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Cadmium transport mediated by soil colloid and dissolved organic matter:A field study

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Journal of Environmental sciences 2010年第1期22卷 106-115页

作者： Zhaoli Li, Lixiang Zhou college of resources and Environmental sciences, nanjing agricultural university, nanjing 2.0095, china. [a] college of resources Environmental sciences Nanjing Agricultural University Nanjing 210095 China

This study investigated the potential role of soil colloids and dissolved organic matter （DOM） in transporting Cd through in situ undisturbed paddy soil monoliths. Brilliant Blue was used as a tracer to assess the effect of preferential flow on Cd down migration. Experimental results showed that deep penetration of Cd and Brilliant Blue into the soil profile took place due to the preferential flow through macropores, mainly earthworm channels, with much of chemicals thus bypassing the soil matrix. Dye tracer and Cd distribution within the soil matrix was fairly restricted to several centimeters. Colloid restrained the migration of both dye and Cd in the matrix and preferential flow area. DOM facilitated the transport of Cd and Brilliant Blue in matrix and macropores by about 10 cm over that of the control. Pearson＇s is correlation analysis revealed strong associations between Brilliant Blue concentrations, exchangeable Cd and total Cd concentrations in three studied plots indicating that they had taken the same preferential flow pathway.

关键词： colloid dissolved organic matter preferential flow dye tracer

Lie comodules and the constructions of Lie bialgebras

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science china Mathematics 2008年第6期51卷 1017-1026页

作者： ZHANG LiangYun college of science,nanjing agricultural university,nanjing 2.0095,china college of science Nanjing Agricultural University Nanjing 210095 China

In this paper,we first give a direct sum decomposition of Lie comodules,and then accord- ing to the Lie comodule theory,construct some(triangular)Lie bialgebras through Lie coalgebras.

关键词： Lie coalgebras Lie comodules Lie bialgebras triangular Lie bialgebras 16W30

Effect of biosurfactant on the sorption of phenanthrene onto original and H_2O_2-treated soils

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Journal of Environmental sciences 2009年第10期21卷 1378-1385页

作者： PEI Xiaohong, ZHAN Xinhua, ZHOU Lixiang college of resources and Environmental sciences, nanjing agricultural university, nanjing 2.0095, china. [a]college of resources and Environmental sciences Nanjing Agricultural University Nanjing 210095 China. E-mail: ***@***

The objective of this study was to examine the effect of biosurfactant on the sorption of phenanthrene （PHE） onto the original or HzO2-treated black loamy soil （typic isohumisols） and red sandy soil （typic ferralisols）. The sorption isotherms were performed with the original and ＂soft＂ carbon-removed soils in the presence and absence of biosurfactant （200 mg/L）. The sorption and degradation of biosurfactant were investigated. The result showed that organic matter played an important role in PHE sorption onto the black loamy and red sandy soils, and the PHE sorption isotherms on the ＂soft＂ carbon-removed soils exhibited more nonlinearity than those on the original soils. The values of partition coefficient （Kd） on the original black loamy soil with or without 200 mg/L biosurfactant were 181.6 and 494.5 mL/g, respectively. Correspondingly, in the red sandy soil, Kd was 246.4 and 212.8 mL/g in the presence or absence of biosurfactant, respectively. The changes of Kd suggested that biosurfactant inhibited PHE sorption onto the black loamy soil, but facilitated PHE sorption onto the red sandy soil. The nonlinearity of PHE sorption isotherm was decreased in the presence of biosurfactant. Site specific sorption might occur during PHE sorption onto both the original and the ＂soft＂ carbon-removed soils in the presence of biosurfactant. It was noted that biosurfactant could also be sorbed onto soils. The maximal sorption capacity of the red sandy soil for biosurfactant was （76.9 ± 0.007） μg/g, which was 1.31 times that of black loamy soil. Biosurfactant was degraded quickly in the two selected soils, and 92% of biosurfactant were mineralized throughout the incubation experiment for 7 d. It implied that biosurfactant should be added frequently when the remediation of polycyclic aromatic hydrocarbon （PAH）-contaminated soils was conducted through PAH desorption approach facilitated by biosurfactant.

