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Research on stability of the accumulated rock-soil body of reservoir bank under rainfall condition

Science china(Technological Sciences) 2009年第9期52卷 2528-2535页

作者： GU ChongShi1,2.WU HaiZhen1,2.& SU HuaiZhi1,2.1 College of Water Resources and Hydropower Engineering,Hohai University,nanjing 2.0098,china 2.National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety,Hohai University,nanjing 2.0098,china 3 Jiangxi Water Conservancy Research institute,Nanchang 33002.,china College of Water Resources and Hydropower Engineering Hohai University Nanjing China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University Nanjing China Jiangxi Water Conservancy Research institute Nanchang China

The shear strength parameters property of rock-soil aggregates in embankment slope of reservoir,that is,the relationship between cohesion and gravel content,between friction angle and gravel content,and the relationship between cohesion and water content,between friction angle and water content,is studied based on the direct shear test results,the shear strength change law of the rock-soil aggregates is given,and the unsaturated shear strength formulation of rock-soil aggregates that could consider suction and saturation degree influence is put forward in this paper,through which the sliding or failure physical mechanism of this type of slope under the condition of rainfall infiltration is studied. Also the 3D unsteady saturated-unsaturated seepage field and its FEM resolving mode are established based on the analysis of the slope rainfall infiltration process. Case study with this method indicates that the minimum safety factor of the accumulated rock-soil aggregates dose not arrive at the moment of rainfall cessation,but appears several hours after the rainfall cessation,this phenomenon is in accordance with the practical slope engineering's failure process and could explain appropriately the slope failure caused by rainfall infiltration. Research results in this paper have an important reference value for the research on stability of the accumulated rock-soil aggregates in embankment slope of reservoir,and can enrich the stability analysis method and relevant theory of reservoir embankment slope.

关键词： reservoir bank slope rock-soil aggregates rainfall infiltration saturated/unsaturated seepage

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Ultra-microbes are the minerogenetic constructors of oceanic polymetallic nodules

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Chinese Science Bulletin 1997年第8期42卷 617-624页

作者： CHEN Jianlin, ZHANG Fusheng and BIAN Lizeng1 Second institute of Oceanography, State Oceanic Administration, Hangzhou 310012. china 2.Center for Materials Analysis, {2. University, {2. 2.0093, china 3. Department of Earth Sciences, {2. University, {2. 2.0093, china Second institute of Oceanography State Oceanic Administration Hangzhou China Centu for Materials Analysis Nanjing University Nanjing China Department of Earth Sciences Nanjing University Nanjing China

Polymetallic nodules (mangnese nodules) are a typical kind of manganese oncolites The distribution of smooth sur-face and knobbly manganese nodules is closely related to the geological background of the mine field. A systematic study on their inner laminae structure and features suggests that they are the products of millions of years reproduction and accumulation of the recently found Miniactinomyces chinensis and Spirisophaerospora pacijica .

关键词： oceanic manganese nodule stromatolite ultra-microbe biolite.

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Global dimension and left derived functors of Hom

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Science china Mathematics 2007年第6期50卷 887-898页

作者： Li-xin MAO & Nan-qing DING institute of Mathematics, nanjing institute of Technology, nanjing 2.1167, china Department of Mathematics, nanjing University, nanjing 2.0093, china institute of Mathematics Nanjing Institute of Technology Nanjing China Department of Mathematics Nanjing University Nanjing China

It is well known that the right global dimension of a ring R is usually computed by the right derived functors of Hom and the left projective resolutions of right R-modules. In this paper, for a left coherent and right perfect ring R, we characterize the right global dimension of R, from another point of view, using the left derived functors of Hom and the right projective resolutions of right R-modules. It is shown that rD(R) ? n (n ? 2. if and only if the gl right Proj-dim M R ? n?2.if and only if Ext n?1(N,M) = 0 for all right R-modules N and M if and only if every (n?2.th Projcosyzygy of a right R-module has a projective envelope with the unique mapping property. It is also proved that rD(R) ? n (n ? 1) if and only if every (n?1)th Proj-cosyzygy of a right R-module has an epic projective envelope if and only if every nth Proj-cosyzygy of a right R-module is projective. As corollaries, the right hereditary rings and the rings R with rD(R) ? 2.are characterized.

