Decadal prediction skill in the ocean with surface nudging in the IPSL-CM5A-LR climate model     

Juliette Mignot  Javier García-Serrano  Didier Swingedouw  Agathe Germe  Sébastien Nguyen  Pablo Ortega  Eric Guilyardi  Sulagna Ray 《Climate Dynamics》2016,47(3-4):1225-1246

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岩浆弧火成岩构造组合与洋陆转换   总被引：15，自引：0，他引：15  

邓晋福  冯艳芳  狄永军  刘翠  肖庆辉  苏尚国  赵国春  孟斐  马帅  姚图 《地质论评》2015,61(3):473-484

本文从岩浆弧的火成岩构造组合、主要地质特征和弧地壳成熟度几个方面,讨论洋陆转换作用及其过程。表征洋俯冲环境的火成岩构造组合主要有英云闪长岩—奥长花岗岩—花岗闪长岩(TTG)组合,高镁安山岩组合,镁安山岩组合,Adakite组合(即高锶低钇中酸性岩)与富铌弧玄武岩组合等。基于火成岩构造组合的配置,讨论了4种可能的洋俯冲壳的壳幔结构:(1)热的年轻的俯冲洋壳与上覆冷的幔楔岩石圈;(2)冷的老的俯冲洋壳与冷的幔楔岩石圈;(3)冷的老的洋壳与热的幔楔软流圈;(4)热的年轻的俯冲洋壳与上覆幔楔软流圈。讨论了弧岩浆前锋作为结构标志以及空间组成极性的构造意义;讨论了弧火山作用的时间极性与弧成熟度及其地壳厚度之间的正相关关系,提出岩浆弧地壳双层结构的模型,下地壳主要为玄武质的基性麻粒岩和角闪岩,上地壳为长英质的TTG片麻岩,相当于大陆壳形成的第一阶段,即新生陆壳。岩浆弧及其洋—陆过渡性的弧地壳是洋俯冲作用形成的洋陆转换带(或增生造山带)的最重要的记录。  相似文献   

Urban flood vulnerability assessment in a densely urbanized city using multi-factor analysis and machine learning algorithms     

Parvin  Farhana  Ali  Sk Ajim  Calka  Beata  Bielecka  Elzbieta  Linh  Nguyen Thi Thuy  Pham  Quoc Bao 《Theoretical and Applied Climatology》2022,149(1-2):639-659

Theoretical and Applied Climatology - Flood is considered as the most devastating natural hazards that cause the death of many lives worldwide. The present study aimed to predict flood...  相似文献   

滨海地区基于避咸蓄淡模式的供水安全临界流量研究——以粤港澳大湾区珠澳供水为例     

涂新军  吴海鸥  陈晓宏  林凯荣  赖荣标 《湖泊科学》2022,34(1):194-206

枯水期咸潮入侵已经严重威胁到了感潮河流区域供水安全.本文通过构建避咸蓄淡供水模型,耦合了咸度预测、河库联合供水调度和供水安全分析模块,为依赖感潮河流为水源地的区域供水安全管理提供了一种整体思路和决策方法.以面向粤港澳大湾区珠海东部及澳门的珠江三角洲磨刀门水道取供水为例,基于潮汐、径流和风等因子及咸度实测数据,较好地拟合了基于BP神经网络的咸度预测模型,及含氯度与超标时间的曲线函数,建立了上游来水和咸度超标时间之间的联系,得到了避咸蓄淡取水时机.咸度预测与当地河库联合供水调度相结合,得到了上游枯水期来水过程的当地区域供需平衡状况.枯水期不考虑水库调蓄的资源性缺水临界需水量为3.22亿m³,水库参与调蓄的工程性缺水临界需水量为3.75亿m³.通过供水安全分析模块,基于设定的风险阈值和临界阈值识别出了不同需水规模的上游来水临界流量特征.对于当地规划的需水规模4.23亿m³,期望上游枯水期临界流量均值约为3372 m³/s.整体上来说,需水规模越大,对上游来水期望的临界流量越大,但同时还与枯水期流量分布有关.  相似文献   

Shear behaviour of subgrade soil with reference to varying initial shear stress and plasticity index     

Silva  Isabella Novais  Indraratna  Buddhima  Nguyen  Thanh Trung  Rujikiatkamjorn  Cholachat 《Acta Geotechnica》2022,17(9):4207-4216

Acta Geotechnica - The influence of stress anisotropy (K) (i.e. the ratio between effective horizontal and vertical stresses) on the shear behaviour of soils has received significant attention in...  相似文献   

Chemical properties of HULIS from three different environments     

T. B. Kristensen  L. Du  Q. T. Nguyen  J. K. Nøjgaard  C. Bender Koch  O. Faurskov Nielsen  A. G. Hallar  D. H. Lowenthal  B. Nekat  D. van Pinxteren  H. Herrmann  M. Glasius  H. G. Kjaergaard  M. Bilde 《Journal of Atmospheric Chemistry》2015,72(1):65-80

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华东沿海ASCAT反演风速的检验和订正   总被引：2，自引：1，他引：1       下载免费PDF全文

