Solving stiff mass transfers in compositional multiphase flow models: Numerical stability and spurious solutions     

Philippe Tardy  Michel Quintard 《Computational Geosciences》1999,3(2):161-183

This paper points out two numerical problems linked to the resolution of compositional multiphase flow models for porous media with the finite‐volume technique. In particular, we consider fluid mixtures featuring fast mass transfers between the phases, hence stiff. In this context, we show how the computation of mass exchange kinetics can be expensive and that erroneous saturation front locations arise. A numerical splitting method is developed which is proven to be stable with advection‐type time steps, whatever the stiffness of the mass transfer. The erroneous front location problem is illustrated and shown to be intrinsically linked to the numerical diffusion. If we assume that the fluids are in thermodynamical equilibrium, we find that spurious solutions can be avoided by deriving and solving a new uncoupled hyperbolic equation for the saturation. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

温度对褐牙鲆资源补充特征的生态效应   总被引：10，自引：2，他引：8  

朱鑫华  王云峰  刘栋 《海洋与湖沼》1999,30(5):477-485

根据１９８０－１９９５年让湾和渤海不记学调查资料,采用自然生态学与实验生态学相结合的方法,综合分析温度对褐牙鲆补充阶段生活史特征及其资源补充过程的影响。结果表明,随地理纬度的增加,褐牙鲆产卵期滞后,生殖季节缩短,在水温从９．６２℃增至１９．８９℃的过程中褐芽鲆的性腺 育指数（ＧＳＩ）出现单一峰值,７月至翌年３月间此值均小于１．０;在实验水温范围（７－２７℃）内,受精卵孵化时数（ｔ）随水温（Ｔ）变化  相似文献   

牙鲆幼鱼对n-3高度不饱和脂肪酸的吸收及与生长关系的初步研究   总被引：9，自引：1，他引：8  

刘洪杰  毛兴华 《海洋与湖沼》1999,30(3):238-244

于1996年9-10月在中国水产科学研究院黄海水产研究所小麦岛实验基地,采用人工投喂的方法,给牙鲆幼鱼投喂含不同含量n-3高度不饱和脂肪酸（n-3HUFA）的人工饵料,研究牙鲆幼鱼对饵料中n-3HUFA的消化、吸收以及n-3HUFA的含量与日增重率、饵料效率的关系。结果表明,在饵料中添加0.60％—2.40％的n-3HUFA可有效提高牙鲆幼鱼的日增重率和饵料效率;肝脏中n-3HUFA的含量与饵料中n-3HUFA（尤其是DHA）的含量成正比;牙鲆幼鱼对饵料中n-3HUFA的表观消化吸收率随其含量的增加呈下降趋势。  相似文献   

Anisotropic structure of the Hikurangi subduction zone, New Zealand—integrated interpretation of surface-wave andbody-wave observations     

Alex Brisbourne  Graham Stuart  & J.-Michael Kendall 《Geophysical Journal International》1999,137(1):214-230

  相似文献   

Three-dimensional sensitivity kernels for finite-frequency traveltimes: the banana–doughnut paradox     

Henk Marquering  F.A. Dahlen  & Guust Nolet 《Geophysical Journal International》1999,137(3):805-815

