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Denitrification in Chongming east tidal flat sediment, Yangtze estuary, china

Science china Earth Sciences 2006年第10期49卷 1090-1097页

作者： WANG Dongqi1,2, CHEN Zhenlou1,3, XU Shiyuan1,2, HU Lingzhen1 & WANG Jun1,2 1. College of Resources & Environment, East china Normal University, Shanghai 200062, china 2. State key laboratory of Estuarine and Coastal Sediment Dynamics and Morphodynamics, East china Normal University, Shanghai 200062, china 3. key laboratory of Geographical Information Science of ministry of education,East china Normal University,Shanghai 200062, china 1. College of Resources & Environment East China Normal University Shanghai 200062 China 2. State key laboratory of Estuarine and Coastal Sediment Dynamics and Morphodynamics East China Normal University Shanghai 200062 China 3. key laboratory of Geographical Information Science of ministry of education East China Normal University Shanghai 200062 China

From July 2003 to July 2004, samples were collected on Chongming Island east tidal flat every two months. The research showed that the nitrous oxide (N2O) production rate was very low in the water, Chongming east tidal flat (CM) sediment was the N2O source of the water. Sediment N2O natural production rate was between -0.08 and 1.74 μmolN·m-2·h-1. N2O natural production rate was higher in the summer. The difference of the N2O natural production rate in the different tidal flats, the correlation between the N2O natural production rate and the denitrification rate, and those with the temperature and DO indicate that middle tidal flat sediment denitrification was the main process of the N2O production, while in the low tidal flat sediment, the production of the N2O came from several processes of the nitrogen cycling. Tidal flat sediment denitrification reaction was stronger in summer and winter but relatively lower in the late autumn and early spring. Seasonal change of the sediment denitrification rate was wide, from 1.12 to 33.34 μmolN·m-2·h-1. Temperature, DO and the coactions of them had the prominent effect on the tidal flat sediment denitrification.

关键词： Yangtze estuary, tidal flat sediment, denitrification, nitrous oxide, effect factor.

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Combined fluorescence and electrochemical investigation on the binding interaction between organic acid and human serum albumin

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Journal of environmental Sciences 2009年第3期21卷 373-379页

作者： CHEN Yan-Min,GUO Liang-Hong State key laboratory of environmental Chemistry and Ecotoxicology,Research Center for Eco-environmental Sciences,Chinese Academy of Sciences,Beijing 100085,china. [a]State key laboratory of environmental Chemistry and Ecotoxicology Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Human serum albumin （HSA） is a plasma protein responsible for the binding and transport of fatty acids and a variety of exogenous chemicals such as drugs and environmental pollutants. Such binding plays a crucial role in determining the ADME （absorption, distribution, metabolism, and excretion） and bioavailability of the pollutants. The binding interaction between HSA and acetic acid （C2）, octanoic acid （C8） and dodecanoic acid （C12） has been investigated by the combination of site-specific fluorescent probe, tryptophan intrinsic fluorescence and tyrosine electrochemistry. For the study of the fatty acid interaction with the two drug-binding sites on HSA, two fluorescent probes, dansylamide and dansyl-L-proline were employed in the displacement measurements. Intrinsic fluorescence of tryptophan in HSA was monitored upon addition of the fatty acids into HSA. Electrocatalyzed response of the tyrosine residues in HSA by a redox mediator was used to investigate the binding interaction. Qualitatively, observations from these three approaches were very similar. HSA did not show any change in the fluorescence and electrochemical experiments after mixing with C2, suggesting there is no significant interaction with the short-chain fatty acid. For C8, the measured signal dropped in a single-exponential mode, indicating an independent and non-cooperative binding. The calculated association constant and binding ratio were 3.1 × 10^6 L/mol and 1 with drug binding Site Ⅰ, 1.1 × 107 L/mol and 1 with Site Ⅱ, and 7.0× 0^4 L/mol and 4 with the tryptophan site, respectively. The measurements with C12 displayed multiple phases of fluorescence change, suggesting cooperativity and allosteric effect of the C12 binding. These results correlate well with those obtained by the established methods, and validate the new approach as a viable tool to study the interactions of environmental pollutants with biological molecules.

