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A two-grid algorithm based on Newton iteration for the stream function form of the Navier-Stokes equations 被引量:1
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作者 SHAO Xin-ping HAN Dan-fu 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2011年第3期368-378,共11页
In this paper, we propose a two-grid algorithm for solving the stream function formulation of the stationary Navies-Stokes equations. The algorithm is constructed by reducing the original system to one small, nonlinea... In this paper, we propose a two-grid algorithm for solving the stream function formulation of the stationary Navies-Stokes equations. The algorithm is constructed by reducing the original system to one small, nonlinear system on the coarse mesh space and two similar linear systems (with same stiffness matrix but different right-hand side) on the fine mesh space. The convergence analysis and error estimation of the algorithm are given for the case of conforming elements. Furthermore, the Mgorithm produces a numerical solution with the optimal asymptotic H^2-error. Finally, we give a numerical illustration to demonstrate the effectiveness of the two-grid algorithm for solving the Navier-Stokes equations. 展开更多
关键词 Two-grid algorithm Navier-Stokes equations Stream function form Reynolds number Newton iteration.
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RESIDUAL A POSTERIORI ERROR ESTIMATE TWO-GRID METHODS FOR THE STEADY (NAVIER-STOKES) EQUATION WITH STREAM FUNCTION FORM
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作者 任春风 马逸尘 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2004年第5期546-559,共14页
Residual based on a posteriori error estimates for conforming finite element solutions of incompressible Navier-Stokes equations with stream function form which were computed with seven recently proposed two-level met... Residual based on a posteriori error estimates for conforming finite element solutions of incompressible Navier-Stokes equations with stream function form which were computed with seven recently proposed two-level method were derived. The posteriori error estimates contained additional terms in comparison to the error estimates for the solution obtained by the standard finite element method. The importance of these additional terms in the error estimates was investigated by studying their asymptotic behavior. For optimal scaled meshes, these bounds are not of higher order than of convergence of discrete solution. 展开更多
关键词 two-level method Navier-Stokes equation residual a posteriori error estimate finite element method stream function form
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Neutral Pion Electromagnetic Form Factor as a Bound System of 3 + 1 Dimensional QCD
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作者 Teruo Kurai 《Journal of Modern Physics》 2024年第7期1036-1044,共9页
We investigate a neutral pion electromagnetic form factor in momentum space and obtain Gaussian-like function for it. The characteristic form of our neutral pion electromagnetic form factor is consistent with the resu... We investigate a neutral pion electromagnetic form factor in momentum space and obtain Gaussian-like function for it. The characteristic form of our neutral pion electromagnetic form factor is consistent with the results published by Jefferson Lab Hall A Collaboration. . 展开更多
关键词 Neutral Pion Electromagnetic form Factor Gaussian-Like function
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Comprehensive form of solution for Lamb's dynamic problem expressed by Green's functions 被引量:1
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作者 丁伯阳 徐庭 +1 位作者 陈军 欧阳明 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2013年第12期1543-1552,共10页
By the analysis for the vectors of a wave field in the cylindrical coordinate and Sommerfeld's identity as well as Green's functions of Stokes' solution pertaining the conventional elastic dynamic equation, the res... By the analysis for the vectors of a wave field in the cylindrical coordinate and Sommerfeld's identity as well as Green's functions of Stokes' solution pertaining the conventional elastic dynamic equation, the results of Green's function in an infinite space of an axisymmetric coordinate are shown in this paper. After employing a supplementary influence field and the boundary conditions in the free surface of a senti-space, the authors obtain the solutions of Green's function for Lamb's dynamic problem. Besides, the vertical displacement uzz and the radial displacement urz can match Lamb's previous results, and the solutions of the linear expansion source u^r and the linear torsional source uee are also given in the paper. The authors reveal that Green's function of Stokes' solution in the semi-space is a comprehensive form of solution expressing the dynamic Lamb's problem for various situations. It may benefit the investigation of deepening and development of Lamb's problems and solution for pertinent dynamic problems conveniently. 展开更多
关键词 Lamb's problem Green's function comprehensive form of solution
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Multi-group pin power reconstruction method based on colorset form functions 被引量:1
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作者 HUANG Hao 《Nuclear Science and Techniques》 SCIE CAS CSCD 2009年第1期60-64,共5页
A multi-group pin power reconstruction method that fully exploits nodal information obtained from global coarse mesh solution has been developed.It expands the intra-nodal flux distributions into nonseparable semi-ana... A multi-group pin power reconstruction method that fully exploits nodal information obtained from global coarse mesh solution has been developed.It expands the intra-nodal flux distributions into nonseparable semi-analytic basis functions,and a colorset based form function generating method is proposed,which can accurately model the spectral interaction occurring at assembly interface.To demonstrate its accuracy and applicability to realistic problems, the new method is tested against two benchmark problems,including a mixed-oxide fuel problem.The results show that the new method is comparable in accuracy to fine-mesh methods. 展开更多
