检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

基于低风险生态流量的黄河生态用水调度研究

水力发电学报 2012年第5期31卷 63-70页

作者：马真臻王忠静郑航 christopher j.gippel Robert Speed 清华大学水沙科学与水利水电工程国家重点实验室北京100084 Fluvial Systems Pty Ltd StocktonNew South WalesAustralia Okeanos Pty Ltd BrisbaneAustralia

以黄河下游为重点生态保护对象,构建水库生态用水调度模型,对黄河基准年和未来水平年不同情景的生态用水调度方案进行优化计算。结果表明:现状工程条件下,通过水库生态用水调度,可以保障河道内生态用水;未来水平年,新增工程措施和流域... 详细信息

以黄河下游为重点生态保护对象,构建水库生态用水调度模型,对黄河基准年和未来水平年不同情景的生态用水调度方案进行优化计算。结果表明:现状工程条件下,通过水库生态用水调度,可以保障河道内生态用水;未来水平年,新增工程措施和流域需水管理可减少社会经济和生态的缺水量,其中水需求管理对于缓解流域缺水效果最好;西线由于调水规模大,缩减缺水量效果显著,对于增加下游生态用水的边际效益较低;新增水库所增加的供水效益不明显。

关键词：水资源管理生态用水调度多目标优化水需求管理低风险环境流黄河下游

Apples to oranges:environmentally derived,dynamic regulation of serotonin neuron subpopulations in adulthood?

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第9期20卷 2596-2597页

作者： christopher j.O’Connell Matthew j.Robson Department of Genetics College of MedicineHarvard UniversityBostonMAUSA james L.Winkle College of Pharmacy Division of Pharmaceutical SciencesUniversity of CincinnatiCincinnatiOHUSA Neuroscience Graduate Program College of MedicineUniversity of CincinnatiCincinnatiOHUSA

Traumatic brain injury(TBI)is a public health problem with an undue economic burden that impacts nearly every age,ethnic,and gender group across the globe(Capizzi et al.,2020).TBIs are often sustained during a dynamic range of exposures to energetic environmental forces and as such outcomes are typically heterogeneous regarding severity and pathology(Capizzi et al.,2020).

关键词： sustained orange dynamic

不同流量情景径流对水质组合事件发生概率的影响研究--以淮河流域蚌埠闸为例

在线全文

学校读者我要写书评

暂无评论

应用基础与工程科学学报 2015年第4期23卷 669-679页

作者：吴绍飞张翔邵全喜 christopher j.gippel 武汉大学水资源与水电工程科学国家重点实验室湖北武汉430072 水资源安全保障湖北省协同创新中心武汉大学湖北武汉430072 澳大利亚联邦科学与工业研究组织数学与信息科学协会温布利WA6913 澳大利亚格里菲斯大学河流协会南森昆士兰4111

河流水量与水质之间相互联系,相互影响,正确认识水量对水质的影响是进行水量水质联合调度的基础.以淮河流域蚌埠闸为例,按蚌埠闸流量高低(低、中、高)分别设置3种情景(对应情景1,2,3),基于Copula函数,分别建立以上3种流量情景下对应的... 详细信息

河流水量与水质之间相互联系,相互影响,正确认识水量对水质的影响是进行水量水质联合调度的基础.以淮河流域蚌埠闸为例,按蚌埠闸流量高低(低、中、高)分别设置3种情景(对应情景1,2,3),基于Copula函数,分别建立以上3种流量情景下对应的蚌埠闸水质变量(CODMn和NH3-N)的联合分布函数,对上述3种不同流量情景下水质变量不同组合事件发生概率进行了分析.结果表明,蚌埠闸上各种水质超标组合事件的发生概率总体上是随着闸上流量的增加而减小的,以III类水为标准,相对于低流量条件(情景1),中等流量条件(情景2)可以显著降低蚌埠闸上两水质同时超标风险,风险率值从情景1下此类事件的概率41%迅速降低至15%,而高流量条件(情景3)可以进一步降低其概率至3%.研究结果可以为当前淮河流域水量水质联合调度提供决策依据.