关键词： absorption, distribution, metabolism, and excretion (ADME) organic acid human serum albumin fluorescence electrochemistry

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Estimation of suspended sediment concentration based on bio-optical mechanism and HJ-1 image in Chaohu Lake

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Science china Earth Sciences 2010年第S1期53卷 58-66页

作者： WANG Qiao1,2,JIN Xin2,LI YunMei2,WU ChuanQing1,Lü Heng2,WANG YanFei2,ZHANG Hong2,YIN Bin2 & ZHU Li1 1Satellite Environment Center,ministry of environmental Protection,Beijing 100029,china 2key laboratory of Virtual Geographic Environment of education ministry,Nanjing Normal University,Nanjing 210046,china 1. Satellite Environment Center Ministry of Environmental Protection Beijing 100029 China2. Key Laboratory of Virtual Geographic Environment of Education Ministry Nanjing Normal University Nanjing 210046 China

Synchronization experiment was conducted in June,2009 to get Inherent Optical Properties(IOP) of water component in Chaohu *** bio-optical mechanism was studied combined with multispectral data of environmental Satellite 1(CCD),and then inversion models of total suspended matter(TSM),inorganic suspended matter(ISM) and organic suspended matter(OSM) concentration were *** data indicated that:the absorption ratio of suspended particulate matter and CDOM to total were almost no change from band 1 to band 2 with about 85% and 9%,*** ratio of pure water to total increased from 0.4% to 5.6%.Water reflectance in these two bands were influenced by absorption of three kinds of components:algae particles absorption surpassed non-algal particles in band 3,and so played an important role in total absorption with about 35.7%;the proportion of pure water absorption and particles matter backscattering both were 99% in band 4,so these two components decided the main inherent optical properties in band *** models of TSM and ISM concentration inversion based on band combination(band 3 + band 4)/(band 1 + band 2) were built,while OSM concentration was estimated by band 4/(band 1 + band 2) *** by image data,RE of TSM concentration between modeled and measured was 33.4%,and RMSE was 18.68 mg/*** of ISM and OSM concentration were 39.9% and 35.2% *** inversion was more accurate when satellite-ground data were just in the same *** this situation,RE of ISM concentration dropped to 25.4%,and that of TSM and OSM reduced to 26.5% and 26.8% as well.

关键词： HJ-1 Satellite bio-optical property Chaohu Lake suspended matter

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Adverse effects of metal exposure on chemotaxis towards water-soluble attractants regulated mainly by ASE sensory neuron in nematode Caenorhabditis elegans

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Journal of environmental Sciences 2009年第12期21卷 1684-1694页

作者： XING Xiaojuan, DU Min, ZHANG Yanfen, WANG Dayong key laboratory of Developmental Genes and Human Disease in ministry of education, Department of Genetics and Developmental Biology, Southeast University Medical School, Nanjing 210009, china. [a] key laboratory of Developmental Genes Human Disease in ministry of education Department of Genetics Developmental Biology Southeast University Medical School Nanjing 210009 China

Chemotaxis to water-soluble attractants is mainly controlled by ASE sensory neuron whose specification is regulated by che-1 in Caenorhabditis elegans. Our data suggested that exposure to high concentrations of metals, such as Pb, Cu, Ag, and Cr, would result in severe defects of chemotaxis to water-soluble attractants of NaCl, cAMP, and biotin. Moreover, the morphology of ASE neuron structures as observed by relative fluorescent intensities and relative size of fluorescent puncta of cell bodies, relative lengths of sensory endings in ASE neurons, and the expression patterns of che-1 were obviously altered in metal exposed animals when they meanwhile exhibited obvious chemotaxis defects to water-soluble attractants. In addition, the dendrite morphology could be noticeably changed in animals exposed to 150 μmol/L of Pb, Cu, and Ag. Furthermore, we observed significant decreases of chemotaxis to water-soluble attractants in Pb exposed che-1 mutant at concentrations more than 2.5 μmol/L, and in Cu, Ag, and Cr exposed che-1 mutant at concentrations more than 50 μmol/L. Therefore, impairment of the ASE neuron structures and functions may largely contribute to the appearance of chemotaxis defects to water-soluble attractants in metal exposed nematodes.

