理论模型

To make a comprehensive view of metapopulation researches, we folly analyze and summarize the present concepts, theories and models of metapopulation in this paper, which primarily includes the dynamical models and simulation approaches of single and competitive metapopulations. Based on the Levin's patch occupant model, the center framework of metapopulation researches, primary principles and mechanisms are discussed. First, Levins rule: the fraction of empty patch will remain constant with habitat destruction as long as metapopulation survives. This rule implies that empty patches have determinant effects on persistence and conservation. Second. Allee effect of metapopulation is incurred by establishing difficulties and dispersal costs, which is important to the studies of reserve area and the minimum available metapopulation size. Third, we analyze the rescue effect that immigrants can reduce the extinction risk of the presented local population. Rescue effect can leads to the improvement of metapopulation sustainability and the decrease of fraction of empty patches. Fourth, the coexistence mechanism of two competing metapopulation is discussed, which suggests that competition-colonization trade off may be prevalent in competing systems. Finally, extinction debt ob tamed from coexistence mechanism is given, which depicts the lost of species richness in the future for the current habitat destruction. After theoretical discussion, we present two popular simulated approaches in metapopulations: probability transition model and stochastic process model.

为了能总观集合种群进展的全局并开展进一步的工作，首先对集合种群的已有概念、理论和模型做了全面的分析和总结；其次对集合种群的发展和概念进行了探讨，以集合种群模型的中心框架：Levins的斑块占据模型为基础，展开对其它原理、效应和机制的探讨；主要包括了Levins原理，即当生境进到破坏时，空斑块比例在集合种群灭绝前保持不变，然后还分析了Allee效应（集合种群的Allee效应主要是由于建群困难和扩散损失造成的）；第三，分析了援救效应：迁人个体可以降低斑块中现有局域种群的灭绝风险，援救效应会增强集合种群的生存力，使空斑块比例下降第四，探讨了两竞争集合种群的共存机制，即竞争－侵占妥协，其共存机制为空间生境中物种共存提供了有力的理论解释。

Firstly, This text has described information fusion technology characteristic, form structure and concrete processing method, and application of information fusion in fault diagnosis proves the feasibility and validity from the angle of information theory. Based on this,it is combined the fault diagnosis of aeroengine with Information fusion, a method and model which the fault diagnosis of aeroengine information fusion is brought forward. a research which combined neural networks with D-S evidence is brought forward. Based on the analysis of single neural network characteristic, the model of roted neural network is put forward. With the simulation based on the example, we can know evidence theory fusion improved the fault diagnosis It is hard to give the basic probability function in the process of using the evidence theory, So the model based on network and D-S evidence is put forword.

本文首先论述了信息融合技术的特点、形式结构和具体的处理方法，并从信息论的角度论证了信息融合技术在故障诊断中的可行性和有效性；在此基础上，将航空发动机故障诊断与信息融合相结合，提出了一种基于信息融合技术的发动机故障诊断模型和方法，并在此基础上，提出和分析了基于人工神经网络和D-S证据理论的信息融合故障诊断，研究了神经网络的建模方法、组建原则和实现策略，并结合诊断实例进行了分析；提出了基于D-S证据理论的决策融合，阐述了D-S证据理论的方法，模型，并结合算例进行了分析。

Based on analysis of the theory and experiment, optimal design ways are suggested. Then the scale-up of pin mill is studied by means of similar theory, which will povide theorecal basis for scale-up of mill from optimal experiment model mill to practice mill.

在理论及实验分析的基础上，提出了销棒粉碎机的设计思路，并采用相似理论对粉碎机的模型放大进行了分析，研究了由优化的实验模型向实体模型放大的方法，为销棒粉碎机的设计提供了理论基础。

First, an energy non-local model is presented to derive the constitutive equation of a new strain gradient theory.

首先，提出了能量非局部模型，并由此模型，得出新应变梯度理论的本构关系；其次，由变分原理，得出相应的有限元公式；再次，给出了微压痕硬度的有限元分析方法；最后，将该理论预测结果与经典理论预测结果以及实验结果进行了对比。

On the basis of this, this article founded the system of signal control theory at Cross Roundabout. This theory system includes the roundabout capacity model, cycle length model, changed interval model, phase model and the range of applicability of this theory.

并在此基础上建立十字环形交叉口信号控制的理论体系，并建立和完善了十字环形交叉口环岛容量的模型、十字环形交叉口信号周期的模型、信号控制相位的确定方法、绿灯间隔时间的模型以及十字环形交叉口信号控制理论的适用范围。

Through the data provided by regular wave model experiment, a dynamicanalysis model and the corresponding numerical analysis method are checked andproved to be reliable which will provide theory instruction to dynamic design methodof breakwaters.

通过实验室提供的规则波模型实验数据对论文中使用的动力分析模型和数值模拟方法进行验证，证明了动力模型及相关理论的可靠性，为实际工程的初步设计提供了理论基础。

The Geographic Information System theory as a guide, point-set topology theory as basis, this paper uses object-oriented method to study on profile-based three-dimensional topological data model and data structure. By use of computational geometry, GIS, computer graphics images, 3DGM, the construction and dynamic updating methods of 3DGM are researched on the basis of amended OO-Solid data model.

本文以地理信息系统理论为指导，以点集拓扑理论为基础，采用面向对象的方法研究了基于剖面的三维拓扑数据模型和数据结构，采用计算几何、地理信息系统、计算机图形图像学等方法研究了基于修正后的OO-Solid数据模型的三维地质模型构建与动态更新方法。

Taking the theory of Customer Satisfaction and Uses and Gratifications as the frame, this paper is to design the model of channel satisfaction, and put forward structured variable and observed variable in the model.

内容提要：本文以&满意度理论&和&使用与满足理论&为理论框架，设计出电视频道满意度评估模型，提出并分析了频道满意度模型的结构变量和观察变量。

A smooth approximation algorithm is then proposed based on hinge-finding algorithm via curved faces approximated to the hinging hyperplanes model, which can obtain a smooth approximation result and hold some good properties of hinge-finding algorithm such as simplicity and effectiveness.

本文对找链接算法做了两点改进，其一是扩充了链接超平面模型，在二维空间上弥补了链接超平面模型表示能力不足这一弱点。仿真实验显示使用扩充后的模型得到了更好的分片线性逼近结果。另一点改进是使用双曲光滑函数构造出了基于找链接算法的光滑逼近算法。理论分析证明了算法的可行性。仿真实验验证了理论分析。

In the development of stress theory, transactional model has become the dominant one; on the other hand, it has been an important trend to assess the role of multiple personality variables in stress process.

在压力理论发展中，交互作用模型已经成为占主导地位的压力理论，另一方面，探讨多人格变量的共同作用已经成为压力研究的一个重要趋势，因而在交互作用模型内探讨多种人格变量的联合作用在压力研究中具有重要的理论意义和实际意义。

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％。