姚日升  涂小萍  丁烨毅  王武军  邬方平  朱万云 《应用气象学报》2015,26(6):735-742

基于2010—2014年ASCAT反演风速、华东沿海14个浮标站和浙江沿海249个自动气象站资料,对华东沿海ASCAT反演风速进行检验和订正。研究表明:站点ASCAT风速误差不仅与离岸距离相关,而且与站点周围地形有关,误差较大的5个浮标站均位于舟山群岛附近海区,平均偏大4.79 m·s-1,其他海区浮标站的ASCAT反演风速平均偏差仅为0.46 m·s-1。ASCAT反演风速与浮标站风速的线性回归可有效减小反演风速误差,订正后误差大幅减小,误差越大的站点订正效果越好。相距160 km内的浮标站点间风速误差呈正相关,且站点间距越小,误差正相关越明显。考虑带影响半径的反距离权重,采用邻站方程订正法和邻站误差订正法分别对华东沿海ASCAT反演风速进行订正,均能明显减小平均偏差和均方根误差,两种方法订正效果接近,即两种方法均有较好的订正效果,可用于实际业务。  相似文献   

Local stress analysis in granular materials at a mesoscale     

Ngoc‐Son Nguyen  Hélène Magoariec  Bernard Cambou 《国际地质力学数值与分析法杂志》2012,36(14):1609-1635

The purpose of this paper is to contribute to the change of scale techniques developed for granular materials. The proposed approach consists in considering an intermediate scale between the macroscales and microscales, called the mesoscale, using the classical homogenization scheme. In this approach, the mesoscale for 2D granular materials was defined at the level of local volumes, called mesodomains, which are local closed structures composed of particles in contact. In this paper, we focused on defining a local stress field at this scale. Two different methods are proposed, both based on the equivalent continuum mean stress but using different approximations of the mean stress tensor for each mesodomain. The two proposed methods were then compared to each other. Analyses performed on the stress field at the mesoscale show that this local field is heterogeneous and, in particular, that its heterogeneity is significantly structured at this scale. The distribution of the local mean stress (first invariant of the local stress tensor) is uniform in any mesodomain, whereas the distribution of the stress deviator (second invariant of the deviatoric part of the local stress tensor) is significantly dependent on the elongation direction and on the elongation degree of the mesodomains. The local stress ratio (ratio of the stress deviator to the mean stress) is higher within the mesodomains that are elongated in the global compression direction than that within the ones elongated in the global extension direction. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Cordilleran vein type Pb-Zn-polymetallic deposits of the Xidamingshan district, Guangxi, SW China: Fluid inclusion and geochemical studies   总被引：1，自引：0，他引：1  

Wei Tu  Yang Song Du  Gong Wen Wang  Ying Ping Lei 《Geology of Ore Deposits》2013,55(6):494-502

There are a lot of clastic-sedimentary-rock-hosted hydrothermal vein type polymetallic deposits in the Xidamingshan district, Guangxi, SW China. Two major ones of them, the Fenghuangshan Pb-Zn-Ag-Mn deposit and the Lujing Pb-Zn deposit, have been selected for fluid inclusion and geochemical research in this paper. From fluid inclusion microthermometry, it has been found that they were deposited from fluid with low salinities at medium to low temperatures and low pressures. From hydrogen, oxygen, sulfur and carbon stable isotope studies as well as some trace element composition of sulfides, we have got the conclusion that they were formed in an intrusion-related ore-forming system, which means that they belong to Cordilleran vein type deposits.  相似文献   

Numerical simulation of micro-bubble drag reduction using population balance model     

K. Mohanarangam  J.Y. Tu  L. Chen 《Ocean Engineering》2009,36(11):863-872

The phenomenon of drag reduction by the injection of micro-bubbles into turbulent boundary layer has been investigated using an Eulerian-Eulerian two-fluid model. Multiple-size group (MUSIG) based on population balance models, which resolve a wide range of bubble sizes taking into account the bubble break-up and coalescence have been used for this purpose. The simulated results are compared against the experimental findings of Madavan et al. [1984. Reduction of turbulent skin friction by micro-bubbles. Physics of Fluids 27, 356-363] and also other numerical studies explaining the sophisticated phenomena of drag reduction. For the two Reynolds number cases considered, the buoyancy with the plate on the bottom configuration is investigated, as from the experiments it is seen that buoyancy seem to play a role in the drag reduction. Numerical model employed in the investigation comprises of a micro-bubble laden flow wherein two independent sets of Reynolds averaged Navier-Stokes (RANS) transport equations were used to describe both the phases of the flow. The shear stress transport (SST) turbulence model is used as the turbulent closure for the primary phase and a zero equation turbulence model is used for the micro-bubbles. Change in the mean streamwise velocity profiles, void fraction, turbulence modification and other results are presented and discussed with corresponding change in the gas injection rates. The complex mechanism of drag reduction are scrutinised and explained in context to our numerical findings. Special attentions have been also devoted to divulge the effect of bubble coalescence and break-up caused by random collision and turbulent impact. Numerical results showed good agreement for the skin-friction coefficients against experimental data throughout various air injection rates. The MUSIG model was found to be one of the best candidates to resolve the bubble dynamics in micro-bubble-induced drag reduction problems.  相似文献