检索结果-南通市图书馆

Effects of hydrodynamics processes on phosphorus fluxes from sediment in large,shallow Taihu Lake

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2007年第9期19卷 1055-1060页

作者： YOU Ben-sheng ZHONG Ji-cheng fan cheng-xin WANG Tong-cheng ZHANG Lu DING Shi-ming State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China. Graduate University of Chinese academy of sciences Beijing 100049 China Jiangsu Provincial academy of Environmental Science Nanjing 210036 China nanjing institute of Environmental sciences State Environmental Protection Administration Nanjing 210042 China

The turnover of phosphorus （P） in lake sediments, a major cause of eutrophication and subsequent deterioration of water quality, is in need of deep understanding. In this study, effects of resuspension on P release were studied in cylindrical microcosms with Yshape apparatus. The results indicated that there was a positive correlation between flux of suspended substance across sediment-water interface （Fss） and the wind speed, and an increasing Fss during each wind process followed by a steady state. The maximal Fss under fight, moderate, and strong wind conditions were 299.9±4..1,573.4.61.7, and 2093.8±215.7 g/m^2, respectively. However, flux of P across sediment-water interface （Fp） did not follow a similar pattern as Fss responding to wind intensity, which increased and reached the maximum in initial 120 rain for fight wind, then decreased gradually, with maximal flux of 9.4.1.9 mg/m^2. A rapid increase of Fp at the first 30 rain was observed under moderate wind, with maximal flux of 11.2±0.6 mg/m^2. Surprisingly, strong wind caused less Fp than under light and moderate wind conditions with maximal flux of 3.5±0.9 mg/m^2. Fss in water column declined obviously during the sedimentation process after winds, but Fp varied with wind regime. No obvious difference was detected on Fp after 8 h sedimentation process, compared with the initial value, which means little redundant P left in the water column after winds.

关键词： hydrodynamic process resuspension sedimentation phosphorus flux Taihu Lake

Geochemistry of Iron,Sulfur and Related Heavy Metals in Metal-Polluted Taihu Lake Sediments

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2008年第5期18卷 564-573页

作者： YIN Hong-Bin fan cheng-xin DING Shi-Ming ZHANG Lu ZHONG Ji-cheng State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology ChineseAcademy of Sciences Nanjing Z10008 （China）. Graduate University of the Chinese academy of sciences Beijing 100049 （China）

To understand the geochemical characteristics of iron and sulfur and the extent of iron-sulfide minerals influencing heavy metal behaviour in metal-polluted sediments of Talhu Lake, two sites, in Meiliang Bay （ML） and Wuli Lake （WL）, were selected to study the fractionation of iron, sulfur and related heavy metals. There were relatively high concentrations of Fe^2＋ and low concentrations of total S^2- in porewaters, indicating that conditions in these sediments favored iron reduction. The concentrations of acid volatile sulfides in sediments were 1.9-9.6 μmol g^-1 at ML and 1.0-11.7 μmool g^-1 at WL, both in the range of values detected in unpolluted lakes. Pyrite-S was 10.2-4..4.μmol g^-1 at ML and 10.3- 33.0 μmol g^-1 at WL, accounting for more than 69% of the reduced inorganic sulfur at both sites. The low degree of sulphidization （〈 14.） and pyritization （〈 10%） indicate that sulfate may be the limiting factor for pyrite formation. The extractability of Mn, Cu, Pb, Zn, Ni, and Cr in sediments all suggest that sulfides are not the major binding phase for these metals during early diagenesis. Sulfur may play a modest role in the geochemistry of iron and traced metals in the sediments.

关键词： heavy metals reactive iron reduced inorganic sulfur Taihu Lake

施氮和增温对鄱阳湖灰化薹草(Carex cinerascens Kukenth.)湿地秋草生长期氧化亚氮排放的影响

在线全文

学校读者我要写书评

暂无评论

湖泊科学 2024年第4期36卷 1152-1162页

作者：程俊翔徐力刚樊龙凤陈曦游海林中国科学院南京地理与湖泊研究所中国科学院流域地理学重点实验室南京210008 中国科学院南京地理与湖泊研究所鄱阳湖湖泊湿地综合研究站九江332899 江西省生态文明研究院南昌330036 中国科学院大学南京学院南京211135 南京工业大学环境科学与工程学院南京211816 江西省科学院流域生态研究所南昌330096

