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Bioelectricity generation and remediation of sul de contaminatedtidal at sediment 预览
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作者 M.Azizul Moqsud 《国际泥沙研究:英文版》 SCIE 2020年第1期91-96,共6页
A dramatic decrease in the catch of shellfish has been observed due to the high amount of Acid Volatile Sulfide(AVS)in the tidal flats in Japan.In the current study,an evaluation of simultaneous bioelectricity generat... A dramatic decrease in the catch of shellfish has been observed due to the high amount of Acid Volatile Sulfide(AVS)in the tidal flats in Japan.In the current study,an evaluation of simultaneous bioelectricity generation and remediation of sulfide contaminated tidal flat sediment has been done.The sediment samples collected from Tokyo Bay and Yamaguchi Bay,Japan,have been used in the laboratory test.A 2 L cylindrical shaped Sediment Microbial Fuel Cell(SMFC)has been used to evaluate the remediation of both sediment samples in the laboratory.Three different electrode materials carbon felt,carbon fiber and bamboo charcoal were used in the experiments to compare their efficiency to reduce the AVS from the sediment and generate bioelectricity.It was observed that the AVS reduction was higher at 5 cm depths for the Tokyo Bay sediment(100%)compared to the Yamaguchi Bay sediment(60%).The larger grain size for the Tokyo Bay sediment was the probable reason for this.The maximum voltage was around 100 and 80 mV for Tokyo Bay and Yamaguchi Bay,respectively. 展开更多
关键词 Acid volatile sulfide BIOELECTRICITY REMEDIATION Tidal flat Sediment microbial fuel cell SEDIMENT
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长江口冲淤交替及变化趋势
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作者 朱博渊 李义天 +4 位作者 岳遥 杨云平 梁恩航 张春财 BORTHWICK Alistair G.L. 《地理学报:英文版》 SCIE CSCD 2020年第1期145-163,共19页
The morphological changing trend of the Yangtze Estuary,the largest estuary of Asia,has become a focus of research in recent years.Based on a long series of topographic data from 1950 to 2015,this paper studied the er... The morphological changing trend of the Yangtze Estuary,the largest estuary of Asia,has become a focus of research in recent years.Based on a long series of topographic data from 1950 to 2015,this paper studied the erosion-deposition pattern of the entire Yangtze Estuary.An alternation between erosion and deposition was found during the past 65 years,which was in correspondence to the alternation between flood and dry periods identified by multi-year average duration days of high-level water flow(defined as discharge≥60,000 m 3/s,namely,D≥60,000)from the Yangtze River Basin.A quantitative relationship was further developed between the erosional/depositional rate of the Yangtze Estuary and the interpreting variables of yearly water discharge,D≥60,000 and yearly river sediment load,with contributing rates of 1%,59%and 40%,respectively.Mechanism behind the alternate erosion and deposition pattern was analyzed by examining residual water surface slope and the corresponding capacity of sediment transport in flood and dry periods.In flood periods,a larger discharge results in steeper slope of residual water level which permits a greater capacity of sediment transport.Therefore,more bed materials can be washed to the sea,leading to erosion of the estuary.In contrast,flatter slope of residual water