检索结果-南通市图书馆

Cryogenian and Ediacaran integrative stratigraphy, biotas, and palaeogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

引用

Science China earth Sciences 2024年

作者： Lang SUN Malik Muhammad Saud Sajid KHAN Chuan YANG Zhixin SUN Bing PAN Shehryar AHMED Lanyun MIAO Weichen SUN Chunlin HU Xiaojuan SUN Cui LUO Bo CHEN Zongjun YIN Fangchen ZHAO Guoxiang LI Maoyan ZHU State key laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of Sciences College of earth and planetary Sciences University of Chinese Academy of Sciences

The complex evolutionary history of the Qinghai-Tibetan Plateau and its surrounding areas, including the continental blocks (Indian, Lhasa, South Qiangtang, Tarim, Olongbuluk, Central Qilian, Alxa, North China, Yangtze, Central Iran and Oman) and the orogenic belts between them, has long been the frontier in earth science research. The Cryogenian and Ediacaran strata are extensively distributed in these blocks. Specifically, relatively complete Cryogenian and Ediacaran successions have been discovered in Oman, Indian, Yangtze, and Tarim blocks, while only the Ediacaran successions have been reported in Iran,the South Qiangtang, Central Qilian, Alxa, and North China blocks. Based on previous studies together with the integration of new materials and advancement obtained through the Second Tibetan Plateau Scientific Expedition and Research, this review aims to synthesize a correlative stratigraphic framework of the representative Cryogenian and Ediacaran sequences from the Qinghai-Tibetan Plateau and its surrounding areas. Furthermore, the Cryogenian and Ediacaran biotas and major geological events in these areas are comprehensively discussed in aspects of current research status. The results indicate that, in general,Ediacaran fossils of each area exhibit distinct features in preservation and assemblage composition, but the typical late Ediacaran fossils Cloudina and Shaanxilithes have been reported from most of these areas. In addition to the two global Cryogenian glaciations, late Ediacaran glaciogenic deposits are extensively recorded in the areas within and around the northern QinghaiTibetan Plateau (including the North China, Alxa, Central Qilian, Olongbuluk, and Tarim blocks, and the North Qilian Accretionary Belt), as well as central and southern Iran. However, further research is required to determine the age, distribution, and origin of these late Ediacaran glaciogenic deposits. Meanwhile, the middle Ediacaran DOUNCE/Shuram Excursion is widely documented in

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Persistent Variations in the East Asian Trough from March to April and the Possible Mechanism

引用

Advances in Atmospheric Sciences 2024年第4期41卷 737-753,I0002-I0004页

作者： Shui YU Jianqi SUN Nansen-Zhu International Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of earth and planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The East Asian trough(EAT)profoundly influences the East Asian spring *** this study,the relationship of the EATs among the three spring months is *** analysis shows that the variation in March EAT is closely related to that of April *** empirical orthogonal function(EEOF)analysis also confirms the co-variation of the March and April *** positive/negative EEOF1 features the persistent strengthened/weakened EAT from March to *** investigation indicates that the variations in EEOF1 are related to a dipole sea surface temperature(SST)pattern over the North Atlantic and the SST anomaly over the tropical Indian *** dipole SST pattern over the North Atlantic,with one center east of Newfoundland Island and another east of Bermuda,could trigger a Rossby wave train to influence the EAT in March−*** SST anomaly over the tropical Indian Ocean can change the Walker circulation and influence the atmospheric circulation over the tropical western Pacific,subsequently impacting the southern part of the EAT in March−*** the SST factors,the Northeast Asian snow cover could change the regional thermal conditions and lead to persistent EAT anomalies from March to *** three impact factors are generally independent of each other,jointly explaining large variations in the EAT ***,the signals of the three factors could be traced back to February,consequently providing a potential prediction source for the EAT variation in March and April.

关键词： spring East Asian trough sea surface temperature snow cover

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Helmholtz decomposition with a scalar Poisson equation in elastic anisotropic media

引用

Petroleum Science 2024年第3期21卷 1597-1610页

作者： Xin-Yu Fang Gang Yao Qing-Qing Zheng Ping-Min Zhang Di Wu Feng-Lin Niu State key laboratory of Petroleum Resources and Engineering China University of Petroleum (Beijing) Unconventional Petroleum Research Institute China University of Petroleum (Beijing) Department of Mathematics College of Science China University of Petroleum (Beijing) College of Geophysics China University of Petroleum (Beijing) Department of earth Environmental and Planetary Sciences Rice University