关键词： biosurfactant phenanthrene sorption "soft" carbon soil

alkaloid Accumulation in Catharanthus roseus Increases with Addition of Seawater Salts to the Nutrient Solution

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Pedosphere 2010年第6期20卷 718-724页

作者： WANG Jing-Yan and LIU Zhao-Pu college of resources and Environmental sciences,nanjing agricultural university,nanjing 2.0095 (china) [a] college of resources and Environmental sciences Nanjing Agricultural University Nanjing 210095 (China)

A sand culture experiment was conducted to determine the effects of different seawater (5% and 10%) treatments on plant growth,inorganic ions,indole alkaloid concentrations and yields of Catharanthus roseus,in an effort to increase the alkaloid yield by artificial *** total fresh and dry weights and tissue K + concentrations decreased,but Na + concentrations increased in the plant roots,stems and leaves of *** under seawater stress as compared to the *** concentrations and yields of vindoline,catharanthine,vinblastine and vincristine increased under seawater *** concentrations and yields of these alkaloids were higher in 5% seawater-treated plants than those in the 10% seawater-treated *** the industrial production,5% seawater treatments could reduce the cost of producing *** the control plants,the highest alkaloid concentrations reached a peak at 100 days after planting,suggesting that plant harvest must be optimized in terms of growth duration.

关键词： indole alkaloid inorganic ions plant growth seawater irrigation seawater stress

Constraints of authigenic carbonates on trace elements (Sr,Mg) of lacustrine ostracod shells in paleoenviron-ment reconstruction and its mechanism

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science china Earth sciences 2008年第5期51卷 654-664页

作者： HU Guang1,2, JIN ZhangDong1 & ZHANG Fei3 1 State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of sciences, Xi’an 710075, china 2 Graduate university of the Chinese Academy of sciences, Beijing 100049, china 3 college of resources and Environmental science, nanjing agricultural university, nanjing 2.0095, china State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China Graduate university of the Chinese Academy of sciences Beijing 100049 China college of resources and Env

Molar ratios of Mg/Ca and Sr/Ca were measured in two species of ostracod shells preserved in the upper core (15–55 m) of the Hequing Basin in Yunnan Province, southwest china. By correlating the molar ratios between Mg/Ca and Sr/Ca and comparing them with Sr concentrations of the sediments, we suggested that: (1) the molar Mg/Ca and Sr/Ca ratio variations in respective ostracod primo reflected the changes in its ambient water composition and ecology; (2) the molar Sr/Ca ratios responded better to the salinity change linearly than Mg/Ca without aragonite precipitation in the system, and otherwise there was no linear relation between them; and (3) the molar Sr/Ca ratios were mainly controlled by salinity and authigenic carbonate precipitation, whereas the molar Mg/Ca ratios were related to both salinity and temperature. In fact, the rate of ostracod growth owing to temperature controls the fluctuation of Mg/Ca in shells. Here, more attentions should be paid to the constraint of authigenic mineral precipitation processes on the trace elements in ostracod shells and to the correlation between these trace elements in biogenic carbonates and compositions of the sediments in systems and in future in vitro experiments.

关键词： ostracod shell molar Sr/Ca ratio molar Mg/Ca ratio environmental response Heqing Basin

A Raw Signal Simulator for Bistatic SAR

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Chinese Journal of Aeronautics 2009年第4期22卷 434-443页

作者： Xia Weijie,Zhou Jianjiang college of Information science and Technology,nanjing university of Aeronautics and Astronautics,nanjing 210016,china [a]college of Information science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

This article proposes a new efficient raw signal simulator for the bistatic synthetic aperture radar （SAR） based on 2D fast Fourier transform （FFT） to deal with cases of both ideal trajectory and trajectory deviation. It begins with analyzing the geometric configuration and the range history of the bistatic SAR in side-looking and squint modes of ideal trajectory as well as trajectory deviation. Then a detailed and mathematical study is conducted on the equivalence relation of bistatic-to-monostatic applications （BTMA） in the case of ideal trajectory and trajectory deviation. also a set of formulas are derived for the equivalence relation between bistatic SAR and monostatic SAR on some reasonable assumptions. Therefore, the application of the simulation method based on the 2D FFT for the monostatic SAR can be extended to the case of bistatic SAR. Finally, the simulation results prove the validity of this method. By comparing the efficiency of the proposed method with that of the time domain method, it is shown that the former is a few orders of magnitude higher.

