检索结果-南通市图书馆

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

引用

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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on the nutrient evolution and its controlling factors of Longgan lake for the last 200 years

引用

Science China Earth sciences 2006年第z1期49卷 193-202页

作者： LIU Jian YANG Xiangdong WANG Sumin key laboratory of lake Sedimentation and environment Chinese Academy of Sciences Nanjing 210008 China Key Laboratory of Lake Sedimentation and Environment Chinese Academy of Sciences Nanjing 210008 China Key Laboratory of Lake Sedimentation and Environment Chinese Academy of Sciences Nanjing 210008 China

Based on the total phosphorous (TP) concentration in sediment core, the TP concentration in lake water quantitatively reconstructed from fossil diatoms and diatom-TP transfer function in the Longgan lake during the last 200 years, the temperature and precipitation data from meteorological observation for the last 50 years, the temperatures and precipitation sequences of climate simulation for the last 200 years, as well as the amount of the agricultural phosphate fertilizer in Longgan area for nearly 50 years, the characteristic and the law of the nutrient status evolution were analyzed, and the influence of the climatic factor, the anthropologic factor and the aquatic biology factor on the nutrient status evolution and its mechanism were discussed for the Longgan lake during the last 200 years. The results showed that, in the nearly 200 years, the TP concentration in the sediment core of the Longgan lake gradually increased, its range of variation was situated between 330-580 mg/kg, the mean value was 388 mg/kg, a nearly 30-year vibration adjustment period existed at 1950 around. The TP concentration in lake water changed in a different way. Before 1950, it had a slow increasing tendency in fluctuated background, to 1950 around it reached up to the mean value (52.18 μg/L), and vibrated and adjusted around the mean value, then it fast declined, its change range was situated between 37.75-62.33 μg/L. The analyses indicated that, in the centennial time scale, the climate change was the main controlling factor, while in the decadal time scale in the recent 50 years, human activities were the leading factors for the nutrient status evolution of the Longgan lake. 60% of the variability of the TP concentration in the sediments and 57% of that in lake water were due to human activities. The differentiation between phosphorus concentration in the sediment and in the lake water reflected the response processes and the adjustment abilities of the lake aquatic ecosystems to th

关键词： Longgan lake, nutrient evolution, controlling factor, climate, human activities.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigation on the eco-toxicity of lake sediments with the addition of drinking water treatment residuals

引用

Journal of environmental sciences 2016年第8期28卷 5-15页

作者： Nannan Yuan Changhui Wang Yuansheng Pei The key laboratory of Water and Sediment sciences Ministry of Education School of Environment Beijing Normal University state key laboratory of lake Science and environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences

Drinking water treatment residuals（WTRs） have a potential to realize eutrophication control objectives by reducing the internal phosphorus（P） load of lake sediments. Information regarding the ecological risk of dewatered WTR reuse in aquatic environments is generally lacking, however. In this study, we analyzed the eco-toxicity of leachates from sediments with or without dewatered WTRs toward algae Chlorella vulgaris via algal growth inhibition testing with algal cell density, chlorophyll content, malondialdehyde content, antioxidant enzyme superoxide dismutase activity, and subcellular structure indices. The results suggested that leachates from sediments unanimously inhibited algal growth, with or without the addition of different WTR doses（10% or 50% of the sediment in dry weight） at different p H values（8–9）, as well as from sediments treated for different durations（10 or 180 days）. The inhibition was primarily the result of P deficiency in the leachates owing to WTR P adsorption, however, our results suggest that the dewatered WTRs were considered as a favorable potential material for internal P loading control in lake restoration projects, as it shows acceptably low risk toward aquatic plants.

关键词： Drinking water treatment residuals lake restoration Sediment Eco-toxicity Algae

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Resolving the influence of nitrogen abundances on sediment organic matter in macrophyte-dominated lakes, using fluorescence spectroscopy

引用

Journal of environmental sciences 2015年第1期27卷 197-206页

作者： Xin Yao Shengrui Wang Lixin Jiao Caihong Yan Xiangcan Jin state key laboratory of environmental Criteria and Risk Assessment State Environmental Protection Key Laboratory for Lake Pollution Control Research Center of Lake Eco-environment Chinese Research Academy of Environmental Sciences School of environment and Planning Liaocheng University