P-and S-wave separation plays an important role in elastic reverse-time migration. It can reduce the artifacts caused by crosstalk between different modes and improve image quality. In addition, P-and Swave separation can also be used to better understand and distinguish wave types in complex media. At present, the methods for separating wave modes in anisotropic media mainly include spatial nonstationary filtering, low-rank approximation, and vector Poisson equation. Most of these methods require multiple Fourier transforms or the calculation of large matrices, which require high computational costs for problems with large scale. In this paper, an efficient method is proposed to separate the wave mode for anisotropic media by using a scalar anisotropic Poisson operator in the spatial *** 2D problems, the computational complexity required by this method is 1/2 of the methods based on solving a vector Poisson equation. Therefore, compared with existing methods based on pseudoHelmholtz decomposition operators, this method can significantly reduce the computational cost. Numerical examples also show that the P and S waves decomposed by this method not only have the correct amplitude and phase relative to the input wavefield but also can reduce the computational complexity significantly.

关键词： Anisotropic media Scalar anisotropic Poisson equation Improved elastic wavefield decomposition

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Spatiotemporal variation of rainy season span and precipitation recorded by lacustrine laminated pollen in the Tibetan Plateau during the past two millennia

引用

Science China earth Sciences 2024年第3期67卷 789-801页

作者： Anning CUI Houyuan LU Juzhi HOU Xingqi LIU Deke XU key laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for earth Science Chinese Academy of SciencesBeijing 100029China College of earth and planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Group of Alpine Paleoecology and Human Adaptation State Key Laboratory of Tibetan Plateau Earth SystemResources and EnvironmentInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Capital Normal University College of Resource Environment and Tourism Beijing 100048China

The quantitative reconstruction of the length of the rainy season and precipitation on the Tibetan Plateau(TP) is crucial for revealing the spatiotemporal evolution of the Westerlies and Asian summer monsoon, as well as its ecological and environmental effects. Accurately determining the start and end times of the rainy season on the Plateau remains *** study determined the start and end times of the rainy season in different locations on the Plateau by identifying precipitation inflection points. We calculated the duration and precipitation amount of the rainy season and established a transfer function between the modern pollen assemblages and them. Then, we reconstructed the rainy season variations in Kusai Lake(northern TP) and Jiang Co(central TP) during the past two millennia. The results showed that, the rainy season precipitation in Kusai Lake recorded five periods of high precipitation: AD 580–680, 1000–1100, 1200–1450, 1550–1780, and 1920–present, corresponding to the stages with long rainy season. The rainy season precipitation sequence in Jiang Co recorded four periods of high precipitation: AD 80–500, 800–950, 1250–1450, and 1780–present, which is consistent with the long rainy season before AD 1000 but unclear afterward. Spatially, rainy season precipitation on the Plateau exhibited four patterns: “wet in both north and south” may be related to abnormally strong summer monsoons;“dry in both north and south” likely associated with weak Westerly wind and weak summer monsoon;“wet in the south and dry in the north” linked to strong summer monsoon and weak Westerly wind;and “dry in the south and wet in the north” connected to weak summer monsoon and strong Westerly wind. This study revealed the spatiotemporal evolution pattern of the rainy season onset and end, duration, and precipitation amount on the Plateau over the past two millennia. It provides natural background support for further understanding the coupling between Westerly wind and Asia

关键词： Tibetan Plateau Past two millennia Rainy season length Rainy season precipitation Quantitative reconstruction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Trace Element Mobility in Subducted Marble and Associated Eclogite:Constraints from UHP Rocks in the Shuanghe Area,Central-East China

引用

Journal of earth Science 2024年第1期35卷 1-15页

作者： Xingao Hou Zhiqiang Yu Shefa Chen Lei Liu Yilin Xiao key laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring Ministry of EducationSchool of Geosciences and Info-PhysicsCentral South UniversityChangsha 410083China key laboratory of Mineralogy and Metallogeny Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China CAS key laboratory of Crust-Mantle Materials and Environments School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China

In order to decipher element mobility in UHP meta-sedimentary rocks in the continental subduction zone,major and trace element compositions are investigated for a continuous profile from a representative UHP region in the Dabie *** the lithologic contact zone,contents of K,Ca,LREE,and LILE exhibit varying degrees of downward trends in both marble and eclogite toward the contact zone,indicating that marble and their associated eclogite can release a large amount of K,Ca,and a small number of LILEs and *** is the main Ti phase in both marble and *** rims around rutile can occasionally be seen in *** of Ti and HFSE exhibit a well-coupled relation among marble and eclogite,indicating that substantial Ti and HFSEs were migrated from eclogite to marble,in accord with the capacity of a melt *** and titanites in marble exhibit a relatively limited variation in Nb/Ta ratios(12.9-16.2),similar to those of titanites in eclogite(14.2-16.7),which demonstrates that rutiles and titanites in marble were sourced from eclogite because of short-distance migrations of Ti and *** to the P-T path and the temperature and pressure conditions of the peak metamorphism reported by previous studies,the eclogite associated with marble may not form supercritical fluids in the subduction zone because of the addition of carbonate minerals.

