模型理论

Firstly, The sufficient con-ditions of the existence and uniquity of the positive equlibria by applying functional derivative isobtained; Secondly, the global attractability of the positive equlibria is investigated by charateristicroots theory and oscillation theory; Thirdly, regarding the delay as a parameter, conditions of theexistence of Hopf bifurcation and the peridic solution, furthermore, the form of the approximateperidic solution are obtained; Finally, Some specific examples are given and the solution diagrameappears by Matlab.

首先利用导数性质，得到了该模型正平衡态存在惟一性的充分条件；其次，利用特征值和振动性理论得到了该模型正平衡态全局渐近稳定性充分条件；然后，应用Hopf分支理论证明了该模型Hopf分支及近似分支周期解的存在性，并给出了周期解的近似表达式；最后，借助于MATLAB数学软件，举例并绘出了模型数值解的拟合图象，验证了文中定理条件的可行性。

A theoretical model is built to investigate the simulation of the infrared characteristic of the metal structure with the PCM false target.Structure parameters of the PCM false target that suit for the simulation are investigated numerically.According to the results,further request on the improvement of the thermal conductivity of PCM is presented.An experimental platform is built and the numerical model is validated experimentally.Three key thermal characteristic components of the false tank(barbette,wheel and front armor plate) are manufactured and tested,and good results are obtained.A method for the thermal conductivity enhancing of PCM by using aluminum fins is studied,the influence of the structure parameters of PCM plates to the simulation effects are investigated numerically,and the reasonable configuration parameters of the PCM plates used to simulate the steel plates of different thickness are obtained.In the study of the application of heat convection method in IR false target,a passive infrared simulation system is designed to simulate the infrared characteristic of metal constructions.The system is made up of pipe-plate,pump,receiver,and working fluid.

在相变材料应用于红外示假的研究中，通过数值模拟，研究确定了适用于制作假目标的相变材料各物性参数的范围，分析了相变材料制作假目标的可行性，并根据所得结果，选取石蜡为研究对象，建立了相变材料模拟金属构件红外特征的理论模型，研究了适用于模拟各金属构件红外特征的相变材料假目标的相关结构参数，得出了相变材料假目标模拟各金属构件红外特征的理论结果，并对相变材料的导热系数这一物性提出了进一步的改进要求；搭建了假目标实验平台，验证了所建理论模型的准确性；以坦克假目标为研究对象，制作了炮塔、负重轮和前上装甲板三个坦克假目标的关键红外热特征部件，并进行了野外实验，取得了较好的结果；以添加铝肋片作为改进相变材料导热能力的手段，理论研究了此类导热增强型相变材料的相关结构参数对模拟效果的影响，得出了模拟不同厚度钢板红外特征的导热增强型相变材料的结构参数及模拟效果。

In the research of theory model, cumulative degradation model of failure mechanism and cumulative exposure model of probability statistic for SDS-ALT are established, and the efficiency principle for SDS-ALT is qualitatively analyzed based on them.

1在理论模型研究中，分别建立了步降应力试验累积退化的失效物理模型与累积失效的概率统计模型，并从理论模型的角度对效率原理进行了定性分析。

The course of coming into being the equilibrious market price is showed under the condition of asymmetric information, and existing information cost by introducing the Grossman-Stiglitz Paradox and the Grossman-Stiglitz Model.

同时，分别对威廉斯模型、沃尔特模型、戈登增长模型、市盈率评估法、资本资产定价模型、套利定价理论和因素定价模型等进行了简单评述，指出其理论假设和应用的局限性。

The second part pays attentions to the hydrodynamical model of solar flare (chromosphere+corona).

论文的下篇则致力于建立耀斑大气动力学理论模型，包括现有耀斑动力学模型评述，构造动力学模型的理论框架，耀斑主相动力学模型，以及耀斑脉冲相动力学模型等四章。

In this dissertation, as for some problems in flood forecast andreservoir regulation, the research had been done based on the special research topic dynamiccontrol on limit water level in flood season using theories of fuzzy optimizing theory,maximum entropy theory, entropy-weighted multi-objective decision making method, geneticalgorithm etc. And the research focused on evaporation calculation, fuzzy description ofcatchraent impoundage, fuzzy similarity calibration method, nolinear watershed concentrationmodel and error distribution maximum entropy model and risk computation of dynamiccontrol reservoir water level in flood season when the flood forecast and precipitation forecastare taken into consideration.

本文从洪水预报和汛限水位动态控制两个研究方向着手，以汛限水位动态控制研究专题的试点水库为工程背景，运用模糊优选理论、极大熵理论、熵权多目标决策法、遗传算法等理论，研究了蒸散发计算和流域蓄水容量的模糊描述、洪水预报模型参数的模糊相似校正方法、流域非线性汇流模型、误差分布的极大熵模型以及考虑洪水预报和降雨预报动态控制水库汛限水位的风险计算方法。

The influences of the structural and movement parameters of the arc-track-type flexible holding and conveying mechanism and the sugarcane stalks geometric parameters on the conditions of sugarcane stalks outward windrowing, windrowing angle and distance were analyzed.

对甘蔗在夹持输送终点抛出后和着地时的运动学进行了理论分析，并建立了数学模型，推导出了甘蔗向外铺放的条件，以及甘蔗铺放距离、铺放角的理论计算公式，分析了圆弧轨道式柔性夹持输送装置结构参数、运动参数、甘蔗几何参数对甘蔗向外铺放、铺放距离、铺放角的相互影响规律；对甘蔗在夹持输送过程中的受力情况进行了理论分析，建立了甘蔗在夹持输送装置中所需最小夹持力模型，以及甘蔗质心距柔性夹持元件上端最大距离模型。

According to the differential explanations on the incentives or decisions of labor migration,this paper categorizes the abroad literatures into three kinds: traditional theory of labor migration(includes Lewis Model,Ranis and Fei's Model,Todaro Model),human capital theory of labor migration,and new theory of labor migration.

依据分析问题的假设条件和对迁移决策的解释，可以把国外关于劳动力迁移的文献分为三类，即传统的劳动力迁移理论(包括刘易斯模型，拉尼斯-费景汉模型，托达罗模型)、人力资本劳动力迁移理论和新劳动力迁移理论。

Theoretical analysis of strip mills AGC had been processed and a three-DOF mathematical model of hydraulic screw-down system had been built,which was specified cylinder displacement and inner gap and adapt to varied control way.

对板带轧机自动厚度控制模型进行了理论分析，建立了三自由度轧机负载的液压压下系统的模型，将缸位移和内辊缝相区分，使其适用于不同的控制方式，进而对厚度计式控制模型、变形的厚度计式控制模型、动态设定控制模型进行了对比研究，指出轧机模数和轧件塑性系数分别对应于自动厚度控制系统的静态指标和动态指标，为控制过程中参数的选取提供理论依据。

For formalized lattice implication algebra theoryT, it is proved thatTis preserved under submodels, unions of chains and homomorphisms;Tis neither complete nor model complete, and hence there exists no built-in Skolem function.

讨论有关格蕴涵代数结构的模型论性质，证明了形式化格蕴涵代数理论T保子模型、保模型链之并、保模型同态，理论T不是完备的、也不是模型完备的，因而不存在内在Skolem函数。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失