数学模型

A new kind of the mathematical discription of fines deposition, release and migration in porous media was formulated. So, a new mathematical tool was given for the quantitative discription of the injectivity decline due to the fines problem.

与现存理论相比，本文提出的数学模型具有如下方面的特点： 1、由于直接从微粒在孔隙内的动力学特征出发，因此，模型中需要由实验确定的模型参数较少，同时，模型中不出现由实验确定的经验的关系式。

Some new conceptions were proposed such as choice of lumping species and model solution etc. The proposed model only needed to input the routine data of feed oils (such as ASTM temperature and density), then predict the yields and properties of products under different working conditions.

对模型进行合理的参数分析，找出模型的重要影响因素，对次要参数进行合理的简化，尽量用最少的参数来表征所建立的物理、数学模型，在集总划分和模型求解等方面均有所创新。

The basic idea Is: using the standard value inserting the dynamic measuring errors which involve systematical errors and random errors, constructing the original error model which is revised at the same time and follows the variable law of the dynamic measuring errors, establishing a more suitable error model.

基本思想是：利用标准量插入动态测量数据实时分离含有系统误差和随机误差的动态测量误差值，建立误差的初始数学模型，并根据不断获得的标准点处的测量误差，实时修正或校正所建的初始误差模型，使误差模型不断跟踪动态测量误差的变化规律，建立更加符合动态测量过程的误差模型。

In order to assist Boost converter design, the working process of the converter at discontinuous current mode was analyzed and a nonlinear mathematical model was estabilished as well. Case study on Matlab/ Simulink was performed with binary logical variable used, the simulation result was consistent with the theoretical analysis which proveed the validitd and feasibility of the proposed model. The model could be used to assist Boost circuit design effectively and supplie a basis for parameter optimization.

为了辅助升压变换器在应用中的设计，分析了电流断续状态下Boost变换器的工作过程，建立了这种状态下的Boost变换器非线性数学模型，在结合二进制逻辑变量，建立了Simulink模块下的变换器仿真模型，研究表明仿真结果与理论分析结果一致，证实了模型的准确性和可行性，这种逻辑与模拟结合的简明通用的模型可以高效辅助Boost电路设计并为参数优选打下了基础。

This make it difficult to know the essence of fluidized beds. In order to viewthe motion behavior of a single particle in a fluidized bed in a reasonable cost, thegas-solid flow in a fluidized bed is modeled by a combined approach of discrete particlemethod and computational fluid dynamics, in which the motion ofindividual Particles is obtained by solving Newton\'s second law of motion and gas flowby the Navier-Stokes equation based on the concept of local average.

为了用数值模拟方法来弥补传统实验方法的不足，达到从单个颗粒的尺度上来研究流化床中颗粒的运动和气体流场的剧烈变化情况的目的，本论文建立了基于用Newton第二定律计算单个颗粒运动轨迹的离散颗粒法和基于区域平均值的计算流体动力学方法的数学模型的建立和求解过程；并依据Newton第三定律建立了DPM模型和CFD模型的耦合模型，编写和调试了DPM和CFD的耦合程序。

By getting over the state of the art about the technique of the tailrace tunnel with sloping ceiling, the research contents and study ways and means are put forward, and the importance to research is explained.

第二章：主要论述了变顶高尾水洞的工作原理、体型设计和适用条件以及过渡过程计算的数值计算模型，重点在于数学模型的建立与分析，明满流交替现象中选择了合理的计算模型和计算方法；第三章：着重介绍了向家坝变顶高尾水洞方案模型试验的研究内容和主要结果。

By getting over the state of the art about the technique of the tailrace tunnel with sloping ceiling, the research contents and study ways and means are put forward, and the importance to research is explained.Chapter 2 introduces the working principle of the tailrace tunnel with sloping ceiling. And the design of body type, appliance condition and the numerical model for transient process are illuminated.

第二章：主要论述了变顶高尾水洞的工作原理、体型设计和适用条件以及过渡过程计算的数值计算模型，重点在于数学模型的建立与分析，明满流交替现象中选择了合理的计算模型和计算方法；第三章：着重介绍了向家坝变顶高尾水洞方案模型试验的研究内容和主要结果。

The physical model and simulation mathematical model for high-frequency floating new structure caseless and common structure auto-rifle are established separately in this dissertation when they are in conditions with or without restrain, the simulation model sets are constructed and some simulation models are tested by the comparison with theoretical value to test value.

本文分别建立了无约束和有约束条件下高频浮动新结构无壳弹枪和常规结构自动步枪的物理模型和仿真数学模型，它们构成了&仿真模型集&，通过理论值和实验值的比较，对部分仿真模型进行了验证。

Aiming at researching on the theory of the shaft-kind parts form error evaluation and its application, on the basis of the analysis for the geometric model of the roundness error and cylindricity error, the linear programming models of the enclosure evaluation were proposed. According to the features of the proposed models, the solution of the optimization algorithms of linear planning was discussed to obtain accurate evaluation results.

为了对轴类零件形状误差评定理论及应用进行研究，在分析轴类零件的圆度、圆柱度误差评定几何模型的基础上，建立了包容拟合评定的规划数学模型，并针对模型的特点，探讨了使用线形规划的单纯形优化算法进行规划模型的求解，从而获得精确的形状误差评定结果。

The authors try to use conceptual model,mathematical model and computer model to reconstruct the formation and evolution of dynamic geomorphic features of tectonic gulches.

尝试从概念模型、数学模型、计算机模型等多个层次构建构造成因的沟谷形成、演变的动态地貌模型。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。