关键词： UHP metamorphism eclogite marble element migration fluid actions geochemistry

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Universal insertion of molecules in ionic compounds under pressure

引用

National Science Review 2024年第1期11卷 120-128页

作者： Feng Peng Yanming Ma Chris J.Pickard Hanyu Liu Maosheng Miao College of physics and Electronic Information Luoyang Normal University Department of Chemistry and Biochemistry California State University Northridge State key laboratory of Superhard Materials & key laboratory of Material Simulation Methods and Software of Ministry of Education College of Physics Jilin University International Center of Future Science Jilin University Department of Materials Science & Metallurgy University of Cambridge Advanced Institute for Materials Research Tohoku University Department of earth Science University of California Santa Barbara

Using first-principles calculations and crystal structure search methods, we found that many covalently bonded molecules such as H2, N2, CO2, NH3, H2O and CH4may react with NaC l, a prototype ionic solid,and form stable compounds under pressure while retaining their molecular structure. These molecules,despite whether they are homonuclear or heteronuclear, polar or non-polar, small or large, do not show strong chemical interactions with surrounding Na and Cl ions. In contrast, the most stable molecule among all examples, N2, is found to transform into cyclo-N5-anions while reacting with NaC l under high pressures. It provides a new route to synthesize pentazolates, which are promising green energy materials with high energy density. Our work demonstrates a unique and universal hybridization propensity of covalently bonded molecules and solid compounds under pressure. This surprising miscibility suggests possible mixing regions between the molecular and rock layers in the interiors of large planets.

关键词： molecule-solid hybrid materials high-pressure crystal structure prediction density functional theory planet interior

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

CAS-ESM2.0 Dataset for the Carbon Dioxide Removal Model Intercomparison Project(CDRMIP)

引用

Advances in Atmospheric Sciences 2024年第5期41卷 989-1000页

作者： Jiangbo JIN Duoying JI Xiao DONG Kece FEI Run GUO Juanxiong HE Yi YU Zhaoyang CHAI He ZHANG Dongling ZHANG Kangjun CHEN Qingcun ZENG International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State key laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China State key laboratory of earth Surface Processes and Resource Ecology College of Global Change and Earth System ScienceBeijing Normal UniversityBeijing 100875China State key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Understanding the response of the earth system to varying concentrations of carbon dioxide(CO_(2))is critical for projecting possible future climate change and for providing insight into mitigation and adaptation strategies in the near *** this study,we generate a dataset by conducting an experiment involving carbon dioxide removal(CDR)—a potential way to suppress global warming—using the Chinese Academy of Sciences earth System Model version 2.0(CASESM2.0).A preliminary evaluation is *** model is integrated from 200–340 years as a 1%yr^(−1) CO_(2) concentration increase experiment,and then to~478 years as a carbon dioxide removal experiment until CO_(2) returns to its original ***,another 80 years is integrated in which CO_(2) is kept *** in the 2-m temperature,precipitation,sea surface temperature,ocean temperature,Atlantic meridional overturning circulation(AMOC),and sea surface height are all *** the ramp-up period,the global mean 2-m temperature and precipitation both increase while the AMOC *** of all the above variables change in the opposite direction in the ramp-down period,with a delayed peak relative to the CO_(2) *** CO_(2) returns to its original value,the global mean 2-m temperature is still~1 K higher than in the original state,and precipitation is~0.07 mm d^(–1) *** the end of the simulation,there is a~0.5°C increase in ocean temperature and a 1 Sv weakening of the *** model simulation produces similar results to those of comparable experiments previously reported in the literature.

