangzhuang Formation (~1350 Ma) of the Jixian System in the North China Block (NCB). Detailed stepwise thermal demagnetization isolated two components. The soft compo- nent (component A) was interpreted as a remagnetization in the recent geomagnetic field. The hard component (compo- nent B) with higher unblocking-temperatures was carried by hematite. Its site-mean direction is D/I = 77.6°/-24.3° (κ = 5.4, α95 = 18.3°, N = 15 sites) before, and D/I = 72.2°/11.5° (κ = 24.6, α95 = 7.9°) after tilt correction. It passes a fold test (Mesozoic folding) at 99% confidence level and reversal test at 95% confidence level. The corresponding pole locates at 17.3°N, 214.5°E (dp = 4.1°, dm = 8.0°). A best fit of paleo- magnetic poles from the NCB, Baltica, Siberia and the ap- parent polar wander path for Laurentia suggests a long-lived connection between these paleo-continents between ~1800 and 1350 Ma.

关键词：古磁学中元古代中国岩石

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发电锅炉材料与防护涂层的磨蚀机制与研究展望

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金属学报 2022年第3期58卷 272-294页

作者：张世宏胡凯刘侠杨阳安徽工业大学先进金属材料绿色制备与表面技术教育部重点实验室马鞍山243002 安徽工业大学材料科学与工程学院马鞍山243002

作为目前主要的电力供应设备和CO_(2)排放场所,随着"碳达峰-碳中和"目标的提出,燃煤发电锅炉逐渐向零碳/低碳排放的生物质发电锅炉和生物质-燃煤混烧发电锅炉方向发展。燃煤及生物质中含硫、含氯组分的腐蚀及磨损行为对锅炉安全长效运... 详细信息

作为目前主要的电力供应设备和CO_(2)排放场所,随着"碳达峰-碳中和"目标的提出,燃煤发电锅炉逐渐向零碳/低碳排放的生物质发电锅炉和生物质-燃煤混烧发电锅炉方向发展。燃煤及生物质中含硫、含氯组分的腐蚀及磨损行为对锅炉安全长效运行构成严重威胁,因此,沉积防护涂层成为提高锅炉耐蚀耐磨性能的便捷高效手段。本文综述了目前燃煤锅炉、生物质锅炉及生物质-燃煤混烧锅炉基体材料和防护涂层在高温腐蚀及冲蚀磨损方面的研究成果,针对燃煤及生物质燃烧环境,总结了高温硫酸盐腐蚀及碱金属氯化物腐蚀机理,阐述了生物质-燃煤混烧环境中灰沉积-冲击机制,介绍了目前锅炉基体材料的应用现状,归纳了在腐蚀和磨损不同环境下合金涂层、陶瓷涂层、金属陶瓷涂层的设计原则、制备方法及应用现状。指出了当前锅炉防护研究亟待解决的问题,包括:热腐蚀机理研究不深入,缺乏准确的腐蚀-磨损预测模型,防护涂层种类较少。最后,提出采用材料基因组工程及机器学习方法来加速材料研发,开展腐蚀-磨损机理及多因素耦合模型的研究,同时强调粉末合成设计-涂层结构设计-服役性能评价一体化研究对新型防护涂层研发的重要性。

关键词：硫腐蚀氯腐蚀冲蚀磨损发电锅炉防护涂层

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Fundamental and Technical Challenges for a Compatible Design Scheme of Oxyfuel Combustion Technology

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Engineering 2015年第1期1卷 139-149页

作者： Chuguang Zheng Zhaohui Liu Jun Xiang Liqi zhang shihong zhang Cong Luo Yongchun Zhao State Key Laboratory of Coal Combustion Huazhong University of Science and Technology

Oxyfuel combustion with carbon capture and sequestration(CCS) is a carbon-reduction technology for use in large-scale coal-fired power plants. Significant progress has been achieved in the research and development of this technology during its scaling up from 0.4 MWth to 3 MWth and 35 MWth by the combined efforts of universities and industries in China. A prefeasibility study on a 200 MWe large-scale demonstration has progressed well, and is ready for implementation. The overall research development and demonstration(RD&D) roadmap for oxyfuel combustion in China has become a critical component of the global RD&D roadmap for oxyfuel combustion. An air combustion/oxyfuel combustion compatible design philosophy was developed during the RD&D process. In this paper, we briefly address fundamental research and technology innovation efforts regarding several technical challenges, including combustion stability, heat transfer, system operation, mineral impurities, and corrosion. To further reduce the cost of carbon capture, in addition to the large-scale deployment of oxyfuel technology, increasing interest is anticipated in the novel and nextgeneration oxyfuel combustion technologies that are briefly introduced here, including a new oxygen-production concept and flameless oxyfuel combustion.

