检索结果-南通市图书馆

Orbital-scale Asian summer monsoon variations:Paradox and exploration

Science China Earth Sciences 2021年第4期64卷 529-544页

作者： Hai CHENG Haiwei ZHANG Yanjun CAI Zhengguo SHI Liang YI Chenglong DENG Qingzhen HAO Youbing PENG Ashish SINHA Hanying LI Jingyao ZHAO Ye TIAN Jonathan BAKER Carlos PEREZ-MEJIAS Institute of Global Environmental Change Xi'an Jiao tong UniversityXi'an 710054China state key laboratory^of loess and quaternary geology1 Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061China key laboratory of Karst Dynamics Ministry of Land and ResourcesInstitute of Karst GeologyChinese Academy of Geological SciencesGuilin 541004China state key laboratory of Marine geology Tongji UniversityShanghai 200092China state key laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China key laboratory of Cenozoic geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Department of Earth Sciences California State University Dominguez HillsCarson 90747USA

The Asian summer monsoon(ASM) is a vast climate system, whose variability is critical to the livelihoods of billions of people across the Asian continent. During the past half-century, much progress has been made in understanding variations on a wide range of timescales, yet several significant issues remain unresolved. Of note are two long-standing problems concerning orbital-scale variations of the ASM.(1) Chinese loess magnetic susceptibility records show a persistent glacial-interglacial dominated ~100 kyr(thousand years) periodicity, while the cave oxygen-isotope(δ18 O) records reveal periodicity in an almost pure precession band(~20 kyr periodicity)—the "Chinese 100 kyr problem".(2) ASM records from the Arabian Sea and other oceans surrounding the Asian continent show a significant lag of 8–10 kyr to Northern Hemisphere summer insolation(NHSI), whereas the Asian cave δ18 O records follow NHSI without a significant lag—a discrepancy termed the "sea-land precession-phase paradox". How can we reconcile these differences? Recent and more refined model simulations now provide spatial patterns of rainfall and wind across the precession cycle, revealing distinct regional divergences in the ASM domain, which can well explain a large portion of the disparities between the loess, marine, and cave proxy records. Overall, we also find that the loess, marine, and cave records are indeed complementary rather than incompatible, with each record preferentially describing a certain aspect of ASM dynamics. Our study provides new insight into the understanding of different hydroclimatic proxies and largely reconciles the "Chinese 100 kyr problem" and "sea-land precession-phase paradox".

关键词： ASM Orbital cycles Precession phase Different climatic proxies

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

Glacier extent changes and possible causes in the Hala Lake Basin of Qinghai-Tibet Plateau

引用

Journal of Mountain Science 2019年第7期16卷 1571-1583页

作者： LI Dong-Sheng CUI Bu-Li WANG Ying XIAO Bei JIANG Bao-Fu School of Resources and Environmental Engineering Ludong UniversityYantai 264025China state key laboratory of loess and quaternary geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061China state key laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China

Glacier is a common sensitivity indicator of environmental and global climate *** the relationship between glacier area and climate change will help reveal glacier change mechanisms and future *** changes are also of great significance to the regulation of regional water *** study selected the Hala Lake Basin in the northeastern Qinhai-Tibet Plateau as a study area,and examined the relationships between the temporal and spatial change of glaciers in the northeastern Qinghai-Tibet Plateau and climate change based on remote sensing imagery,climatological data,and topographic data during the past 30 *** showed that glacier area in the Hala Lake basin fluctuated and decreased from106.24 km2 in 1986 to 78.84 km2 in 2015,with a decreasing rate of 0.94 km2·*** number of glacier patches,mean patch area,and largest patch index all decreased from 1986 to 2015,while the splitting index increased from 1986 to 2015,indicating that the landscape fragmentation of glacier in the Hala Lake Basin was increasing significantly during the study *** area change was mainly concentrated in the slopes>25°with an altitude of 4500-5000 m,and the retreating rate of glacier of sunny slope was obviously higher than that of shady *** center of glacier in the basin moved from southwest to northeast towards high *** of the response of glacier extent to climate change showed that temperature was the dominant factor affecting glacier area dynamic change in the Hala Lake *** is predicted that in future several years,the glacier area will decrease and fragment continually as a result of global warming on the Tibetan Plateau.

关键词： Glacier extent Climate change Hala Lake Basin Qinghai-Tibet Plateau

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

Where were the monsoon regions and arid zones in Asia prior to the Tibetan Plateau uplift?