关键词： CAS-ESM2.0 CDRMIP carbon dioxide removal AMOC temperature precipitation sea surface height

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Long radial coherence of electron temperature fluctuations in non-local transport in HL-2A plasmas

引用

Chinese physics B 2024年第2期33卷 413-420页

作者：石中兵方凯锐李景春邹晓岚卢兆旸闻杰王占辉丁玄同陈伟杨曾辰蒋敏季小全佟瑞海李永高施陪万钟武律许敏 Southwestern Institute of physics Chengdu 610041China Department of earth and Space Sciences Southern University of Science and TechnologyShenzhen 518055China Shenzhen key laboratory of Nuclear and Radiation Safety College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China CEA IRFMSaint-Paul-lez-Durance 13108France

The dynamics of long-wavelength(kθ<1.4 cm^(-1)),broadband(20 kHz–200 kHz)electron temperature fluctuations(Te/Te)of plasmas in gas-puff experiments are observed for the first time in HL-2A *** a relatively low density(ne(0)■0.91×10^(19)m^(-3)–1.20×10^(19)m^(-3))scenario,after gas-puffing the core temperature increases and the edge temperature *** the contrary,temperature fluctuation drops at the core and increases at the *** show the non-local emergence is accompanied with a long radial coherent length of turbulent *** in a higher density(ne(0)?1.83×10^(19)m^(-3)–2.02×10^(19)m^(-3))scenario,the phenomena are not ***,compelling evidence indicates that E×B shear serves as a substantial contributor to this extensive radial *** finding offers a direct explanatory link to the intriguing core-heating phenomenon witnessed within the realm of non-local transport.

关键词： nuclear fusion non-local transport tokamak gas-puffing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

地震反射剖面揭示阿尔泰山陆内逆冲造山机制

引用

Science Bulletin 2024年第11期69卷 1757-1766页

作者：张蕾赵连锋赵亮谢小碧田小波肖文交姚振兴 key laboratory of earth and planetary physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China State key laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Institute of Geophysics and planetary physics University of California at Santa CruzCA 95064USA Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China

The Altai orogen is a typical intracontinental orogen in Central Asia that experienced far-field deformation associated with Indian-Eurasian plate convergence. This region is characterized by uplift comparable to that of the Tianshan Mountains but has a distinct strain rate. Half of the Indo-Asia strain is accommodated by the Tianshan Mountains, whereas the Altai Mountains accommodates only 10%. To elucidate how the Altai Mountains produced such a large amount of uplift with only one-fifth of the strain rate of the Tianshan Mountains, we constructed a detailed crustal image of the Altai Mountains based on a new 166.8-km deep seismic reflection profile. The prestack migration images reveal an antiform within the Erqis crust, an ~10 km Moho offset between the Altai arc and the East Junggar area, and a major south-dipping(30° dip) thrust in the lower crust beneath the Altai Mountains, which is connected to the Moho offset. The south-dipping thrust not only records the southward subduction of the Ob-Zaisan Ocean in the Paleozoic but also controlled the Altai deformation pattern in the Cenozoic with the Erqis antiform. The Erqis antiform prevented the extension of deformation to the Junggar crust. The southdipping thrust in the lower crust of the Altai area caused extrusion of the lower crust, generating uplift at the surface, thickening of the crust, and steep(~10 km) Moho deepening in the Altai Mountains. This process significantly widened the deformation zone of the Altai Mountains. These findings provide a new geodynamic model for describing how inherited crustal structure controls intraplate deformation without strong horizontal stress.

关键词： Altai mountains Deep seismic reflection profile Subduction-accretion process Intraplate deformation pattern

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical Analysis of Surcharge Effect on Stability and Interaction Mechanism of Slope-Pile-Footing System

引用

Journal of earth Science 2024年第3期35卷 955-969页

作者： Chao Xu Lei Xue Yuan Cui Mengyang Zhai key laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for earth Science Chinese Academy of SciencesBeijing 100029China College of earth and planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Yellow River laboratory Zhengzhou UniversityZhengzhou 450001China

To investigate the stability and interaction mechanism of the slope-pile-footing system under surcharge effects,the finite difference method(FDM)was adopted to analyze the response laws of the stability of the reinforced slope,evolution of the critical slip surface,stress characteristic of retaining structures,deformation and failure modes of the slope foundation and building footing under surcharge parameters,including the surcharge intensity,the surcharge position,and the surcharge *** results show that surcharge parameters significantly affect the stability and the deformation characteristics of the slope-pile-footing *** speaking,with the increasing surcharge intensity and the decreasing surcharge position and width,the deformation and failure mode of the system will gradually evolve in a direction that is harmful to its *** interaction mechanism of the slope-pile-footing system is further clarified as the load transfer of the building footing,the generation of the additional stress in the slope foundation,and the adjustment of pile bending moment due to the stress ***,the safety of anti-slide piles will determine the stability of the slope foundation and building *** findings are expected to provide guidance for the comprehensive development and utilization of filled slopes after reinforcement.

关键词： slope-pile-footing system slope stability interaction mechanism finite difference method geotechnical engineering safety engineering.

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：