关键词：富氧燃烧技术设计哲学兼容燃煤发电厂燃烧稳定性减排技术预可行性组成部分

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Early diagenetic growth of carbonate concretions in the upper Doushantuo Formation in South China and their significance for the assessment of hydrocarbon source rock

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Science China Earth Sciences 2008年第9期51卷 1330-1339页

作者： DONG Jin zhang shihong JIANG GanQing ZHAO QingLe LI HaiYan SHI XiaoYing LIU JunLai State Key Laboratory of Geological Process and Mineral Resources China University of GeosciencesBeijing 100083China Department of Geoscience University of NevadaLas VegasNV 89154-4010USA

Mineralogical and textural characteristics and organic carbon composition of the carbonate concretions from the upper Doushantuo Formation (ca. 551 Ma) in the eastern Yangtze Gorge area reveal their early diagenetic (shallow) growth in organic-rich shale. High organic carbon content (up to 10%) and abundance of framboidal pyrites in the hosting shale suggest an anoxic or euxinic depositional environment. Well-preserved cardhouse clay fabrics in the concretions suggest their formation at 0-3 m burial depth, likely associated with microbial decomposition of organic matter and anaerobic oxidation of methane. Gases through decomposition of organic matter and/or from methanogenesis created bubbles and cavities, and anaerobic methane oxidation at the sulfate reduction zone resulted in carbonate precipitation, filling in bubbles and cavities to form spherical structures of the concretions. Rock pyrolysis analyses show that the carbonate concretions have lower total organic carbon (TOC) content but higher effective carbon than those in the host rocks. This may be caused by enclosed organic matter in pores of the concretions so that organic matter was protected from further modification during deep burial and maintained high hydrocarbon generating potential even in over-matured source rock. As a microbialite sensu latu, concretions have special growth conditions and may provide important information on the microbial activities in depositional and early burial environments.

关键词： Doushantuo Formation carbonate concretion sedimentary environment hydrocarbon source rock

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South China's Gondwana connection in the Paleozoic:Paleomagnetic evidence

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Progress in Natural Science:Materials International 2004年第1期14卷 86-91页

作者： zhang shihong*(School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China) China Univ Geosci Sch Earth Sci & Resources Beijing 100083 Peoples R China

The reconstruction in which the South China Block (SCB) lies along the Great India Australia region of Gondwana margin is tested by using existing Paleozoic paleomagnetic data. Under the proposed reconstruction, all six high quality paleopoles from the SCB between the Early Cambrian and late Early Devonian (～400 Ma) are in good agreement with coeval paleopoles from Gondwana. Thereafter, the apparent polar wander paths for the SCB and Gondwana diverge markedly. This indicates that the SCB had been part of Gondwana and the connection was intact from at least Early Cambrian until late Early Devonian, but they began to separate by late Middle Devonian (～375 Ma).

关键词： South China block Gondwana paleomagnetism reconstruction

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Magnetic Fabric Study of Late Holocene Sediments in Huangqihai Lake,Inner Mongolia and its Sedimentary Significance

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Acta Geologica Sinica(English Edition) 2013年第1期87卷 186-196页

作者： DONG Jin GAO Rui WANG Yong zhang shihong YAO Peiyi CHI Zhenqing ZHAO Zhili Institute of Geology Chinese Academy of Geological Sciences Key Laboratory of Earth Probe and Geodynamics Ministry of Land and Resources of the People's Republic of China State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences

The detailed magnetic susceptibility anisotropy study on the sediments of two sections, which are located in the lake-center and the lakeshore of the Huangqihai Lake, Inner Mongolia, revealed their hydrodynamics and sedimentary environment changes in the recent 2000 years. The results show that the sediments of two sections both display normal depositional magnetic fabrics, of which the minimum susceptibility axes （K3） are oriented perpendicular to the bedding plane and the maximum magnetic susceptibility axes （K~） lie parallel with the bedding plane. In addition, the iakeshore presents higher magnetic anisotropy degree （P）, magnetic foliation （F） and current factor （F~） than the lake-center, showing that the lakeshore has higher flow velocity. For the west Huangqihai Lake （HQW） section in the lake-center, the magnetic matrix grain degree （Q） and the inclination of the minimum susceptibility axes sharply increased and decreased, respectively, at a depth of about 10 cm, 24 cm, 45 cm and 74 cm, which indicate abnormal depositional events with strong kinetic energy. Through comparative analysis, the HQW section can be divided into three stages from top to bottom. The upper stage was a stable depositional environment with strong hydrodynamic energy and low water level, which shows relatively higher Fs value and the Q value varies similarly with P and F. The middle stage was a stable depositional environment with high water level and low hydrodynamic energy, intermitted with high-energy abnormal events, which shows relatively lower Fs and the Q value was negatively correlated with P and F. The lower stage was an unstable depositional environment with low hydrodynamic energy and high water level, which shows relatively lower P, F, and F~ value.

关键词： magnetic fabric hydrodynamics sedimentary environment Huangqihai Lake InnerMongolia

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