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Dynamic calculation model and seismic response for frame supporting structure with prestressed anchors

science china(Technological sciences) 2010年第7期53卷 1957-1966页

作者： DONG JianHua1’2, ZHU YanPeng1, ZHOU Yong1 & MA Wei2 1 College of Civil Engineering, Lanzhou University of Technology, Lanzhou 730050, china 2 state key laboratory of Frozen soil Engineering, Cold and Arid Regions Environmental and Engineering Research institute, chinese academy of sciences, Lanzhou 730000, china 1. College of Civil Engineering Lanzhou University of Technology Lanzhou 730050 China2. State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

A dynamic calculation model of frame supporting structures with prestressed anchors for the slope stability is proposed. The frame and soil are closely contacted in the role of prestressed anchors and they cannot be separated along the whole slope. The lateral displacement of frame and soil is nearly in phase. The movement characteristic satisfies the theory of elastic foundation beam. The frame is treated with elastic foundation beam in this model. The influence of prestressed anchors is simplified as linear spring and damped system related with velocity. Under the condition of horizontal earthquake excitation, the equation of vibration response is established by using the model of dynamic Winkler beam and the analytical solutions are obtained for simple harmonic vibration. This method is applied to a case record for illustration of its capability, in order to verify the method, 3D nonlinear FEM (ADINA) is used to analyze the seismic performance of this case, the comparative results show that the design and the analysis are safe and credible by using the proposed method. The calculation model provides a new way for earthquake analysis and seismic design of slope stability supported by frame structure with prestressed anchors.

关键词： frame supporting structure with prestressed anchor slope dynamic calculation model seismic performance seismic design

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Distribution and Migration of Heavy Metals in Undisturbed Forest soils:A High Resolution Sampling Method

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Pedosphere 2008年第3期18卷 386-393页

作者： RUAN Xin-Ling ZHANG Gan-Lin NI Liu-Jian HE Yue state key laboratory of soil and sustainable agriculture Institute of Soil Science chinese academy of sciences Nanjing 210008 （China） Graduate School of the chinese academy of sciences Beijing 100049 （China） College of Resources and Environmental sciences Nanjing Agricultural University Nanjing 210095 （China）

The vertical distribution and migration of Cu,Zn,Pb,and Cd in two forest soil profiles near an industrial emission source were investigated using a high resolution sampling method together with reference element ***-meter soil profile was sectioned horizontally at 2 cm intervals in the first 40 cm,5 cm intervals in the next 40 cm,and 10 cm intervals in the last 20 *** migration distance and rate of heavy metals in the soil profiles were calculated according to their relative concentrations in the profiles,as calibrated by the reference element *** enrichment of heavy metals appeared in the uppermost layer of the forest soil,and the soil heavy metal concentrations decreased down the profile until reaching their background *** calculated average migration rates of Cd,Cu,Pb,and Zn were 0.70,0.33,0.37,and 0.76 cm year-1,respectively,which were comparable to other methods.A simulation model was proposed,which could well describe the distribution of Cu,Zn,Pb,and Cd in natural forest soils.

关键词： distribution heavy metals high resolution sampling method migration rate

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Plastic deformation of nanocrystalline nickel

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science china(Technological sciences) 2009年第8期52卷 2216-2221页

作者： WU XiaoLei state key laboratory of Nonlinear Mechanics, institute of Mechanics, chinese academy of sciences, Beijing 100190, china state key laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China

A high-resolution electron microscopy study has uncovered the plastic behavior of accommodating large strains in nanocrystalline (NC) Ni subject to cold rolling at liquid nitrogen temperature. The activation of grain-boundary-mediated-plasticity is evidenced in NC-Ni, including twinning and formation of stacking fault via partial dislocation slips from the grain boundary. The formation and storage of 60? full dislocations are observed inside NC-grains. The grain/twin boundaries act as the barriers of dislocation slips, leading to dislocation pile-up, severe lattice distortion, and formation of sub-grain boundary. The vicinity of grain/twin boundary is where defects preferentially accumulate and likely the favorable place for onset of plastic deformation. The present results indicate the heterogeneous and multiple natures of accommodating plastic strains in NC-grains.

关键词： nanocrystalline metal plastic deformation deformation twinning dislocation microstructure

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Denitrification Losses and N_2O Emissions from Nitrogen Fertilizer Applied to a Vegetable Field

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Pedosphere 2006年第3期16卷 390-397页

作者： CAO Bing He Fa-Yun Xu Qiu-Ming Yin Bin CAI Gui-Xin state key laboratory of soil and sustainable agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China） Graduate School of the chinese academy of sciences Beijing 100039 （China） institute of Plant Nutrition and Resources Beijing Academy of Agricultural and Forestry Sciences Beijing 100089 （China）