level occurs in dry periods,and deposition dominates the estuarine area due to the decreased capacity of sediment transport and the increased backwater effect of flood-tide.Coastal dynamics and estuarine engineering projects alter the local morphological changes,but slightly affect the total erosional/depositional rate of the whole estuarine region.Heavy sedimentation within the Yangtze Estuary after the impoundment of the Three Gorges Dam can be attributed to the reduced occurrence frequency of flood years due to water regulation by the dam,and largely(at least 36%-52%)sourced from the sea.Deposition is still possible to occur in the Yangtze Estuary in the future,because the multi-year average D≥60,000 is unlikely to 展开更多
关键词 Yangtze Estuary erosion and deposition ALTERNATION total sediment load evolutional trend
Regularity of sediment transport and sedimentation during oods inthe lower Yellow River, China 预览
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作者 Qingchao Guo Zhao Zheng +1 位作者 Liemin Huang Anjun Deng 《国际泥沙研究:英文版》 SCIE 2020年第1期97-104,共8页
The flood season is the main period of flow,sediment transport,and sedimentation in the lower Yellow River(LYR).Within the flood season,most of the flow,sediment transport,and sedimentation occurs during flood events.... The flood season is the main period of flow,sediment transport,and sedimentation in the lower Yellow River(LYR).Within the flood season,most of the flow,sediment transport,and sedimentation occurs during flood events.Because of the importance of floods in forming riverbeds in the LYR,the regularity of sediment transport and sedimentation during floods in the LYR was studied.Measured daily discharge and sediment transport rate data for the LYR from 1960 to 2006 were used.A total of 299 floods were selected;these floods had a complete evolution of the flood process from the Xiaolangdi to the Lijin hydrological stations.For five hydrological stations(Xiaolangdi,Huayuankou,Gaocun,Aishan,and Lijin),a correlation was first established for floods of different magnitudes between the average sediment transport rate at a given station and the average sediment concentration at the closest upstream station.The results showed that the sediment transport rate at the downstream station was strongly correlated with the inflow(upstream station)sediment concentration during a flood event.A relation then was established between sedimentation in the LYR and the average sediment concentration at the Xiaolangdi station during a flood event.From this relation,the critical sediment concentrations were obtained for absolute erosion,sedimentation equilibrium,and absolute deposition during floods of different magnitudes in the LYR.The results of the current study contribute to a better understanding of the mechanisms of sediment transport and the regularity of sedimentation in the LYR during floods,and provide technical support to guide the joint operation of reservoirs and the regulation of the LYR. 展开更多
关键词 Sediment transport Floods SEDIMENTATION Lower Yellow River
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International Journal of Sediment Research(IJSR)-Order Form(2020)(ISSN 1001-6279) 预览
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《国际泥沙研究:英文版》 SCIE 2020年第1期I0002-I0004,共3页