关键词 群组管理 LWR 二维多群辐射 输运过程 原子核
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A FORM FUNCTION METHOD FOR FORM FINDING OF TENSION STRUCTURE
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作者 孙宗光 赵俭斌 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第11期1277-1281,共5页
A new form function involving parameters Pi is presented. On the basis of the form function, an initial form of tension structure was Sound by interpolating through the control points on boundary of the structure. The... A new form function involving parameters Pi is presented. On the basis of the form function, an initial form of tension structure was Sound by interpolating through the control points on boundary of the structure. The form function can be controlled by changing beta (1) according to the pre-tension and the boundary of the structure. The final form of a tension structure should be an equilibrium system under the pretension. To examine the nature of the initial form, the FEM was used. Many examples show that the initial form gives a very ideal result for equal or unequal pre-tension in two directions of the structure. In general cases, there is little difference between the initial form and the final one. 展开更多
关键词 tension structure form finding form function
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A modeling approach for fuzzy programming with echelon form membership functions
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作者 WEN Bo LI HongGuang CHEN XiaoChun 《北京化工大学学报(自然科学版)》 CAS CSCD 北大核心 2018年第1期78-83,共6页
In order to solve fuzzy mathematical programming with soft constraints,the initial models must first be converted into crisp models.Membership functions are employed to describe the fuzzy right-hand side parameters ne... In order to solve fuzzy mathematical programming with soft constraints,the initial models must first be converted into crisp models.Membership functions are employed to describe the fuzzy right-hand side parameters needed to achieve this conversion.In some cases,echelon form membership functions(EFMFs)are required to depict the actual fuzzy situation.However,due to their discrete properties,fuzzy programming problems with such membership functions cannot be modeled by traditional methods.Motivated by these challenges,this paper introduces a novel absolute value representation modeling approach to formulate fuzzy programming using EFMFs.This approach can translate a discrete model to a continuous one which can then be easily solved.Finally,by means of a numerical example,the effectiveness of our new approach is demonstrated. 展开更多
关键词 echelon form membership function fuzzy right-hand side absolute value representation
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Form and Function——An Overview
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作者 李艳 《海外英语》 2012年第18期228-229,共2页
Long before,the research of form has already entered its heyday,but the study of function is a somewhat new branch of language study.This essay is an attempt to take a brief look at the most significant distinction be... Long before,the research of form has already entered its heyday,but the study of function is a somewhat new branch of language study.This essay is an attempt to take a brief look at the most significant distinction between"form and function",and then aims at making clear the definition of"form and function"in discourse analysis. 展开更多
关键词 form function DISCOURSE ANALYSIS
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Grand Zero Density Estimates of L-functions Associated with Cusp Forms
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作者 LI Ying-jie 《Chinese Quarterly Journal of Mathematics》 CSCD 2012年第1期79-86,共8页
In this paper a zero-density estimate of the large sieve type is given for the automorphic L-function L f (s,χ),where f is a holomorphic cusp form and χ a Dirichlet character of mod q.
关键词 zero density L-function cusp form
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Plasma spray forming of functionally graded materials mould
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作者 赵紫玉 方建成 李洪友 《中国有色金属学会会刊:英文版》 CSCD 2005年第2期427-431,共5页
A new technology of functionally graded materials(FGM) mould fabricated by plasma spraying and arc spraying was developed. According to applied characteristic of plastic mould, the reasonable coatings of FGM were desi... A new technology of functionally graded materials(FGM) mould fabricated by plasma spraying and arc spraying was developed. According to applied characteristic of plastic mould, the reasonable coatings of FGM were designed and their microstructures were analyzed. At the same time, some key problems were solved including spray mould fabricating, FGM forming and demoulding, etc. The results show that the service performance of the FGM mould is much more excellent than the one composed of the traditional materials, and the life span can also be greatly increased. The technology will have a significant influence on materials development in mould industry. 展开更多
关键词 溅射成型 功能分级材料 塑料模具 等离子体
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FORM AND FUNCTION OF EGYPTIAN BREAD MOLDS
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作者 Sheldon Lee Gosline 《Journal of Ancient Civilizations》 1999年第0期27-44,共18页
关键词 VI IV OK form AND function OF EGYPTIAN BREAD MOLDS
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TRANSFORMATION OF SYMMETRIC MULTIPLICATIVE FUNCTIONALS
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作者 AnHong YingJiangang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第4期451-457,共7页
In the present paper the transformation of symmetric Markov processes by symmetric martingale multiplicative functionals is studied and the corresponding Dirichlet form is formulated.
