检索结果-南通市图书馆

Relationship between erosion and sediment yield in drainage basins of loess gully-hilly areas

在线全文

学校读者我要写书评

暂无评论

Journal of geographical sciences 2001年第1期11卷 71-79页

作者： CHEN Hao (institute of Geographic sciences and natural {3. research, CAS, beijing 100101, china) institute of Geographic sciences and natural {3. research CAS Beijing China

From a long-term point of view, the balance between erosion and sediment yield in a drainage system can basically realize, i.e., the delivery ratio can be close to 1. However, substantial variations among individual rainfall events or between annual delivery ratio exist, causing frequent sediment retaining or re-erosion and re-delivery of the retained sediments in a short period of time. Thus the delivery ratio will be 1. The sediment delivery ratio is closely related to the spatial distribution of rainfall and magnitude of rise and fall of peak flood and that of runoff depth in the drainage system. Delivery ratio of single event in a drainage system and changes of delivery capacity of silt-laden runoff in various classes of gullies can be expressed by transformation mechanism of shear force of a single rainstorm event with flood resulting from increase and decrease of peak flood per unit area.

关键词： delivery ratio interaction flood and geomorphology dynamic mechanism rainstorm flood

“Tali Glaciation” on Massif Diancang

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2007年第11期50卷 1685-1692页

作者： YANG JianQiang1, CUI ZhiJiu2, YI ChaoLu1, SUN JiMin3.& YANG LiRong3.1 institute of Tibetan Plateau research, chinese academy of sciences, {3. 100085, china 2 College of Environmental sciences, Peking University, {3. 100871, china 3.institute of Geology and Geophysics, chinese academy of sciences, {3. 100029, china 1. institute of Tibetan Plateau research Chinese Academy of Sciences Beijing 100085 China 2. College of Environmental sciences Peking University Beijing 100871 China 3. institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

The term of ''Tali Glaciation'' is nominated from Massif Diancang in Yunnan Province. The confusing process of the term''s being put forward is confirmed through literature checking. Based on several times of field trip, the glacial landforms in this region are studied in detail, and the magnitude of the glaciation was determined. According to the numerical ages from TL, AIMS ^(14)C and OSL dating, the earliest glacial advance on Massif Diancang occurred at 3.—40 ka BP, followed by the advances at the last stage of the last glaciation, the late glacial and neoglations in turn, until glaciers vanished at 1.2—1.5 ca. a BP in this region. It can be concluded that glaciers were limited above 3.00 m a.s.l., and no glaciers existed on the lower part and adjacent mountains since the last glaciation.

关键词： Massif Diancang,Tali Glaciation,glacial landform,glaciation sequence,numerical dating

The study on Sanmenxia annual flow forecasting in the Yellow River with mix regression model

在线全文

学校读者我要写书评

暂无评论

Science china(Technological sciences) 2004年第z1期47卷 118-126页

作者： JIANG Xiaohui1, LIU Changming1,2, WANG Yu3.& WANG Hongrui1 1. beijing Normal University, beijing 100875, china 2. {3. of Geographic Science and natural resources, chinese academy of sciences, beijing 100101, china 3. Reconnaissance, Planning, Design and research {3., YRCC, Zhengzhou 450003. china beijing Normal Univ Beijing 100875 Peoples R China chinese Acad Sci Inst Geog Sci & Nat Resources Beijing 100101 Peoples R China YRCC Reconnaissance Planning Design & Res Inst Zhengzhou 450003 Peoples R China

This paper established mix regression model for simulating annual flow, in which annual runoff is auto-regression factor, precipitation, air temperature and water consumption are regression factors; we adopted 9 hypothesis climate change schemes to forecast the change of annual flow of Sanmenxia Station. The results show : (1) When temperature is steady, the average annual runoff will increase by 8.3. if precipitation increases by 10%; when precipitation decreases by 10%, the average annual runoff will decrease by 8.2%; when precipitation is steady, the average annual runoff will decrease by 2.4% if temperature increases 1℃; if temperature decreases 1℃, runoff will increase by 1.2%. The mix regression model can well simulate annual runoff. (2) As to 9 different temperature and precipitation scenarios, scenario 9 is the most adverse to the runoff of Sanmenxia Station of Yellow River; i.e. temperature increases 1℃ and precipitation decreases by 10%. Under this condition, the simulated average annual runoff decreases by 10.8%. On the contrary, scenario 1 is the best to the enhancement of runoff; i.e. when temperature decreases 1 ℃ precipitation will increase by 10%, which will make the annual runoff of Sanmenxia increase by 10.6%.

