数值方法
- 与 数值方法 相关的网络例句 [注:此内容来源于网络,仅供参考]
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The computing plots of the solutions from the two methods were inconsistent under the specified boundary-initial conditions, which stirred up the debate of the effectiveness of Maxwell's equations in lossy medium. It is found that the differences between the two numerical curves can be viewed as the Gibbs phenomenon caused by cutting off the high frequency components in computing the infinite integral of the numerical curve of Harmuth's solution.
通过比较两种解析解的数值曲线得出:两者的差异在于求解Harmuth解的数值曲线时,采取无穷积分的高频截断近似产生了吉布斯现象;在计算Harmuth解的数值曲线时不断增大积分上限,其数值曲线的振荡不断向不连续点处收缩,而且衰减加快,因此在求解Harmuth解的数值曲线时,若积分区间取为理想无限大,则可以预见相同计算精度下两种方法的电场解的数值曲线是一致的。
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In the present work,the existence and uniqueness results aboutperiodic boundary value problems for different kinds of the nonlin-ear periodically perturbed nonconservative systems are establishedthrough the discretization technique,under suitable assumptions,by using global inverse function theorem and result about the ex-istence and uniqueness of periodic solution for nonhomogeneouslyfirst order linear periodic boundary value problem.
本文的第一章概述了在讨论原问题解的存在唯一性过程中以及构造和分析相关的数值求解方法时将要用到的全局反函数定理、有关矩阵特征值的若干重要引理、线性常微分方程非齐次周期问题解的存在唯一性定理和单参数影射方法及有关结论,并简单回顾了已有的证明非线性微分方程周期边值问题解的存在唯一性的方法,其中包括谱理论、最大最小化形式方法、摄动技术和全局反函数理论方法,最后,介绍了两类数值求解非线性微分方程问题的方法。
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And the author integrated the ship maneuvering, numeric analysis, the solution method for inverse problems and the control theory, and made the decision that the regularization method is adopted to obtain the coefficients of ship maneuvering, and that immune genetic algorithm is used as the numerical algorithm of the regularization method.
通过分析,综合船舶操纵性,数值分析,反问题的数值解法和控制理论等相关知识,决定采用正则化方法反演船舶操纵运动相互干扰系数,用结合免疫遗传算法的正则化方法作为数值解法来建立船舶操纵运动灰箱模型。
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This paper brief introduce numerical method of algebraic equation,points out their shortcoming of missing multiple root and put forward one new kind of method--multiple derivation numerical method.
本文对通常代数方程的数值计算方法特点进行了简介并给以分析,指出了这些解法无法得出重根数的缺陷,提出了一种新的解决方法———多次求导数值计算法,使得数值计算法更加清晰、明了,且可得出重根数。
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Comparison with the classical fourth-order LWC scheme shows that the NAD-type methods have many advantages. They can generate clearer snapshots of wave fields without any visible dispersion. To obtain the results without any numerical dispersion, the time cost by the LWC schemes is about 559, 1222 and 1955 times of that taken by ONADM, RNADM and SNADM, receptively. Besides, the storage space of ONADM is roughly about 3.3% of that needed for the fourth-order LWC scheme, while of RNADM and SNADM is about 5.8‰.
和经典的4阶LWC格式相比:NAD类算法在粗网格下可以有效的压制数值频散,得到清楚的波场快照;在达到消除数值频散要求时,4阶LWC格式的计算时间是ONADM计算时间的559倍,是RNADM方法计算时间的1222倍,是SNADM方法计算时间的1955倍;而此时ONADM方法存储量只有4阶LWC存储量的3.3%,RNADM方法和SNADM方法的存储量只有4阶LWC格式存储量的5.8‰。
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In this thesis, the methods for solving eigenvalue problems and conventional reanalysis methods are studied firstly. Then, a new reanalysis method for real modal reanalysis of structures subjected to topological modification with added degrees of freedom is presented. This method is composed of the single step perturbation method and the Rayleigh-quotient iteration. The numerical examples show that this reanalysis method is very effective and high-quality.
