检索结果-南通市图书馆

Origin of the Red Earth sequence on the northeastern Tibetan Plateau and its implications for regional aridity since the middle Miocene

引用

Science china Earth Sciences 2006年第5期49卷 505-517页

作者： WANG Xianyan1,7, LU Huayu1,2, JI Junfeg3, WANG Xiaoyong1,7, ZHAO Jingbo4, HUANG Baochun5 & LI Zhen6 1. SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, china 2. department of Urban and Resources Sciences, Nanjing university, Nanjing 210093, china 3. department of Earth Sciences, Nanjing university, Nanjing 210093, china 4. department of geography, Shaanxi normal university, Xi’an 710062, china 5. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, china 6 department of geography, qinghai normal university, xining 810008, china 7. Graduate School of the Chinese Academy of Sciences, Beijing 100039, china SKLLQG Institute of Earth Environment Chinese Academy of Sciences Xi’an China Graduate School of the Chinese Academy of Sciences Beijing China department of Urban and Resources Sciences Nanjing University Nanjing China department of Earth Sciences Nanjing University Nanjing China department of geography Shaanxi Normal University Xi’an China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China department of geography Qinghai Normal University Xining China

The Red Earth deposit around xining, northeastern Tibetan Plateau, has beenstudied in terms of soil micro-structure, grain-size distribution, major- and trace-elementchemistry and magne-tostratigraphy. Field investigations indicate that the Red Earth sequenceconsists of 25 visually definable yellow-brown and weakly-developed soils interbedded with reddishstrongly-developed soils, and has a similar structure to the aeolian Red Clay deposit on the ChineseLoess Plateau. Grain-size analysis shows that the Red Earth deposit is very fine-grained with anegligible sand fraction ( > 63 μm). Thin-section observations under light microscopy show that thedeposit has a clayey texture and the coarse fraction ( > 10 μm) mainly consists of quartz,feldspar and micas. Pyroxene and hornblende were also observed. This mineralogical composition ofthe coarse fraction is similar to that of the Quaternary loess. In addition, all of the mineralgrains are semi angular semi-angular and are generally finer than 63 μm. There is a good agreementbetween the major and minor trace element chemistry of loess-soil units and the Red Earth *** REE distributions of the loess-soil and the Red Earth deposit are similar in shape, withenriched LREE and fairly flat HREE profiles and a clear negative Eu anomaly. The geochemicalcharacteristics of the Red Earth deposit are also identical to those of upper continental crust,thus indicating a wind-blown origin. Magnetostratigraphic investigation shows that onset of the RedEarth deposition predates 11.4 Ma BP (13.6 Ma at a nearby site). The distribution of the reportedMiocene aeolian loess at Qin''an of the Loess Plateau is still unknown. Our results indicate thatthis aeolian deposit had extended to the northeastern Tibetan Plateau by at least the middleMiocene. The similarity of the element geochemistry between the Red Earth deposit and the overlyingloess shows that they may have similar sources and dynamic transport system, and may indicate thatthe

关键词： Red Earth deposit, Northeastern Tibetan Plateau, aeolian deposit, aridity of Asia, the middle Miocene.

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

Study on sea water intrusion into palaeochannels on south coastal plain of the Laizhou Bay by the Bohai Sea

引用

Acta Oceanologica Sinica 2003年第1期22卷 69-74页

作者： Han Mei geography department, Shandong normal university, Jinan 250014, china geography department Shandong Normal University Jinan 250014 China

The palaeochannel evolution in the study region is divided into four stages by such methods as 14C dating. Sea water intrusion through palaeochannels has been studied as a focal point. Palaeochannels are the main passageways through which the sea water intrudes at a higher speed, through many means and in a changeable dynamic state.

