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混凝土碳化与氯离子侵蚀共同作用研究 被引量:72
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作者 牛荻涛 孙丛涛 《硅酸盐学报》 EI CAS CSCD 北大核心 2013年第8期1094-1099,共6页
处于除冰盐环境和海洋大气环境中的混凝土结构将受到碳化和氯离子侵蚀的共同作用。通过盐溶液浸泡与碳化交替方式,研究了碳化作用对混凝土中氯离子扩散的影响。结果表明:碳化作用加快了混凝土中氯离子扩散速度,提高了混凝土中的氯离子含... 处于除冰盐环境和海洋大气环境中的混凝土结构将受到碳化和氯离子侵蚀的共同作用。通过盐溶液浸泡与碳化交替方式,研究了碳化作用对混凝土中氯离子扩散的影响。结果表明:碳化作用加快了混凝土中氯离子扩散速度,提高了混凝土中的氯离子含量,相对于混凝土碳化对结合氯离子的释放作用,碳化导致的混凝土微观结构重分布对氯离子扩散的加速作用占主导地位。分析了碳化混凝土中的碳化钙分布和碳化深度,结果表明,用化学试剂法测试混凝土碳化深度时,碳化与未碳化交界处位于混凝土部分碳化区,交界处碳酸钙含量变化范围为5.4%~10.8%。 展开更多
关键词 混凝土 碳化 氯离子 耦合作用 扩散
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动载-环境耦合作用下氯离子在混凝土中的扩散性能研究 被引量:12
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作者 王彩辉 孙伟 +3 位作者 蒋金洋 孙国文 叶邦土 韩建德 《工业建筑》 CSCD 北大核心 2010年第11期1-5,31,共6页
为了研究动荷载与环境因素(温度、氯盐)耦合作用下氯离子在混凝土中的传输行为,设计出一套试验机制,以研究此工况下混凝土的饱水性能、不同应力水平下氯离子的传输行为及动载与温度耦合作用下氯离子的传输行为。试验结果显示,此工况下... 为了研究动荷载与环境因素(温度、氯盐)耦合作用下氯离子在混凝土中的传输行为,设计出一套试验机制,以研究此工况下混凝土的饱水性能、不同应力水平下氯离子的传输行为及动载与温度耦合作用下氯离子的传输行为。试验结果显示,此工况下混凝土的饱水度均在99%以上,可认为氯离子在混凝土中的传输以扩散为主;氯离子的扩散系数随应力水平和温度的提高而加快;并得到此条件下氯离子扩散的活化能为19.9 kJ/mol;通过寿命预测模型得到常温下钢筋混凝土大桥的寿命为89.1a。 展开更多
关键词 耦合 动载 应力水平 温度 氯离子 扩散
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RATIONAL SPECTRAL COLLOCATION METHOD FOR A COUPLED SYSTEM OF SINGULARLY PERTURBED BOUNDARY VALUE PROBLEMS 被引量:4
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作者 Suqin Chen Yingwei Wang Xionghua Wu 《Journal of Computational Mathematics》 SCIE CSCD 2011年第4期458-473,共16页
A, novel collocation method for a coupled system of singularly perturbed linear equations is presented. This method is based on rational spectral collocation method in barycentric form with sinh transform. By sinh tra... A, novel collocation method for a coupled system of singularly perturbed linear equations is presented. This method is based on rational spectral collocation method in barycentric form with sinh transform. By sinh transform, the original Chebyshev points are mapped into the transformed ones clustered near the singular points of the solution. The results from asymptotic analysis about the singularity solution are employed to determine the parameters in this sinh transform. Numerical experiments are carried out to demonstrate the high accuracy and efficiency of our method. 展开更多
关键词 Singular perturbation coupled system Rational spectral collocation method Boundary layer REACTION-diffusion Convection-diffusion.