本文首先在对常规的特征值数值求解方法和重分析方法研究的基础上,针对实模态的自由度增加的结构拓扑修改重分析,提出了一种新方法,该方法由于结合了单步摄动法和瑞利商逆迭代法两者的优点,应当是一种比较理想的重分析方法,算例的数值结果也有力的验证了该方法确实是一种高精度、十分有效的实模态重分析方法。
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The primary studying works and characteristics:1 To summarize reinforcing theory of cement mixing pile composite foundation2 To analyze the primary mechanics characters and changing rules of cement mixing pile, based on analysis of test data both indoor and outdoor.3 To discuss siding frictional resistance, ending resistance, ultimate bearing capacity of simple mixing pile and effectiveness factor of grouped piles, loading ratio of soil between piles under cushion cap of grouped piles and stress ratio of pile and soil and so on, and use many computation method and experimentation method to ensure bearing capacity of mixing piles composite foundation.4 To point out and analyze eight sides flaws and problems of the bearing capacity calculation method of mixing pile compositefoundation which ensured by national and normative method/ formula.5 To apply test results of loading tests and a few settlement observation data, use gray theory to predicate ultimate bearing capacity of deep mixing piles, actual example demonstrate engaging between theoretical predicted value and actual value.6 To apply groovy layerwise summation method to discuss entity piles method, double foundation method, equivalent layerwise summation method and consolidation theoretical method and so on, especially by combination of engineering example, use FEM to calculate or discuss the settlement and changing rules of composite foundation.7 To discuss problems of critical length of composite foundation by combination of engineering example and numerical analysis method, and analyze the contrast of critical length between simple pile load and most area load of composite foundation, not only critical length of composite foundation is relative to modulus ratio between piles and soil, but also upside load distribution area of composite foundation.
主要的研究工作与特色为:(1)总结了水泥搅拌桩复合地基的加固原理;(2)在对室内外试验资料进行统计分析的基础上,系统分析了搅拌桩水泥土的主要力学特性及其变化规律;(3)探讨了搅拌单桩的侧摩阻力、端阻力、极限承载力及群桩效率系数、群桩承台下桩间土荷载分担比及桩土应力比等,提出用多种计算方法并结合试验方法来综合确定搅拌桩复合地基的承载力;(4)明确指出和分析了按国家有关规范的方法确定搅拌桩复合地基承载力所存在的八个方面的缺陷与问题;(5)利用过去没有加载至破坏阶段的载荷试验成果和较少的沉降观测数据,尝试了用灰色理论预测深层搅拌桩的极限承载力,实例表明理论预测值与实测值吻合较好;(6)在常规分层总和法的基础上,探讨了复合地基沉降计算的实体墩基法、双层地基法、等效作用分层总和法、固结理论法等,特别是结合工程实例,用有限元数值计算等方法计算和讨论了搅拌桩复合地基的沉降及其变化规律;(7)结合工程实例,用数值分析方法探讨了复合地基临界桩长的问题,指出和分析了单桩荷载下的临界桩长与复合地基大面积荷载下的临界桩长存在很大的差别,复合地基的临界桩长不仅与桩土模量比有关,而且与复合地基上部荷载分布面积有关。
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The geology research of carbonate reservoirs in Ordovician of Tahe oilfield showed that many large dissolved vugs and fractures were developed. The spread of the reservoir take on a very heterogeneous state. And the typical fractured-vuggy reservoirs was formed. According to the combination of the various spaces, the formation was divided into vuggy formation, fractured-vuggy formation and fractured formation. The research showed that development of the vug is relevant to the its position on the structure, the fractures, the water surface and the weathering surface. Multi-phase charge and recharge of the oil in the reservoirs resulted in the complexity of the fluid distribution. So the"Bottle Model"was brought forward to explain the movement of the water-oil contact. The special storage space and the complex fluid distribution lead to the unstability of the production and the complexity of the water cut. In order to explain the characteristic of the fracture-vug unit was brought forward and the basic principle and method of the partition of the fracture-vug unit was formed. The classification and evaluation of the units were performed according the reserve and energy. Based on the research of geology characteristic and the fluid flow in the reservoir the comprehensive numerical simulation plan of the fractured-vuggy reservoirs were established. Through the selection of the simulation unit, fluid flow type and parameter equivalent the triple media reservoir simulation model was established. Considering the practical application the model was resolved by the DKR decomposition conjugate grads method. Based on the fine reservoir description of Dsitrict IV of the Tahe oilfield the various space type were classified and combined together. The geology model of Unit S48 was constructed. Two typical single well model was established according to the geology and the dynamic phenomena. Finally the single well model and the Unit S48 were simulated by the triple media reservoir simulator. Via the local grid refinement and coarsening in the simulation good matchs were gained. Based on the results of the simulation the reserve distribution, percent of reserve produced in various space and the natural energy were analyzed. The fluid was storaged in the fractures and vugs mostly and more than 90% the produced oil came from the systems. The energy belonged to the active one. The results of simulation accorded with the fact and showed the validity and practicability the research and the simulator.
