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三维悬沙模型及河岸边界追踪方法Ⅰ-泥沙模型

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水力发电学报 2010年第6期29卷 99-105页

作者：胡德超张红武钟德钰丁赟尹小玲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 长江科学院河流研究所武汉430010

建立了无结构、z坐标网格上的三维悬移质泥沙数学模型,为保证计算的守恒性,泥沙输运方程使用有限体积法求解;为使泥沙模型的求解对水流模型的求解不形成附加的稳定限制条件,泥沙输运方程使用亚循环分步模式离散。使用了垂向亚网格技术,... 详细信息

建立了无结构、z坐标网格上的三维悬移质泥沙数学模型,为保证计算的守恒性,泥沙输运方程使用有限体积法求解;为使泥沙模型的求解对水流模型的求解不形成附加的稳定限制条件,泥沙输运方程使用亚循环分步模式离散。使用了垂向亚网格技术,使垂向网格能实时地贴合和追踪自由水面和床面,相对于传统的z坐标网格提高了计算精度;同时,在垂向亚网格技术中,为避免因泥沙冲淤产生的垂向小尺度网格对计算时间步长的限制,提出了垂向网格融合技术对底层网格进行处理。借助直壁复式明渠、异重流潜入的水槽实测资料对模型进行了检验,计算结果与试验资料符合良好。

关键词：泥沙动力学三维 z坐标网格融合直壁复式明渠异重流

Cardiovascular computed tomography in cardiovascular disease:An overview of its applications from diagnosis to prediction

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Journal of Geriatric Cardiology 2024年第5期21卷 550-576页

作者： zhong-Hua SUN Discipline of Medical Radiation Science Curtin Medical SchoolCurtin UniversityPerthAustralia Curtin Health Innovation Research Institute(CHIRI) Curtin UniversityPerth 6012Australia

Cardiovascular computed tomography angiography(CTA)is a widely used imaging modality in the diagnosis of cardiovascular *** in CT imaging technology have further advanced its applications from high diagnostic value to minimising radiation exposure to *** addition to the standard application of assessing vascular lumen changes,CTA-derived applications including 3D printed personalised models,3D visualisations such as virtual endoscopy,virtual reality,augmented reality and mixed reality,as well as CT-derived hemodynamic flow analysis and fractional flow reserve(FFRCT)greatly enhance the diagnostic performance of CTA in cardiovascular *** widespread application of artificial intelligence in medicine also significantly contributes to the clinical value of CTA in cardiovascular *** value of CTA has extended from the initial diagnosis to identification of vulnerable lesions,and prediction of disease extent,hence improving patient care and *** this review article,as an active researcher in cardiovascular imaging for more than 20 years,I will provide an overview of cardiovascular CTA in cardiovascular *** is expected that this review will provide readers with an update of CTA applications,from the initial lumen assessment to recent developments utilising latest novel imaging and visualisation *** will serve as a useful resource for researchers and clinicians to judiciously use the cardiovascular CT in clinical practice.

关键词： diagnosis cardiovascular prediction

Eigenvalues for the Clamped Plate Problem of L_(ν)^(2) Operator on Complete Riemannian Manifolds

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2223-2243页

作者： Ling zhong ZENG Jiangxi Provincial Center for Applied Mathematics&School of Mathematics and Statistics Jiangxi Normal UniversityNanchang 330022P.R.China

L_(ν) operator is an important extrinsic differential operator of divergence type and has profound geometric *** this paper,we consider the clamped plate problem of L_(ν)^(2)operator on a bounded domain of the complete Riemannian manifolds.A general formula of eigenvalues of L_(ν)^(2) operator is *** this general formula,we obtain some estimates for the eigenvalues with higher order on the complete Riemannian *** several fascinating applications,we discuss this eigenvalue problem on the complete translating solitons,minimal submanifolds on the Euclidean space,submanifolds on the unit sphere and projective *** particular,we get a universal inequality with respect to the L_(II) operator on the translating ***,it is very difficult to get universal inequalities for weighted Laplacian and even Laplacian on the complete Riemannian ***,this work can be viewed as a new contribution to universal estimate.

