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新生代特提斯海峡关闭过程及其圈层耦合效应

科学通报 2024年第2期69卷 184-199页

作者：孙继敏沙金庚王世骐中国科学院地质与地球物理研究所北京100029 中国科学院大学地球与行星科学学院北京100049 中国科学院南京地质与古生物研究所南京210008 中国科学院古脊椎动物与古人类研究所北京100044

新生代是地球历史上岩石圈、水圈、大气圈、生物圈发生宏观巨变的重要地质时期,包括了冈瓦纳大陆的快速裂解、海峡的开启与闭合、海洋与大气环流的重组、温室到冰室的气候转型以及动植物的快速演替,因而是开展圈层耦合研究的关键地质时... 详细信息

新生代是地球历史上岩石圈、水圈、大气圈、生物圈发生宏观巨变的重要地质时期,包括了冈瓦纳大陆的快速裂解、海峡的开启与闭合、海洋与大气环流的重组、温室到冰室的气候转型以及动植物的快速演替,因而是开展圈层耦合研究的关键地质时期.本文以特提斯海峡为例,从地球系统科学角度,阐述特提斯海峡的闭合过程、时间及其对生物圈、海洋环流、大气圈的链式影响和反馈.核心思想如下:特提斯海峡自渐新世至中-中新世晚期(34∼12.8 Ma)历经了阶段性的演化过程,渐新世时期的特提斯海峡很好地连通了低纬度的印度洋-古地中海-大西洋;早中新世时(21∼19 Ma),伴随着非洲-阿拉伯板块与欧亚大陆的汇聚,海峡的连通能力下降了90%;中-中新世气候适宜期(17∼15 Ma)以海岸潟湖相为主、夹浅海相环境;15∼12.8 Ma期间演化为陆相环境为主、夹短暂的周期性海侵,且具有10万年的准周期;12.8 Ma之后,海峡永久关闭.特提斯海峡的闭合过程对生物圈产生了显著影响,伴随海峡的逐渐闭合,海洋无脊椎动物的腹足类、棘皮类,逐渐从特提斯海向印度洋、西太平洋迁移.对哺乳动物而言,尽管早中新世已经有零星的哺乳动物在非洲-阿拉伯与欧亚大陆之间迁徙,但真正大规模的哺乳动物双向迁徙主要发生在18∼17 Ma之后.此时,以海岸潟湖相为主的海峡已不足以构成善于利用迁徙路径的哺乳动物的地理屏障,表现为非洲的灵长类、长鼻类、蹄兔类等向欧亚大陆迁徙.而欧亚大陆的食肉类、犀类、猪类、反刍类、啮齿类等向非洲-阿拉伯迁徙.特提斯海峡的关闭对海洋环流也有重要影响,主要表现为特提斯海峡的关闭减少了来自低纬的温暖、高盐海水向大西洋及印度洋南部的注入,由此降低了低纬的热量向南半球高纬的径向输送,在一定程度上加强了东南极冰盖的扩张及南极的变冷.特提斯海的退缩以及特提斯海峡在13 Ma左右的永久关闭,也深刻影响到南亚季风环流,表现为索马里急流和南亚季风的加强.

关键词：阿拉伯与欧亚大陆汇聚特提斯海峡闭合海陆分布地球圈层相互作用环境效应

青藏高原中部伦坡拉盆地新生代地层年代、古环境与古高度研究综述

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科学通报 2024年第18期69卷 2463-2479页

作者：孙继敏李建国刘卫国靳春胜中国科学院地质与地球物理研究所北京100029 中国科学院大学地球与行星科学学院北京100049 中国科学院南京地质与古生物研究所南京210008 中国科学院地球环境研究所西安710061

新生代以来,地球上最为显著的地貌变化就是印度与亚洲板块碰撞导致的青藏高原隆升.长期以来,关于碰撞的起始时间、碰撞方式与过程以及古高度等均有较大的争议.本文主要针对近年在古高度重建方面最受关注的高原中部伦坡拉盆地的研究进行... 详细信息