塔河油田奥陶系碳酸盐岩油藏的地质研究表明,其储层中发育着很多大型的溶蚀洞、缝,储层的平面展布呈现出极度的非均质性,形成了典型的缝洞型碳酸盐岩油藏,根据各种孔隙介质在储层中的组合,将储层分为了溶洞型、裂缝-溶洞型和裂缝型三类;研究表明溶洞储层的发育和构造位置、裂缝的发育、潜水面和风化面的位置等因素有关;多期充注的油气成藏模式导致了流体复杂的赋存状态,由此提出了所谓的"瓶子模型",解释生产过程中油水界面的变化;特殊的储集空间类型和流体分布特征导致油田在开发过程中表现出很大的不确定性和含水变化的复杂性,为了合理的解释油气田开发过程中的动态特征,提出了"缝洞单元"的概念,并制定了"缝洞单元"纵横向划分的基本原则和依据及划分方法,并对"缝洞单元"进行了分类和评价;基于地质特征和流体在其中流动规律的研究,提出了缝洞型碳酸盐岩油藏的数值模拟综合解决方案,通过模拟单元的选择、流动类型和参数的等效,建立了三重介质油藏三维三相数值模拟模型,采用不完全LU分解预处理共轭梯度法进行了求解;在塔河油田4区精细油藏描述的基础上,将各种类型的孔隙空间进行了归类组合,建立了S48单元的地质模型;通过对油井生产动态进行分析研究,建立了两类和油井地质、生产动态相对应的单井模型;最后应用三重介质油藏数值模拟软件对单井模型和S48单元进行了数值模拟,通过局部加密和粗化等技术模拟流体流动规律,取得了很好的拟合效果;结合数值模拟结果,分析了各种介质中的储量分布、储量产出的百分比以及地层的能量,认为塔河油田缝洞型油藏中流体绝大多数储集于缝洞系统之中,所产出流体90%以上也来自于缝洞系统,其底水能量属于较充足的类型;模拟结果和油田实际情况符合较好,说明了地质研究和油藏数值模拟研究的正确性。
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The geology research of carbonate reservoirs in Ordovician of Tahe oilfield showed that many large dissolved vugs and fractures were developed. The spread of the reservoir take on a very heterogeneous state. And the typical fractured-vuggy reservoirs was formed. According to the combination of the various spaces, the formation was divided into vuggy formation, fractured-vuggy formation and fractured formation. The research showed that development of the vug is relevant to the its position on the structure, the fractures, the water surface and the weathering surface. Multi-phase charge and recharge of the oil in the reservoirs resulted in the complexity of the fluid distribution. So the"Bottle Model"was brought forward to explain the movement of the water-oil contact. The special storage space and the complex fluid distribution lead to the unstability of the production and the complexity of the water cut. In order to explain the characteristic of the fracture-vug unit was brought forward and the basic principle and method of the partition of the fracture-vug unit was formed. The classification and evaluation of the units were performed according the reserve and energy. Based on the research of geology characteristic and the fluid flow in the reservoir the comprehensive numerical simulation plan of the fractured-vuggy reservoirs were established. Through the selection of the simulation unit, fluid flow type and parameter equivalent the triple media reservoir simulation model was established. Considering the practical application the model was resolved by the DKR decomposition conjugate grads method. Based on the fine reservoir description of Dsitrict IV of the Tahe oilfield the various space type were classified and combined together. The geology model of Unit S48 was constructed. Two typical single well model was established according to the geology and the dynamic phenomena. Finally the single well model and the Unit S48 were simulated by the triple media reservoir simulator. Via the local grid refinement and coarsening in the simulation good matchs were gained. Based on the results of the simulation the reserve distribution, percent of reserve produced in various space and the natural energy were analyzed. The fluid was storaged in the fractures and vugs mostly and more than 90% the produced oil came from the systems. The energy belonged to the active one. The results of simulation accorded with the fact and showed the validity and practicability the research and the simulator.