关键词 Markov processes Dirichlet forms multiplicative functional.
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A Sociolinguistic Study of Husband-to-Wife Address Forms and Functions in Rural Jordanian Community
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作者 Awni Shati M. Etaywe 《宏观语言学》 2017年第2期84-117,共34页
关键词 语言学 民族文化 文化传统 语用学
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论叙述者的功能与形态:“框架”与“人格化”
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作者 赵毅衡 孙少文 《内蒙古社会科学》 北大核心 2024年第4期39-45,共7页
叙述的生成和传达是叙述者独有的底线功能。在叙述生成时,各要素的选择与组合依据的是已有的文化程式、规定和媒介属性。这些程式、规定和媒介构成叙述文本的框架,叙述者也随之形成。此阶段的叙述者为“框架叙述者”。在传达叙述时,传... 叙述的生成和传达是叙述者独有的底线功能。在叙述生成时,各要素的选择与组合依据的是已有的文化程式、规定和媒介属性。这些程式、规定和媒介构成叙述文本的框架,叙述者也随之形成。此阶段的叙述者为“框架叙述者”。在传达叙述时,传达意向使叙述者呈现出不同程度的人格化,人格化因此也作为叙述者在叙述文本中显身的方式,此阶段的叙述者为“人格化叙述者”。“框架—人格”叙述者观全面把握了叙述者的功能和形态。受述者作为叙述者传达的对象而存在。依据叙述者人格化程度可以得出叙述者向受述者传达叙述的两种基本方式。 展开更多
关键词 “框架—人格”叙述者 功能 形态 受述者
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松花江干流造床水沙动力及河相关系的探究
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作者 张幸农 假冬冬 陈长英 《泥沙研究》 CAS CSCD 北大核心 2024年第4期47-52,66,共7页
在分析松花江干流河道特性的基础上,基于实测资料,探究了造床水沙动力条件和河相关系。结果表明,枯水期和涨水期水流的造床作用不甚明显,主汛期水流是主要造床动力,退水期水流也具有一定造床作用;通过对比河道特征流量和计算得到的造床... 在分析松花江干流河道特性的基础上,基于实测资料,探究了造床水沙动力条件和河相关系。结果表明,枯水期和涨水期水流的造床作用不甚明显,主汛期水流是主要造床动力,退水期水流也具有一定造床作用;通过对比河道特征流量和计算得到的造床流量,说明常年洪水的造床作用依然十分有限,只有3~5年一遇的较大洪水才会形成较为明显的造床作用;河道河床呈现宽浅型,主槽相对窄小,洪漫滩地宽阔,中游段主槽河相关系系数√B/H在2~5之间,上游段和下游段大多超过5;基于河床最小活动性假设,得到河相关系与流量及含沙量之间的关系式,采用造床流量针对主槽进行检验,公式相符性较好。 展开更多
关键词 松花江 水流动力 造床作用 河相关系
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医用X射线防护材料的研究进展
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作者 李伟 魏乐倩 +4 位作者 王泽宇 王莎莎 毛吉富 王富军 王璐 《产业用纺织品》 2024年第6期11-18,31,共9页
介绍了医用X射线与生物系统的相互作用机理及物理防护原理,分析了具有医用X射线屏蔽能力的柔性复合材料的研究进展。探讨了铅、铋、钨等防X射线功能颗粒及聚合物基材的性能特征,总结了涂层法、溶胶-凝胶法、纺丝法等成型方法的优缺点。... 介绍了医用X射线与生物系统的相互作用机理及物理防护原理,分析了具有医用X射线屏蔽能力的柔性复合材料的研究进展。探讨了铅、铋、钨等防X射线功能颗粒及聚合物基材的性能特征,总结了涂层法、溶胶-凝胶法、纺丝法等成型方法的优缺点。研究表明,现有X射线防护材料在提升防护效果和使用便捷性方面具有重要意义,但面临性能优化和成本控制方面的挑战。未来研究应聚焦新型功能颗粒的开发、复合材料结构设计的优化及环保高效屏蔽材料的探索等方面,以进一步提升医用X射线防护材料的性能,拓宽其应用前景。 展开更多
关键词 X射线 防护材料 屏蔽效率 医用 功能粒子 成型方法
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Functional Enrichment of Utopian Distribution of Plant Life-Forms
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作者 James N. Furze Quanmin Zhu +1 位作者 Feng Qiao Jennifer Hill 《American Journal of Plant Sciences》 2013年第12期37-48,共12页