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Stability of Coupled Impulsive Markovian Jump Reaction-Diffusion Systems on Networks 被引量:4
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作者 LI Yanbo KAO Yonggui 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2016年第5期1269-1280,共12页
This paper is devoted to the investigation of stability for a class of coupled impulsive Markovian jump reaction-diffusion systems on networks(CIMJRDSNs). By using graph theory, a systematic method is provided to cons... This paper is devoted to the investigation of stability for a class of coupled impulsive Markovian jump reaction-diffusion systems on networks(CIMJRDSNs). By using graph theory, a systematic method is provided to construct global Lyapunov functions for the CIMJRDSNs. Based on Lyapunov functions and stochastic analysis method, some novel stability principles associated with the topology property of the networks are established. 展开更多
关键词 coupled stochastic reaction-diffusion systems impulsive Markovian switching NETWORKS stability.
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Representation of a Class of Linear Operators with Coupled Domain in a Product Space and Its Applications
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作者 Jing XU Jun Jie HUANG Alatancang CHEN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2023年第2期326-338,共13页
This paper is concerned with the representation problem of a coupled operator in a product space.A necessary and sufficient condition is given for a class of operators with closed range to have a one-sided coupled ope... This paper is concerned with the representation problem of a coupled operator in a product space.A necessary and sufficient condition is given for a class of operators with closed range to have a one-sided coupled operator matrix representation.The applications of this result in a delay equation and in a diffusion-transport system with dynamical boundary conditions are further presented. 展开更多
关键词 coupled operator diffusion-transport equation delay equation dynamical boundary condition
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Two-way coupled analysis of lithium diffusion and diffusion induced finite elastoplastic bending of bilayer electrodes in lithium-ion batteries 被引量:2
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作者 Jun YIN Xianjun SHAO +2 位作者 Bo LU Yicheng SONG Junqian ZHANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2018年第11期1567-1586,共20页
A fully coupling model for the diffusion induced finite elastoplastic bending of bilayer electrodes in lithium-ion batteries is proposed. The effect of the mechanical stress on the lithium diffusion is accounted for b... A fully coupling model for the diffusion induced finite elastoplastic bending of bilayer electrodes in lithium-ion batteries is proposed. The effect of the mechanical stress on the lithium diffusion is accounted for by the mechanical part of the chemical potential derived from the Gibbs free energy along with the logarithmic stress and strain. Eight dimensionless parameters, governing the stress-assisted diffusion and the diffusion induced elastoplastic bending, are identified. It is found that the finite plasticity starting from the interface of the bilayer increases the chemical potential gradient and thereby facilitates the lithium diffusion. The full plastic flow makes the abnormal lithium concentration distribution possible, i.e., the concentration at the lithium inlet can be lower than the concentration at the interface(downstream). The increase in the thickness of the active layer during charging is much larger than the eigen-stretch due to lithiation, and this excess thickening is found to be caused by the lithiation induced plastic yield. 展开更多
关键词 lithium ion battery bilayer electrode coupled diffusion finite elastoplastic bending
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Surface diffuse discharge mechanism of well-aligned atmospheric pressure microplasma arrays 被引量:1
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作者 周仁武 周儒森 +6 位作者 庄金星 李江炜 陈茂冬 张先徽 刘东平 Kostya (Ken) Ostrikov 杨思泽 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第4期222-230,共9页