关键词： global dimension projective resolution envelope 16E10 16E30 16E05

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Holocene grassland vegetation, climate and human impact in central eastern Inner Mongolia

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Science china Earth Sciences 2005年第7期48卷 1025-1039页

作者： HUANG Fei1, Kealhofer Lisa2. XIONG Shangfa3 & HUANG Fengbao1 1. nanjing institute of Geology and Paleontology,Chinese Academy of Sciences,nanjing 2.0008,china 2. Anthropology and Sociology Department,Santa Clara University,CA 95053,USA 3. institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 10002.,china nanjing institute of Geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China Anthropology and Sociology Department Santa Clara University CA 95053 United States institute of Geology and Geoohysics Chinese Academy of Sciences Beijina 100029 China

Phytolith and pollen preserved in the Taipusi Banner paleosol profile, central eastern Inner Mongolia, provide evidence of Holocene grassland vegetation, climate and human impact. The combined phytolith and pollen records reveal a major change in vegetation composition about 5000 a BP. Before 5000 a BP, the vegetation was dominated by Aneurolepidium Chinese-Stipa grandis grassland of C4 grasses. After 5000 a BP, C4 grasses rapidly retreated, indicating a shift to colder and more arid conditions. The gradual invasion of Stipa krylovii, Ag-ropyron desertorum, Ephedra, Chenopodiaceae and Caragana reveal the onset of grassland degeneration. Between 10000 and 872. a BP, the Aneurolepidium Chinese-Stipa grandis grassland included a small proportion of Artemisia shrub and Echionopos type plants, implying a strong winter monsoon and very weak summer monsoon. From 872. to 7000 a BP, C4 grasses were common, indicating a strengthening of the summer monsoon. Between 7000 and 5000 a BP, the Holocene thermal maximum was evident, with a significant expansion of C4 grasses and the presence of some trees (such as Pinus and Betula, and so on) in or near the study site. From 42.0?000 a BP, a sandy grassland of Artemisia and Agropyron desertorum together with Aster-type taxa occurred. Precipitation amelioration took place between 3000 and 2.70 a BP, with a rapid development of Echinops type plants and a small expansion of C4 grasses. From 2.70 a BP to present, human activities accelerated the process of grassland degeneration.

关键词： phytolith and pollen records grassland environment change human impact Holocene central eastern Inner Mongolia.

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A good example of high-energy radiation delay event

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Chinese Science Bulletin 1997年第4期42卷 313-315页

作者： GAN Weiqun and Rieger Erich1 Purple Mountain Observatory, nanjing 2.0008, china 2. Max-Planck {2. of Extraterrestrial Physics, Garching 85740,Germany Purple Mountain Observatory Nanjing China Max-Planck institute of Extraterrestrial Physics Garching Germany

THE delay of high-energy radiation of solar flares can be divided into two types: one is the energy-dependent delay in the hard X-ray regime, the other is the delay between the hard X-rays and instantaneous γ-ray line (GRL) emissions. Both types have different physical meanings. The former reflects the difference in acceleration or transportation of energetic electrons with various energies, while the latter reflects such a difference between the energetic electrons

关键词： sun. flare X-ray γ-ray.

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Pedodiversity: a controversial concept

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Journal of Geographical Sciences 2001年第1期11卷 110-116页

作者： CHEN Jie1, ZHANG Xue-lei1, GONG Zi-tong1, WANG Jun2.(1. institute of Soil Science, CAS, nanjing 2.0008, {2. 2. Surveying and Mapping Bureau of Jiangsu Province, nanjing 2.0008, {2.) institute of Soil Science CAS Nanjing China Surveying and Mapping Bureau of Jiangsu Province Nanjing China

The concept of pedodiversity and its measurement methodology proposed and developed by Ibá?ez research term is introduced. An attempt to apply pedodiversity to analyze spatial soil variation and distribution patterns on the global scale is briefly demonstrated. Furthermore, constructive comments and criticisms on pedodiversity and its measurement from the noted pedologists and ecologists are outlined. Finally, potential applications of pedodiversity in soil science and other relevant disciplines are discussed.

关键词： pedodiversity soil global distribution spatial variation species richness species evenness Shannon Index

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A novel multi-relay cross-layer cooperative communication strategy based on Jackson queuing model

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Science china(Information Sciences) 2010年第4期53卷 842-853页

作者： XU XiaoRong1,2. & ZHENG BaoYu1 1institute of Signal Processing and Transmission, nanjing University of Posts and Telecommunications, nanjing 2.0003, china 2.ollege of Telecommunication Engineering, Hangzhou Dianzi University, Hangzhou 310018, china institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing China College of Telecommunication Engineering Hangzhou Dianzi University Hangzhou China

A novel multi-relay cooperative communication strategy based on Jackson queuing model is pro-posed, which is implemented via a cross-layer design between the physical (PHY) layer and the medium access control (MAC) layer. In the PHY layer, we focus mainly on system outage performance by analyzing in detail the relationship between the SNR threshold and the outage probabilities. While in the MAC layer, system model is treated as a Jackson queuing network, and the queue discipline for each node is assumed to be GI/M/1 model. System throughput and delay performance for the proposed strategy are also illustrated. Simulation results of the proposed cross-layer scheme are presented to validate our theoretical derivations. It is revealed that, the number of cooperative nodes influences system outage performance at high spectral efficiency regimes in the PHY layer while the proposed strategy provides a better throughput and delay performance than conventional schemes in the MAC layer.

