检索结果-南通市图书馆

Rates and processes affecting As speciation and mobility in lake sediments during aging

Journal of Environmental Sciences 2018年第4期30卷 338-347页

作者： Alan Lock Dirk Wallschlager nelson belzile Graeme Spiers Celine Gueguen Environmental and Life Sciences Graduate Program Trent University School of the Environment Department of Chemistry and Water Quality CentreTrent University Department of Chemistry Laurentian University School of the Environment Departments of Earth Sciences and BiologyLaurentian University School of the Environment and Chemistry Department Trent University

Sediments from an arsenic（As） contaminated groundwater vent site were used to investigate As（ Ⅲ） binding, transformation and redistribution in native and iron oxide amended lake sediments using aging spiked batch reactions and a sequential extraction procedure that maintains As（V） and As（ Ⅲ） speciation. In the native sediments, fractionation analysis revealed that 10% of the spiked As（ Ⅲ） remained intact after a 32-day aging experiment and was predominantly adsorbed to the strongly sorbed（NH4H2PO4 extractable） and amorphous Fe oxide bound（H3PO4 extractable） fractions. Kinetic modelling of the experimental results allowed identifying the dominant reaction path for depletion of dissolved As（ Ⅲ） to As（ Ⅲ）absorbed on to the solid phase, followed by oxidation in the solid phase. Arsenite was initially adsorbed primarily to the easily exchangeable fraction（（NH4）2SO4 extractable）, then rapidly transformed into As（V） and redistributed to the strongly sorbed and amorphous Fe oxide bound fractions. Oxidation of As（ Ⅲ） in recalcitrant fractions was less efficient. The iron oxide amendments illustrated the controls that iron oxides can have on As（ Ⅲ） binding and transformation rates. In goethite amended samples As（ Ⅲ） oxidation was faster and primarily occurred in the strongly sorbed and amorphous Fe oxide bound fractions. In these samples,19.3 μg Mn was redistributed（compared to the native sediment） from the easily exchangeable and crystalline Fe oxide bound fractions to the strongly sorbed and amorphous Fe oxide bound fractions, indicating that goethite may act as a catalyst for Mn（Ⅱ） oxidation, thereby producing sorbed Mn（ Ⅲ/Ⅳ ）, which then appears to be involved in rapidly oxidizing As（ Ⅲ）.

关键词： Arsenite Oxidation Fractionation Redistribution Modelling

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

Seasonal variations of phosphorus species in the Tuohe River, China. Part Ⅰ. Sediments

引用

Journal of Oceanology and Limnology 2018年第6期36卷 1950-1961页

作者：徐青余晓平郭亚飞邓天龙 CHEN Yu-Wei nelson belzile Tianjin Key Laboratory of Marine Resources and Chemistry College of Chemical Engineering and Materials ScienceTianjin University of Sciences and Engineering School of Architecture and Civil Engineering Chengdu University Department of Chemistry and Biochemistry Laurentian University

Sediment cores were collected at an upstream site(Jintang) and a downstream site(Neijiang) in summer and winter in the Tuohe River, which is one of the five largest tributaries of the Changjiang(Yangtze) River in China. A sequential leaching procedure was applied to determine the concentrations of the different forms of solid phosphorus, including exchangeable phosphorus(Exc-P) as well as phosphorus associated with iron oxides(Fe-P), with aluminum oxides(Al-P), with apatite(Ca-P) and with the residual fraction(Res-P), as correlated with water content and total organic carbon. The seasonal variations and the vertical distributions of phosphorus species in sediments at both sampling sites demonstrated that: 1) total phosphorus(TP) in summer and winter were ranged between 1 313–2 330, 1 491–2 228 mg/kg in Jintang and 543–2 128, 603–1 175 mg/kg in Neijiang, respectively. It can predicated the pollution of TP in Jintang is serious than that in Neijiang both in summer and winter; 2) total inorganic phosphorus(TIP) was the dominant form of TP; 3) Ca-P was the main chemical forms of TIP in the sediments. Based on the profiles in sediments and bio-available phosphorus data, it revealed that bio-available phosphorus(BAP) represented only a minor portion(0.61%–3.59%) of TP, and the vertical distribution of soluble reactive phosphorus(SRP) in corresponding porewaters was more abundant in the upper layer of the sediment, which suggests that BAP may be converted to non-bioavailable phosphorus in deeper layer of the sediment of this dynamic system.