新生代以来,地球上最为显著的地貌变化就是印度与亚洲板块碰撞导致的青藏高原隆升.长期以来,关于碰撞的起始时间、碰撞方式与过程以及古高度等均有较大的争议.本文主要针对近年在古高度重建方面最受关注的高原中部伦坡拉盆地的研究进行了综述,旨在总结年代学、古环境演变以及古高度重建方面的进展和分歧.首先,伦坡拉盆地的新生代地层年代近年获得了长足的进展,特别是在伦坡拉盆地的牛堡组和丁青组地层陆续发现了10层左右的凝灰岩,为限定地层时代提供了很好的绝对年龄约束,牛堡组的时代已经从此前的古新世-始新世调整为始新世-早渐新世,丁青组则为晚渐新世至晚中新世.其次,伦坡拉盆地牛堡组的植物化石揭示了早始新世晚期(47 Ma)为热带亚热带湿润的森林环境,始新世晚期(39 Ma)则为亚热带开阔森林环境.丁青组的植被类型以暖温带针阔叶混交林为主.丁青组中、下部地层记录了40万年准周期的干湿旋回,表明地球轨道的长周期偏心率波动驱动了该时期伦坡拉盆地的古降水变化;而丁青组上部的稳定同位素记录揭示了14 Ma以来高原中部发生的降温与干旱增强事件,而且该事件是对14 Ma以来东南极冰盖扩张、全球持续变冷事件的响应.此外,伦坡拉盆地牛堡组中段及丁青组含有丰富的动植物化石.近年,越来越多的生物学证据(包括植物大化石与孢粉)表明,伦坡拉盆地在晚始新世的古高度基本在2000~2700 m左右,晚渐新世-早中新世初期(26~20 Ma)的古高度为3000~3200 m.即便到晚中新世早期的12 Ma,水生浮叶植物的证据表明,伦坡拉盆地古湖面的最大高度为3400 m,由此表明伦坡拉盆地的海拔高度很可能在晚中新世以后仍有1200 m左右的上升.

关键词：青藏高原隆升伦坡拉盆地牛堡组与丁青组时代古环境古高度

High-resolution anisotropy of magnetic susceptibility record in the central Chinese Loess Plateau and its paleoenvironment implications

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Science China Earth Sciences 2012年第3期55卷 488-494页

作者： LIU WeiMing sun jimin Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

We analyze high-resolution anisotropy of magnetic susceptibility (AMS) of the loess-paleosol successions at Luochuan, central Chinese Loess Plateau, in order to investigate the AMS characteristics and their climatic implications. Our results indicate a normal sedimentary magnetic fabric for almost of all samples, characterized by minimum susceptibility axes grouped in an almost vertical direction. Magnetic foliation and anisotropy degree show upwards decreasing trend due to decreasing post-depositional compaction. Magnetic lineations show no preferred directions and thus cannot indicate paleowind patterns. AMS parameters at Luochuan are controlled by particle size, pedogenesis, and sedimentary compaction. The high peaks of magnetic foliation and anisotropy degree of L2, L3, L6, L9, and L15 correspond to the coarse particle sizes of these loess beds, indicating the grain-size dependence of AMS.

关键词： Chinese loess anisotropy of magnetic susceptibility Quaternary Luochuan

不同提取工艺桔梗多糖的理化性质分析及其对奥沙利铂体内分布的影响

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食品工业科技 2024年第18期45卷 326-333页

作者：孙济民吴亚运梁敏杰赵瑞芝王岩广东药科大学中药学院广东广州510000 广州中医药大学第二临床医学院广东广州510000

目的:探究不同提取工艺桔梗多糖(PGP)的理化性质,不同提取工艺所得的PGP对奥沙利铂(OXA)体内分布的影响。方法:本研究采用了热水提取(HW)、醋酸辅助提取(CA)、氨水辅助提取(KA)、超声辅助提取(UA)制备桔梗多糖,通过红外光谱、紫外光谱... 详细信息