关键词： chemotaxis water-soluble attractant ASE neuron che-1 Caenorhabditis elegans

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EXPERIMENTS OF THREE-DIMENSIONAL FLOW STRUCTURE IN BRAIDED RIVERS

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Journal of Hydrodynamics 2009年第2期21卷 228-237页

作者： HUA Zu-lin GU Li CHU Ke-jian key laboratory of Integrated Regulation and Resource Development on Shallow Lakes of ministry of education College of Environmental Science and Engineering Hohai University Nanjing 210098 China State key laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing210098 China

The braided river is a typical river pattern in nature, but there is a paucity of comprehensive data set describing the three-dimensional flow field in the braided river. A physical model experiment was used to study the flow characteristics in the typical braided river with a mid-bar between two anabranches. In the experiment, two kinds of mid-bar with the ratios of its length to maximal width of 3 and 5 were considered. Moreover, the mid-bar could be moved to adjust the width of two anabranches. The detailed measurements of velocity were conducted using an acoustic Doppler velocimeter over a grid defined throughout the whole braided river region, including the bifurcation, two anabranches and the confluence. In two kinds of mid-bar braided models, a separation zone was observed in the anabranch of the model in which the ratio of length to maximal width of mid-bar is 3, however the separation zone was not found in another model in which the ratio is 5. In addition, the opposite secondary cells were observed at the bend apex of anabranch in two models, and different longitudinal velocity distributions in the entrance region of anabranch account for this opposite flow structure. Finally, turbulent kinetic energy were shown and compared in different situations. The high turbulence occurs at the place with strong shear, especially at the boundary of the separation zone and the high velocity passing flow.

关键词： braided river three-dimensional flow structure secondary flow turbulent kinetic energy

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Use of the modified viral satellite DNA vector to silence mineral nutrition-related genes in plants: silencing of the tomato ferric chelate reductase gene, FRO1, as an example

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Science china(Life Sciences) 2008年第5期51卷 402-409页

作者： HE XiuXia1,2,JIN ChongWei1, LI GuiXin3, YOU GuangYi4, ZHOU XuePing3 & ZHENG ShaoJian4 1 key laboratory for environmental and Ecosystem Health of the ministry of education, College of environmental and Resource Science, Zhejiang University, Hangzhou 310029, china 2 College of Life Science, Changchun University of Science and Technology, Changchun 130022, china 3 Institute of Biotechnology, Zhejiang University, Hangzhou 310029, china 4 State key laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou 310058, china 1. key laboratory for environmental and Ecosystem Health of the ministry of education College of Environmental and Resource Science Zhejiang University Hangzhou 310029 China 2. College of Life Science Changchun University of Science and Technology Changchun 130022 China 3. Institute of Biotechnology Zhejiang University Hangzhou 310029 China 4. State key laboratory of Plant Physiology and Biochemistry College of Life Science Zhejiang University Hangzhou 310058 China

Virus-induced gene silencing (VIGS) is potentially an attractive reverse-genetics tool for studies of plant gene function, but whether it is effective in silencing mineral nutritional-related genes in roots has not been demonstrated. Here we report on an efficient VIGS system that functions in tomato roots using a modified viral satellite DNA (DNAmβ) associated with Tomato yellow leaf curl china virus (TYLCCNV). A cDNA fragment of the ferric chelate reductase gene (FRO1) from tomato was inserted into the DNAmβ vector. Tomato roots agro-inoculated with DNAmβ carrying both a fragment of FRO1 and TYLCCNV used as a helper virus exhibited a significant reduction at the FRO1 mRNA level. As a consequence, ferric chelate reductase activity, as determined by visualization of the pink FeBPDS3 complex was significantly decreased. Our results clearly demonstrated that VIGS system can be employed to investigate gene function associated with plant nutrient uptake in roots.