关键词：径流与水质关系不同流量情景 Copula函数淮河

1956—2008年鄱阳湖流域水沙输移趋势及成因分析

在线全文

学校读者我要写书评

暂无评论

水科学进展 2014年第5期25卷 658-667页

作者：罗蔚张翔邓志民陈龙 christopher j.gippel 武汉大学水资源与水电工程科学国家重点实验室湖北武汉430072 江西省水利规划设计院江西南昌330029 水资源安全保障湖北省协同创新中心湖北武汉430072 Australian Rivers Institute Griffith UniversityNathan Queensland 4111Australia

利用鄱阳湖流域代表性水文站1956—2008年实测年径流量及年输沙量资料序列,采用Mann-Kendall秩相关检验法,研究鄱阳湖流域水沙量年际变化趋势和可能发生突变的时间,并从流域降雨、用水、水库拦沙、水土流失及其治理等方面分析了鄱阳湖... 详细信息

利用鄱阳湖流域代表性水文站1956—2008年实测年径流量及年输沙量资料序列,采用Mann-Kendall秩相关检验法,研究鄱阳湖流域水沙量年际变化趋势和可能发生突变的时间,并从流域降雨、用水、水库拦沙、水土流失及其治理等方面分析了鄱阳湖流域水沙变化的主要影响因素。研究结果表明:鄱阳湖地区来水量和出湖水量有小幅增大趋势;鄱阳湖流域来沙量呈异常显著减小趋势,发生突变的年份为1998—1999年;实测出湖沙量从2002年开始呈明显的减少趋势。通过对有关影响因素的研究,发现鄱阳湖流域气候变化降雨量减少对近10年鄱阳湖出入湖径流量的减少影响显著;水库滞沙是鄱阳湖入湖沙量减少的主要原因;出湖沙量变化主要受上游水库群的影响,还有近年湖区采砂的影响。

关键词：鄱阳湖水沙 Mann-Kendall检验趋势分析成因分析

在线全文

学校读者我要写书评

暂无评论

气候变化下水资源脆弱性的适应性管理新认识

水科学进展 2015年第2期26卷 279-286页

作者：夏军石卫雒新萍洪思宁理科 christopher j.gippel 武汉大学水资源与水电工程科学国家重点实验室湖北武汉430072 中国科学院陆地水循环及地表过程重点实验室北京100101 水资源安全保障湖北省协同创新中心湖北武汉430072 Australian Rivers Institute Griffith University

气候变化下的水资源脆弱性和适应性管理研究成为全球和国家应对气候变化和保障水资源安全重点关注的问题,也是中国可持续发展面对的重大战略问题。介绍了水资源脆弱性和适应性管理的国内外最新研究进展;针对国家重大需求和国际科学前沿... 详细信息

气候变化下的水资源脆弱性和适应性管理研究成为全球和国家应对气候变化和保障水资源安全重点关注的问题,也是中国可持续发展面对的重大战略问题。介绍了水资源脆弱性和适应性管理的国内外最新研究进展;针对国家重大需求和国际科学前沿问题,综述了气候变化下水资源脆弱性和适应性管理存在的问题与挑战。提出了气候变化下水资源脆弱性与适应性管理理论与方法研究以应对气候变化的无悔为准则,与社会经济可持续发展、成本效益分析、利益相关者的多信息源的分析与综合决策相结合为原则,对适应性管理与脆弱性组成的互联互动系统及其风险与不确定性进行分析的新认识。

关键词：气候变化水资源脆弱性适应性管理新认识

在线全文

学校读者我要写书评

暂无评论

基于鱼类保护目标的太子河环境流量研究

环境科学学报 2012年第12期32卷 3143-3151页

作者：张远王丁明王西琴孟伟 gippel christopher j 中国环境科学研究院环境基准与风险评估国家重点实验室流域水生态保护技术研究室北京100012 河北联合大学建筑工程学院唐山063009 中国人民大学农业与农村发展学院北京100872 Fluvial Systems Pty Ltd StocktonNew South WalesAustralia 2295

环境流量是流域水资源合理配置的基础.因此,本文借鉴FLOWS法,以太子河重要鱼类为保护目标,构建了流量组分与鱼类生态需求关系模型.同时,结合栖息地指标与流量关系曲线,计算了包含基流、脉冲流、平滩流和漫滩流4种组分在内的太子河环境流... 详细信息

环境流量是流域水资源合理配置的基础.因此,本文借鉴FLOWS法,以太子河重要鱼类为保护目标,构建了流量组分与鱼类生态需求关系模型.同时,结合栖息地指标与流量关系曲线,计算了包含基流、脉冲流、平滩流和漫滩流4种组分在内的太子河环境流量.结果表明:太子河本溪、辽阳、唐马寨河段鱼类保护年基流量分别为2.93×108、3.12×108、2.88×108m3;现状径流总体可以满足年基流量的要求,但水文过程需要通过水库调度以匹配鱼类生态过程.推荐的各河段脉冲流、平滩流和漫滩流的量级、频率、历时、出现时间等水文参数,可以体现环境流量组分与自然径流过程的一致性要求.该研究可为太子河流域水库生态调度提供理论依据.