关键词： phosphorus species vertical distribution seasonal variation Tuohe River

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

含蛭石晶层间层矿物的可交换性阳离子及交换容量研究

引用

岩石矿物学杂志 2003年第4期22卷 391-396页

作者：彭同江刘福生 John Huang nelson belzile 孙红娟西南科技大学矿物材料及应用研究所四川绵阳621002 劳伦丁大学化学系

对采自新疆尉犁蛭石矿、河南灵宝—陕西潼关蛭石矿的工业蛭石矿物样品进行了可交换性阳离子与交换容量研究 ,发现新疆尉犁蛭石矿金云母蛭石中可交换性阳离子主要为Na+ 和Ca2 + ,其次为Mg2 + 、K+ 、Ba2 + 和Sr2 + ;而河南灵宝—陕西潼... 详细信息

对采自新疆尉犁蛭石矿、河南灵宝—陕西潼关蛭石矿的工业蛭石矿物样品进行了可交换性阳离子与交换容量研究 ,发现新疆尉犁蛭石矿金云母蛭石中可交换性阳离子主要为Na+ 和Ca2 + ,其次为Mg2 + 、K+ 、Ba2 + 和Sr2 + ;而河南灵宝—陕西潼关蛭石矿工业蛭石样品的可交换性阳离子主要为Ca2 + 和Mg2 + ,其次为Na+ 、K+ 等。金云母蛭石和绿泥石蛭石间层矿物的阳离子交换容量随间层结构中蛭石晶层的含量增加而增大 ,一般在 5 6 .92～ 98.95mmol/ 10 0g之间 ,仅为蛭石最大阳离子交换容量的一半。金云母蛭石样品阳离子交换容量大小与K2 O含量呈负相关关系 ,与 (Na2 O +CaO)

关键词：金云母-蛭石绿泥石-蛭石间层矿物可交换性阳离子阳离子交换容量

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

黄龙钙华纹层石特征与成因分析

引用

矿物学报 2019年第1期39卷 55-63页

作者：冯晨旭董发勤代群威霍婷婷 nelson belzile 西南科技大学环境与资源学院四川绵阳621010 西南科技大学固体废物处理与资源化教育部重点实验室四川绵阳621010 Department of Chemistry and Biochemistry Laurentian University

为了探究黄龙钙华纹层石剖面褐-白相间混积纹层的特征与成因,对黄龙钙华样品进行了采集和分析。通过微波消解法分析不同颜色纹层钙华样品有机碳含量,并用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、元素分析仪等对样品的晶相、形貌、元素... 详细信息

为了探究黄龙钙华纹层石剖面褐-白相间混积纹层的特征与成因,对黄龙钙华样品进行了采集和分析。通过微波消解法分析不同颜色纹层钙华样品有机碳含量,并用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、元素分析仪等对样品的晶相、形貌、元素和Mg/Ca比等进行了分析。结果表明,黄龙钙华褐-白纹层有机碳含量、Mg/Ca比存在明显差异,褐色纹层有机碳含量、Mg/Ca分别高于相邻的白色纹层,有机碳的含量随着沉积顺序(由老到新)逐渐变大。钙华剖面年层中的褐-白相间纹层不仅受到微生物、植物等生物的影响,还受不同温度、水动力等气候因素的调控,即黄龙钙华剖面年层中出现褐-白相间纹层为生物-气候双成因。其结果可为寻找黄龙钙华沉积过程中生物参与证据提供一定的理论基础。