IJSR is the journal of THE WORLD ASSOCIATION FOR SEDIMENTATION AND EROSION RESEARCH(WASER)and is edited by the International Research and Training Center on Erosion and Sedimentation(IRTCES).
关键词 SEDIMENTATION JOURNAL SEDIMENT
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雨污分流制泵站旱天放江后上游调水对受纳河道水质的影响 预览
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作者 韩啸 陶红 +4 位作者 李飞鹏 陈蒙蒙 陈闽南 刘伟 殷广艺 《净水技术》 CAS 2020年第1期130-135,共6页
旱天放江是造成上海市城区河道污染的主要原因之一。以虬江为研究对象,探究分流制泵站旱天放江后,调水对受纳河道水质的影响。选取放江当天至调水第7 d,分析对比受纳水体上游至下游,各采样断面水体中COD、TP、氨氮以及沉积物中TOC含量... 旱天放江是造成上海市城区河道污染的主要原因之一。以虬江为研究对象,探究分流制泵站旱天放江后,调水对受纳河道水质的影响。选取放江当天至调水第7 d,分析对比受纳水体上游至下游,各采样断面水体中COD、TP、氨氮以及沉积物中TOC含量的差异。结果表明,放江后和调水连续7 d后,各断面水体中水质检测指标以及沉积物中TOC含量均高于放江前。放江开始至调水第7 d,虬江水体中COD、TP、氨氮含量均呈现先递减后趋向于平稳的趋势,沉积物中TOC含量呈现递增的趋势。受调水作用的影响,上游水体中COD、TP、氨氮以及沉积物中TOC含量均低于下游。 展开更多
关键词 城区河道 调水 虬江 沉积物 分流制泵站 旱天放江
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阳宗海南岸沉积物对藻砷富集的影响 预览
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作者 王先拓 韩毅 +2 位作者 李丰超 王静怡 杨辉 《净水技术》 CAS 2020年第1期75-79,共5页
文中介绍砷(As)在沉积物-水-植物体系的迁移、富集规律。在采样分析云南阳宗海南岸表层沉积物、表层及底层水样、植物As含量的基础上,通过室内藻类静置培养试验,研究阳宗海南岸沉积物对藻类砷富集的影响。结果:60 d室内培养后,对照上清... 文中介绍砷(As)在沉积物-水-植物体系的迁移、富集规律。在采样分析云南阳宗海南岸表层沉积物、表层及底层水样、植物As含量的基础上,通过室内藻类静置培养试验,研究阳宗海南岸沉积物对藻类砷富集的影响。结果:60 d室内培养后,对照上清液总As浓度为(1.38±0.11)μg/L,藻总As含量为(0.73±0.01)μg/g;加入表层沉积物后上清液总As浓度为(3.78±2.68)μg/L,藻总As含量为(1.48±0.67)μg/g。加入表层沉积物后上清液总As及藻总As含量平均值和标准差均有所升高,经Kolmogorov-Smirnov秩和检验,表层沉积物加入对上清液总As浓度影响不显著,但对藻总As富集影响显著。 展开更多
关键词 沉积物 砷形态 砷富集 阳宗海
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红树林沉积物中微生物驱动硫循环研究进展
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作者 方安琪 贺志理 +2 位作者 王成 杨超 颜庆云 《微生物学报》 CAS CSCD 北大核心 2020年第1期13-25,共13页
红树林滨海湿地是在周期性咸水、淡水作用下形成的特殊生态系统,其沉积物中有机质含量丰富,微生物驱动的营养物质循环活跃。由于红树林沉积物中硫酸盐含量高、硫化物种类多,因此红树林是研究硫元素生物地球化学循环过程和机制的理想系... 红树林滨海湿地是在周期性咸水、淡水作用下形成的特殊生态系统,其沉积物中有机质含量丰富,微生物驱动的营养物质循环活跃。由于红树林沉积物中硫酸盐含量高、硫化物种类多,因此红树林是研究硫元素生物地球化学循环过程和机制的理想系统。本文综述了红树林生态系统中主要的硫元素循环过程,重点总结了硫氧化和硫酸盐还原过程及其功能微生物,分析了影响硫氧化和硫酸盐还原的主要环境因素,并对红树林沉积物中微生物驱动硫循环的重点研究方向进行了展望。鉴于微生物驱动的硫循环过程耦合碳、氮和金属元素循环,本文可为深入探究微生物驱动的生物地球化学元素循环耦合机制提供参考。 展开更多
关键词 红树林 沉积物 微生物群落 硫氧化 硫酸盐还原 耦合过程
Occurrence and transfer of heavy metals in sediments and plants of Aegiceras corniculatum community in the Qinzhou Bay, southwestern China 预览
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作者 Xing Huang Xueping Wang +2 位作者 Xiuzhen Li Zhongzheng Yan Yongguang Sun 《海洋学报:英文版》 SCIE CAS CSCD 2020年第2期79-88,共10页
Mangrove wetlands can reduce heavy metal pollution by trapping heavy metals.In this study,the concentration,transport and bioaccumulation of Cr,Cd,Cu,Zn and Pb in the sediments and different parts of Aegiceras cornicu... Mangrove wetlands can reduce heavy metal pollution by trapping heavy metals.In this study,the concentration,transport and bioaccumulation of Cr,Cd,Cu,Zn and Pb in the sediments and different parts of Aegiceras corniculatum at four different sites in the Qinzhou Bay in southwestern China were investigated.The results showed that although the potential ecological risk of all five heavy metals was slight,the concentration of Cr was at a moderate pollution level due to the emissions of industries and aquaculture waste water.Core sediment records indicated that the concentrations of heavy metals at the depth of 0–20 cm were relatively high,showing an increasing trend of heavy metals over the past 20–30 years.Cr,Cu,Pb and Cd accumulated mainly in the roots of A.corniculatum,while Zn accumulated mainly in the stems.Aegiceras corniculatum showed the strongest transport capacity for Zn and Cu and the strongest bioaccumulation ability for Cd.Compared with other mangrove communities,A.corniculatum can be chosen as a restoration species in tropical and subtropical coastal zones polluted by Zn,Cu and Cd. 展开更多