关键词： Mean curvature flows L_(ν)^(2)operator clamped plate problem eigenvalues Riemannian manifolds translating solitons

不同治理模式下黄河河口段冲淤演变的数值模拟

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水力发电学报 2018年第4期37卷 68-78页

作者：马睿韩铠御张红武钟德钰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 青海大学省部共建三江源生态与高原农牧业国家重点实验室西宁810016

黄河河口为弱潮陆相河口,具有区间来水量少、来沙量高、河口延伸速度快的特征,进入河口的沙量对特定流路河口冲淤演变起主导作用。在前人研究基础上,认为预测河口段河长延伸值必须考虑陆上和滨海淤积量的共同影响,再基于1958年汛后—200... 详细信息

黄河河口为弱潮陆相河口,具有区间来水量少、来沙量高、河口延伸速度快的特征,进入河口的沙量对特定流路河口冲淤演变起主导作用。在前人研究基础上,认为预测河口段河长延伸值必须考虑陆上和滨海淤积量的共同影响,再基于1958年汛后—2000年汛后利津以下实测资料建立了河口段各部分累计淤积量与利津站累计来沙量的相关关系,利用准二维水沙数学模型对黄河下游及河口段进行耦合模拟,在年均来沙3亿t、6亿t和8亿t这3种设计水沙系列条件下,计算了黄河下游小浪底—河口段现状治理模式和"两道防线"治理模式对黄河河口各部分累计冲淤量、西河口以下河长延伸值等特征量的影响。其结果表明:黄河河口段未来50年在现状治理模式和"两道防线"治理模式下均呈淤积趋势,在三种水沙条件下"两道防线"治理模式的河口段淤积量较之现状模式增淤量分别为2.10亿t、3.48亿t和4.20亿t;同时,"两道防线"治理方案中设置的防护堤对西河口以下河长有明显影响,与现状模式相比河长延伸值分别增加1.27 km、2.07 km、2.49 km。

关键词：黄河河口水沙数学模型 “两道防线”治理模式淤积量河长延伸值

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黄河内蒙古河段非汛期和汛期冲淤量计算方法

地理学报 2015年第7期70卷 1137-1148页

作者：王彦君吴保生王永强钟德钰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

基于多沙河流"多来多排"的经验输沙公式,建立了考虑上站来沙量、前期河床累计淤积量、临界输沙水量及干支流泥沙粒径影响的非汛期和汛期输沙量一般表达式。在此基础上,根据黄河内蒙古河段1952-2010年实测的水沙资料,将其应用于黄河内蒙... 详细信息

基于多沙河流"多来多排"的经验输沙公式,建立了考虑上站来沙量、前期河床累计淤积量、临界输沙水量及干支流泥沙粒径影响的非汛期和汛期输沙量一般表达式。在此基础上,根据黄河内蒙古河段1952-2010年实测的水沙资料,将其应用于黄河内蒙古河段巴彦高勒—三湖河口河段、三湖河口—头道拐河段以及巴彦高勒—头道拐全河段非汛期和汛期输沙量的计算,并应用输沙率法计算了各河段1952-2010年的非汛期和汛期冲淤量及其相应的累计冲淤量。通过输沙量、冲淤量和累计冲淤量计算值与实测值的对比表明,各河段非汛期和汛期输沙量、冲淤量及相应的累计淤积量计算值与实测值的吻合较好,其中非汛期和汛期输沙量计算值和实测值之间的相关系数R2分别约为0.93和0.97;非汛期和汛期冲淤量计算值与实测值之间的相关系数R2分别约为0.80和0.90;非汛期和汛期累计冲淤量之间的相关系数R2分别约为0.94和0.99。结果表明,就吻合程度而言,累计冲淤量优于年冲淤量,汛期优于非汛期。本文建立的冲淤量方法能够很好模拟该河段长历时的非汛期和汛期冲淤过程,可为黄河内蒙古河段输沙量及长期淤积发展趋势的分析提供科学依据。

关键词：黄河内蒙古河段输沙量冲淤量非汛期和汛期

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青海省碳中和路径及实现途径研究

应用基础与工程科学学报 2022年第6期30卷 1331-1345页

作者：谢笛田颖琳王光谦李铁键钟德钰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 青海大学水利水电学院青海西宁810016 青海大学省部共建三江源生态与高原农牧业国家重点实验室青海西宁810016