关键词：钙华纹层石特征成因黄龙

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

Function and dysfunction of GEMIN5:understanding a novel neurodevelopmental disorder

引用

Neural Regeneration Research 2024年第11期19卷 2377-2386页

作者： Charles H.nelson Udai B.Pandey Department of Pediatrics Division of Child NeurologyChildren’s Hospital of PittsburghUniversity of Pittsburgh Medical CenterPittsburghPAUSA Children’s Neuroscience Institute Children’s Hospital of PittsburghUniversity of Pittsburgh Medical CenterPittsburghPAUSA

The recent identification of a neurodevelopmental disorder with cerebellar atrophy and motor dysfunction(NEDCAM)has resulted in an increased interest in GEMIN5,a multifunction RNA-binding *** the largest member of the survival motor neuron complex,GEMIN5 plays a key role in the biogenesis of small nuclear ribonucleoproteins while also exhibiting translational regulatory functions as an independent *** many questions remain regarding both the pathogenesis and pathophysiology of this new disorder,considerable progress has been made in the brief time since its *** this review,we examine GEMIN5 within the context of NEDCAM,focusing on the structure,function,and expression of the protein specifically in regard to the disorder ***,we explore the current animal models of NEDCAM,as well as potential molecular pathways for treatment and future directions of *** review provides a comprehensive overview of recent advances in our understanding of this unique member of the survival motor neuron complex.

关键词： cerebellar atrophy GEMIN5 neurodevelopmental disorder neurological disease SMN complex

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

BIOACCUMULATION OF SELENIUM AND MERCURY IN FRESHWATER ORGANISMS:A PROTECTIVE EFFECT

BIOACCUMULATION OF SELENIUM AND MERCURY IN FRESHWATER ORGANI...

引用

40th IUPAC Congress

作者： nelson belzile John M. Gunn Yves Alarie Tania Delonchamp Department of Chemistry and Biochemistry Cooperative Freshwater Ecology Unit Cooperative Freshwater Ecology Unit Department of BiologyLaurentian UniversitySudburyOntario P3E 2C6 CANADA Cooperative Freshwater Ecology Unit Department of BiologyLaurentian UniversitySudburyOntario P3E 2C6 CANADA Department of Biology University of OttawaOttawaOntario K1N 6N5 CANADA

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

三乙烯四胺(TETA)抑制磁黄铁矿氧化的机理研究

引用

环境化学 2005年第5期24卷 528-532页

作者：蔡美芳党志 nelson belzile 陈雨薇华南理工大学环境科学与工程学院广州510640 Department of Chemistry & Biochemistry Laurentian University SudburyOntarioCanadaP3E2C6

本文分别对三乙烯四胺(TETA)抑制磁黄铁矿在空气和Thiobacillus ferrooxidans细菌作用下的氧化过程进行了研究.结果表明:TETA不但能有效防止磁黄铁矿在85—90%湿度空气中的氧化,还能显著阻止Thiobacillus ferrooxidans对样品的生物氧化... 详细信息

本文分别对三乙烯四胺(TETA)抑制磁黄铁矿在空气和Thiobacillus ferrooxidans细菌作用下的氧化过程进行了研究.结果表明:TETA不但能有效防止磁黄铁矿在85—90%湿度空气中的氧化,还能显著阻止Thiobacillus ferrooxidans对样品的生物氧化.与对照样品相比,在空气中氧化90d和被细菌氧化42d后,经TETA简单包膜处理样品的氧化程度分别降低了54·7%和82·07%.TETA通过在样品表面形成一层致密的膜来隔绝样品与氧气的接触,从而抑制了磁黄铁矿的空气氧化;碱性TETA还能通过提高反应体系的pH值、恶化嗜酸细菌Thiobacillus ferrooxidans的生存环境来阻止样品的生物氧化.

