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Combined Effect of Nutrient and Pest Management on Soil Ecological Quality in Hybrid Rice Double-Cropping System

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Pedosphere 2003年第2期13卷 129-138页

作者： A.SUBHANI Natural resources science Department College of Environmental and Resources Sciences Zhejiang Univer-sity

The mineral fertilizers (NPK) and pesticide, including herbicides, insecticides and fungicides, were applied alone or in combination and the soil sampling was done at different growth stages during the crop cycle to study the changes in soil organic matter, microbial biomass and their activity parameters in a paddy soil with different nutrient and pest management practices in a hybrid rice double-cropping system. A consistent increase in the electron transport system (ETS) activity was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or with pesticides increased ETS activity, while a decline of ETS activity was noticed with pesticides alone as compared with the control. Nearly an increasing trend in soil phenol content was observed with the progression of crop growth stages, while the usage of pesticides alone caused maximum increments in the soil phenol content. The soil protein content was found nearly stable with fertilizers and/or pesticides application at various growth stages in both crops taken. But notable changes were noticed at different growth stages probably because of fluctuations in moisture and temperature at particular stages, which might have their effects on N mineralization. Marked depletions in the phospholipid content were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also produced slight changes, in which a higher decline was noticed with pesticide application alone compared with the control.

关键词： electron transport system (ETS) hybrid rice phenol phospholipid protein

Developing land use scenario dynamics model by the integration of system dynamics model and cellular automata model

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science china Earth sciences 2005年第11期48卷 1979-1989页

作者： HE Chunyang, SHI Peijun, CHEN Jin, Li Xiaobing, PAN Yaozhong, LI Jing, LI Yuechen & LI Jinggang Key Laboratory of environmental Change and Natural Disaster, Ministry of Education of china, Beijing Normal university college of resources science & Technology, Beijing Normal university, Beijing 100875, china Key Laboratory of environmental Change and Natural Disaster Ministry of Education of China Beijing Normal University China college of resources science & Technology Beijing Normal University Beijing China

Modeling land use scenario changes and its potential impacts on the structure and function of the ecosystem in the typical regions are helpful to understanding the interactive mechanism between land use system and ecological system. A Land Use Scenario Dynamics (LUSD) model by the integration of System Dynamics (SD) model and Cellular Automata (CA) model is developed with land use scenario changes in northern china in the next 20 years simulated in this paper. The basic idea of LUSD model is to simulate the land use scenario de-mands by using SD model at first, then allocate the land use scenario patterns at the local scale with the considerations of land use suitability, inheritance ability and neighborhood effect by using CA model to satisfy the balance between land use scenario demands and supply. The application of LUSD model in northern china suggests that the model has the ability to reflect the complex behavior of land use system at different scales to some extent and is a useful tool for assessing the potential impacts of land use system on ecological system. In addition, the simulated results also indicate that obvious land use changes will take place in the farming-pastoral zone of northern china in the next 20 years with cultivated land and urban land being the most active land use types.

关键词： system dynamics, cellular automata, scenario, land use, model

Temporal variation of suspended sediment load in the Pearl River due to human activities

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International Journal of Sediment Research 2011年第4期26卷 487-497页

作者： Wei ZHANG,Shousheng MU,Yanjing ZHANG,and Kaimin CHEN 1 Assoc.Prof.,State Key Laboratory of Hydrology-Water resources and Hydraulic Engineering,Hohai university, nanjing,210098,china, 2,4 Graduate student,college of Harbor,Coastal and Offshore Engineering,Hohai university,nanjing,210098, china 3 Prof.,china Institute of Water resources and Hydropower Research,Beijing,100038,china Assoc. Prof. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China Graduate student College of Harbor Coastal and Offshore Engineering Hohai University Nanjing 210098 China Prof. China Institute of Water Resources and Hydropower Research Beijing 100038 China

Data on sediment flux at three hydrologic stations from the 1950s to 2006 are utilized to study the decadal,annual,and monthly variations in suspended sediment load delivered from the Pearl River to the *** show that variations in sediment flux from three main tributaries,including the West River,the North River and the East River,are spatially *** nearly 90%of the suspended sediment load comes from the West River,its variation has dominated the overall tendency of sediment flux in the entire Pearl *** a significant decreasing trend exists in the annual variation of the total sediment flux,the decadal change can be divided into an increasing phase and a decreasing phase,with the turning point between the two phases in the late *** the 1950s to the 1980s,the average annual river sediment flux increased by 30.43%.However,sediment flux has decreased significantly since the 1990s,with the average sediment flux being 38.60%less in the 2000s than that in the *** current sediment flux is also 52.93%less than its peak in the 1980s. The monthly variation pattern of the suspended sediment load transport to the sea is more interesting. For the West River,all months show a decreasing trend,and for most months the reduction values are ***,for the East River the sediment load shows a decrease trend in the dry season and an increase trend in the wet *** method of regression analysis was used to study the influence of precipitation in the variation on the sediment *** was found that the climate change is not the main driving force behind the variation in suspended sediment *** the 1990s, intensive land use destroyed the vulnerable ecosystem of the upper Pearl River,and speeded up the process of rocky ***,aggravated soil erosion caused an increase in suspended sediment ***,sediment retention within reservoirs had begun to play a dominant role after the massive constru