引用

National Science Review 2015年第4期2卷 403-416页

作者： Xiaodong Liu Qingchun Guo Zhengtang Guo Zhi-Yong Yin Buwen Dong Robin Smith state key laboratory of loess and quaternary geology Institute of Earth Environment Chinese Academy of Sciences CAS Center for Excellence in Tibetan Plateau Earth Sciences University of the Chinese Academy of Sciences key laboratory of Cenozoic geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences Department of Environmental & Ocean Sciences University of San Diego National Centre for Atmospheric Science University of Reading

The impact of the Tibetan Plateau uplit on the Asian monsoons and inland arid climates is an important but also controversial question in studies of paleoenvironmental change during the Cenozoic. In order to achieve a good understanding of the background for the formation of the Asian monsoons and arid environments, it is necessary to know the characteristics of the distribution of monsoon regions and arid zones in Asia before the plateau uplit. In this study, we discuss in detail the paterns of distribution of the Asian monsoon and arid regions before the plateau uplit on the basis of modeling results without topography from a global coupled atmosphere–ocean general circulation model, compare our results with previous simulation studies and available biogeological data, and review the uncertainties in the current knowledge. Based on what we know at the moment, tropical monsoon climates existed south of 20?N in South and Southeast Asia before the plateau uplit, while the East Asian monsoon was entirely absent in the extratropics. hese tropical monsoons mainly resulted from the seasonal shits of the Inter-Tropical Convergence Zone. here may have been a quasi-monsoon region in central-southern Siberia. Most of the arid regions in the Asian continent were limited to the latitudes of 20–40?N, corresponding to the range of the subtropical high pressure year-around. In the meantime, the present-day arid regions located in the relatively high latitudes in Central Asia were most likely absent before the plateau uplit. he main results from the above modeling analyses are qualitatively consistent with the available biogeological data. hese results highlight the importance of the uplit of the Tibetan Plateau in the Cenozoic evolution of the Asian climate patern of dry–wet conditions. Future studies should be focused on efects of the changes in land–sea distribution and atmospheric CO2 concentrations before and ater the plateau uplit, and also on cross-comparisons between numer

关键词： the Tibetan Plateau uplit the Asian monsoons

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

Modeling micro-particle deposition in human upper respiratory tract under steady inhalation

引用

Particuology 2011年第1期9卷 39-43页

作者： Jianhua Huang Lianzhong Zhang Suyuan Yu School of Physics Nankai University Tianjin 300071 China state key laboratory of loess and quaternary geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China Institute of Nuclear Energy and New Energy Technology Tsinghua University Beijing 100084 China

A representative human upper respiratory tract （URT） with idealized oral region and asymmetric tracheo- bronchial （TB） airway has been modeled, and laminar-to-turbulent airflow for typical inhalation modes as well as micro-particle transport and deposition has been simulated using CFX10.0 software from Ansys Inc. on a personal computer. The asymmetric TB airway could not be replaced by an extended straight tube as outlet of the oral region while investigating the tracheal airflow field and particle deposition. Compared to an idealized oral airway with an extended straight tube, several differences could be noted：（i） The laryngeal jet extends further down the trachea and inclines towards the anterior wall; （ii） the turbulence level in trachea is less and decays more quickly; （iii） three recirculation zones are visible with intense adverse current after the glottis; （iv） deposition of small particles in trachea is reduced due to lower turbulence. Refined unstructured mesh with densified boundary layer mesh could be a proper substitute for the structured mesh in the human URT model with asymmetric TB airway. Based on the refined unstructured mesh, the physiological structure of uvula in the soft palate is properly simulated in the present human URT model.

关键词： Human upper airway model Asymmetric tracheobronchial (TB) airway Particle deposition Computational fluid-particle dynamic simulations

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

The elemental carbon record in Weinan loess section since the last 21 ka

引用

Chinese Science Bulletin 2001年第18期46卷 1541-1544页

作者： YANG Ying SHEN Chengde YI Weixi SUN Yanmin LIU Dongsheng Guangzhou Institute of Geochemistry Chinese Academy of SciencesGuangzhou 510640China Xi’an state key laboratory of loess and quaternary geology Chinese Academy of SciencesXi’an 710061China Institute of geology and Geophysics Chinese Academy of Sciences Beijing 100029China

We studied the records of elemental carbon (EC) of the last 21 ka in the Weinan loess section, Shanxi Province. The variations of EC abundance and δ13CEC value along with depth (or age) were presented. There are four large peaks of EC abundance around the following years: 20.16 ka, 17.76 ka, 11.97 ka and 4.49 ka. Climatic situation was changed rapidly during these periods. The peaks around 11.97 ka and 20.16 ka are particularly sharp, occurring over intervals of tens to hundreds of years, which could represent short-duration intense events. δ13CEc values in the upper 4 m of the Weinan loess section vary between -11.71‰ and -21.34‰, which suggests that the vegetation pattern of the last 21 ka on the loess Plateau is G4-dominated grasses.