A controlled experiment was designed to resolve the influence of nitrogen abundance on sediment organic matters in macrophyte-dominated lakes using fluorescence *** biomass showed coincident growth trends with time, but different variation rates with nitrogen treatment. All plant growth indexes with nitrogen addition（N, NH4Cl100, 200, 400 mg/kg, respectively） were lower than those of the control group. Four humiclike components, two autochthonous tryptophan-like components, and one autochthonous tyrosine-like component were identified using the parallel factor analysis model. The results suggested that the relative component changes of fluorescence in the colonized sediments were in direct relation to the change of root biomass with time. In the experiment, the root formation parameters of the plants studied were significantly affected by adding N in sediments, which may be related to the reason that the root growth was affected by N *** a low concentration of N to sediments can play a part in supplying nutrients to the plants. However, the intensive uptake of NH4^＋may result in an increase in the intracellular concentration of ammonia, which is highly toxic to the plant cells. Hence, our experiment results manifested that organic matter cycling in the macrophyte-dominated sediment was influenced by nitrogen enrichment through influencing vegetation and relevant microbial activity.

关键词： Colonized sediment Non-colonized sediment Nitrogen enrichment Submersed macrophyte Sediment organic matter Fluorescence feature

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

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

引用

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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Efects of physical and chemical characteristics of surface sediments in the formation of shallow lake algae-induced black bloom

引用

Journal of environmental sciences 2013年第12期25卷 2353-2360页

作者： Qiushi Shen Cheng Liu Qilin Zhou Jingge Shang Lei Zhang ChengXin Fan University of Chinese Academy of sciences state key laboratory of lake Science and environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences

Surface sediments are closely related to lake black blooms. The dissolved oxygen （DO） distribution and its penetration depth in surface sediments as well as the migration and transformation of redox sensitive elements such as Fe and S at the sediment-water interface are important factors that could influence the formation of the black bloom. In this study, dredged and undredged sediment cores with different surface properties were used to simulate black blooms in the laboratory. The Micro Profiling System was employed to explore features of the DO and ∑H2S distribution at the sediment-water interface. Physical and chemical characteristics in sediments and pore waters were also analyzed. The results showed that sediment dredging effectively suppressed the black blooms. In the undredged treatment, DO penetration depth was only 50 μm. Fe^2＋ concentrations, ∑H2S concentrations, and ∑H2S production rates were remarkably higher in surface sediments and pore waters compared to control and dredged treatments. Furthermore, depletion of DO and accumulation of Fe^2＋ and ∑H2S in surface sediments and pore waters provided favorable redox environments and necessary material sources for the blooms. The study results proved that physical and chemical characteristics in surface sediments are important factors in the formation of the black bloom, and could provide scientific guidance for emergency treatment and long-term pre-control of black blooms.

关键词： black bloom sediment-water interface dredging sediment micro interface lake

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of elevated CO_2 on dynamics of microcystin-producing and non-microcystin-producing strains during Microcystis blooms

引用

Journal of environmental sciences 2015年第1期27卷 251-258页

作者： Li Yu Fanxiang Kong Xiaoli Shi Zhen Yang Min Zhang Yang Yu state key laboratory of lake Science and environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences University of Chinese Academy of sciences

In an attempt to elucidate the effects of different CO2concentrations（270, 380, and 750 μL/L） on the competition of microcystin-producing（MC-producing） and non-MC-producing Microcystis strains during dense cyanobacteria blooms, an in situ simulation experiment was conducted in the Meiliang Bay of lake Taihu in the summer of 2012. The abundance of total Microcystis and MC-producing Microcystis genotypes was quantified based on the 16 S r DNA and mcy D gene using real-time PCR. The results showed that atmospheric CO2 elevation would significantly decrease the p H value and increase the dissolved inorganic carbon（DIC） *** in CO2 concentration did not show significant influence on the abundance of total Microcystis population. However, CO2 concentrations may be an important factor in determining the subpopulation structure of Microcystis. The enhancement of CO2 concentrations could largely increase the competitive ability of non-MC-producing over MC-producing Microcystis, resulting in a higher proportion of non-MC-producing subpopulation in treatments using high CO2 concentrations. Concurrently, MC concentration in water declined when CO2 concentrations were elevated. Therefore, we concluded that the increase of CO2 concentrations might decrease potential health risks of MC for human and animals in the future.