A stable and homogeneous well-aligned air microplasma device for application at atmospheric pressure is designed and its electrical and optical characteristics are investigated. Current-voltage measurements and intens... A stable and homogeneous well-aligned air microplasma device for application at atmospheric pressure is designed and its electrical and optical characteristics are investigated. Current-voltage measurements and intensified charge coupled device (ICCD) images show that the well-aligned air microplasma device is able to generate a large-area and homogeneous discharge at the applied voltages ranging from 12 kV to 14 kV, with a repetition frequency of 5 kHz, which is attributed to the diffusion effect of plasma on dielectric surface. Moreover, this well-aligned microplasma device may result in the uniform and large-area surface modification of heat-sensitive PET polymers without damage, such as optimization in hydrophobicity and biocompatibility. In the biomedical field, the utility of this well-aligned microplasma device is further testified. It proves to be very efficient for the large-area and uniform inactivation of E. coli cells with a density of 103/cm2 on LB agar plate culture medium, and inactivation efficiency can reach up to 99% for 2-min treatment. 展开更多
关键词 surface diffusion intensified charge coupled device surface modification bacterial inactivation
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Coexistence in a mutualistic model with cross-diffusion in a heterogeneous environment 被引量:2
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作者 Badradeen Adam Zhigui Lin Abdelrazig K. Tarboush 《International Journal of Biomathematics》 SCIE 2018年第6期59-75,共17页
To understand the impact of environmental heterogeneity and mutualistic interaction of species, we consider a mutualistic model with cross-diffusion in a heterogeneous environ- ment. Semi-coexistence states have been ... To understand the impact of environmental heterogeneity and mutualistic interaction of species, we consider a mutualistic model with cross-diffusion in a heterogeneous environ- ment. Semi-coexistence states have been studied by using the corresponding eigenvalue problems, and sufficient conditions for the existence and non-existence of coexistence states are given. Our results show that the model possesses at least one coexistence solution if the intrinsic populations growth rates are big or free-diffusion and cross-diffusion coefficients are weak. Otherwise, the model have no coexistence solution. The true solutions are obtained by utilizing the monotone iterative schemes. In order to illustrate our analytical results, some numerical simulations are given. 展开更多
关键词 Mutualistic model strongly-coupled CROSS-diffusion coexistence.
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Scaling limits of interacting diffusions in domains
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作者 Zhen-Qing CHEN Wai-Tong (Louis) FAN 《Frontiers of Mathematics in China》 SCIE CSCD 2014年第4期717-736,共20页
We survey recent effort in establishing the hydrodynamic limits and the fluctuation limits for a class of interacting diffusions in domains. These systems are introduced to model the transport of positive and negative... We survey recent effort in establishing the hydrodynamic limits and the fluctuation limits for a class of interacting diffusions in domains. These systems are introduced to model the transport of positive and negative charges in solar cells. They are general microscopic models that can be used to describe macroscopic phenomena with coupled boundary conditions, such as the popula- tion dynamics of two segregated species under competition. Proving these two types of limits represents establishing the functional law of large numbers and the functional central limit theorem, respectively, for the empirical measures of the spatial positions of the particles. We show that the hydrodynamic limit is a pair of deterministic measures whose densities solve a coupled nonlinear heat equations, while the fluctuation limit can be described by a Gaussian Markov process that solves a stochastic partial differential equation. 展开更多
关键词 Hydrodynamic limit fluctuation interacting diffusion reflecteddiffusion Dirichlet form non-linear boundary condition coupled partiMdifferential equation MARTINGALES stochastic partial differential equation Guassian process