关键词 Aegiceras corniculatum sediment heavy metals accumulation
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Two-dimensional numerical simulation of sediment transport usingimproved critical shear stress methods 预览
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作者 Zhiyong Feng Guangming Tan +3 位作者 Junqiang Xia Caiwen Shu Peng Chen Ran Yi 《国际泥沙研究:英文版》 SCIE 2020年第1期15-26,共12页
Research on the critical shear stresses for erosion and deposition for cohesive sediment has attracted substantial attention from both engineering and theoretical viewpoints due to their importance in sediment transpo... Research on the critical shear stresses for erosion and deposition for cohesive sediment has attracted substantial attention from both engineering and theoretical viewpoints due to their importance in sediment transport theory.Previous studies have proposed a large number of empirical and semiempirical methods to estimate the critical erosion and deposition shear stress,but comparative analyses and validation of the existing methods are still lacking,leaving questions regarding the applicability ranges of the methods.The current paper evaluates the performance and applicability range of five critical erosion shear stress methods derived from different hypotheses on sediment transport for flume experiments and natural tidal rivers using a process-based model.In addition,the effect of the critical deposition shear stress on sediment transport is investigated.The results show that the different critical erosion shear stress methods yield distinctly different prediction results,and their performance and applicability ranges are discussed by comparing their predictions with measured sediment concentrations from the Shenzhen River and measured geometric changes from the Partheniades'flume experiment.The hiding and exposure effect has been recognized as a crucial factor in the incipient motion of sediment on nonuniform beds.A sensitivity analysis of selective deposition and continuous deposition justifies the existence of the critical deposition shear stress.The current study highlights the performance and applicability ranges of the existing critical shear stress methods in sediment transport modeling for uniform and nonuniform beds,which will enrich understanding of the underlying mechanisms of erosion and deposition of cohesive sediment. 展开更多
关键词 Cohesive sediment Critical shear stress Hiding and exposure effect Numerical modeling Shenzhen river
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海洋沉积过程的铀系放射性核素示踪技术:物源识别、沉积、再悬浮 预览
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作者 林武辉 余克服 +2 位作者 王英辉 刘昕明 陈立奇 《海洋地质与第四纪地质》 CAS CSCD 北大核心 2020年第1期60-70,共11页
放射性核素示踪技术被广泛应用于海洋学研究。海洋沉积物是许多物质的归宿,海洋沉积过程的研究常关注3个关联问题:物质来源、沉积速率、再悬浮过程。针对这3个问题,在南海9个珊瑚礁区、北部湾涠洲岛海域、珠江口、北冰洋、南大洋等多个... 放射性核素示踪技术被广泛应用于海洋学研究。海洋沉积物是许多物质的归宿,海洋沉积过程的研究常关注3个关联问题:物质来源、沉积速率、再悬浮过程。针对这3个问题,在南海9个珊瑚礁区、北部湾涠洲岛海域、珠江口、北冰洋、南大洋等多个海区利用典型的铀系放射性核素(210Pb、226Ra、234Th、238U)示踪技术开展海洋沉积过程研究。物源识别方面,研究发现珊瑚礁区沉积物具有极低的226Ra/238U活度比值(<0.1),显著低于其他海区的226Ra/238U活度比值(0.5~1.0),该独特性质可以应用于珊瑚礁区的沉积物/悬浮物来源示踪,是其他传统元素地球化学方法(Al、Ti、稀土元素)的补充。沉积速率方面,基于210Pb的恒定通量恒定沉积速率(Constant Flux Constant Sedimentation Model,CFCS)模式,定量计算了广西涠洲岛珊瑚礁区沉积柱样的沉积速率(3.7±0.6 mm/a),该结果低于中国多个近岸海域的沉积速率(5~96 mm/a)。沉积物再悬浮方面,提出利用“残余234Th”(不同于过剩234Th)示踪海洋沉积物再悬浮过程,并成功应用于北冰洋、南海、南大洋。 展开更多