湿地是地球上十分重要的氮库,而且对大气氮沉降增加、气候变暖等全球变化响应非常敏感。目前关于湿地氧化亚氮(N_(2)O)的研究还存在较大的区域不均衡性,湿地N_(2)O排放对全球变化的响应也具有很大的不确定性。因此,本研究通过在鄱阳湖... 详细信息

湿地是地球上十分重要的氮库,而且对大气氮沉降增加、气候变暖等全球变化响应非常敏感。目前关于湿地氧化亚氮(N_(2)O)的研究还存在较大的区域不均衡性,湿地N_(2)O排放对全球变化的响应也具有很大的不确定性。因此,本研究通过在鄱阳湖灰化薹草(Carex cinerascens Kukenth.)湿地开展N_(2)O通量原位监测及全球变化模拟实验,以揭示鄱阳湖灰化薹草湿地N_(2)O排放变化特征及其对施氮和增温的响应关系。结果表明,鄱阳湖灰化薹草湿地总体上是N_(2)O弱源,平均N_(2)O通量为(5.77±1.4.)μg/(m^(2)·h)。施氮对鄱阳湖灰化薹草湿地N_(2)O通量有显著影响,相对于不施氮,施氮可显著提升2.7倍的N_(2)O排放通量。增温及其与施氮的交互作用对N_(2)O通量的影响不显著。鄱阳湖灰化薹草湿地N_(2)O排放过程主要由湿地植物调节,而与空气温度、土壤温度、土壤水分等非生物因素无显著相关关系。研究结果有利于深入认识全球变化与湖泊湿地N_(2)O排放的互馈作用,并为评估全球变化背景下湖泊湿地N_(2)O收支平衡提供重要支撑;未来还需要加强多因子交互作用研究并开展长期连续监测,从而为阐明湿地氮循环对全球变化的响应机制和构建气候预测模型提供验证数据和理论依据。

关键词：鄱阳湖湿地温室气体 N_(2)O 全球变化氮沉降气候变暖

Influence of Sediment Dredging on Chemical Forms and Release of Phosphorus

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2008年第1期18卷 34-44页

作者： ZHONG Ji-cheng YOU Ben-Sheng fan cheng-xin LI Bao ZHANG Lu DING Shi-Ming State Key Laboratory of Lake Science and Environment Nanjin9 Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 (China) Graduate School of the Chinese academy of sciences Beijin9 100089 (China)

A laboratory experiment was carried out through a six-month incubation of undredged （control） and dredged cores to study the effect of sediment dredging on phosphorus （P） release from the sediment in the Taihu Lake. During the experiment, dredging the upper 30 cm layer could efficiently reduce the interstitial PO4.3-P concentration and different P forms in the sediment. The P fluxes of the undredged and dredged cores ranged from -5.1 to 304..6 and -60.7 to 14.4.g·m^-2·d^-1, respectively. The fluxes of the dredged cores were generally lower than those of the control. Differences in the fluxes between the dredged and undredged cores were statistically significant （P 〈 0.05） from March to June 2006. The sediment P in the dredged cores had a lower release potential than that in the control. Dredging can be considered as a useful measure for rehabilitating the aquatic ecosystem after the external P loading in the Talhu Lake catchment was efficiently reduced.

关键词： phosphorus forms phosphorous release sediment dredging Taihu Lake

绿色基础设施供需适配关系演进特征及其规律--以南京市为例

在线全文

学校读者我要写书评

暂无评论

生态学报 2024年第2期44卷 463-475页

作者：赵海霞顾斌杰王俊淇范金鼎李欣中国科学院南京地理与湖泊研究所南京210008 中国科学院大学南京学院南京211135 苏州科技大学环境科学与工程学院苏州215009

绿色基础设施(GI)供需均衡对维护城市或区域生态系统稳定,提升国土空间治理体系和治理能力现代化水平,推动城市高质量发展具有重要意义。从绿色基础设施供需适配关系的视角出发,运用生态系统服务价值法对GI服务供给进行测度,从社会、经... 详细信息