运用2000~2019年青海省能源消费和牲畜养殖数据,分析了青海省历史碳排放变化情况,并基于可拓展的随机性环境影响评估(STIRPAT)模型和社会经济发展数据,构建了未来碳排放的预测模型.在此基础上,结合国际耦合模式比较计划第六阶段(CMIP6)... 详细信息

运用2000~2019年青海省能源消费和牲畜养殖数据,分析了青海省历史碳排放变化情况,并基于可拓展的随机性环境影响评估(STIRPAT)模型和社会经济发展数据,构建了未来碳排放的预测模型.在此基础上,结合国际耦合模式比较计划第六阶段(CMIP6)多模式的净生态系统生产力数据,对青海省在未来不同发展情景下的净碳排放量趋势进行了评估,确定了各情景下碳中和的发展路径.此外,分析了当前青海省能源利用状况和植被生长的主要限制因素,从减少碳排放量和增加碳汇两个角度对青海省碳中和的途径给出了针对性的建议.结果表明,青海省净碳排放量已于2018年达到峰值,若实行全面绿色发展政策,则有望在2037年实现净零排放.为实现这一目标,一方面,青海省应大力推进能源改革,提高电气化水平,进一步增加清洁能源消费占比;另一方面,青海省应采取针对性工程措施,降低水、光、热等气候因素特别是水分对当地植物生长效率的限制,增加生物固碳量.

关键词：碳中和碳排放清洁能源生物固碳青海省 STIRPAT模型情景分析

Hot versus cold subduction initiation

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National Science Review 2024年第2期11卷 101-102页

作者： zhong-Hai Li Key Laboratory of Computational Geodynamics College of Earth and Planetary SciencesUniversity of Chinese Academy of Sciences

In the framework of plate tectonics, subduction initiation(SI) indicates the birth of a plate convergent boundary, which is a key point of plate tectonics and Wilson's cycle; however, its dynamic process is not well c... 详细信息

关键词： DRIVEN CRUST

Weakly Compact Sets and Riesz Representation Theorem in Musielak Sequence Spaces

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Acta Mathematica Sinica,English Series 2024年第2期40卷 467-484页

作者： Wan zhong GONG Si Yu SHI zhong Rui SHI Department of Mathematics Anhui Normal UniversityWuhu 241000P.R.China Smeal College of Business Pennsylvania State UniversityUniversity ParkPennsylwania 16802USA Department of Mathematics Shanghai UniversityShanghai 200444P.R.China

In this work,we give some criteria of the weakly compact sets and a representation theorem of Riesz's type in Musielak sequence spaces using the ideas and techniques of sequence spaces and Musielak ***,as an immediate consequence of the criteria considered in this paper,the criteria of the weakly compact sets of Orlicz sequence spaces are deduced.

关键词： Compact set weak topology Banach space dual space Musielak sequence spaces

Analysis of gravity wave activity during stratospheric sudden warmings in the northern hemisphere

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Earth and Planetary Physics 2024年第2期8卷 415-422页

作者： XuanYun Zeng Guang zhong School of Physics and Electronic Sciences Changsha University of Science and TechnologyChangsha 410000China Key Laboratory of Geospace Environment Chinese Academy of SciencesUniversity of Science&Technology of ChinaHefei 230026China

Due to the significant changes they bring to high latitude stratospheric temperature and wind,stratospheric sudden warmings(SSWs)can have an impact on the propagation and energy distribution of gravity waves(GWs).The variation characteristics of GWs during SSWs have always been an important *** temperature data from January to March in 2014−2016,provided by the Constellation Observing System for Meteorology,Ionosphere and Climate(COSMIC)mission,we have analyzed global GW activity at 15−40 km in the Northern Hemisphere during SSW *** the SSWs that we studied,the stratospheric temperature rose in one or two longitudinal regions in the Northern Hemisphere;the areas affected extended to the east of 90°*** these SSWs,the potential energy density(E_(p)of GWs expanded and covered a larger range of longitude and altitude,exhibiting an eastward and downward *** E_(p)usually increased,while partially filtered by the eastward zonal *** zonal winds weakened or turned westward,E_(p)began to *** SSWs,the E_(p)usually *** observations can serve as a reference for analyzing the interaction mechanism between SSWs and GWs in future work.

关键词： stratospheric sudden warming gravity wave wind filter