关键词 放射性核素 沉积物 示踪 珊瑚礁 残余234Th
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Impact of seawater acidifi cation on shell property of the Manila clam Ruditapes philippinarum grown within and without sediment 预览
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作者 YUAN Hongmei XU Xian +2 位作者 YANG Feng ZHAO Liqiang YAN Xiwu 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2020年第1期236-248,共13页
Although the impact of ocean acidification on marine bivalves has been previously investigated under mainly controlled laboratory conditions,it is still unclear whether the impact of acidification on sediment-burrowin... Although the impact of ocean acidification on marine bivalves has been previously investigated under mainly controlled laboratory conditions,it is still unclear whether the impact of acidification on sediment-burrowing species differs between those within or without sediment.In order to fill this gap in our knowledge,we compared shell properties of the infaunal Manila clam(Ruditapes philippinarum)exposed to three pH concentrations(7.4,7.7,and 8.0),within and without sediments.In the first experiment(140 d),clams were exposed to seawater in an acidification system without sediment.A decrease in shell weight corresponding to the increase in dissolution rate was observed in the group ofpH 7.4,at which shell color disappeared or whitened.SEM observations confirmed the changes of the external shell surface.In the second experiment(170 d),sediment was placed at the bottom of each exposure chamber.The effects were found obvious in shell dissolution rate and shell color in the shell specimens exposed to overlying seawater but not found in the shell specimens exposed to sediment.Although the experimental period was longer in the second experiment,shell specimens in the first experiment were more seriously damaged than those in the second experiment under acidic seawater conditions.Our results,in relation to the defense function of the shell,show that marine bivalves in burrowing behavior are more adaptable to seawater acidification than those who do not burrow into sediment. 展开更多
关键词 OCEAN ACIDIFICATION SEDIMENT Manila CLAM (Ruditapes philippinarum) SHELL properties
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湖北鄂州城市湖泊底泥重金属空间分布特征与污染评价 预览
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作者 栾约生 张为 +2 位作者 石纲 吴敏 林莉 《长江科学院院报》 CSCD 北大核心 2020年第1期30-36,83,共8页
以湖北省鄂州市某湖泊底泥重金属为研究对象,在调查和分析的基础上,采用地质累积指数和潜在生态危害指数对底泥中的重金属分布以及污染状况进行评价。结果表明:从柱状底泥纵向分布来看,该湖底泥重金属含量整体上呈现从上到下递减的变化... 以湖北省鄂州市某湖泊底泥重金属为研究对象,在调查和分析的基础上,采用地质累积指数和潜在生态危害指数对底泥中的重金属分布以及污染状况进行评价。结果表明:从柱状底泥纵向分布来看,该湖底泥重金属含量整体上呈现从上到下递减的变化趋势,上层底泥重金属含量最高;从空间分布上看,3个湖区重金属污染程度排序是西湖区域>东湖区域>中湖区域。地质累积指数评价结果显示该湖底泥重金属主要以无污染-中度污染为主,底泥中重金属污染程度的大小排序为Cd>Zn>Cu>Pb>Ni>Cr>Hg>As;潜在生态危害指数法的评价结果显示底泥中As、Ni、Cu、Pb、Cr和Zn生态风险水平较低,Cd和Hg存在着不同程度的潜在生态风险,Cd的潜在生态风险最高。研究成果为该湖泊的污染调查和评价分析提供参考,并为湖泊后续的保护和水环境系统的可持续发展提供科学依据。 展开更多
关键词 城市湖泊 底泥 重金属 地质累积指数 潜在生态危害指数
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库布齐沙漠生态光伏电站不同覆盖类型下土壤粒度特征 预览
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作者 杨世荣 蒙仲举 +3 位作者 党晓宏 党梦娇 刘湘杰 石涛 《水土保持研究》 CSCD 北大核心 2020年第1期112-118,共7页