绿色基础设施(GI)供需均衡对维护城市或区域生态系统稳定,提升国土空间治理体系和治理能力现代化水平,推动城市高质量发展具有重要意义。从绿色基础设施供需适配关系的视角出发,运用生态系统服务价值法对GI服务供给进行测度,从社会、经济、生态和环境四方面综合评价GI需求,研究南京市GI供需适配关系的演进情势,揭示其时空配置的差异性。结果表明:(1)2000—2020年,南京市GI供给呈主城低、郊区高的分布格局,总供给、人均供给和单项供给均先减后增。(2)GI总需求逐年减少,形成从中心城区向郊区递减的三个圈层。(3)南京市共划出9个供需适配类型,对应11个辖区划出99个供需适配类型组合区,供需适配较好区与较差区分别占全市国土面积的26%和4.%,呈不均衡分布。(4.主城区较适应的匹配类型是低供给-中需求,郊区维持低供给-低需求较符合区域发展实际,并针对不同类型区优化提升提出对策建议。

关键词：绿色基础设施供需测度适配关系空间分异南京市

维普期刊数据库博看期刊

Effects of sludge dredging on the prevention and control of algae-caused black bloom in Taihu Lake,china

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2013年第3期25卷 430-440页

作者： Wei He Jingge Shang xin Lu chengxin fan State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences University of Chinese academy of sciences

Algae-caused black bloom （also known as black water agglomerate） has recently become a critical problem in some Chinese *** has been suggested that the occurrence of algae-caused black bloom was caused by the cooperation of nutrient-rich sediment with dead algae,and sludge dredging was adopted to control black bloom in some lakes of *** this article,based on the simulation of black bloom using a Y-shape apparatus for modeling natural conditions,both un-dredged and dredged sites in three areas of Taihu Lake,china were studied to estimate the effects of dredging on the prevention and control of black *** the experiment,drained algae were added to all six sites as an additional organic load;subsequently,the dissolved oxygen decreased rapidly,dropping to 0 mg/L at the sediment-water *** bloom did not occur in the dredged sites of Moon Bay and Nan Quan,whereas all three un-dredged sites at Fudu Port,Moon Bay and Nan Quan experienced black *** bloom also occurred at the dredged site of Fudu Port one day later than at the other sites,and the odor and color were lighter than at the other *** color and odor of the black water mainly result from the presence of sulfides such as metal sulfides and hydrogen sulfide,among other chemicals,under reductive *** color and odor of the water,together with the high concentrations of nutrients,were mainly caused by the decomposition of the algae and the presence of nutrient-rich ***,the removal of the nutrient-rich sediment by dredging can prevent the occurrence and control the degree of algae-caused black bloom in Taihu Lake.

关键词： Taihu Lake algae-caused black bloom sediment sludge dredging

Two energy balance closure approaches： applications and comparisons over an oasis-desert ecotone

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2017年第1期9卷 51-64页

作者： PAN xin LIU Yuanbo fan xingwang GAN Guojing Key Laboratory of Watershed Geographic sciences Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China University of Chinese academy of sciences Beijing 100049 China

Studies of energy balance that rely on eddy covariance（EC） are always challenged by energy balance closure, which is mainly caused by the underestimations of latent heat flux（LE） and sensible heat flux（Hs）. The Bowen ratio（BR） and energy balance residual（ER） approaches are two widely-used methods to correct the LE. A comprehensive comparison of those two approaches in different land-use types is essential to accurately correcting the LE and thus improving the EC experiments. In this study, two energy balance approaches（i.e., BR and ER） were compared to correct the LE measured at six EC sites（i.e., three vegetated, one mixed and two non-vegetated sites） in an oasis-desert ecotone of the Heihe River Basin, china. The influences of meteorological factors on those two approaches were also quantitatively assessed. Our results demonstrated that the average energy closure ratio（（LE＋Hs）/（Rn–Gs）; where Rn is the surface net radiation and Gs is the surface soil heat flux） was approximately close to 1.0 at wetland, maize and village sites, but far from 1.0 at orchard, Gobi and desert sites, indicating a significant energy imbalance at those three latter sites. After the corrections of BR and ER approaches that took into account of soil heat storage, the corrected LE was considerably larger than the EC-measured LE at five of six EC sites with an exception at Gobi site. The BR and ER approaches yielded approximately similar corrected LE at vegetated and mixed sites, but they generated dissimilar results at non-vegetated sites, especially at non-vegetated sites with low relative humidity, strong wind, and large surface-air temperature difference. Our findings provide insight into the applicability of BR and ER approaches to correcting EC-based LE measurements in different land-use types. We recommend that the BR-corrected and ER-corrected LE could be seriously reconsidered as validation references in dry and windy areas.