关键词： bistatic synthetic aperture radar raw signal simulation fast Fourier transform

A relative local variational principle for topological pressure

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science china Mathematics 2010年第6期53卷 1491-1506页

作者： MA XianFeng1,CHEN ErCai2,3,& ZHANG AiHua2,4 1Department of Mathematics,East china university of science and Technology,Shanghai 200237,china 2School of Mathematics and Computer science,nanjing Normal university,nanjing 210097,china 3Center of Nonlinear science,nanjing university,nanjing 210093,china 4college of Mathematics and Physics,nanjing university of Posts and Telecommunications,nanjing 210046,china 1. Department of Mathematics East China University of Science and Technology Shanghai 200237 China2. School of Mathematics and Computer Science Nanjing Normal University Nanjing 210097 China3. Center of Nonlinear Science Nanjing University Nanjing 210093 China4. College of Mathematics and Physics Nanjing University of Posts and Telecommunications Nanjing 210046 China

We define the relative local topological pressure for any given factor map and open cover,and prove the relative local variational principle of this *** precisely,for a given factor map π:(X,T)→(Y,S) between two topological dynamical systems,an open cover U of X,a continuous,real-valued function f on X and an S-invariant measure ν on Y,we show that the corresponding relative local pressure P(T,f,U,y) satisfies sup μ∈M(X,T){ hμ(T,U|Y)+∫X f(x)dμ(x) :πμ=ν}=∫Y P(T,f,U,y)dν(y),where M(X,T) denotes the family of all T-invariant measures on ***,the supremum can be attained by a T-invariant measure.

关键词： pressure conditional entropy relative local variational principle

MODELING OF WATER DYNAMICS AND POLLUTANT SPREADING IN THE LUOMAHU RESERVOIR FOR WATER TRANSFER FORM SOUTH TO NORTH OF china

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Journal of Hydrodynamics 2001年第4期13卷 14-23页

作者： Wang Chao college of Water resources and Environment, Hohai university, nanjing 210098, china college of Water resources and Environment Hohai University

Water quality is the key problem of the East-Line Project of Water Transfer from South to North china. In this paper, the principles of a 1D and 2D-integrated mathematical model for describing the dynamics of water in a flow-through river, canals and lakes was worked out. The numerical method and model algorithm were developed. The efficiency of the model was estimated by applying it to studying water dynamics in the Luomahu reservoir and simulating the spreading process of a polluted water mass and the evolution of the concentration. The results of calculations are used to assess water environmental quality and to manage water resource in the Luomahu reservoir and the Jinghang-Canal for the Project of Water Transfer from South to North china.

关键词： mathematical model integral stream function water quality Water Transfer from South to North Project

Back analysis of mechanical parameters of roller compacted concrete dam

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science china(Technological sciences) 2010年第3期53卷 848-853页

作者： GU ChongShi 1,2,3,LI Bo 1,XU GuangLei 4 &YU Hong 1,2,3 1 State Key Laboratory of Hydrology-Water resources and Hydraulic Engineering,Hohai university,nanjing 210098,china 2college of Water Conservancy Hydropower,Hohai university,nanjing 210098,china 3National Engineering Research Center of Water resources Engineering Safety,Efficient Utilization and nanjing 210098,china 4 nanjing Hydraulic Research Institute,nanjing 210029,china 1. State Key Laboratory of Hydrology-Water resources and Hydraulic Engineering Hohai University Nanjing 210098 China2. College of Water Conservancy Hydropower Hohai University Nanjing 210098 China3. National Engineering Research Center of Water Resources Engineering Safety Efficient Utilization and Nanjing Nanjing 210098 China4. Nanjing Hydraulic Research Institute Nanjing 210029 China

In view of the diversity and complexity of mechanical parameters of roller compacted concrete dam(RCCD),the uniform design method,partial least-squares regression(PLS)and least squares support vector machine(LSSVM)were applied to the back analysis of RCCD with the use of the complex nonlinear relationship between dam mechanical parameters and dam *** the process of back analysis,the initial samples of parameters were designed with uniform design ***,a transversely isotropic model of RCCD was established by *** *** this model,training samples of LSSVM model could be *** then,the complex nonlinear relationship between relative values of hydraulic components of dam displacements and mechanical parameters was ***,actual relative values of dam hydraulic components are isolated from the measured data of dam displacements by using *** inputting the isolated relative values into LSSVM model,the back analysis values of RCCD mechanical parameters can be *** example analysis showed that mechanical parameters obtained by the above-mentioned back analysis method are reasonable,and the back analysis method is feasible.

关键词： roller compacted concrete dam mechanical parameters back analysis