关键词： forecast annual flow, mix regression model, Sanmenxia Station

Improvement of Ecological Footprint Method and Application in Henan Province

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Population,resources and Environment 2005年第1期3卷 44-48页

作者： Niu Shuhai, Jin Fengjun & Liu Yi institute of geographical sciences and {3. resources research, CAS, beijing 100101, china institute of geographical sciences and {3. resources research CAS Beijing 100101 China

The measure of sustainable development has always been an important and difficulty subject, and the major evaluation model has three types: indicators based on system theory and methods, indicators relied on economic valuation of the environment, sustainability indicators including biophysical assessments. The ecological footprint analysis initiated by William E. Rees, one of the indicators including biophysical assessments, gets rid of the defects of the other models. Ecological footprint has gradually become popular on account of the measuring indexes based on scientific theory, innovative thought-way and its wide adaptability. This paper introduces the conception and computation method, making a progress and making up for the method of ecological footprint, and finally, makes an application analyses through Henan province regional sustainable development.

关键词： sustainable development ecological footprint input/occupancy-output model integrated development degree

Identification of the Angel -related elements in cyprinid fishes and their phylogenetic implications

在线全文

学校读者我要写书评

暂无评论

Progress in natural Science:Materials International 2007年第2期17卷 168-171页

作者： WANG Li, HE Shunping and CHEN Yiyu ( institute of Hydrobiology, chinese academy of sciences, Wuhan 43.072, china Graduate School of the chinese academy of sciences, beijing 10003., china National natural Science Foundation of china, beijing 100085, china) [a]chinese academy of sciences Institute of Hydrobiology Wuhan China [b]Graduate School of the chinese academy of sciences Beijing China [c]National natural Science Foundation of china Beijing China

Angel-related element belongs to the family of miniature inverted-repeat transposable elements (MITEs). In this paper we report the identification of an Angel- related element in the series Leuciscini of cyprinid fishes, which is located in the second intron of the growth hormone (GH) gene. We have also found that this element is absent in orthologous locus in the series Barbini of cyprinid fishes, that provides new evidence for the monophyly of the series Leuciscini. The insertion of Angel -related element into the GH gene might take place in the common ancestor of the series Leuciscini after its divergence from the series Barbini. The high sequence divergence and relatively broad species distribution of Angel-related elements implies that they might be ancient transposons which appeared about 26 million years ago.

关键词： Angel -related elements the series Leuciscini monophyly.

Validity of the Bouchet's complementary relationship at 102 observatories across china

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth sciences 2009年第5期52卷 708-713页

作者： YU JingJie1,2,ZHANG YongQiang3.LIU ChangMing1,2 1 institute of Geographic sciences and natural {3. research,chinese academy of sciences,beijing 100101,china 2 Key Laboratory of Water Cycle and Related Land Surface Processes,chinese academy of sciences,beijing 100101,china 3.CSIRO Land and Water,PO Box 1666,Canberra ACT 2601,Australia institute of Geographic sciences and natural {3. research Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Water Cycle and Related Land Surface Processes Chinese Academy of Sciences Beijing 100101 China CSIRO La

Bouchet in 1963.hypothesized that for large homogeneous land surface with minimum advection of heat and moisture,there exists a 1:1 complementary relationship of potential and actual evaporation coupled through land-atmosphere *** complementary relationship has been widely used to estimate regional actual evaporation and explain the pan evaporation *** examine the standardized potential evaporation(potential evaporation divided by wet environment evaporation) at 102 observatories at different elevations across ***,the relationship is appropriate at the low elevations(<1000 m).With the increase of elevation,vapor transfer power becomes much less than radiation energy budget because of lower vapor pressure deficit and stronger global solar *** a result,at the high elevations(over 1000 m),the excess energy resulted by limited moisture availability is not enough to be converted into drying power of the *** result suggests that the complementary relationship is asymmetric at the high elevations.

关键词： evaporation complementary relationship elevation china

The species diversity of fusulinaceans and high-frequency sea-level changes in the Carboniferous-Permian boundary section at Xikou, Zhen'an County,Shaanxi Province, china

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2006年第7期49卷 673-683页

作者： ZHANG Haijun1, WANG Xunlian2, DING Lin1, XIA Guoying3.& WANG Lei2 1. institute of Tibetan Plateau research, chinese academy of sciences, {3. 100085, china 2. Faculty of Earth sciences and Mineral resources, china University of Geosciences, {3. 100083. china 3. Tianjin institute of Geology and Mineral resources, Tianjin 3.0170, china 1. institute of Tibetan Plateau research Chinese Academy of Sciences Beijing 100085 China 2. Faculty of Earth sciences and Mineral resources China University of Geosciences Beijing 100083 China 3. Tianjin institute of Geology and Mineral resources Tianjin 300170 China