  相似文献   

甜水海钻孔TS95若干地球化学指标的非线性分析与意义   总被引：1，自引：0，他引：1  

周厚云  朱照宇  李世杰  李炳元  向明菊  余素华 《湖泊科学》2001,13(2):97-102

应用关联维分析和R／S分析对西昆伦甜水海孔TS95的4项指标（FeO,Fe2O3,Fe2O3/FeO和有机碳）进行分析,发现它们存在明显的混沌特征和Hurst现象,4项指标的混沌吸引子分别为：FeO－2．8;Fe2O3－3．2;Fe2O／FeO－2．9;有机碳2．5,饱和嵌入维数为5到6,表明控制该地区气候环境演化的动力系统是由有限维数确定的混沌系统,构筑该系统所需变量至少3到4个,最多5到6个,这种体上与深海氧同位素比较接近,与黄土剖面一些指标差异较大,4项指标折Hurst指数（FeO－0．85;Fe2O3－0．76;Fe2O3／FeO－0．65;有机碳－0．74）显示该地区气候环境演化存在明显的持续性成分,这与早期的研究一致,很可能与青藏高原的构造抬升有关,表明除了全球性气候环境波动背景外,局域性因素,如肝藏高原构造抬升和未海地区水系变迁,都会在各种气候环境演化的替代性指标上有所反映。4项指标Hurst指数的差异可能反映FeO容易迁移,受到了流域水系变化的影响,因而有机碳和Fe2O3可能是反映这种环境演化持续性分更好的指标。  相似文献   

泉州湾桐花树和老鼠簕根际土壤细菌和真菌群落特征比较          下载免费PDF全文

郑智胜  黄卫红  陈小尘  黄兆斌  薛喜枚  陈锦江  张秋芳 《应用海洋学学报》2023,42(4):686-697

红树植物根际土壤微生物对近海生物地球化学循环及其生物多样性等起着重要作用,受地上部和土壤性质影响,两种不同药用红树植物桐花树（Aegiceras corniculatum）和老鼠簕（Acanthus ilicifolius）根际土壤微生物群落组成可能存在独特性。本研究分别以细菌 16S rRNA基因和真菌ITS 基因为分子标记,采用高通量测序技术分析比较了桐花树和老鼠簕根际土壤微生物多样性特征及其与土壤理化性质之间的关系。结果表明：①老鼠簕根际土壤细菌和真菌多样性与丰富度均显著高于桐花树,且两者之间的细菌和真菌组成皆存在明显差异（P<0.05）;②两者根际土壤细菌和真菌门和属的优势（大于1%）物种组成皆相似;在门水平,桐花树根际土壤主要优势物种变形菌门（Proteobacteria）和未分类门（unclassified_k_Fungi）的相对丰度显著高于老鼠簕,而拟杆菌门（Bacteroidota）、脱硫杆菌门（Desulfobacterota）、子囊菌门（Ascomycota）和担子菌门（Basidiomycota）则相反;在属水平,桐花树的主要优势物种硝化螺菌属（Nitrospira）和Denitromonas属的相对丰度显著高于老鼠簕,而枝孢菌属（Cladosporium）和囊状担子菌属（Cystofilobasidium）则相反;③桐花树根际土壤pH、总碳和总酚含量皆显著高于老鼠簕,pH和总酚显著影响细菌群落组成,而总碳和总硫则显著影响真菌群落组成;此外,pH、总碳和总氮是影响细菌物种的主要因素,而总酚、pH和总碳是影响真菌物种的主要因素。本研究揭示了桐花树和老鼠簕根际土壤细菌和真菌多样性存在明显差异并与土壤理化性质密切相关,可为今后从不同红树物种所具备的独特功能根际微生物菌群来开发相关资源及保护近海的生态环境提供新的视角。  相似文献   

一种地震资料处理结果的发布策略及其实现     

朱振宇  刘洪 《煤田地质与勘探》2005,33(1):73-76

基于C/S和B/S的混合发布模式, 本文给出了一个关于地震资料的“分散计算-集中存储-即时发布”系统解决方案, 介绍了系统框架、相应的开发技术、客户端应用软件及部分实现。实际应用效果表明, 该方案可以提高运行效率, 便于维护和升级, 其可以与一般的信息发布相结合, 实现动态的企业级WEB应用。   相似文献   

High-resolution magnetostratigraphy and micropalaeontology across the J/K boundary strata at Brodno near ilina, western Slovakia: summary of results     

Vclav Hou a  Miroslav Krs  Marta Krsov  Otakar Man  Petr Pruner  Daniela Venhodov 《Cretaceous Research》1999,20(6):699