以亿利生态光伏电站3种不同立地条件的光伏电板阵列内沉积物为研究对象,利用激光衍射技术研究地表不同位置0~5 cm沉积物粒度组成,计算平均粒径、标准偏差、分形维数等粒度参数。结果表明:(1)光伏区沉积物以细沙、中沙、极细沙为主。其... 以亿利生态光伏电站3种不同立地条件的光伏电板阵列内沉积物为研究对象,利用激光衍射技术研究地表不同位置0~5 cm沉积物粒度组成,计算平均粒径、标准偏差、分形维数等粒度参数。结果表明:(1)光伏区沉积物以细沙、中沙、极细沙为主。其中甘草光伏区还有少量的粉沙,其体积百分含量为2.93%,裸沙光伏区土壤细沙粒、中沙粒体积百分比分别为74.03%和23.24%,秸秆光伏区细沙粒、中沙粒颗粒体积百分比分别为82.76%和14.41%。(2)秸秆和甘草光伏区极细沙粒百分含量上升,分选性变差,峰态平缓,偏度近似对称,分形维数数值增大,但相比裸沙光伏区,甘草光伏区的标准偏差和峰态值有一定的规律,但秸秆光伏区的标准偏差和峰态值无明显规律。(3)挟沙气流受到光伏电板倾斜角的加速,对光伏电板板间、板下、基座三处位置的土壤颗粒粗细分配不均,且铺设秸秆不足以能使土壤颗粒的细粒组分朝良好趋势发展,种植甘草可以使土壤细粒组分增多。 展开更多
关键词 粒度特征 沉积物 光伏电站 库布齐沙漠
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青藏高原东北缘尖扎盆地沉积物矿物特征及其古环境意义 预览
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作者 王祎 符超峰 +1 位作者 宋友桂 杨彦峰 《地球科学与环境学报》 CAS 北大核心 2020年第1期86-98,共13页
应用X射线衍射对青藏髙原东北缘尖扎盆地加让剖面11.8~5.8 Ma的地层沉积物进行矿物分析,结果表明加让剖面沉积物矿物组分主要包括碎屑矿物、碳酸盐矿物和黏土矿物。其中,以碎屑矿物居多,主要是石英、斜长石、云母类矿物(白云母、黑云母)... 应用X射线衍射对青藏髙原东北缘尖扎盆地加让剖面11.8~5.8 Ma的地层沉积物进行矿物分析,结果表明加让剖面沉积物矿物组分主要包括碎屑矿物、碳酸盐矿物和黏土矿物。其中,以碎屑矿物居多,主要是石英、斜长石、云母类矿物(白云母、黑云母),及少量尖晶石、辉石类矿物(普通辉石、锰钙辉石及顽火辉石等)、金红石、刚玉、磁铁矿、钛磁铁矿、榍石、霞石,偶见锆石、石榴子石、锐钛矿;碳酸盐矿物以方解石居为主,白云石占比较少;黏土矿物中,绿泥石占比最高,还有少量赤铁矿、蛭石和沸石。以全岩矿物指标研究为主,结合加让剖面沉积相演化特点,并以磁化率变化为参考,进行系统的矿物学研究,获得了尖扎盆地在11.8~5.8 Ma蕴含的古气候环境演化大致可分为4个阶段:11.8~10.0 Ma,气候干冷期;10.0~8.6 Ma,气候暖湿波动期;8.6~6.2 Ma,气候温暖湿润期;6.2~5.8 Ma,气候干冷期。在约10.0、8.6、7.2 Ma附近,主要矿物占比及组合特征有明显改变,当时的古环境状况发生急剧变化,可能揭示青藏高原东北缘在10~8 Ma期间广泛发生了一系列较强烈的构造运动,来源于周边山脉的剥蚀使得研究区沉积的近源物质增多,约7.2 Ma之后的古环境演化过程主要受青藏高原构造隆升以及全球气候变冷协同影响。 展开更多
关键词 沉积物 轻矿物 重矿物 矿物特征 X射线衍射 古环境 尖扎盆地 青藏高原
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Coastal landscape evolution tracked from late Holocene wave-cut benches in the Sinan Archipelago,Southwest Korea 预览
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作者 Sung-Ja Choi Bokchul Kim +1 位作者 Yong Sik Gihm Sanghoon Kwon 《地学前缘:英文版》 CAS CSCD 2020年第1期293-301,共9页
Glacio-isostatic adjustment(GIA)and tectonic activity are important factors in the formation of marine terraces.Late Holocene wave-cut benches in the eastern part of the West Sea of Korea,also called the Yellow Sea,ca... Glacio-isostatic adjustment(GIA)and tectonic activity are important factors in the formation of marine terraces.Late Holocene wave-cut benches in the eastern part of the West Sea of Korea,also called the Yellow Sea,can be divided into two steps:531 cm above sea level(ASL)for the upper bench(T2)and 464-481 cm ASL for the lower bench(T1).Sediments on the benches a re classified into four units,and are interpreted to be beach deposits acco rding to gravel shape,textu re,and seaward inclination.The ove rlying sediment indicates that T2 was formed at approximately 530 cm ASL before 2900 yr BP,and T1 at approximately 460-480 cm ASL before 1520 yr BP.Late Holocene(4000-2000 yr BP)relative sea level(RSL)curves based on GIA models are inconsistent with the wave-cut bench elevations.Comparing T1 and T2 benches to the RSL curves of the West Sea,the upper and the lower benches were uplifted by approximately 5-8 m and 4-7 m,respectively.Although the area is several hundred kilometers away from plate boundaries,the high frequency of earthquakes in the West Sea may have induced the uplift of wave-cut benches during the last 2000 years.These indicate that the west coast of the Korean Peninsula(KP)should no longer be considered an area of subsidence,but be assigned to a regime of uplift during the late Holocene. 展开更多
关键词 West Sea of Korea Yellow Sea Late Holocene Wave-cut benches Beach sediment UPLIFT TECTONICS