关键词： Microcystis Microcystin Inorganic carbon Real-time PCR Harmful cyanobacterial blooms

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Abiotic factors in colony formation:effects of nutrition and light on extracellular polysaccharide production and cell aggregates of Microcystis aeruginosa

引用

Chinese Journal of Oceanology and Limnology 2013年第4期31卷 796-802页

作者：阳振孔繁翔 state key laboratory of lake Science and environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences

Colony morphology is important for Microcystis to sustain a competitive advantage in eutrophic lakes. The mechanism of colony formation in Microcystis is currently unclear. Extracellular polysaccharide （EPS） has been reported to play an important role in cell aggregate formation of some phytoplankton. Microcystis aeruginosa was cultivated under varied abiotic conditions, including different nutrient, light, and temperature conditions, to investigate their effects on EPS production and morphological change. The results show that nutrient concentration and light intensity have great effects on EPS production in M. aeruginosa. There was a considerable increase in EPS production after M. aeruginosa was cultivated in adjusted culture conditions similar to those present in the field （28.9 mg C/L, 1.98 mg N/L, 0.65 mg P/L, light intensity： 100 μtmol/（m2.s））. These results indicate that abiotic factors might be one of the triggers for colony formation in Microcystis.

关键词： Microcystis colony formation abiotic factors cell aggregates

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on Energy Spectrum Instability in the Processes of Propagating and Breaking of Focusing Waves

引用

China Ocean Engineering 2019年第1期33卷 86-93页

作者： ZHANG Yi-hui LIANG Shu-xiu SUN Zhao-chen state key laboratory of lake Science and environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences state key laboratory of Coastal and Offshore Engineering Dalian University of Technology

Based on phase focusing theory, focusing waves with different spectral types and breaking severities were generated in a wave flume. The time series of surface elevation fluctuation along the flume were obtained by utilizing 22 wave probes mounted along the mid-stream of the flume. Based on the wave spectrum obtained using fast Fourier transform(FFT), the instability characteristics of the energy spectrum were reported in this paper. By analyzing the variation of total spectral energy, the total spectral energy after wave breaking was found to clearly decrease, and the loss value and ratio gradually increased and tended to stabilize with the enhancement of breaking severity for different spectral types. When wave breaking occurred, the energy loss was primarily in a high-frequency range of f/fp>1.0, and energy gain was primarily in a low-frequency range of f/fp<1.0. As the breaking severity increased, the energy gain-loss ratio decreased gradually, which demonstrates that the energy was mostly dissipated. For plunging waves, the energy gain-loss ratio reached 24% for the constant wave steepness(CWS) spectrum, and was slightly larger at approximately 30% for the constant wave amplitude(CWA) spectrum, and was the largest at approximately 42% for the Pierson-Moskowitz(PM) spectrum.

关键词： phase focusing wave breaking wave surface wave steepness

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Variation of Floods Characteristics and Their Responses to Climate and Human Activities in Poyang lake, China

引用

Chinese Geographical Science 2015年第1期25卷 13-25页

作者： LI Xianghu ZHANG Qi state key laboratory of lake Science and environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences

The Poyang lake is one of the most frequently flooded areas in China. Understanding the changing characteristics of floods as well as the affecting factors is an important prerequisite of flood disaster prevention and mitigation. The present study identified the characteristics variations of historical floods in the Poyang lake and their tendencies based on the Mann-Kendall(M-K) test, and also investigated the related affecting factors, both from climate and human activities. The results revealed that the highest flood stages, duration as well as hazard coefficient of floods showed a long-term increasing linear trend during the last 60 years with the M-K statistic of 1.49, 1.60 and 1.50, respectively. And, a slightly increasing linear trend in the timing of the highest stages indicated the floods occurred later and later during the last six decades. The rainfall during the flood season and subsequent discharges of the Changjiang(Yangtze) River and runoff from the Poyang lake Basin were mainly responsible for the severe flood situation in the Poyang lake in the 1990 s. In addition, the intensive human activities, including land reclamation and levee construction, also played a supplementary role in increasing severity of major floods. While, the fewer floods in the Poyang lake after 2000 can be attributed to not only the less rainfall over the Poyang lake Basin and low discharges of the Changjiang River during flood periods, but also the stronger influences of human activity which increased the floodwater storage of the Poyang lake than before.

关键词： flood characteristics water level land reclamation Changjiang River Poyang lake

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：