塔河油田奥陶系碳酸盐岩油藏的地质研究表明,其储层中发育着很多大型的溶蚀洞、缝,储层的平面展布呈现出极度的非均质性,形成了典型的缝洞型碳酸盐岩油藏,根据各种孔隙介质在储层中的组合,将储层分为了溶洞型、裂缝-溶洞型和裂缝型三类;研究表明溶洞储层的发育和构造位置、裂缝的发育、潜水面和风化面的位置等因素有关;多期充注的油气成藏模式导致了流体复杂的赋存状态,由此提出了所谓的&瓶子模型&,解释生产过程中油水界面的变化;特殊的储集空间类型和流体分布特征导致油田在开发过程中表现出很大的不确定性和含水变化的复杂性,为了合理的解释油气田开发过程中的动态特征,提出了&缝洞单元&的概念,并制定了&缝洞单元&纵横向划分的基本原则和依据及划分方法,并对&缝洞单元&进行了分类和评价;基于地质特征和流体在其中流动规律的研究,提出了缝洞型碳酸盐岩油藏的数值模拟综合解决方案,通过模拟单元的选择、流动类型和参数的等效,建立了三重介质油藏三维三相数值模拟模型,采用不完全LU分解预处理共轭梯度法进行了求解;在塔河油田4区精细油藏描述的基础上,将各种类型的孔隙空间进行了归类组合,建立了S48单元的地质模型;通过对油井生产动态进行分析研究,建立了两类和油井地质、生产动态相对应的单井模型;最后应用三重介质油藏数值模拟软件对单井模型和S48单元进行了数值模拟,通过局部加密和粗化等技术模拟流体流动规律,取得了很好的拟合效果;结合数值模拟结果,分析了各种介质中的储量分布、储量产出的百分比以及地层的能量,认为塔河油田缝洞型油藏中流体绝大多数储集于缝洞系统之中,所产出流体90%以上也来自于缝洞系统,其底水能量属于较充足的类型;模拟结果和油田实际情况符合较好,说明了地质研究和油藏数值模拟研究的正确性。
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The results of our numerical simulation show that the numerical method applied in our paper is practical, the calculation results match the actual situation properly; the digital images from numerical simulation possess a positive significance in understanding and improving the heat flow distribution of the meat dry kiln. The proposed method provides a feasible approach to analyze and improve the flow field of meat dry kiln with numerical simulation.
数值计算的结果表明:本文所用的数值计算方法是可行的,基本符合实际情况;所得计算结果分析图像对了解干燥窑中流场的分布情况和如何改善干燥窑流场分布具有积极的参考意义,本文所提出的方法为采用数值计算方法分析改善干燥窑流场问题提供了一种可行的手段。
- 推荐网络例句
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We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.
索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称;三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起,称之为挽歌体诗人或者史诗诗人,他们被称为诗人,似乎只是因为遵守格律写作,而非他们作品的模仿本质。
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The relationship between communicative competence and grammar teaching should be that of the ends and the means.
交际能力和语法的关系应该是目标与途径的关系。
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This is not paper type of business,it's people business,with such huge money involved.
这不是纸上谈兵式的交易,这是人与人的业务,而且涉及金额巨大。