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菲与纳米银对胶州湾表层沉积物反硝化作用的复合毒性效应评价 预览
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作者 孙鹏飞 白洁 +3 位作者 李岿然 白晓岩 田延昭 赵阳国 《中国海洋大学学报:自然科学版》 CAS CSCD 北大核心 2020年第1期104-114,共11页
多环芳烃(PAHs)与纳米材料污染已对沉积物生态系统和人类生存环境构成严重威胁,其复合污染的毒性效应环境危害可能更大。为了深入探讨PAHs与纳米材料对近岸表层沉积物反硝化作用的复合毒性效应,本文选取位于胶州湾(JZB)的大沽河河口区(D... 多环芳烃(PAHs)与纳米材料污染已对沉积物生态系统和人类生存环境构成严重威胁,其复合污染的毒性效应环境危害可能更大。为了深入探讨PAHs与纳米材料对近岸表层沉积物反硝化作用的复合毒性效应,本文选取位于胶州湾(JZB)的大沽河河口区(DRE)E站和湾内S站,分别以菲和纳米银代表PAHs和纳米材料,通过测定不同剂量单一及复合污染下沉积物反硝化潜势(PDA)的变化,结合浓度相加模型(CA)、独立作用模型(IA)和中效/联合指数等效图法(CI)三种复合毒性评价方法,评价菲和纳米银对沉积物反硝化潜势的复合毒性效应,并对评价方法进行了优选。结果表明,两种污染物浓度越高,对研究区域反硝化潜势的抑制作用越大。菲、纳米银单一及复合作用下对河口区沉积物反硝化潜势的EC50值分别为44.62、112.49和64.86 mg·kg-1,对湾内分别为61.79、147.05和96.18 mg·kg-1。菲单一作用对反硝化潜势的抑制效应强于纳米银,但复合污染的抑制效应更强。两种污染物对河口区的沉积物反硝化潜势抑制效应强于湾内,可能与河口区具有较高Eh和沉积物颗粒度及较低的pH、盐度和有机质含量有关。三种毒性效应评价方法的结果表明,菲和纳米银的复合污染对2个站位反硝化潜势的毒性效应均为协同作用,且对大沽河河口区的协同作用更强。此外,CI法对复合效应的预测结果比CA和IA法更为接近实际观测值,且CI不需要考虑污染物作用模式的限制,因此认为CI法更适用于评价混合污染对沉积物反硝化作用复合影响的效果。本研究结果表明,菲和纳米银会增强彼此对反硝化菌及反硝化功能的毒性效应,由此推断,PAHs和纳米材料在环境中同时存在时比其单独存在对沉积环境的危害更大。 展开更多
关键词 纳米银 沉积物 反硝化作用 复合毒性
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藻类生长对沉积物上磷迁移转化的影响 预览
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作者 李苓 王彦 +1 位作者 郭智俐 曹晓燕 《中国海洋大学学报:自然科学版》 CAS CSCD 北大核心 2020年第3期88-94,共7页
通过模拟中肋骨条藻(Skeletonema costatum)和沉积物共存体系,探究了富营养化条件下,藻类与沉积物对无机磷的吸收/吸附作用的相互影响。采用自制的金汞伏安微电极测定了藻与沉积物共存体系中溶解氧(DO)的含量变化,分析了体系中溶解氧含... 通过模拟中肋骨条藻(Skeletonema costatum)和沉积物共存体系,探究了富营养化条件下,藻类与沉积物对无机磷的吸收/吸附作用的相互影响。采用自制的金汞伏安微电极测定了藻与沉积物共存体系中溶解氧(DO)的含量变化,分析了体系中溶解氧含量变化与磷消耗速率以及沉积物中磷形态分布变化之间的关系。结果表明,在本课题研究范围内,共存的藻类与沉积物互相影响彼此对磷的消耗过程,1.0×10^4、5.0×10^4和1.0×10^5 cells/mL三种初始藻密度的中肋骨条藻(Skeletonema costatum)48 h后对磷的吸收百分比分别达54.7%、73.4%、93.8%,添加沉积物后分别降至21.3%、34.1%和51.9%;沉积物对培养基介质中的无机磷的吸附百分比为42.5%,加入三种不同藻密度的藻体后分别降至9.1%、2.8%及0.3%。高密度藻与沉积物共存体系的耗磷速率与体系DO含量呈显著负相关(p<0.05)。体系中DO浓度降低会促进沉积物中Fe-P向水体中释放,从而导致沉积物中铁结合态磷(Fe-P)含量的降低。可交换态磷(Ex-P)、有机磷(OP)和Fe-P是藻类存在时沉积物向水体中较易释放的形态。 展开更多
关键词 沉积物 富营养化 金汞伏安微电极 溶解氧
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广东红树林沉积物有毒金属分布及生态风险评价 预览
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作者 张起源 秦颖君 +3 位作者 刘香华 周雯 刘谞承 赵建刚 《生态环境学报》 CSCD 北大核心 2020年第1期183-191,共9页
随着工业化和城镇化的进程加快,红树林重金属污染物总量逐年增加,其生态环境保护的压力日渐加大。准确评估同一背景值下广东省红树林有毒金属的现状及潜在生态风险,探讨有毒金属含量的分布特征及其影响因素,对于了解广东省红树林有毒金... 随着工业化和城镇化的进程加快,红树林重金属污染物总量逐年增加,其生态环境保护的压力日渐加大。准确评估同一背景值下广东省红树林有毒金属的现状及潜在生态风险,探讨有毒金属含量的分布特征及其影响因素,对于了解广东省红树林有毒金属污染状况、红树林的生态环境保护等具有重要意义。采集了广州南沙、深圳福田、珠海淇澳岛、湛江附城等4处典型红树林湿地表层沉积物样品,研究分析了广东红树林湿地沉积物中11种有毒金属(Cu、Pb、Zn、Cd、As、Cr、Mn、Ni、Co、Ti、V)的含量及分布特征,用Hakanson潜在生态风险指数法对红树林沉积物有毒金属的生态风险进行了评价。结果表明,(1)广州南沙红树林湿地中Cr、Cu、Pb、Zn、Ni、As、Cd含量最高;Mn、Co、V、Ti含量则以珠海淇澳岛最高;深圳、湛江红树林沉积物有毒金属含量低于广州、珠海。(2)广州、珠海红树林沉积物有毒金属综合潜在生态风险分别处于“严重”和“很严重”水平,而深圳、湛江的潜在生态风险为“轻度”水平;广州、珠海红树林沉积物中Cd潜在生态风险分别为“极严重”、“严重”水平。(3)聚类分析结果表明,除Cr、Mn外,其余有毒金属两两之间呈显著正相关(P<0.05)关系,表明广东红树林沉积物中多数有毒金属来源相近,具有同源性;多数有毒金属含量与TP、TOC呈显著正相关(P<0.05),而与pH值呈显著负相关(P<0.05),红树林沉积物中TP、TOC含量越高,pH值越低,沉积物中有毒金属含量越高。(4)主成分分析结果表明,不同研究区域有毒金属来源各异:广州以城市和工业污水的排放污染为主,深圳主要受河流带来的陆源污染影响,珠海淇澳岛受外源污染影响较大,湛江则多源于城市生产废水和生活污水的排放。 展开更多
关键词 红树林 沉积物 有毒金属 潜在生态风险
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Experimental study of near-bed concentration and sediment verticalmixing parameter for vertical concentration distribution in the surfzone 预览
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作者 Yang Zhang Zhili Zou +1 位作者 Wushan Xue Dapeng Sun 《国际泥沙研究:英文版》 SCIE 2020年第1期27-41,共15页