关键词：太子河环境流量鱼类保护 FLOWS法流量组分

Studying turbulence structure near the wall in hydrodynamic flows:An approach based on the Schur decomposition of the velocity gradient tensor

在线全文

学校读者我要写书评

暂无评论

journal of Hydrodynamics 2022年第5期34卷 806-825页

作者： christopher j.Keylock School of Architecture Building and Civil EngineeringLoughborough UniversityLeicestershireUK

The Schur decomposition of the velocity gradient tensor(VGT)is an alternative to the classical Cauchy-Stokes decomposition into rotation rate and strain rate ***,there have been several strands of work that have employed this decomposition to examine the physics of turbulence dynamics,including approaches that combine the Schur and Cauchy-Stokes *** are briefly reviewed before the latter approach is set *** partitions the rotation rate and strain rate tensors into normal/local and non-normal/non-local *** then study the relation between the VGT dynamics and ejection-sweep events in a channel flow *** show that the sweeps in particular exhibit novel behaviour compared with either the other quadrants,or the flow in general,with a much-reduced contribution to the dynamics from the non-normal terms above the viscous *** particular,the reduction in the production term that is the interaction between the non-normality and the normal straining reduces in the log-layer as a consequence of an absence of alignment between the non-normal vorticity and the strain rate *** have been early forays into using the Schur transform approach for subgrid-scale modelling in large-eddy simulation(LES)and this would appear to be an exciting way forward.

关键词： Turbulence channel flow velocity gradient tensor Schur decomposition

Development process for a higher capacity Propsetter~ system

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

International journal of Mining Science and Technology 2018年第1期28卷 121-126页

作者： christopher j.Brown Product Development-Strata Worldwide LLC

As longwall tailgate support technologies continue to be developed and improved, strata worldwide has worked to design and manufacture a revised Propsetter to provide additional support capacity and enable applications at greater mine *** support is targeted for tailgate applications, however, it can also be utilized for roof support in various types of mining *** paper describes the design changes for enhancing the support capacity of the Propsetter to more closely align its performance with other support technologies currently being employed in longwall *** changes to each design aspect of the Propsetter was key to successfully improving the roof support's load capacity while maintaining controlled *** the load capacity would allow a mine to improve support efficiency with a smaller, less intrusive support compared to support alternatives and reduce the cost per foot of supported *** target support capacity was 711–890 k N at 50 mm of deformation to more closely match the performance of competing tailgate supports such as the 610 mm-diameter CAN~.To achieve this goal, changes were made to all design aspects of the Propsetter: diameter, wedge cut depth and angle, pod size, and confinement *** results from the NIOSH Mine Roof Simulator verified that these design changes were successful in increasing the capacity of the Propsetter to the 711–890 k N range at fifty mms of deformation.

关键词： Propsetter Can Longwall mining Tailgate roof support Controlled deformation

Plasma-catalysis: Is it just a question of scale?

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2019年第2期13卷 264-273页

作者： j.christopher Whitehead School of Chemistry The University of ManchesterManchester M13 9PLUK

The issues of describing and understanding the changes in performance that result when a catalyst is placed into plasma are discussed. The different chemical and physical interactions that result and how their combination might produce beneficial results for the plasma-catalytic processing of different gas streams are outlined with particular emphasis being placed on the different range of spatial and temporal scales that must be considered both in experiment and modelling. The focus is on non-thermal plasma where the lack of thermal equilibrium creates a range of temperature scales that must be considered. This contributes in part to a wide range of inhomogeneity in different properties such as species concentrations and electric fields that must be determined experimentally by in situ methods and be incorporated into modelling. It is concluded that plasmacatalysis is best regarded as conventional catalysis perturbed by the presence of a discharge, which modifies its operating conditions, properties and outcomes often in a very localised way. The sometimes used description "plasma-activated catalysis" is an apt one.

关键词： plasma catalysis plasma-activated catalysis non-thermal plasma CO2 conversion