目的:探究不同提取工艺桔梗多糖(PGP)的理化性质,不同提取工艺所得的PGP对奥沙利铂(OXA)体内分布的影响。方法:本研究采用了热水提取(HW)、醋酸辅助提取(CA)、氨水辅助提取(KA)、超声辅助提取(UA)制备桔梗多糖,通过红外光谱、紫外光谱、凝胶色谱、高效液相色谱等方法测定多糖的理化性质;建立OXA电感耦合等离子体-质谱(ICP-MS)体内分析方法,考察OXA单用组、OXA联用PGP-HW组、OXA联用PGP-CA组、OXA联用PGP-KA组、OXA联用PGP-UA组SD大鼠体内奥沙利铂分布的变化;使用Western Blot方法来测定肺组织中Oct-2和Pg-P蛋白的表达水平,考察PGP改变OXA体内分布的机制。结果:四种桔梗多糖在理化性质方面呈现出明显的区别。其中,PGP-KA的得率最高;四种桔梗多糖红外图谱均具备典型的多糖特征吸收峰;在分子量组成上,它们主要由7 kDa和3790 kDa两个分子量构成,但各自的分子量分布比例有所不同。此外,这四种桔梗多糖都含有甘露糖(Man)、鼠李糖(Rha)、半乳糖醛酸(GalA)、葡萄糖(Glu)、半乳糖(Gal)以及阿拉伯糖(Ara),但比例存在差异;四种多糖粒径主要集中在300 nm左右,且具有良好的溶液稳定性;与OXA单用组比,OXA联用PGP-CA组、OXA联用PGP-KA组分别增加肺组织OXA含量为36.93%和35.12%,且OXA联用PGP-KA组显著(P<0.05)增加Oct-2蛋白表达水平,而P-g-P蛋白表达水平无显著差异。结论:不同的提取工艺获得的PGP的理化性质不同,其中OXA联用PGP-CA组和OXA联用PGPKA组能显著增加OXA在肺组织分布水平,其机制可能与增加肺组织中Oct-2的表达量有关。

关键词：提取工艺桔梗多糖奥沙利铂多糖构效关系体内分布

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Stepwise advance of the Mu Us Desert since late Pliocene:Evidence from a red clay-loess record

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Chinese Science Bulletin 1999年第13期44卷 1211-1214页

作者： Zhongli Ding jimin sun Dongsheng Liu Institute of Geology Chinese Academy of Sciences Beijing China

Analyses of paleomagnetic polarity reversals, magnetic susceptibility and grain size on the red clay-loess sequence, about 280 m thick, at Jingbian show that this sequence contains most of the stratigraphic units recorded in the standard red clay-loess sections of the Loess Plateau over the past 3.5 Ma. Using sand particle percentage ( > 63 μm%) of the eolian sequence as a proxy indicator of desert extent and aridity in the dust source regions, it is found that during the past 3.5 Ma, there are three important climatic events indicating the advance of the Mu Us Desert. The events occurred at about 2.6, 1.1 and 0.6 MaBP, respectively. The stepwise advance of the Mu Us Desert may be linked closely to increase in global ice volume and uplift of the Tibetan Plateau in the late Cenozoic.

关键词： loess desert Quaternary.

Chronology of environmental events over East Asia during the past 130 ka

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Chinese Science Bulletin 1998年第21期43卷 1761-1769页

作者： Zhongli Ding jimin sun Zhiwei Yu Dongsheng Liu Chinese Acad Sci Inst Geol Beijing 100029 Peoples R China China Univ Min Dept Geol Xuzhou 221008 Peoples R China

In the transitional region between the Loess Plateau and deserts, 4 sections located respectively at Yuling, Hengshan, Dingbian and Huining of China are studied. The high-resolution paleoclimatic records obtained show that environmental events on varying time scales have happened over East Asia. These events are dated with the time scales established using the recently-developed approach of Automatic Orbital Tuning. This leads to the establishment of the chronology of the environmental events.

关键词： environmental events time scale Chinese loess.