关键词： Palaeochannel sea water intrusion south coastal plain of Laizhou Bay

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

Geomorphologic evidence of phased uplift of the northeastern qinghai-Tibet Plateau since 14 million years ago

引用

Science china Earth Sciences 2004年第9期47卷 822-833页

作者： LU Huayu1, WANG Xiaoyong1, AN Zhisheng1, MIAO Xiaodong1, ZHU Rixiang3, MA Haizhou2, LI Zhen4, TAN Hongbing2 & WANG Xianyan1 1. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075 china 2. qinghai Institute of Salt Lakes, Chinese Academy of Sciences. xining 810008, china 3. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, china 4. department of geography, qinghai normal university, xining 810008, china State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining China department of geography Qinghai Normal University Xining China

A typical sequence of fluvial terraces and aeolian deposits overlying these ter- races were multidisciplinary investigated. New evidences for uplift process of the northeastern qinghai-Tibetan Plateau in the past 14 million years were obtained. At least 11 river terraces along Huangshui, the first-class tributary of Yellow River, at the xining-Huzhu region are identi- fied. While the first one (T1) is classified as an accumulation terrace, the others are all basement river terraces, which consist of the Tertiary sandstone and siltstone bedrock, fluvial gravel and pebbles and the overlying aeolian loess-Red Clay deposit. Samples from the aeolian deposits were examined for paleomagnetic stratigraphic reconstruction (1030 samples), luminescence dating (16 samples), magnetic susceptibility and grain-size distribution (more than 4000 sam- ples). The luminescence dating and stratigraphic correlation suggest that terraces of Tll, T10, T8, T7, T3, T2, T1 were formed at 14, 11.3, 1.55, 1.2, 0.15, 0.07 and 0.01 million years ago, re- spectively. Sedimentological analysis and geomorphological observation indicate that formation and evolution of these terraces were mainly driven by tectonic uplift. Therefore, the terrace se- quence provides an ideal geological record, of the uplift process of the northeastern during the past 14 million years, and the timings of the terraces formation are regarded as the timings of tectonic uplift. The significant uplifting events took place at 14, 11.3, 1.2 and 0.15 mil- lion years ago, respectively. The fluvial incision at the xining-Huzhu region is less than 100 m during a period of ~12 million years in the Miocene era (between the Tll and T9), while the Huangshui River had incised 432 m during the past 1.2 million years (from T7 to the present floodplain). The river incision process clearly demonstrates that accelerated rising of the north- eastern qinghai-Tibet Plateau during the late Cenozoic, and provides new evidence of previous thoughts

关键词： river terrace, tectonic uplift, loess-Red Clay, the past 14 million years, northeastern 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

Mo_(2)P Monolayer as a Superior Electrocatalyst for Urea Synthesis from Nitrogen and Carbon Dioxide Fixation:A Computational Study

引用

Energy & Environmental Materials 2024年第1期7卷 207-214页

作者： Dongxu Jiao Zhongxu Wang Yuejie Liu qinghai Cai Jingxiang Zhao Carlos R.Cabrera Zhongfang Chen College of Chemistry and Chemical Engineering and Key Laboratory of Photonic and Electronic Bandgap Materials Ministry of EducationHarbin Normal UniversityHarbin 150025China Modern Experiment Center Harbin Normal UniversityHarbin 150025China Heilongjiang Province Collaborative Innovation Center of Cold Region Ecological Safety Harbin 150025China department of Chemistry and Biochemistry The University of Texas at El PasoEl Paso TX 79968USA department of Chemistry University of Puerto RicoRio Piedras CampusSan JuanPuerto Rico 00931USA

Urea synthesis through the simultaneous electrocatalytic reduction of N_(2)and CO_(2)molecules under ambient conditions holds great promises as a sustainable alternative to its industrial production,in which the development of stable,highly efficient,and highly selective catalysts to boost the chemisorption,activation,and coupling of inert N_(2)and CO_(2)molecules remains rather ***,by means of density functional theory computations,we proposed a new class of two-dimensional nanomaterials,namely,transition-metal phosphide monolayers(TM_(2)P,TM=Ti,Fe,Zr,Mo,and W),as the potential electrocatalysts for urea *** results showed that these TM_(2)P materials exhibit outstanding stability and excellent metallic ***,the Mo_(2)P monolayer was screened out as the best catalyst for urea synthesis due to its small kinetic energy barrier(0.35 eV)for C-N coupling,low limiting potential(-0.39 V),and significant suppressing effects on the competing side *** outstanding catalytic activity of the Mo_(2)P monolayer can be ascribed to its optimal adsorption strength with the key^(*)NCON species due to its moderate positive charges on the Mo active *** findings not only propose a novel catalyst with high-efficiency and high-selectivity for urea production but also further widen the potential applications of metal phosphides in electrocatalysis.