关键词： Pearl River Sediment flux Human activities Rocky desertification Dam construction

Boron isotopic fractionation in laboratory inorganic carbonate precipitation:Evidence for the incorpora-tion of B(OH)_3 into carbonate

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science china Earth sciences 2008年第12期51卷 1776-1785页

作者： XIAO YingKai1,2, LI HuaLing1,3, LIU WeiGuo4, WANG XiuFang1 & JIANG ShaoYong5 1 Qinghai Institute of Salt Lakes, Chinese Academy of sciences, Xining 810008, china 2 State Key Laboratory of environmental Geochemistry, Institute of Geochemistry, Chinese Academy of sciences, Guiyang 550002, china 3 nanjing Institute of Geology and Mineral resources, nanjing 210016, china 4 State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of sciences, Xi’an 710075, china 5 State Key Laboratory for Mineral Deposits Research, Department of Earth sciences, nanjing university, nanjing 210093, china Qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining China State Key Laboratory of environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang China nanjing Institute of Geology and Mineral resources Nanjing China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China State Key Laboratory for Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing China

A laboratory inorganic carbonate precipitation experiment at high pH of 8.96 to 9.34 was conducted, and the boron isotopic fractionations of the precipitated carbonate were measured. The data show that boron isotopic fractionation factors (αcarb-3) between carbonate and B(OH)3 in seawater range 0.937 and 0.965, with an average value of 0.953. Our results together with those reported by Sanyal and collabo-rators show that the αcarb-3 values between carbonate and B(OH)3 in solution are not constant but are negatively correlated with the pH of seawater. The measured boron isotopic compositions of carbonate precipitation (δ11Bcarb) do not exactly lie on the best-fit theoretical δ 11B4-pH curves and neither do they exactly parallel any theoretical δ 11B4-pH curves. Therefore, it is reasonable to argue that a changeable proportion of B(OH)3 with pH of seawater should also be incorporated into carbonate except for the dominant incorporation of B(OH)4- in carbonate . Hence, in the reconstruction of the paleo-pH of sea-water from boron isotopes in marine biogenic carbonates, the use of theoretical boron isotopic frac-tionation factor (α4-3) between B(OH)4- and B(OH)3 is not suitable. Instead, an empirical equation should be established.

关键词： boron isotopic fractionation biogenic carbonate B(OH)3 incorporation

Assessment model of dam operation risk based on monitoring data

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science china(Technological sciences) 2007年第z1期50卷 144-152页

作者： WU ZhongRu1,2?, SU HuaiZhi1,2 & GUO HaiQing1 1 college of Water Conservancy and Hydropower Engineering, Hohai university, nanjing 210098, china 2 National Engineering Research Center of Water resources Efficient Utilization and Engineering Safety, nanjing 210098, china college of Water Conservancy and Hydropower Engineering Hohai University National Engineering Research Center of Water resources Efficient Utilization and Engineering Safety

Although the dams produce remarkable social and economic benefits, the threat made by unsafe dams to the life and property of people who live in the lower river area is un-negligible. Based on the monitoring data which reflect the safety condition of dams, the risk degree concept is proposed and the analysis system and model for evaluating risk degree (rate) are established in this paper by combining the reliability theory and field monitoring data. The analysis method for risk degree is presented based on Bayesian approach. A five-grade risk degree system for dam operation risk and corresponding risk degree is put forward according to the safety condition of dams. The operation risks of four cascade dams on some river are analyzed by the model and approach presented here and the result is adopted by the owner.

关键词： dam monitoring data operation risk degree analysis model

NUMERICAL STUDY OF HYDRODYNAMICS OF MULTIPLE TANDEM JETS IN CROSS FLOW

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Journal of Hydrodynamics 2011年第6期23卷 806-813页

作者： XIAO Yang TANG Hong-wu LIANG Dong-fang ZHANG Jiu-ding State Key Laboratory of Hydrology-Water resources and Hydraulic Engineering Nanjing 210098 China college of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China Department of Engineering University of Cambridge Cambridge UK

The hydrodynamics of a single jet and four tandem jets in a cross flow are simulated by using the Computational Fluid Dynamics （CFD） software Fluent. The realizable model is used to close the Reynolds-Averaged equations. The flow characteristics of the jets, including the jet trajectory, the velocity field and the turbulent kinetic energy are obtained with various jet-to-cross flow velocity ratios in the range of 2.38-17.88. It is shown that a single jet penetrates slightly deeper than the first jet in a jet group at the same , although the difference decreases with the decrease of . It is also found that the way in which the velo-city decays along the centerline of the jet is similar for both a single jet and the first jet in a group, and the speed of the decay increases with the decrease of . The downstream jets in a group are found to behave differently due to the sheltering effect of the first jet in the group. Compared with the first jet, the downstream jets penetrate deeper into the cross flow, and the velocity decays more slowly. The circulation zone between the two upstream jets in the front is stronger than those formed between the downstream jets. The Turbulent Kinetic Energy （TKE） sees a distinct double-peak across the cross-sections close to each nozzle, with low values in the jet core and high values in the shear layers. The double-peak gradually vanishes, as the shear layers of the jet merge further away from the nozzle, where the TKE assumes peaks at the jet centerline.