A field experiment was conducted on chinese cabbage （Brassica campestris L. ssp. pekinensis （Lour.） Olsson） in a nanjing suburb in 2003. The experiment included 4 treatments in a randomized complete block design with 3 replicates： zero chemical fertilizer N （CK）; urea at rates of 300 kg N ha^-1 （U300） and 600 kg N ha^-1 （U600）, both as basal and two topdressings; and polymer-coated urea at a rate of 180 kg N ha^-1 （PCU180） as a basal application. The acetylene inhibition technique was used to measure denitrification （N2 ＋ N2O） from intact soil cores and N2O emissions in the absence of acetylene. Results showed that compared to （3K total denitrification losses were significantly greater （P ≤ 0.05） in the PCU180, U300, and U600 treatments,while N2O emissions in the U300 and U600 treatments were significantly higher （P ≤ 0.05） than （3K. In the U300 and U600 treatments peaks of denitrification and N2O emission were usually observed after N application. In the polymer-coated urea treatment （PCU180） during the period 20 to 40 days after transplanting, higher denitrification rates and N2O fluxes occurred. Compared with urea, polymer-coated urea did not show any effect on reducing denitrification losses and N2O emissions in terms of percentage of applied N. As temperature gradually decreased from transplanting to harvest, denitrification rates and N2O emissions tended to decrease. A significant （P ≤0.01） positive correlation occurred between denitrification （r = 0.872） or N2O emission （r = 0.781） flux densities and soil temperature in the CK treatment with a stable nitrate content during the whole growing season.

关键词： denitrification loss N2O emission polymer-coated urea urea vegetable field

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Spatial Prediction of Heavy Metal Pollution for soils in Peri-Urban Beijing, china Based on Fuzzy Set Theory

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Pedosphere 2006年第5期16卷 545-554页

作者： TAN Man-Zhi XU Fang-Ming CHEN Jie ZHANG Xue-Lei CHEN Jing-Zhong state key laboratory of soil and sustainable agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China） Graduate school of the chinese academy of sciences Beijing 100039 Chengdu University of Technology Chengdu 610059 （China） nanjing Station of soil and Fertilizer Nanjing 210036 （China）

Fuzzy classification combined with spatial prediction was used to assess the state of soil pollution in the peri-urban Beijing area. Total concentrations of As, Cr, Cd, Hg, and Pb were determined in 220 topsoil samples （0-20 cm） collected using a grid design in a study area of 2 600 kin2. Heavy metal concentrations were grouped into three classes according to the optimum number of classes and fuzziness exponent using the fuzzy comean （FCM） algorithm. Membership values were interpolated using ordinary kriging. The polluted soils of the study area induced by the measured heavy metals were concentrated in the northwest corner and eastern part, especially the southeastern part close to the urban zone, whereas the soils free of pollution were mainly distributed in the southwestern part. The soils with potential risk of heavy metal pollution were located in isolated spots mainly in the northern part and southeastern corner of the study region. The FCM algorithm combined with geostatistical techniques, as compared to conventional single geostatistical kriging methods, could produce a prediction with a quantitative uncertainty evaluation and higher reliability. Successful prediction of soil pollution achieved with FCM algorithm in this study indicated that fuzzy set theory had great potential for use in other areas of soil science.

关键词： continuous classification fuzzy c-means heavy metal soil pollution spatial prediction

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SILICA-SUPPORTED NICKEL AND ZIRCONIUM CATALYSTS FOR BRANCHED POLYETHYLENE

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chinese Journal of Polymer science 2003年第4期21卷 453-458页

作者：孙文华 state key laboratory of Engineering Plastics The Center for Molecular sciences institute of Chemistry chinese academy of sciences Beijing 100080 china chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Engn Plast Beijing 100080 Peoples R China

8-Aminoquinoline nickel dichloride and bis(cyclopentadienyl)zirconium dichloride (Cp_2ZrCl_2) were supportedsimultaneously on silica to produce branched polyethylene successfully by combined polymerization. The supportedpolymerization results showed that the molecular weight of polyethylene increased while the molecular weight distributionbecame wider and the molecular chains of oligomers remaning in the final solution became shorter as compared to theoligomers obtained in polymerization processes with pure 8-aminoquinoline nickel dichloride catalysis, as well as theCp_2ZrCl_2 and nickel combination system. With decreasing amount of Ni catalyst in the supported catalyst, the molecular chains of oligomers in the resulting solution became shorter, while α-olefin selectivity increased.

关键词： 8-Aminoquinoline nickel dichloride, Cp_2ZrCl_2 Silica supported catalysts Branched polyethylene

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Nitrate Accumulation in soil Profile of Dry Land Farming in Northwest china

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Pedosphere 2003年第4期13卷 367-374页

作者： FAN Jun, HAO Ming-De and SHAO Ming-Anstate key laboratory of soil Erosion and Dryland Farming on the Loess Plateau, institute of soil and Water Conservation, the chinese academy of sciences, Yangling 712100 (china). state key laboratory of soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation the Chinese Academy of Sciences Yangling 712100 China