The study on the interrelation between sea-level changes and biodiversity with its evolu-tion has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws of life-environment coevolution in geological history. In this paper, the stratigraphic distribution of fusulinacean fauna in the Carboniferous-Permian boundary section at Xikou, Zhen’an County, Shaanxi Province, is analyzed quantitatively, and the relationship between the species diversity of fusulinaceans and relative sea-level changes is discussed. As a whole, the spe-cies numbers of fusulinacean fauna experience a rapid increase and an obvious decline in Xikou, Zhen’an County, from the Late Carboniferous to the Early Permian. There is a significant increase in species diversity around the Carboniferous-Permian boundary, which is one of the biggest bio-events of the fusulinacean fauna, and represents the radiation of Pseudoschwagerininae subfamily in the studied area. Integrated fusulinacean species diversity into sequence stratigraphic framework, de-tailed study suggests that the species diversity of the fusulinaceans is closely related to its relative stratigraphic location, and is essentially controlled by the sea-level changes, especially by the high-frequency sea-level changes. Generally, the species diversity of fusulinaceans is low, and the number of first and last appearance datum is small in the lower unit of high-frequency depositional cycle formed during the quick rise of the sea level; whereas the species diversity of fusulinaceans is high, and the number of first and last appearance datum is large in the upper unit of high-frequency cycle formed during the slow fall of the sea level. Within the third-order depositional sequence, the species diversity of the fusulinaceans at the first flooding surfaces and the maximum flooding surfaces is low, and it increases upward. The fusulinacean species diversity is low within the transgressive syst

关键词： fusulinaceans, species diversity, high-frequency cyclothem, sequence stratigraphy, sea-level changes, Carboniferous-Permian boundary, Zhen'an, Shaanxi.

The Application of Multiple Evaluating Methods on the Comprehensive Evaluation of Urban-rural Interaction and Conjunctional Development of china

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Population,resources and Environment 2005年第2期3卷 35-41页

作者： Duan Juan 1,2, Lu Qi 1 & Wen Yuyuan 3. institute of Geographic sciences and natural {3. research, chinese academy of sciences,beijing 100101, china2 Graduate School of chinese academy of sciences, beijing 10003.,china3.institute of Regional Economics and Urban Management sciences, Renmin Univercity of china,beijing 100872, china institute of Geographic sciences and natural {3. research Chinese Academy of Sciences Beijing 100101 China Graduate School of chinese academy of sciences Beijing 100039 China institute of Regional Economics and Urban Management sciences Beijing 100872 China

Urban-rural interaction and conjunctionaldevelopment is the effective way of harmonizingurban-rural relationship and promoting urban-ruraldevelopment. However, there are differences in thelevel of urban-rural interaction and conjunctionaldevelopment of china. How to measure and reflectthe difference properly is a decision-makingfoundation for optimizing urban-rural developmentof different regions. The paper employs multiplemethods to evaluate and order the urban-ruralinteraction and conjunctional development of 3.provinces (municipalities) in china. Kendall’s Wconsistency coefficient is employed to give a consistenttest for the evaluation result series, and the resultsof multiple methods are aggregated as the finalevaluation value. The results reflect the level ofregional urban-rural interaction and conjunctionaldevelopment in china.

关键词： Urban-rural interaction urban-ruralconjunctional development comprehensive evaluation consistency test.

An improved method for evaluating the seasonal variability of total suspended sediment flux field in the Yellow and East china Seas

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment research 2011年第1期26卷 1-14页

作者： PANG Chongguang~1,YU Wei~2,YANG Yang~3.and HAN Danxiu~4 institute of Oceanology,chinese academy of {3.,Qingdao 266071,china, 2 institute of Oceanology,chinese academy of {3.,Qingdao 266071,china,Graduate School of chinese academy of sciences,beijing 10003.,china 3.institute of Oceanology,chinese academy of {3.,Qingdao 266071,china,Graduate School of chinese academy of sciences,beijing 10003.,china 4 china University of Petroleum,beijing 102249,china [a] Doctor researcher institute of Oceanology chinese academy of sciences Qingdao 266071 china [b] institute of Oceanology chinese academy of sciences Qingdao 266071 china Graduate School of chinese academy of sciences beijing 10003. china [c] institute of Oceanology chinese academy of sciences Qingdao 266071 china Graduate School of chinese academy of sciences beijing 10003. china [d] china University of Petroleum beijing 102249 china

The suspended sediment flux field in the Yellow and East china Seas(YECS) displays its seasonal variability.A new method is introduced in this paper to obtain the flux field via retrieval of ocean color remote sensing data,statistical analysis of historical suspended sediment concentration data,and numerical simulation of three-dimensional(3.) flow *** components of the sediment flux field include(i) surface suspended sediment concentration inverted from ocean color remote sensing data;(ii) vertical distribution of suspended sediment concentration obtained by statistical analysis of historical observation data;and(iii) 3. flow field modeled by a numerical *** the improved method,the 3. suspended sediment flux field in the YECS has been *** comparison with the suspended sediment flux field solely based on the numerical simulation of a suspended sediment transport model,the suspended sediment flux field obtained by the improved method is found to be more *** 3. suspended sediment flux field from ocean colour remote sensing and in situ observation are more closer to the ***,by quantitatively analyzing the newly obtained suspended sediment flux field,the quantity of sediment erosion and deposition within the different regions can be *** sediment exchange between the Yellow Sea and the East china Sea can be *** mechanism of suspended sediment transport in the YECS can be better *** particular,it is suggested that the long-term transport of suspended sediment is controlled mainly by the circulation pattern,especially the current in winter.

关键词： Suspended sediment flux field Seasonal variability Yellow and East china Seas Regression equation Numerical simulation