Paleoclimatic and provenance implications of magnetic parameters from the Miocene sediments in the Subei Basin

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Earth and Planetary Physics 2020年第3期4卷 308-316页

作者： YouSheng Li jimin sun ZhiLiang Zhang Bai Su ShengChen Tian MengMeng Cao Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Thick sediments from foreland basins usually provide valuable information for understanding the relationships between mountain building,rock denudation,and sediment *** this paper,we report environmental magnetic measurements performed on the Miocene sediments in the Subei Basin,northeastern Tibetan *** results show two different ***,the bulk susceptibility and SIRM,ARM,and HIRM mainly reflect the absolute-concentration of magnetic minerals;all have increased remarkably since 13.7 Ma,related to provenance change rather than climate ***,the ratios of IRM100mT/SIRM,IRM100mT/IRM30mT,and IRM100mT/IRM60mT,together with the redness and S ratio,reflect the relative-concentration of hematite,being *** vertical changes correlate in general with the long-term Miocene climatic records of marine oxygen isotope variations,marked by the existence of higher ratios between 17 and 14 *** may imply that global climate change,rather than uplift of the Tibetan Plateau,played a dominant role in the long-term climatic evolution of the Subei area from the early to middle Miocene.

关键词： Environmental magnetism MMCO global cooling the Subei Basin

Pedogenic carbonate isotope record of vegetational evolution since late Miocene in Loess Plateau

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Chinese Science Bulletin 1999年第11期44卷 1034-1038页

作者： Shiling Yang Zhongli Ding Zhaoyan Gu jimin sun Shangfa Xiong Chinese Acad Sci Inst Geol Beijing 100029 Peoples R China

lsotopic analyses for paleovegetational evolution have been carried out on samples of the pedogenic carbonate nodules in the Red Clay-Loess sequence at Lingtai （35°N）, the Loess Plateau. Stable carbon isotopic composition indicates that （ ⅰ ） C4 plants might be present at least by7.0 Ma; （ ⅱ ） C4 plants expanded gradually between ～4.0 and ～3.2 Ma, and their biomass fraction was up to 50%; and （ ⅲ ） the biomass of C4 vegetation since ～2.0 Ma seems to have been decreased to the level （about 20%） before 4.0 Ma. C4 plant expansion at Lingtai cannot be fully understood with the 'global C4 expansion' model because it occurred much later up to 3.0 Ma than in Pakistan, which indicates that some changes in the regional climatic system may also contribute to C3/C4 shift except changes in atmospheric CO2 concentrations and temperature. The latitudinal zone for C3/C4 transition seems to move southwards slightly in East Asia, compared with the case in North America where 37°N is the ideal

关键词： pedogenic carbonate palaeovegetation shift atmospheric CO2 concentrations.

Control of electromechanical performance in 3D printing latticestructured BaTiO_(3) piezoelectric ceramics

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Journal of Advanced Ceramics 2024年第7期13卷 987-1001页

作者： Zhujun Jiang Yinghong sun jimin Chen Yong Zeng Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China Beijing Engineering Research Center of 3D Printing for Digital Medical Health Beijing University of TechnologyBeijing 100124China

Barium titanate(BaTiO_(3))piezoelectric ceramics with triply periodic minimal surface(TPMS)structures have been frequently used in filters,engines,artificial bones,and other fields due to their high specific surface area,high thermal stability,and good heat ***,only a limited number of studies have analyzed the effect of various parameters,such as different wall thicknesses and porosities of TPMS structures,on ceramic electromechanical *** this study,we first employed vat photopolymerization(VPP)three-dimensional(3D)printing technology to fabricate high-performance BaTiO_(3) *** investigated the slurry composition design and forming process and designed a stepwise sintering postprocessing technique to achieve a density of 96.3%and a compressive strength of 250±25 MPa,with the piezoelectric coefficient(d_(33))reaching 263 pC/***,we explored the influence of three TPMS structures,namely,diamond,gyroid,and Schwarz P,on the piezoelectric and mechanical properties of BaTiO_(3) ceramics,with the gyroid structure identified as exhibiting optimal ***,we examined the piezoelectric and mechanical properties of BaTiO_(3) ceramics with the gyroid structure of varying wall thicknesses and porosities,thus enabling the modulation of ceramic electromechanical performance.

关键词： three-dimensional(3D)printing piezoelectric ceramics porous structure mechanical properties electrical properties