关键词： virus-induced gene silencing roots ferric chelate reductase

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Colonization of periphytic ciliated protozoa on an artificial substrate in mariculture waters with notes on responses to environmental factors

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Progress in natural Science:Materials International 2009年第10期19卷 1235-1240页

作者： Jiqiu Li a,b,Henglong Xu b,Xiaofeng Lin a,Weibo Song a,b a laboratory of Protozoology,key laboratory of Ecology and environmental Science in Guangdong Higher education,South china Normal University,Guangzhou 510631,china b laboratory of Protozoology,KLM,Ocean University of china,Qingdao 266003,china [a]laboratory of Protozoology Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education South China Normal University Guangzhou 510631 China [b]laboratory of Protozoology KLM Ocean University of China Qingdao 266003 China

Colonization of periphytic ciliates and their usefulness for monitoring water quality were evaluated using the glass slide method in two enclosed mariculture ponds used to culture crab larva and in a natural seawater *** results revealed that(1) the ciliate species composition and colonizing process differed between the culturing ponds and the natural reservoir and(2) the dominant ciliate species showed a greater distribution in terms of both the abundance and the occurrence *** study also demonstrated that structural parameters were strongly related to water *** example,the abundance was positively associated with NO3-N and soluble reactive phosphate(P 3-N and NH3-N) and temperature(P < 0.05).These findings support the evidence that periphytic ciliates are useful bioindicators of water quality in enclosed mariculture ecosystems.

关键词： Periphytic ciliates Colonization process environmental factors

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Estimation of Sand Transportation Rate for Fixed and Semi-Fixed Dunes Using Meteorological Wind Data

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Pedosphere 2009年第1期19卷 129-136页

作者： HU Xia LIU Lian-You LI Shun-Jiang XIAO Bi-Lin LIU Mu-Xin key Lab of Environment change and natural disaster Ministry of Education Beijing Normal Univeristy Beijing 100875 （China） Academy of disaster Reduction and Emergency Management Ministry of Civil Affairs/Ministry of Education Beijing Normal University Beijing 100875 （China） State key laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 21008 （China） Institute of Plant Nutrition and Resources Beijing Academy of Agriculture and Forestry Sciences Beijing 100097 （China） Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 （China）

Taibus County, Inner Mongolia, china, lies in a farming-pastoral ecotone, where severe wind erosion and various aeolian sand hazards are prevalent and fixed and semi-fixed sand dunes occur frequently. This study was conducted to investigate the relationships between sand transportation rate and wind speed for the fixed and semi-fixed sand dunes based on field measurements. The annual quantity of soil erosion by wind was estimated using meteorological wind data. The results indicated that the sand transportation rate in Taibus County in 2000 was 57.38 kg cm-1 year-1 for the semi-fixed dunes and 4.56 kg cm-1 year-1 for the fixed dunes. The total duration of erosive winds covered 12.5% of the time of the year, and spring posed the highest potential of sand transportation. Wind with low speed (≤ 17 m s-1) and high frequency plays a dominant role in sand transportation, while strong wind (≥ 17 m s-1) with low frequency significantly enhanced the sand transportation. Erosive wind speed, directions, and frequency were three crucial dynamic factors influencing sand hazards in the farming-pastoral ecotone. The dominant factors intensifying sand and dust storms in Taibus County might be related to the favorable wind condition in combination with the durable drought, which led to land desertification and vegetation degradation.