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Linearization of Systems of Nonlinear Diffusion Equations
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作者 康静 屈长征 《Chinese Physics Letters》 SCIE CAS CSCD 2007年第9期2467-2470,共4页
We investigate the linearization of systems of n-component nonlinear diffusion equations; such systems have physical applications in soil science, mathematical biology and invariant curve flows. Equivalence transforma... We investigate the linearization of systems of n-component nonlinear diffusion equations; such systems have physical applications in soil science, mathematical biology and invariant curve flows. Equivalence transformations of their auxiliary systems are used to identify the systems that can be linearized. We also provide several examples of systems with two-component equations, and show how to linearize them by nonlocal mappings. 展开更多
关键词 POTENTIAL SYMMETRIES CONVECTION EQUATIONS coupled diffusion CLASSIFICATION
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A COUPLED DYNAMIC MODEL OF BRAND ACCEPTANCE AND PROMOTIVE INFORMATION SPREADING
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作者 Qian Pan Haoxiang Xia Shuangling Luo 《Journal of Systems Science and Systems Engineering》 SCIE EI CSCD 2018年第5期677-689,共13页
When people try to decide to buy or not to, they are often influenced by both their inherentopinions and the social marketing activities e.g. advertising, social news with strong point of view.Then people will make th... When people try to decide to buy or not to, they are often influenced by both their inherentopinions and the social marketing activities e.g. advertising, social news with strong point of view.Then people will make their final choice, or even convince other people to buy. After all, this is thebrand acceptance formation process. Factually, the dynamics of brand acceptance is essentially aninterwoven dynamics of endogenous opinion dynamics disturbed by an information diffusion process.To have a better understanding of the dynamics of brand acceptance, we propose and analyze a coupledagent-based dynamic model that combines the Majority-Rule-based Voter model in opinion dynamicswith the SI Model for information spreading to analyze the dynamics of brand acceptance in socialmedia. We focus on two important parameters in diffusion dynamics: the decayed transmission rate (fl)and the diffusion frequency (f). When the system is stable, the order parameter of the system is theduration time (r). In the absence of opinion interaction, the simulation results indicate that, when abrand tries to occupy a larger market share through social marketing approaches, it is always effectiveto let the opponent to be the propaganda target. While with the Majority-Rule-based Voter Modelincluded, we observe that the opinion interaction could have a dual function, which shows that a brandholding a small market share in the first place needs to adopt diverse marketing approaches accordingto different marketing environment types. 展开更多
关键词 coupled dynamics social marketing dynamics of brand acceptance opinion dynamics diffusion dynamics
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Evaluation of Fast Flood Diffusion through a Drainage Channel: A Flood Disaster Case Study of Japan’s Kinugawa River, September 10, 2015
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作者 Kazuaki Ohtsuki Yasuo Nihei 《Journal of Water Resource and Protection》 2017年第9期1063-1081,共19页
On September 10, 2015, unprecedented flood was occurred in Kinugawa River basin located on eastern Japan. It inundated 40 km2 of flood plain in Joso city, Ibaraki Prefecture, and more than 4000 people there called for... On September 10, 2015, unprecedented flood was occurred in Kinugawa River basin located on eastern Japan. It inundated 40 km2 of flood plain in Joso city, Ibaraki Prefecture, and more than 4000 people there called for help despite supposedly having sufficient time to evacuate. Some said that small initial flood before main severe flood arrived made them make a mistake in deciding whether to evacuate or stay there, despite having to actually evacuate in reality. This study focused on flood behaviour in this area, in particular, the effect of a small drainage channel lying on the flood plain which caused fast flood diffusion in case of occurring huge