This study summarizes the final results of magnetostratigraphic and micropalaeontological investigations of the Tithonian/Berriasian boundary (J/K) limestones at the locality of Brodno near ilina, Western Carpathians, West Slovakia. The aim is to prepare the background for correlation of a Late Tithonian and Early Berriasian biostratigraphic zonation with global magnetoevents (manifested in detailed magnetostratigraphic profiles) between the Tethyan realm and other regions, particularly the Boreal and Pacific realms. Suitable physical properties of the limestones studied, a favourable geological setting and rich microfossil assemblages (calpionellids) at Brodno (magnetozones M21r to M18r) allowed a systematic collection of new data on the original synoptic section, which now has the character of a high-resolution profile across the J/K boundary. Two reverse subzones detected within magnetozones M20n and M19n are named ‘Kysuca Subzone’ and ‘Brodno Subzone’, respectively. Both can be correlated with analogous subzones in the M-sequence of marine anomalies. Their existence can also be confirmed in the Bosso Valley section in Umbria, central Italy. A detailed study of the interval between magnetozones M20n and M17r in the Bosso Valley profile is presently in its final stage. Both magnetostratigraphic profiles, from the Brodno and Bosso Valley localities, were thoroughly investigated in the intervals close to the J/K boundary and are still unique among continent-based profiles in the detection and precise definition of both reverse subzones within M20n and M19n. Samples collected from the boundary strata of the reverse Kysuca Subzone at Brodno indicated a transition from N (R) to R (N) polarity of the Earth's palaeomagnetic field within a time interval of c. ±5 ka. Limestone samples (total number N=368) were subjected to progressive thermal demagnetization in 10–12 thermal fields and to subsequent multi-component analysis of remanence. The C-component, as the carrier of palaeomagnetic directions, was determined in the temperature interval of 300° to 540°, or possibly 580°C. Magnetomineralogical analyses of pilot samples and unblocking temperatures determined for all samples showed that magnetite is the carrier of remanent magnetization. The positions of the individual events of calpionellid stratigraphy relative to the global magnetic polarity timescale are precisely defined. The base of the Calpionella Standard Zone, which is considered a provisional J/K boundary indicator in ammonite-free sections in the Tethyan realm, lies within magnetozone M19n at the level of 35% of its local thickness. None of the boundaries in the calpionellid zonation coincides precisely with any of those in the palaeomagnetic zonation, but the first appearance ofCalpionella grandalpina , indicating the base of the Intermedia Subzone, lies in close proximity to the base of magnetozone M19r.  相似文献   

基于线粒体COI和16S rRNA基因研究3个地理群体黑龙江河蓝蛤的遗传多样性     

孙超  刘志鸿  杨爱国  周丽青  吴彪  严加坤  侯丫  董春光 《海洋科学》2015,39(1):39-45

采用通用引物对辽宁盘锦、辽宁大连、山东日照的3个地理群体黑龙江河蓝蛤(Potamocorbula amurensis)COI和16S r RNA序列进行扩增、测序分析,得到30条658bp的COI基因部分序列和27条450 bp的16S r RNA基因部分序列。其中COI和16S r RNA基因部分序列T、C、A、G和A+T的平均含量分别为45.4%和32.0%、13.5%和13.3%、20.7%和29.3%、20.4%和25.3%、66.1%和61.3%,AT含量高于GC含量,这与其他软体动物门动物的COI和16S r RNA的观测结果相近。COI和16S r RNA分别检测到了24个单倍型、43个核苷酸多态位点和9个单倍型、19个核苷酸多态性位点。AMOVA分析表明,3个群体间COI和16S r RNA部分基因总遗传分化系数分别为Fst=0.0090(P0.001)和Fst=0.0674(P0.001),群体内遗传分化远大于群体间、群体内存在较高的遗传分化。用NJ法构建分子进化树,3个地理群体的黑龙江河蓝蛤聚为一个族群,有少数个体和其他群体的个体聚在一起。  相似文献