关键词： elemental carbon fire history Weinan loess section δ13C paleoenvironment.

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

An Analysis of Tree-Ring Density in Zhungeer County,Inner Mongolia

An Analysis of Tree-Ring Density in Zhungeer County,Inner Mo...

引用

2011 International Symposium on Water Resource and Environmental Protection(ISWREP 2011)

作者： Yinke YANG Wenke WANG Yu LIU Hongbin YANG Huiming SONG School of Environmental Science and Engineering Chang'an University state key laboratory of loess and quaternary geology The Institute of Earth EnvironmentChinese Academy of Sciences

ISBN: (纸本)9781612843377

This paper establishes the ring width chronology for pine（pinus tabulaeo frmis）,and the four density chronologies for the early wood,late wood,maximum and minimum in Zhungeer County,Inner *** analysis of chronology displays that tree-ring density contains more complex climate change information than the width *** tree-ring chronologies and meteorological data related to the density analysis,the paper shows that there is good correlation between the density tree-ring chronology in Zhungeer County and the annual precipitation in the region;there is negative correlation between the early wood density and minimum density and the rainfall;there is significantly positive correlation between maximum latewood density and the rainfall.A reasonable explanation can be given to both the positive and negative correlation from a physiological point of view of the trees.

关键词： tree-ring density climate change Zhungeer County pinus tabulaeo frmis

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Evaluating the soil quality of newly created farmland in the hilly and gully region on the loess Plateau, China

引用

Journal of Geographical Sciences 2019年第5期29卷 791-802页

作者：陈怡平毋俊华王洪马吉福苏翠翠王凯博王益 state key laboratory of loess and quaternary geology Institute of Earth EnvironmentCAS University of the Chinese Academy of Sciences

In order to better understand the quality of newly created farmland(NF) as well as slope and check-dam farmland(CF) soil quality, two typical traditional farmland areas within the hilly and gully region of Chinese loess Plateau were selected as controls in this *** results of this study initially reveal that pH values for slope farmland(SF) and CF were significantly lower(P lable N, total phosphorus(P), available P, total potassium(K) and available K and has also enhanced concentrations of soil copper(Cu), zinc(Zn), iron(Fe), and manganese(Mg)as well as soil cadmium(Ca), lead(Pb), chromium(Cr), and mercury(Hg). These latter elements occur in the concentration sequence of SF > CF > NF. Overall, results indicate that long-term planting negatively impacts soil health because of the accumulation of toxic heavy metals. This means that farmland planted over longer timescales needs to lie fallow to enable it to rehabilitate while NF requires the addition of organic matter as well as rotational utilization in order to facilitate the development of green agriculture.

关键词： loess Plateau land use soil quality heavy metals

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

Stable isotopes and chloride ion of precipitation events in the northeastern Tibetan Plateau, China

引用

Journal of Mountain Science 2021年第4期18卷 834-846页

作者： CUI Bu-li LI Dong-sheng JIANG Bao-fu WANG Ying WANG Ya-xuan WANG Long-sheng LI Xiao-yan state key laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China School of Resources and Environmental Engineering Ludong UniversityYantai 264025China state key laboratory of loess and quaternary geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China