关键词： C-N coupling density functional theory Mo_(2)P monolayer urea synthesis

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

A Complete Solution to the Chromatic Equivalence Class of Graph Bn-8,1,4

引用

Journal of Mathematical Research with Applications 2012年第3期32卷 253-268页

作者： Yaping MAO,Chengfu YE,Shumin ZHANG department of Mathematics,qinghai normal university,qinghai 810008,P.R.china department of Mathematics Qinghai Normal University Qinghai 810008

Two graphs are defined to be adjointly equivalent if and only if their complements are chromatically *** the properties of the adjoint polynomials and the fourth character R;（G）,the adjoint equivalence class of graph B;is *** to the relations between adjoint polynomial and chromatic polynomial,we also simultaneously determine the chromatic equivalence class of B;that is the complement of B;.

关键词： chromatic equivalence class adjoint polynomial the smallest real root the fourth character.

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

STUDY ON SPATIAL LANDSCAPE PATTERN OF YANTAI CITY BASED ON RS AND GIS

引用

Chinese Geographical Science 2003年第3期13卷 254-258页

作者： WU Quan-yuan (department of geography, Shandong normal university, Jinan 250014, P. R. china) department of geography Shandong Normal University Jinan P. R. China

Influenced by artificial factors, landscape pattern of Yantai City, Shandong Province changes continuously. Revealing its landscape pattern and its changing process has a practical significance for the urban development and layout. Zhifu District, Development Zone, Laishan District and Fushan District in Yantai City were selected to study the landscape pattern. Remote sensing technology was used to obtain landscape information of different periods. Under the support of Geographic Information System (GIS), the spatial landscape pattern of Yantai City was analyzed and simulated by using various special quantitative analysis models. The analysis shows that built-up area lies in the center of Yantai City, the outside is vegetable land, irrigated land, dry land, garden land and woodland.

关键词： landscape remote sensing geographic information system yantai city

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

Issues of the Holocene transgression on the southern plain of the Changjiang Delta

引用

Acta Oceanologica Sinica 1988年第4期7卷 578-590页

作者： Yan Qinshang and Hong Xueqing department of geography, East china normal university, Shanghai, china Dept. of geography East China Normal Univ. Shanghai China. China

The paper deals with the question of Holocene transgression on the southern plain of the Changjiang *** the beginning of the transgression, the paleovalleys of the Changjiang and Qiantang Rivers were covered by sea water at *** shoreline of 8000-7500 yr BP coincided with the -7m isobath of paleotopography. Sea level had already been the present level about 7000-6500 years ago, and the Holocene transgression reached its maximum extent. During the period, the Changjiang and Qiantang Rivers and the Dongtiaoxi valley were turned into estuaries; the eastern area of Shanghai became a shallow sea; some of the bays and lagoons were distributed on the Hang-Jia-Hu and Tao-Ge Plain; the hilly region around the Taihu Lake was coastal marsh and freshwater swamp. Gangshen on the west of Shanghai was formed 7000-4000 yr BP, and during the last 4000 years, the eastern coastal plain of Shanghai advanced quickly toward the sea, and partial clear land of the western Taihu Lake was enclosed and charged into a fre

关键词： Ho Issues of the Holocene transgression on the southern plain of the Changjiang Delta

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

Politeness Principle and the Choice of Address Forms in Intercultural Communication

引用

海外英语 2011年第9X期 289-290页

作者： TIAN Yan-ping(Foreign Languages department,qinghai normal university,xining 810008,china) Foreign Languages department Qinghai Normal University Xining 810008 China

This paper makes a tentative study of the politeness strategies stressed in the choice of address forms in Chinese,American and Japanese culture under the guidance of Politeness Principle by Brown and *** a comprehensive analysis,It is concluded that the major function of English address forms is to indicate solidarity and realize positive politeness,In contrast,both Chinese and Japanese address forms emphasize deference and help achieve negative politeness;It is the author's hope that a better understanding of these addressing rules in different cultures will benefit effective use of these languages and help avoid miscommunication in intercultural communication.