A long-term fertilizer experiment on dry land of the Loess Plateau, northwestchina, has been conducted since 1984 to study the distribution and accumulation of NO_3-N down to adepth of 400 cm in the profile of a coarse-textured dark loessial soilafter continuous winter wheatcropping. Thirteen fertilizer treatments consisted of four levels of N and P applied alone or incombination. Annual N and P (P_2O_5) rates were 0, 45, 90, 135 and 180 kg ha^(-1). After 15successive cropping cycles, the soil samples were taken from each treatment for analysis of NO_3-Nconcentration. The results showed that NO_3-N distribution in the soil profile was quite differentamong the treatments. The application of fertilizer N alone resulted in higher NO_3-N concentrationin the soil profile than the combined application of N and P, showing that application of P couldgreatly reduce the NO_3-N accumulation. With an annual application of 180 kg N ha^(-1) alone, a peakin NO_3-N accumulation occurred at 140 cm soildepth, and the maximum NO_3-N concentration in thesoils was 67.92 mg kg^(-1). The amount of NO_3-N accumulated in the soil profile decreased as thecumulative N uptake by the winter wheat increased. Application of a large amount of N resulted inlowerN recoveries in winter wheat and greater NO_3-N accumulation in soil profile. KO_3-N did notenter underground water in the study region; therefore, there is no danger of underground waterpollution. Amount of NO_3-N accumulation can be predicted by an equation according to annual N and Prates based on the results of this experiment.

关键词： dry land long-term fertilizer experiment NO_3-N accumulation wheat

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3D thermo-hydro-mechanical-migratory coupling model and FEM analyses for dual-porosity medium

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science china(Technological sciences) 2010年第8期53卷 2172-2182页

作者： ZHANG YuJun 1&ZHANG WeiQing 2 1 state key laboratory of Geomechanics and Geotechnical Engineering,institute of Rock and soil Mechanics, chinese academy of sciences,Wuhan 430071,china 2School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,china 1. state key laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China2. School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China

One kind of 3D coupled thermo-hydro-mechanical-migratory model for saturated-unsaturated dual-porosity medium was established,in which the stress field and the temperature field are single,but the seepage field and the concentration field are double,and the influences of sets,spaces,angles,continuity ratios,stiffness of fractures on the constitutive relationship of the medium can be *** relative three-dimensional program of finite element method was also *** comparing with the existing computation example,reliability of the model and the program were *** a hypothetical nuclear waste repository as a calculation example,the radioactive nuclide leak was simulated numerically with both the rock mass and the buffer being unsaturated media,and the temperatures,negative pore pressures,flow velocities,nuclide concentrations and normal stresses in the rock mass were *** results showed that the temperatures,negative pore pressures and nuclide concentrations in the buffer all present nonlinear changes and distributions that even though the saturation degree in porosity is only about 1/9 of that in fracture,the flow velocity of underground water in fracture is about 6 times of that in porosity because the permeability coefficient of fracture is almost four orders higher than that of porosity,and that the regions of stress concentration occur at the vicinity of two sides of the boundary between buffer and disposal pit wall.

关键词： dual-porosity medium thermo-hydro-mechanical-migratory coupling three-dimensional model FEM analysis

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The developmental trend of labrum and median eyes of Orsten-type preserved Phosphatocopina (Crustacea)

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science china Earth sciences 2010年第1期53卷 18-26页

作者： LIU Zheng 1,2 & DONG XiPing 1,2 1 School of Earth and Space sciences,Peking University,Beijing 100871,china 2 state key laboratory of Palaeobiology and Stratigraphy,nanjing institute of Geology and Palaeontology,chinese academy of sciences,nanjing 210008,china 1. School of Earth and Space sciences Peking University Beijing 100871 China2. State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China

The Phosphatocopina (Crustacea,Arthropoda) is an important group of 'Orsten-type' preserved *** is resolved as the sister-group of *** we study the labrum,the median eyes,and the inner lamella of Phosphatocopina based on the selected specimens respectively from western Hunan,South china,and *** labrum characters of different species exhibit interspecific *** ratio of labrum length/shield length is significant to the reconstruction of the ontogeny of *** labrum characters should be introduced to the diagnosis of *** the earliest growth stage,the median eyes were inconspicuous,almost as flat as the other area of the ***,with the growth of the individuals they became *** were two obviously concave structures on the ventral side of the hypostome in later stages,which were the positions where the median eyes should have been *** addition,the two modes of preservation of the inner lamella,i.e.,that of shrinking and that of bulging up,are interpreted as the preservational artifact herein.

关键词： Phosphatocopina Crustacea Orsten-type preservation morphology ontogeny Cambrian South china Sweden

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SOLID PHASE TRANSITION OF SYNDIOTACTIC POLYSTYRENE IN SUPERCRITICAL CO_2

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chinese Journal of Polymer science 2002年第3期20卷 191-196页

作者： Yu-ying Li Jia-song He state key laboratory of Engineering Plastics, Center for Molecular science, institute of Chemistry chinese academy of sciences, Beijing 100080 china chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Engn Plast Beijing 100080 Peoples R China

Solid phase transition of the a form crystals to the 3 form crystals in syndiotactic polystyrene (sPS) samples has occurred in supercritical CO2. This transformation is different from those detected under other conditions. The effects of some factors (e.g. time, temperature, and pressure) on the solid phase transformation of sPS in supercritical CO2 were analyzed in detail. Experimental results show that longer time, higher temperature or higher pressure favors the transformation of the a form crystals to the beta form crystals.

关键词： solid phase transition syndiotactic polystyrene supercritical CO2

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