关键词： energy balance closure eddy covariance Bowen ratio-energy balance approach energy balance residualapproach Heihe River Basin

基于环境DNA技术和形态学鉴定的浮游植物多样性比较

在线全文

学校读者我要写书评

暂无评论

湖泊科学 2024年第5期36卷 1336-1352,I0001-I0003页

作者：程云山任艺晨席贻龙刘燕茹何虎范方威陈东宜李化炳安徽师范大学生态与环境学院芜湖241002 中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室南京210008 中国科学院抚仙湖高原深水湖泊研究站玉溪652500 河北大学生命科学学院保定071002 中国科学院大学北京100049 中国科学院大学中丹学院北京100049

浮游植物是湖泊生态系统的重要组成部分,检测其物种多样性和群落组成对了解湖泊生态系统功能具有重要意义。近年来,环境DNA技术越来越多地被应用于生态学调查中;但对于浮游植物的多样性检测,该方法与传统形态学鉴定获得结果的一致性尚... 详细信息

浮游植物是湖泊生态系统的重要组成部分,检测其物种多样性和群落组成对了解湖泊生态系统功能具有重要意义。近年来,环境DNA技术越来越多地被应用于生态学调查中;但对于浮游植物的多样性检测,该方法与传统形态学鉴定获得结果的一致性尚不清楚,并且缺少基于环境DNA技术对真核浮游植物与原核浮游植物进行同时检测的研究。为此,本文比较研究了不同牧食强度下中宇宙实验体系中环境DNA技术和形态学鉴定在检测浮游植物(包括真核与原核浮游植物)物种多样性和群落组成上的异同。研究结果显示:(1)基于18S rRNA基因的环境DNA技术与形态学鉴定获得的浮游植物alpha多样性(物种多样性和Shannon-Wiener多样性指数)在不同牧食强度下中宇宙实验体系中的变化趋势一致;(2)与形态学鉴定结果相比,基于16S rRNA基因和18S rRNA基因的环境DNA技术能够检测到更多的浮游植物种类,并且能够很好地展现不同处理组中浮游植物群落组成的差异;(3)基于18S rRNA基因的环境DNA技术在浮游植物多样性检测上具有更高的精确性。尽管环境DNA技术在监测浮游植物生物量方面存在局限,但是其在浮游植物生物多样性检测方面比形态学鉴定具有显著的优势。本研究对环境DNA技术同时应用于真核和原核浮游植物检测进行了尝试,并证实了基于18S rRNA基因的环境DNA技术在浮游植物物种多样性和群落组成检测中具有更高的分辨率和精确性,可提供更加丰富的数据,为在浮游植物多样性研究和水生态环境监测中推广使用环境DNA技术提供了依据。

关键词：环境DNA 形态学鉴定浮游植物多样性

Sulfur-containing amino acid methionine as the precursor of volatile organic sulfur compounds in algea-induced black bloom

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2013年第1期25卷 33-43页

作者： xin Lu chengxin fan Wei He Jiancai Deng Hongbin Yin State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences University of School of the Chinese academy of sciences State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences

After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds （VOSCs）： methanethiol （MESH）, dimethyl sulfide （DMS）, dime^yl disulfide （DMDS）, dimethyl trisulfide （DMTS） and dimethyl tetrasulfide （DMTeS）. Even in the untreated control without a methionine addition, methionine and its catabolites （VOSCs, mainly DMDS） were found in considerable amounts that were high enough to account for the water＇s offensive odor. However, blackening only occurred in two methionine-amended treatments. The VOSCs production was observed to precede black color development, and the reaching of a peak value for total VOSCs was often followed by water blackening. The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs. In addition, DMDS was found to be the most abundant species produced after the addition of methionine alone, and DMTeS appeared to be the most important compound produced after the addition of methionine＋glucose. These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom. The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds, such as DMTS and DMTeS.

关键词： algal blooms black bloom methionine volatile organic sulfur compounds sulfur-containing amino acid