overflowing. Field investigations starting on time of the disaster with high-resolution positioning system were conducted to obtain spatial maps of flood depth and height. For appropriate modelling of the effect of small channel, we applied simulation model coupling 1-dimensional (1D) and 2-dimensional (2D) hydraulic scheme on the field and compared results from the 1D/2D coupled model and model without 1D scheme. The models provided information that the flood could reach 4 hours earlier to the city central of Joso city comparing in case of model without 1D scheme. The water depth rose irregularly and it was more confusing and difficult for the victims to make appropriate evacuation act. 展开更多
关键词 FLOOD diffusion 1- and 2-Dimensional coupled FLOOD Simulation CHANNEL Kinugawa RIVER
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一类具耦合的化学反应扩散系统的奇摄动 被引量:1
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作者 陈松林 《应用数学和力学》 CSCD 北大核心 1995年第6期511-517,共7页
本文研究一类带耦合项的化学反应扩散方程组解的性态,利用上下解理论证得解的存在性,然后在一定的参数环境下考虑了相应的奇摄动问题,并给出一致有效的渐近解。
关键词 奇摄动 迭代法 扩散反应方程 化学反应
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一类具交错扩散的强耦合退化抛物方程组解的整体存在与非存在性 被引量:1
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作者 高景璐 韩玉柱 高文杰 《数学杂志》 CSCD 北大核心 2014年第5期947-958,共12页
本文研究了一类具交错扩散的强耦合拟线性退化抛物方程组初边值问题正古典解的局部存在,整体存在与非整体存在性.利用正则化方法和先验估计技巧证明了该问题正古典解的局部存在性,并且分别给出了该问题是否存在整体古典解的充分条件.结... 本文研究了一类具交错扩散的强耦合拟线性退化抛物方程组初边值问题正古典解的局部存在,整体存在与非整体存在性.利用正则化方法和先验估计技巧证明了该问题正古典解的局部存在性,并且分别给出了该问题是否存在整体古典解的充分条件.结果表明当种群内竞争强于种群间互惠作用时,此问题存在整体解;而当两种群具有强互惠作用时,所有解都是非整体的. 展开更多
关键词 退化抛物方程组 强耦合 整体存在 非整体存在 交错扩散
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基于微分动力学方程的相互关联网络故障传播联合演化模型 被引量:1
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作者 杨宇骐 罗光胜 《通信技术》 2019年第10期2452-2460,共9页
研究网络遭受相继故障后的演化机理是网络科学的重要课题之一。现有研究少有涉及到关联网络间的相互影响作用。随着网络中节点复杂度和智能化的提升,仅考虑单个网络节点之间的耦合关系是难以客观反映网络状态的演变规律。针对现有渗流... 研究网络遭受相继故障后的演化机理是网络科学的重要课题之一。现有研究少有涉及到关联网络间的相互影响作用。随着网络中节点复杂度和智能化的提升,仅考虑单个网络节点之间的耦合关系是难以客观反映网络状态的演变规律。针对现有渗流模型只便于分析异构网络之间一一对应关系的情况,本文中采用弱化网络之间作用形式而强调作用效果的方法,建立了有电网供能的计算机网络相继故障传播演化模型。同时通过将电网和计算机网络构成的庞大的联合网络投影到计算机网络层面(即只保留至少一端为计算机网络节点的连边),降低了模型的难度。通过模拟实验,电站小规模的随机故障可引发计算机网络相继故障,并达到使其发生大规模随机故障的效果。 展开更多
关键词 耦合网络 相继故障 传播模型
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Analytical solution for coupled diffusion of three-components liquid in porous pellet 被引量:1
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作者 徐曾和 王锦霞 《中国有色金属学会会刊:英文版》 CSCD 2005年第1期176-183,共8页
The coupled three-components liquid diffusion within a porous pellet was investigated. The coupled diffusion model was given according to irreversible thermodynamics, and the rigorous solutions of the model subject to... The coupled three-components liquid diffusion within a porous pellet was investigated. The coupled diffusion model was given according to irreversible thermodynamics, and the rigorous solutions of the model subject to the homogeneous boundary conditions of the first kind are derived by employing Hankel transform technique and the standard technique resolving ordinary differential system. The method can also be used to solve the other coupled diffusion problems within a pellet with different kinds of boundary conditions. Then the case computations were conducted. The calculation results show that the effect of interdiffussion on the concentration of components depends upon the diffusion time strongly, after a long diffusion period, a very small cross diffusion coefficient will induce the observable change of concentration profile, and that, when the cross coefficients are close to 5%7% of the main coefficients, the significant effect of coupled diffusion on the concentration profiles of components is observed. The case computations also show that interdiffussion can induce non-monotonous concentration profiles. So, for the diffusion taking place within ternary system, the concentration profiles obtained by the analysis of interdiffussion can be very different from that obtained by the equivalent binary system analysis method. 展开更多
关键词 三重系统 耦合扩散 解析解 不可逆热力学 多孔球团矿
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一个强耦合抛物系统解的‖·‖L^2(Ω)和‖·‖V_2(Q_T)估计
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作者 许志奋 吴斌 《西南大学学报(自然科学版)》 CAS CSCD 北大核心 2007年第12期16-20,共5页
考虑一个强耦合抛物系统的初边值问题,通过利用Hlder不等式、最大值原理,以及先验估计的技巧给出了这类系统解的‖.‖L^2(Ω),和‖.‖V_2(Q_T)估计.