Stable isotopes and chloride ion of precipitation are ideal environmental tracers to explain and reveal the formation and evolution mechanisms of water bodies. It is crucial to investigate the stable isotopes and chloride in precipitation events in the northeastern part of the Tibetan Plateau(NETP) due to the limitation of available data. This study sampled each event of precipitation during the period from July 2018 to June 2019 and the monthly dustfall in the NETP to investigate the temporal changes of stable isotopes and chloride in precipitation, and to reveal the moisture source of precipitation over the NETP using a back trajectory model. Results showed that the δ^(2)H values of precipitation ranged from-183.51‰ to 17.75‰, and the δ^(18)O values ranged from-25.18‰ to 0.48‰. The slope of the Local Meteoric Water Line was slightly lower than 8 due to the effect of belowcloud secondary evaporation on the precipitation process. Most d-excess values were higher than 10‰ because moisture recycled from the continent and Qinghai Lake surface mixed with precipitation. The chloride in precipitation accounted for 86.5% of the annual total deposition mass of chloride(1329.64 mg/m2), indicating that precipitation was the main source of chloride in the NETP. The temperature and amount effects of stable isotope in the precipitation were obvious in the NETP. The precipitation was predominantly derived from the Westerly Circulation from September through May and the East Asian Monsoon from June to August, with precipitation amounts of 246.5 mm and 178.0 mm, respectively, indicating that the precipitation over the NETP brought by the Westerly Circulation was more than that brought by the East Asian Monsoon. The air mass over the NETP transited in late May and early September, and a slight change in transition period would mainly be related to the intensity of the East Asian Monsoon, which is strongly influenced by El Ni?o-Southern Oscillation. These results provide not only bas

关键词： Stable isotope Chloride ion Precipitation Moisture source Northeastern Tibetan Plateau

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

Mechanism of accelerated dissolution of mineral crystals by cavitation erosion

引用

Acta Geochimica 2020年第1期39卷 11-42页

作者： Haotian Su Weijian Zhou state key laboratory of loess and quaternary geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061China Shaanxi key laboratory of Accelerator Mass Spectrometry and Application Xi'an AMS CenterXi'an 710061China University of Chinese Academy of Sciences Beijing 100049China

Cavitation,a phenomenon produced by a moving fluid,is ubiquitous in the water environment of the Earth's surface and its related mechanical action in the process of cavitation leads to the widespread erosion of rock in *** the mechanical action of flowing water body that accelerates the rock mass loss and fragmentation of rock(abrasion,erosion,and etching)and other phenomena have been much studied,its acceleration of mineral crystal dissolution is rarely *** physical mechanism of effect is not yet *** cavitation bubble produced in the cavitation process is at the micron level,and its related mechanical action leading to the accumulation of rock mineral dissolution is manifested in time and space in the process of the chemical element's migration between water and rock *** erosion may be one of the important driving forces for the migration of geochemical elements within the lithosphere and *** this paper,based on the crystal dissolution stepwave dynamic theory and the theoretical derivation and calculation of Gibbs free energy change of the mineral crystals plastic deformation which caused by the mechanical action of cavitation erosion,we give the possible mechanism of accelerating the transient dissolution of mineral crystals by cavitation erosion—the cavitation bubbles on the surface of the near crystal release the high speed micro-jet and shock wave perpendicular to the surface during the collapsing,in which the water hammer pressure produced by micro-jet at the solid–liquid interface causes instantaneous plastic deformation on the crystal surface under the condition that it is larger than the yield stress of the *** the influence of the thermal effect of the plastic deformation process and the change of Gibbs free energy(the dislocation elastic strain energy of plastic deformation on the crystal surface may be included),the local instantaneous dissolution rate of the mineral surface is accelerated.T

关键词： Cavitation erosion Mineral dissolution Plastic deformation Stepwave Gibbs free energy

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

Magnetostratigraphic dating of mammalian fossils in Junggar Basin,northwest China

引用

Chinese Science Bulletin 2007年第11期52卷 1526-1531页

作者： ZHANG Rui YUE LePing WANG JianQi Paleomagnetism and Geochronology laboratory SKL-LE Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China key laboratory for Continental Dynamics of Ministry of Education Department of Geology Northwest University Xi'an 710069 China state key laboratory of loess and quaternary geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China

The first detailed chronology for the late Oligocene to early Miocene continental record in northern Junggar Basin is presented,based on rock magnetic experiments and magnetostratigraphic investiga-tions of a 192 m thick mammal-bearing section in the Ulungur River area. Magnetites and hematites were identified as the main carriers for the characteristic remanent magnetization,and the resulting polarity sequence allows an unambiguous correlation to the geomagnetic polarity time scale (GPTS). Furthermore,the Tieersihabahe fauna layer occurs below the Paleocene/Neocene boundary,and the Suosuoquan fauna layer is just above the Neocene onset. Therefore,the age of the Tieersihabahe fauna and Suosuoquan fauna layers can be definitely estimated to be about 25.2 Ma and 22.5 Ma,respectively.

关键词：哺乳动物中国准葛尔盆地化石测定年龄

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

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：