数学模型

Besides, a nonlinear mathematical model is established on the base of non-equilibrium thermodynamic theory and phase equilibrium principle.

从非平衡态热动力学和相平衡的角度，推出了非饱和多孔介质的热湿迁移的数学控制方程，根据本文所研究的对象，对该控制方程进行了简化，建立了蔬菜热湿迁移的一维非线性数学模型，并给出了求解该数学模型的定解条件。

The article covers the full research on such aspects as mathematic description, numerical analysis method and their practical applications. The diphase heating surface is divided into a hot water section, a evaporation section and a micro overheat section , the problems of model switching are avoided successfully between subcritical and supercritical working condition in the model of The diphase heating surface, and the model can be used for between subcritical and supercritical working condition without causing the model stiff infinity prick up problem. The mathematical model and dynamic characteristic account is unified and predigested for the diphase heating surface of once—through boiler under subcritical and supercritical pressure, and propose that the working conditions at phase change point could be used as divide criterion between water region and steam region under supercritical pressure, the problems are solved successfully between water and steam phase change point under supercritical pressure.

本文在过程的数学描述、数值分析以及实际应用等方面进行了系统的研究分析，将双相受热面统一划分为热水段、蒸发段和微过热段三段，所建立的双相受热面模型不但成功地避免了超临界工况与亚临界工况间的模型切换，而且消除了由区段划分欠妥所引起的模型刚性无限加剧的问题，统一并简化了超临界及亚临界压力下直流锅炉双相区段的数学模型和动态特性计算，而且提出了利用相变点工况作为超临界压力下划分汽水区域的标准，解决了超临界压力下水与蒸汽的相变点问题。

The mechanics model of tramcar and track,mathematical model of tramcar based on the Newton's second law and mathematical model based on the Bernoulli-Euler Beam theory are built respectively.

建立了大型矿车与矿井运输轨道的耦合动力学模型，根据牛顿第二定律建立了矿车振动数学模型，根据伯努利—欧拉梁模型建立轨道振动数学模型，以Simulink为仿真工具对矿车越过轨道连接处的台阶时车体及轨道的振动特性进行了动态模拟。

Modeling is one of the main methods used to research our world. Different kinds of models can be settled to solve different problems, such as physical models, mathematical models, figural models etc.

建模是人类认识世界和改造世界的主要方法之一，常用的数学模型有物理模型，数学模型，图示模型等等。

Based on the dynamical system of a tuberculosis spread m odel, the dynamical behavior of a tuberculosis spread model with constant immigr ation was discussed, and the local and global asymptotic stability of the endemi c equilibrium on this model is studied by using Hurwitz criterion and multiple m atrix theory. Sufficient conditions for the local and global asymptotically stab ility of the endemic equilibrium on this model are obtained.

在结核病传播的数学模型的动力学系统基础上，利用 Hurwitz 判据和复合矩阵理论，讨论了具有常数移入的结核病传播的数学模型的动力学性质，研究了具有常数移入的结核病模型的地方病平衡点的局部和全局渐近稳定性，得到了具有常数移入的结核病模型的地方病平衡点是局部和全局渐近稳定的充分条件。

According to development of the activated-sludge process and the mechanism theories of IAWQ-ASM, a whole frame model, a systematic mathematics model and an expense target function model were established in this paper, which were used for on...

本文根据污水处理活性污泥法工艺的发展趋势，基于IAWQ-ASM机理模型理论，建立了一套完整的用于活性污泥法脱氮除磷A2／O工艺系统方案设计的框架模型、系统数学模型以及费用目标函数模型，并将其整合为一个数学最优规划问题予以求解。

All above works represent some exploring and creative effort to upgrade level and efficiency for design of activated-sludge process.According to development of the activated-sludge process and the mechanism theories of IAWQ-ASM, a whole frame model, a systematic mathematics model and an expense target function model were established in this paper, which were used for on...

本文根据污水处理活性污泥法工艺的发展趋势，基于IAWQ-ASM机理模型理论，建立了一套完整的用于活性污泥法脱氮除磷A2／O工艺系统方案设计的框架模型、系统数学模型以及费用目标函数模型，并将其整合为一个数学最优规划问题予以求解。

A mathematical model of airlift-loop reactor was developed with the two-fluid model and the theory of two-phase flow.

采用双流体模型和气液二相流体动力学理论建立了气升式环流反应器流体流动的数学模型，在此模型的基础上利用溶质渗透理论和各向同性湍流理论建立了局部液相体积传质系数数学模型。

Based on the water environment spatial data mining and visualization method, the paper presents these main characteristics and innovations:①Measurement of contamination fluxes:A scene-based research strategy is proposed:measurement /water quality analysis→flow field simulation→contamination transformation rule→fluxes scene simulation→temporal-spatial rule analysis.②Serial numerical models of water environment in the Qiantang River:The controlled equations of the flow field model of the main river,united controlled equations of the main contamination fluxes and water quality prediction model at emergent time are set up.③GIS-based water quality and contamination fluxes decision-making assistance system:A water environment database has been set up;based on MapX and C#.net platform,a system has been developed to facilitate visual inquiry,decision-making and graphics export.

本文基于水环境空间数据挖掘与可视化的研究方法与体系，研究中的主要特色与创新点为：①河流污染物通量测算的技术与方法：提出了基于工况测量/水质分析→流场模拟→污染规律解析→通量情景模拟→时空规律分析的研究方案；②钱塘江水环境模拟系列数学模型：建立了钱塘江干流研究区域流场数学模型的控制方程、主要污染物通量模型的联合控制方程、突发污染事故水质预报模型的基本方程；③基于GIS的水质预报与污染物通量决策支持系统的研发：建立水环境时空数据库，基于MapX和C#。net平台进行系统的构建与开发，为研究的系列成果提供可视化的查询、决策与图形输出。

Under this condition, a lot of new influence factors appear, the superficial model of coalbed methane is no longer suitable, so we set up the coalbed methane seepage model considered slip effect and porosity pressure, set up the coalbed methane seepage model considered coupling of slip effect and temperature field, set up the coalbed methane seepage model considered coupling of the slip effect and two phase of water - gas in this paper.

而进入深部开采后出现了许多新的影响因素使得原有的浅部煤层气渗流模型不再适用，因此本文建立了考虑滑脱效应及孔隙压力的煤层气渗流模型，建立了考虑滑脱效应及温度场耦合的煤层气渗流的数学模型，建立了考虑滑脱效应的水气耦合煤层气渗流数学模型。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。