关键词 强耦合 自扩散 交叉扩散 初边值问题
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Mathematical modeling and optimal control problems in brain tumor targeted drug delivery strategies
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作者 Aziz Belmiloudi 《International Journal of Biomathematics》 2017年第4期235-296,共62页
In this paper, we present a mathematical model that describes tumor-normal cells inter- action dynamics focusing on role of drugs in treatment of brain tumors. The goal is to predict distribution and necessary quantit... In this paper, we present a mathematical model that describes tumor-normal cells inter- action dynamics focusing on role of drugs in treatment of brain tumors. The goal is to predict distribution and necessary quantity of drugs delivered in drug-therapy by using optimal control framework. The model describes interactions of tumor and normal cells using a system of reactions^diffusion equations involving the drug concentration, tumor cells and normal tissues. The control estimates simultaneously blood perfusion rate, reabsorption rate of drug and drug dosage administered, which affect the effects of brain tumor chemotherapy. First, we develop mathematical framework which mod- els the competition between tumor and normal cells under chemotherapy constraints. Then, existence, uniqueness and regularity of solution of state equations are proved as well as stability results. Afterwards, optimal control problems are formulated in order to minimize the drug delivery and tumor cell burden in different situations. We show existence and uniqueness of optimal solution, and we derive necessary conditions for optimality. Finally, to solve numerically optimal control and optimization problems, we propose and investigate an adjoint multiple-relaxation-time lattice Boltzmann method for a general nonlinear coupled anisotropic convection-diffusion system (which includes the developed model for brain tumor targeted drug delivery system). 展开更多
关键词 Optimal control coupled nonlinear reaztion-diffusion equations anisotropicbrain tumor growth diffusion tensor drug delivery chemotherapy real-time monitoringof distribution logistic growth pointwise controllers adjoint system population dyna-mics magnetic resonance imaging (MRI) convection-enhanced delivery (CED) adjointmultiple-relaxation-time lattice Boltzmann method multiscale Chapman-Enskog expan-sion optimization of therapies.
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ON NONLINEAR COUPLED REACTION-DIFFUSION SYSTEMS
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作者 梅茗 《Acta Mathematica Scientia》 SCIE CSCD 1989年第2期163-174,共12页
In this paper, the problem of initial boundary value for nonlinear coupled reaction-diffusion systems arising in biochemistry, engineering and combustion_theory is considered.
关键词 ON NONLINEAR coupled REACTION-diffusion SYSTEMS ID
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挥发性污染物苯在水气界面耦合扩散的浓度分布
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作者 徐杰 吴慧芳 陈丽萍 《环境工程学报》 CAS CSCD 北大核心 2013年第12期4673-4677,共5页
为研究苯水体泄漏后水气污染的浓度时空分布,利用挥发性污染物水气耦合扩散模型进行预测计算,预测结果与水槽实验相结合,准确地描述了苯在水气界面耦合扩散的浓度分布规律:沿水流方向(x轴)浓度随时间向前推移,距离投放点越远,浓度峰值越... 为研究苯水体泄漏后水气污染的浓度时空分布,利用挥发性污染物水气耦合扩散模型进行预测计算,预测结果与水槽实验相结合,准确地描述了苯在水气界面耦合扩散的浓度分布规律:沿水流方向(x轴)浓度随时间向前推移,距离投放点越远,浓度峰值越小,出现时刻越晚;沿水流深度方向(y轴)浓度分布关于投放点z=0.20 m纵断面对称,在水气界面和空间变化界面(水槽边缘)浓度出现极小值,随着挥发量的增加,浓度峰值出现的位置由水中推移至大气中;沿水流宽度方向(z轴)浓度由投放点向两侧推移。分析了亨利常数、水流速度及风速对苯耦合扩散浓度分布的影响。 展开更多
关键词 苯污染 耦合扩散 模拟验证 浓度分布 影响因素
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