Two formulae for the near-bed concentration(Ca)and the sediment vertical mixing parameter(m)are established based on a large scale wave flume experiment.The advantage of the new formulae is that the turbulent kinetic ... Two formulae for the near-bed concentration(Ca)and the sediment vertical mixing parameter(m)are established based on a large scale wave flume experiment.The advantage of the new formulae is that the turbulent kinetic energy induced by wave breaking can be taken into account;the formula for Ca is in terms of the near-bed,time-averaged turbulent kinetic energy,and the formula for m is in terms of depth-and time-averaged turbulent kinetic energy.A new expression for suspended sediment load also is established by depth integration of the vertical distribution of the suspended sediment concentration obtained on basis of the new formulae.Equation validation is done by comparing the predicted Ca and m to measurements for different types of waves(regular wave,wave group,and irregular wave),and good agreement is found.The advantages of the proposed formulae over previous formulae also are discussed. 展开更多
关键词 Near-bed concentration Sediment vertical mixing parameter Turbulent kinetic energy Surf zone Wave type
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The uncertainty of the Shannon entropy model for shear stressdistribution in circular channels 预览
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作者 Amin Kazemian-Kale-Kale Hossein Bonakdari +1 位作者 Azadeh Gholami Bahram Gharabaghi 《国际泥沙研究:英文版》 SCIE 2020年第1期57-68,共12页
The shear stress distribution at alluvial stream beds and banks is one of the essential parameters in channel stability analysis.In the current paper,a novel uncertainty analysis method based on the framework of a Bay... The shear stress distribution at alluvial stream beds and banks is one of the essential parameters in channel stability analysis.In the current paper,a novel uncertainty analysis method based on the framework of a Bayesian Forecasting System(BFS)is presented to evaluate the Shannon entropy model for prediction of the shear stress distribution in both circular rigid-bed and alluvial-bed channels.The Johnson and Box-Cox transformation functions were applied to select the optimum sample size(SS)and corresponding transformation factor for determining a 95%confidence bound(CB)for the Shannon entropy model.The Shapiro-Wilk(SW)test is applied according to the SS used to evaluate the power of transformation functions in the data normalization.The results show that the error distribution between predicted and experimental shear stress values generated using the Box-Cox transformation is closer to a Gaussian distribution than the generated using the Johnson transformation.The indexes of the percentage of the experimental values within the CB(Nin)and Forecast Range Error Estimate(FREE)are applied for the uncertainty analyses.The lower values of FREE equal to 1.724 in the circular rigid-bed channel represent the low uncertainty of Shannon entropy in the prediction of shear stress values compared to the uncertainty for the circular alluvial-bed channel with a FREE value equal to 7.647. 展开更多
关键词 Uncertainty analysis Shear stress distribution Shannon entropy Confidence bound Johnson transformation Box-Cox transformation Circular with sediment bed
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