关键词： politeness principle address forms positive politeness negative politeness intercultural communication

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

Impact on the Yangtze (Changjiang) Estuary from its drainage basin: Sediment load and discharge

引用

Chinese Science Bulletin 2001年第S1期46卷 73-80页

作者： CHEN Zhongyuan & ZHAO YiwenState Key Laboratory for Estuarine and Coastal Research, East china normal university, Shanghai 200062, china department of geography, East china normal university, Shanghai 200062, china State Key Laboratory for Estuarine and Coastal Research East China Normal University Shanghai China department of geography East China Normal University Shanghai China

This paper focuses on the sediment transport and freshwater discharging from upper Yangtze drainage basin downstream, primarily on the basis of multiyear hy-drological data collected from three major hydrological gauge stations (Yichang, Hankou and Datong). Data indicate highest sediment load in Yichang (5.6×108 t/a), lowest in Hankou (5.1×108t) and second highest in Datong (5.4×108 t). This fluctuations are identical with what has been observed from the annual flood season. About one thirds of the sediment load are trapped in the middle Yangtze River course, where meandering river pattern prevails; rest of them are directly transported to the river mouth area via lower Yangtze River channel, where the river is typically confined by the exposed base rock and almost none is being trapped, instead, minor being drained to the mainstream from the local tributaries. To recognize this sediment delivery and river flow media is vital, because it can highlight morphologic/topographic correlation between the

关键词： sediment load discharge estuarine impact the Yangtze River.

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 change of geographical distribution of two Asian species of rhinoceros in Holocene

引用

Journal of Geographical Sciences 1998年第1期8卷 84-89页

作者： Liu Hongjie department of geography, South china normal university, Guangzhou 510631, china

At present only five species of rhinoceros surrive in the world, among which three in Asia No wild rhinoceros has been found alive in East Asia now But many recent evidences reveal the fact that rhinoceros still lived not very long ago in the East Asian Continent of Holocene The attention to East Asia rhinoceros in Holocene first arose from archaeological studies on ancient ruins in china Archaeologists first found some subfossil skeletons of rhinoceros in ruins of Yin Dynasty in Anyang of Henan in the 1930s Then more skeletons of rhinoceros were found in many other Neolithic Ages runis, such as in Tonghai (Yunnan), Nanning (Guangxi), Xichuan (Henan), Yuyao (Zhejiang), and Haian (Jiangsu).(Guangxi Archaeological Team 1972; Jia 1977; Wu 1983; Huang and Liang 1984; Xu 1990). Moreover, Zhou Benxiong reported some rhinoceros teeth containing residual organic matter found in caves in the middle and lower reaches of Yangtze River According to a number of very now skeletons of rhinoceros found in some caves in Central china and South china, Yang Zhongjian drew the inferences that rhinoceros might live in the Southern part of china until in the Han Dynasty (about 2000 yrs B P ) at least These discoveries provided the material evidences for the distribution of rhinoceros in East Asian Continent Recently, some scholars brought forward more new information about Chinese rhinoceros from the analysis of historical records and investigations of unearthed cultural relics respectively (Wen and He 1981; Sun 1982). Based on the above materials and informations, this paper is going to deal with the species of rhinoceros once living in East Asia from the viewpoint of zoo geography At last, we brouhgt up the evolution process of the rhinoceros in distribution in Asia with comprehensive analysis of physiographical elements and human activities

关键词： rhinoceros geographical distribution evolution process East Asia Holocence

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：