关键词：磁黄铁矿三乙烯四胺氧化 Thiobacillus ferrooxidans 机理研究 TETA 空气氧化生物氧化细菌作用

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

四川三台钙蒙脱石的矿物学与有机化处理研究

引用

矿物学报 2004年第1期24卷 48-54页

作者：彭同江 nelson belzile 孙红娟 Yuewei Chen John Huang 刘福生西南科技大学矿物材料及应用研究所四川绵阳621002 Laurentian University

对四川三台钙蒙脱石进行了矿物学和有机化处理研究。化学成分分析、晶体化学式与层间可交换阳离子数计算、X射线衍射分析和热分析都表明三台膨润土属钙基膨润土,属型为切托 Otay型。用十八烷基三甲基氯化铵、十八烷基二甲基苄基氯化铵... 详细信息

对四川三台钙蒙脱石进行了矿物学和有机化处理研究。化学成分分析、晶体化学式与层间可交换阳离子数计算、X射线衍射分析和热分析都表明三台膨润土属钙基膨润土,属型为切托 Otay型。用十八烷基三甲基氯化铵、十八烷基二甲基苄基氯化铵、十二烷基二甲基苄基氯化铵三种季铵盐阳离子表面活性剂对四川三台钙蒙脱石进行了有机化处理。结果表明,用十八烷基三甲基氯化铵处理的效果最好。

关键词：矿物学有机化处理钙蒙脱石十八烷基三甲基氯化铵

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

Assessment of challenges and strategies for driving energy transitions in emerging markets:A socio-technological systems perspective

Energy Geoscience

引用

Energy Geoscience 2024年第2期5卷 81-100页

作者： nelson S.Chipangamate Glen T.Nwaila Wits Mining Institute University of the Witwatersrand1 Jan Smuts Ave.Johannesburg2000South Africa School of Geosciences University of the WitwatersrandPrivate Bag 3Wits2050South Africa

The pursuit of improved quality of life standards has significantly influenced the contemporary mining model in the 21st *** era is witnessing an unprecedented transformation driven by pressing concerns related to sustainability,climate change,the just energy transition,dynamic operating environments,and complex social *** transitions present both opportunities and *** aim of this study is to provide an extensive literature review on energy transition to identify the challenges and strategies associated with navigating transformations in energy *** these transformations is particularly critical in the face of the severe consequences of global warming,where an accelerated energy transition is viewed as a universal *** a socio-technological systems perspective,specifically through the application of Actor Network Theory(ANT),this research provides a theoretical foundation while categorising challenges into five distinct domains and outlining strategies across these different *** insights are specifically tailored for emerging market countries to effectively navigate energy transition while fostering the development of resilient ***,our findings highlight that energy transition encompasses more than a mere technological shift;it entails fundamental changes in various systemic socio-economic *** focusing on the role of social structures in transitions,this study makes a significant and innovative contribution to ANT,which has historically been criticised for its limited acknowledgement of social ***,we propose an emerging market energy transition framework,which not only addresses technological aspects,but also integrates social *** framework paves the way for future research and exploration of energy transition *** outcomes of this study offer valuable insights to policymakers,researchers,and practitioners engaged in t

关键词： Actor network theory Energy transition Social innovation Technology Actor inclusive policy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Resource management at the network edge for federated learning

引用

Digital Communications and Networks 2024年第3期10卷 765-782页

作者： Silvana Trindade Luiz F.Bittencourt nelson L.S.da Fonseca Institute of Computing State University of CampinasCampinasBrazil

Federated learning has been explored as a promising solution for training machine learning models at the network edge,without sharing private user *** limited resources at the edge,new solutions must be developed to leverage the software and hardware resources as the existing solutions did not focus on resource management for network edge,specially for federated *** this paper,we describe the recent work on resource manage-ment at the edge and explore the challenges and future directions to allow the execution of federated learning at the *** such as the discovery of resources,deployment,load balancing,migration,and energy effi-ciency are discussed in the paper.

关键词： Resource management Edge computing Federated learning Machine learning

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

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：