关键词： multiple tandem jets jet in cross flow realizable model flow dynamics

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淹水条件下水稻田中磷的淋溶研究

土壤 2003年第6期35卷 506-509,517页

作者：谢学俭冉炜沈其荣南京农业大学资源与环境科学学院南京210095

采用地下垂直埋入钢管收集土壤淋溶液的方法,在江苏宜兴对水稻生长季节内稻田土壤中P向下迁移作了研究,重点主要集中在淋溶液中P的浓度、渗漏速度以及P的淋溶量测定几个方面.结果表明,在整个水稻生长季中淋溶液的溶解P与全P浓度均不高,... 详细信息

采用地下垂直埋入钢管收集土壤淋溶液的方法,在江苏宜兴对水稻生长季节内稻田土壤中P向下迁移作了研究,重点主要集中在淋溶液中P的浓度、渗漏速度以及P的淋溶量测定几个方面.结果表明,在整个水稻生长季中淋溶液的溶解P与全P浓度均不高,溶解P的浓度维持在0.02mg/L以下,全P的浓度则在0.03～0.08mg/L之间;土壤直渗速度为0.53cm/天;本实验方法测得的淋溶量中,整个水稻生长季在施P量为30kg/hm2的条件下,P的淋溶量为3.77 kg/hm2,其各土壤层次中土壤表层淋溶量所占比例最大,占各层总淋溶量的36%.

关键词：溶解P 全P 淋溶迁移

Cadmium Release in Contaminated Soils due to Organic Acids

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Pedosphere 2004年第2期14卷 223-228页

作者： LIAOMin XIEXiao-Mei Departmentofresourcesscience CollegeofEnvironmentalandResourceSciencesZhejiangUniversityHangzhou310029（China）.E-mail：liaomin@***

There is limited information on the release behavior of heavy metals fromnatural soils by organic acids. Thus, cadmium release, due to two organic acids (tartrate andcitrate) that are common in the rhizosphere, from soils polluted by metal smeltersor tailings andsoils artificially contaminated by adding Cd were analyzed. The presence of tartrate or citrate at alow concentration (= 2 mmol L^(-1) for citrateand >= 15 mmol L^(-1) for tartrate) apparently promoted Cd release. Under the same conditions, theCd release in naturally polluted soils was less than that of artificially ***, as the initial pH rose from 2 to 8 in the presence of citrate, a sequentialvalley and then peak appeared in the Cd release curve, while in the presence of tartrate the Cdrelease steadily decreased. In addition, Cd release was clearly enhanced as the electrolyteconcentration of KNO_3 or KC1 increased in the presence of 2 mmol L^(-1) tartrate. Moreover, ahigher desorption of Cd was shown with the KCl electrolyte compared to KNO_3 for the sameconcentration levels. This implied that the bioavailability of heavy metals could be promoted withthe addition of suitable types and concentrations of organic acids as well as reasonable fieldconditions.

关键词： artificially contaminated soil cadmium organic acid polluted soil release

Relation of Mineralizable N to Organic N Components in Dark Loessial Soils

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Pedosphere 2003年第3期13卷 279-288页

作者： LI JUMEI and LI SHENGXIUcollege of Natural resources and environmental sciences, Northwestern science and Technology university of Agriculture and Forestry, Yangling, Shaanxi 712100 (china) college of Natural resources and environmental sciences Northwestern Science and Technology University of Agriculture and Forestry Yangling Shaanxi 712100 (China)

Mineralizable N and organic N components in different layers (0～15, 15～30,30～45, 45～60, 60～80 and 80～100 cm) of six soils with different fertilities sampled from YongshouCounty, Shaanxi Province, china, were determined by the aerobic incubation method and the Bremnerprocedure, respectively. Correlation, multiple regression and path analyses were performed to studythe relation of mineralizable N to organic N components. Results of correlation and regressionanalyses showed that the amounts of the N mineralized were parallel to, and significantly correlatedwith, the total acid hydrolyzable N, but was not so with the acid-insoluble N. Of the hydrolyzableN, the amino acid N and the ammonia N had a highly consistent significant correlation with themineralized N, and their partial regression coefficients were significant in the regressionequations, showing their importance in contribution to the mineralizable N. The amino sugar N, onthe other hand, had a relatively high correlation with the mineralized N, but their partialregression coefficients were not significant in the regression equations. In contrast, thehydrolyzable unknown N had no such relations. Path analysis further indicated that the amino acid Nand ammonia N made great direct contributions to the mineralized N, but the contributions of theamino sugar N were very low. These strongly suggested that the mineralized N in the soils tested wasmainly from the hydrolyzable N, particularly the amino acid N and ammonia N which are the majorsources for its production.

关键词： acid-insoluble N hydrolyzable N mineralizable N organic N component