关键词： multi-relay cooperative communication cross-layer design Jackson queuing model outage prob- abilities GI/M/1 model system throughput delay performance

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STABILITY ANALYSIS OF RIVERBANK SUBJECT TO SEEPAGE

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International Journal of Sediment Research 2007年第4期22卷 282-291页

作者： Yan LU1, Yongjun LU2. and Xingnong ZHANG3 1 Postdoctoral Fellow, nanjing Hydraulic Research institute, State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering Science, nanjing, china 2.002.. 2.Prof., nanjing Hydraulic Research institute, nanjing, china 2.002. 3 Prof., nanjing Hydraulic Research institute, nanjing, china 2.002.. nanjing Hydraul Res Inst Nanjing 210029 Peoples R China

The stability of riverbanks subject to seepage is studied experimentally and theoretically in this paper. By including seepage in a 3-dimensional theoretical analysis, the study first shows how the critical slope or angle of repose of a cohesionless material is related to the ratio of the hydraulic gradient of seepage to its critical value under the fluidization condition. The critical stable slope is shown to be related to not only the hydraulic gradient but also the seepage direction. Measured laboratory data reasonably fit well with the theoretical relationship for the case of injection and suction. The data reveal that the slope is reduced with injection and increased with suction, respectively. Additionally, the study identifies the seepage direction which results in a minimum critical stable slope for a certain hydraulic gradient of seepage.

关键词： Seepage Riverbank Stability Critical stable slopes Angle of repose Erosion

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A high-resolution late Pleistocene record of pollen vegetation and climate change from Jingning, NW china

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Science china Earth Sciences 2006年第2期49卷 154-162页

作者： LI Chunhai12. TANG Lingyu1, FENG Zhaodong3,4, ZHANG Hucai2. WANG Weiguo3 & AN Chenbang3 1. nanjing institute of Geology and Palaeontology, Chinese Academy of Sciences, nanjing 2.0008, china 2. Nanjng institute of Geography and Limnology, Chinese Academy of Sciences, nanjing 2.0008, china 3. Environment and Resources College, Lanzhou University, Lanzhou 730000, china 4. Beijing Normal University, Beijing 100875, china nanjing institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing China Nanjng institute of Geography and Limnology Chinese Academy of Sciences Nanjing China Environment and Resources College Lanzhou University Lanzhou China Beijing Normal University Beijing China

With the support of 18 AMS-14C data, a high-resolution pollen record from the Suancigou section at Jingning, Gansu Province was established. Our results showed that the vegetation ex-perienced a series of changes characterized by the alternative growth and decline of forest and steppe components during the period from 44.2.to 11 ka B.P. in the Jingning area. Over the period of 44―2. ka B.P. (MIS3), coniferous forests were flourishing, indicating a humid climate with the tem-perature being lower than that of the present. Since 2. ka B.P., the vegetation was dominated by steppe-desert steppe under a cold and dry condition, and entered the Last Glacial Maximum domi-nated by desert steppe. Several periods of the marked decrease in the arborous pollen content in Suancigou well corresponded to the North Atlantic Heinrich events, especially to Heinrich event 3, further supporting that the Heinrich events were well reflected by the pollen record in the Loess Pla-teau as well.

关键词： Western Loess Plateau, pollen record, climatic change, late Pleistocene.

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Distributed optimization using virtual and real game strategies for multi-criterion aerodynamic design

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Science china(Technological Sciences) 2008年第11期51卷 1939-1956页

作者： TANG ZhiLi1, BAI Wen2.& DONG Jun3 1 College of Aerospace Engineering, nanjing University of Aeronautics & Astronautics, nanjing 2.0016, {2. 2.Chinese Aeronautics Computation Technique Research institute, Xi’an 710068, {2. 3 Chinese Aerodynamic Research institute on Aeronautics, Shenyang 110034, {2. College of Aerospace Engineering Nanjing University of Aeronautics & Astronautics Nanjing China Chinese Aeronautics Computation Technique Research institute Xi’an China Chinese Aerodynamic Research institute on Aeronautics Shenyang China

This paper introduces the virtual and real game concepts to investigate multi-criterion optimization for optimum shape design in aerodynamics. The constrained adjoint meth- odology is used as the basic optimizer. Furthermore, the above is combined with the vir- tual and real game strategies to treat single-point/multi-point airfoil optimization. In a symmetric Nash Game, each optimizer attempts to optimize one’s own target with ex- change of symmetric information with others. A Nash equilibrium is just the compromised solution among the multiple criteria. Several kinds of airfoil splitting and design cases are shown for the utility of virtual and real game strategies in aerodynamic design. Successful design results confirm the validity and efficiency of the present design method.

关键词： multi-criterion optimization Nash equilibrium virtual game real game aerodynamics distributed computing

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