Adaptive fuzzy neural inference systems are used to illustrate the primary nodal number of plant life-forms. Categorization of two candidate areas is carried out using the water-energy dynamic (for Ecuador, South Amer... Adaptive fuzzy neural inference systems are used to illustrate the primary nodal number of plant life-forms. Categorization of two candidate areas is carried out using the water-energy dynamic (for Ecuador, South America) and Macedonia, Southern Europe), within which the life-form spectra are distributed. Genetic optimization methods are used to expand the primary nodal number to the complete number of life-form categories. The distribution of the elements exhibits a stochastic, binomial distribution and the utopia line and curve are summarized which enhance accuracy of the climatic data and of the consequent numbers of plant species occurrences. Expansion of the distribution of each life-form category is approximated within the Z utopia hyperplane with use of the functional approximation algorithm. This process gives additional structure and informative value to the Z plane, enhancing our ability to make informed policy decisions concerning species and ecosystem conservation. 展开更多
关键词 Adaptive Neural Fuzzy Inference System PLANT LIFE-form Genetic Optimization Stochastic UTOPIA functionAL Approximation Algorithm
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n 的多项式为系数的幂级数和函数注记
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作者 张奇业 王创坤 徐宇鑫 《大学数学》 2024年第1期99-107,共9页
研究了以n的多项式为系数的幂级数的和函数的求解问题,给出了这类幂级数和函数的一种求解方法,并得到了其和函数的通用计算公式,通过实例验证了公式的正确性.文中还得到了两个关于组合数的等式.
关键词 幂级数 多项式系数 和函数 通用形式 数学归纳法
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现代汉语隐性否定研究综述 被引量:1
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作者 张明辉 闫语萌 《昭通学院学报》 2024年第1期74-81,共8页
隐性否定以“无显性否定形式”和“具有否定意义”为条件,学界大体从概念界定、表达形式、语用功能以及新理论视角等方面对隐性否定加以研究。对目前的隐性否定研究成果进行梳理和总结,以求明确学界在隐性否定研究领域的现状和不足,从... 隐性否定以“无显性否定形式”和“具有否定意义”为条件,学界大体从概念界定、表达形式、语用功能以及新理论视角等方面对隐性否定加以研究。对目前的隐性否定研究成果进行梳理和总结,以求明确学界在隐性否定研究领域的现状和不足,从而确定接下来的研究方向和目标。 展开更多
关键词 隐性否定 概念界定 表达形式 语用功能 类型学 构式语法
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论经济法中的国家主体
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作者 张守文 《现代法学》 北大核心 2024年第1期121-133,共13页
经济法中的国家主体,具有不同于政府等主体的特殊性。基于经济宪法和经济法的相关规定,国家主体在经济法中具有独立地位,其经济职能的履行和经济职权的行使,应受经济宪法和经济法的约束,以体现国家理性的要求。此外,经济法中的国家主体... 经济法中的国家主体,具有不同于政府等主体的特殊性。基于经济宪法和经济法的相关规定,国家主体在经济法中具有独立地位,其经济职能的履行和经济职权的行使,应受经济宪法和经济法的约束,以体现国家理性的要求。此外,经济法中的国家主体在总体上是“现代国家”“经济国家”,并在经济法的各个部门法中具体体现为预算国家、税收国家、债务国家、规制国家等多种国家形态。研究经济法中的国家主体,应结合国家目的或国家目标、国家任务、国家职能、国家理性或国家理由等影响因素,分析具体的国家形态,由此有助于审视法律规定背后的法治原理和法治问题,揭示经济法制度中国家主体存续和发展的内在逻辑,并在法治框架下解决国家调制行为的合宪性、合法性问题,切实保障市场主体的合法权益。依循上述研究路径,有助于提炼经济法中的国家理论或国家主体理论,深化经济法学主体理论乃至整体总论的研究,推动经济法治和国家治理体系的完善。 展开更多
关键词 经济法 国家主体 国家职能 国家理性 国家形态
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