关键词： fixed and semi-fixed dunes meteorological wind data sand transportation rate wind erosion

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Phosphorus forms and distribution in the sediments of Poyang Lake,china

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International Journal of Sediment Research 2011年第2期26卷 230-238页

作者： XIANG Su-lin and ZHOU Wen-bin 1 Lecturer,key Lab of Poyang Lake Ecology and Bio-resource Utilization,ministry of education,Nanchang University,Nanchang 330047,china and Department of environmental Engineering,East china JiaoTong University,Nanchang 330013,china, 2 Prof,key Lab of Poyang Lake Ecology and Bio-resource Utilization,ministry of education,Nanchang University,Nanchang 330047,china [a]Lecturer Key Lab of Poyang Lake Ecology and Bio-resource Utilization Ministry of Education Nanchang University Nanchang 330047 China and Department of Environmental Engineering East China JiaoTong University Nanchang 330013 China [b]Prof. Key Lab of Poyang Lake Ecology and Bio-resource Utilization Ministry of Education Nanchang University Nanchang 330047 China

The forms and distribution of phosphorus in the sediments of Poyang Lake were studied using chemical extraction methods to understand the potential release and adsorption of *** results showed that phosphorus in the sediments mainly consisted of inorganic phosphorous species, including iron bound phosphorus,calcium bound phosphorus,aluminium bound phosphorus and dissolved phosphorus,as well as organic phosphorous *** spatial distribution of phosphorus species in surface sediments showed a decreasing trend from the outlet to the entrance of Poyang *** content of total phosphorus in the surface sediments ranged from 688.29 to 825.36 mg/kg, and inorganic phosphorous was the major phosphorus *** bound phosphorus was the dominant form of inorganic phosphorous,accounting for greater than 40%of the total phosphorus, while calcium bound phosphorus and aluminium bound phosphorus accounted for more than 20%, and dissolved phosphorus accounted for less than 5%.The content of organic phosphorus in surface sediments was lower,accounting for less than 15%.Total phosphorus was positively correlated with iron bound phosphorus,aluminium bound phosphorus,calcium bound phosphorus and organic phosphorous,while organic phosphorous was positively correlated with iron bound phosphorus and aluminium bound phosphorus,but only weakly related to calcium bound *** all six sites, the contents of total phosphorus and phosphorus forms in the core sediments obviously decreased with depth,while they were significantly enriched in the surface *** total phosphorus and phosphorus forms contents were significantly higher in the upper layers and had a tendency to decrease toward the bottom of the core,regardless of the phosphorus *** addition,the average contents of total phosphorus and various phosphorus forms decreased rapidly with sediment depth from 0-20 cm,and then decreased slightly from 20-30 cm.

关键词： Poyang Lake Phosphorus forms Distribution characteristics Sediment

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environmental archaeology of the Dachang region in the Daning Valley,the Three Gorges reservoir region of the Yangtze River,china

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Chinese Science Bulletin 2008年第S1期53卷 140-152页

作者： ZHANG Yun 1 &ZHU Cheng 2 1 State key laboratory of Vegetation and environmental change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093, china 2 School of Geographic and Oceanographic Sciences,Nanjing University,Nanjing 210093,china 1. State key laboratory of Vegetation and environmental change Institute of Botany Chinese Academy of Sciences Beijing 100093 China 2. School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210093 China

environmental archaeology of archaeological sites on both sides of the Dachang section in the Daning River,the Three Gorges of the Yangtze River,shows that riverbed evolution has a great influence on the distribution of archaeological sites during the prehistorical and historical period,and it restricts human activity and the development of ancient *** investigation,dating data,paleocurrent analysis of 100 gravels on the riverbed and archaeological excavation reveal that the riverbed of the Dachang section developed in the Shuangyantang region during the early stage,after about 30 kaBP it shifted westward gradually and reached the present *** with the westward shift,the focus of ancient culture changed for several *** the Western Zhou Dynasty's period,the east riverbank of the Daning River was the main residential *** the Han Dynasty,along with the westward shift,the living space of ancient people was no longer confined to the east riverbank and the focus of culture moved *** the Zhangjiawan site became the main dwelling *** the late Han Dynasty, the villages were flooded and the ancients had to immigrate to a high *** of the Han and the Jin Dynasties outcropped on the flood plain of the east bank because their surface sediments were eroded by several flood events and the westward shift of the riverbed.

关键词： the Daning River environmental archaeology the Shuangyantang site the Zhangjiawan site tombs of the Han and the Jin Dynasties

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