理论模型

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。

In this paper,the nonstandard analysis theory is used for inducing a metric space by a Loeb measure space.On this basis,a metric space is induced by a internal finitely additive measure space.The close relationship between the metric space induced by a Loeb measure space and the metric space induced by a internal finitely additive measure space is illustrated with the concepts and some properties of Loeb measure.Then,some properties of the metric space that induced by a internal finitely additive measure space are studied.In the first two chapters,we first Succinctly present the origin,development and research states of the nonstandard analysis.Then,the theoretical foundation of nonstandard analysis as well as the axiomatic nonstandard analysis are given.Finally, the nonstandard model and the saturation model are discussed,as well as some natures of the nonstandard model and several equivalent conditions of saturation model are given.

本文利用非标准分析理论，在由Loeb测度空间导出度量空间的基础上，由内有限可加测度空间导出了度量空间，并借助Loeb测度的概念和若干性质证明了由标准的测度空间导出的度量空问和由内有限可加测度这个非标准的测度空间导出的度量空间有着密切的关系，在此关系的基础上还研究了由有限可加测度这个非标准的测度空间导出的度量空间的性质在第一、第二章里，我们首先简单介绍了非标准分析的产生、发展及研究现状，接着给出了非标准分析的理论基础以及公理化的非标准分析，进而讨论了非标准模型和饱和模型，并给出了非标准模型的一些性质和饱和模型的若干等价条件。

Based on consider hereinbefore, this dissertation discusses several aspects on the problem of the sustainable and optimum exploitation of groundwater resources as follows:①reviewed entirely the origin and evolvement of the concept "sustainable development", stated and commented the study status in queue on"sustainable development"around national and international range, thorough discussed the science connotation about the concept "sustainable development";②looked back and commented across-the aboard some furthest basic concept and proposition related to groundwater resources, put forward self opinions on a few existent mistake points of view and chaos understandings;③expatiated entirely on the content and meaning of the theory of changeable groundwater resources system, contrast with the traditional methods of groundwater resources calculation and evaluation, combined example to show the application of this theory;④thorough analyzed the difficult and complexity to forecast the groundwater resources, fully stated the traditional methods of groundwater resources forecasting, pointed out the characteristic and applying condition of these forecasting method, introduced the main ideas and methods of wavelet analysis developed recently, and the MATLAB software be known as the fifths era computer language, and its accessory wavelet analysis toolbox, applied these methods and tools to analyze the groundwater dynamic curve, adopted the B-J method and Morte-Carlo method, combined with the theory of changeable groundwater resources system, discussed the new view on the forecast of groundwater resources;⑤synthetically analyzed the characteristics and limitations of the present all kind of groundwater manage model, combined mathematical programming, mathematical statistics, random process and the theory of variation system of groundwater resources on the unite optimum attempter of surface water and groundwater, emphasized how to make the model more nicety, more simple, more practicality;⑥analyzed the inside condition and outside condition to assure the sustainable and optimum exploitation of groundwater resources, the inside conditions are the follows: correct resources idea, scientific methods of resources calculation and evaluation, credible forecast methods of resources, exercisable measures of resources management, the outside conditions are the follows: the development idea of high layer, the transform of manage system, the matched policy and rule of law, the adjusted of economy lever, the improve of cultural diathesis, the boosting up of water-saving consciousness and detail measures, the control of population rising, the prevention and cure of water pollute, the renew and rebuild of ecology;⑦scan the sustainable and optimum exploitation of groundwater resources from the high level of metagalaxy, earth system science, and philosophy;⑧point out the more directions on groundwater resources.

它将为制定水资源的可持续发展目标和战略决策提供科学依据，为制定社会、经济可持续发展战略提供理论基础。基于以上考虑，论文主要从以下几方面对地下水资源可持续开发问题进行了比较深入的探讨：①全面回顾了"可持续发展"概念的由来与演变，对国内外"可持续发展"的研究现状进行了述评，并对"可持续发展"概念的科学内涵进行了深入探讨；②对涉及地下水资源的一些最基本的概念和命题进行了全面的回顾和评述，对目前仍然存在的一些错误观点和混乱认识提出了自己的见解；③全面阐述了地下水资源变值系统理论的内容和意义，并与传统的地下水资源计算评价方法进行了对比分析，结合实例具体说明了方法的应用；④深入分析了地下水资源预测预报工作的极端重要性和复杂性，对传统的地下水资源动态预测方法进行了全面的评述，指出了各类预测预报方法的特点及适用条件，对最近二十多年刚发展起来的小波分析技术的主要思想和方法及其应用范围，以及号称第五代计算机语言的MATLAB软件和附带的小波分析工具箱进行了介绍，并应用于地下水动态过程线的分析，采用时间序列中的B-J法，蒙特卡罗方法，与地下水资源变值系统理论相结合，探讨了地下水动态资料分析和地下水资源预测预报的新思路；⑤综合分析了现今各类地下水管理模型的特点及缺陷，将数学规划、数理统计、随机过程等与地下水变值系统理论相结合进行地表水地下水或多水源的联合优化调度，使模型更准确、更实用；⑥对保证地下水资源可持续开发的内部条件和外部条件进行了分析，内部条件主要是正确的资源观，科学的资源计算与评价方法，可靠的资源预测预报技术，可操作的资源管理措施，外部条件主要是高层发展思路、管理体制的变革、配套的政策法规、经济杠杆的调节、人文素质的提高、节水意识的增强及具体节水措施、人口增长的控制、水体污染的防治、生态的恢复和重建等；⑦从宇宙科学、地球系统科学及哲学的高度审视地下水资源的可持续开发；⑧指出了地下水资源可持续开发的进一步研究方向。

Relationship between IL and relevant network parameters is presented by network theory. Network structure of EMI power line filter and its computation method for IL are discussed. Common mode and differential mode equivalent circuit model of single-phase power line filter and the high frequency distribution parameters model of filter device are established. Meanwhile, the main characters of soft ferrite are analyzed, and its implement on the EMI power line filter and its equivalent circuit model are given. According to the preceding theory, the software for IL of power line filter and the design of filter inductor are programmed. The difference between the imitative and practical results is analyzed, and the rational of the equivalent circuit model is tested.

文中应用网络理论分析了EMI电源滤波器的插入损耗与相关网络参量的关系，讨论了EMI电源滤波器的基本网络结构及其插入损耗的计算方法，建立了单相电源滤波器的共模及差模等效电路模型及滤波器件的高频分布参数模型，然后分析了软磁铁氧体材料的主要性质，讨论了软磁铁氧体在EMI电源滤波器中的应用，建立了软磁铁氧体磁芯的等效电路模型，最后根据以上理论编制了滤波器插损分析软件和滤波电感设计软件，并对软件仿真结果与实际测试结果进行了对比分析，验证了各个等效电路模型的合理性。

Discrete calculus , discrete probability distribution s, discrete Fourier transform s, discrete geometry , discrete logarithm s, discrete differential geometry , discrete exterior calculus , discrete Morse theory , difference equation s, and discrete dynamical system s.

在应用数学中，离散模型连续模型的离散近似。在离散模型中，离散方程are fit to 数据。使用递推关系是这种建模方式的一般方法。时标微积分是差分方程理论与微分方程理论的统一，应用在需要建立离散和连续同步数据模型的领域。

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。

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％。