共查询到20条相似文献,搜索用时 78 毫秒
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在本文中,研究了注入轴对称模腔非牛顿流体非定常流动.本文的第二部份研究了上随体Maxwell流体管内热流动.对于注入模腔流动.其本构方程采用幂律流体模型方程.为了避免在表现粘度中温度关系引起的非线性.引进了一特征粘度的概念.描述本力学过程的基本方程是,本构方程、定常状态的运动方程、非定常能量方程及连续方程.该方程组在空间是二维问题,在数学上是三维问题.采用分裂差分格式求得本方程组的数值解答.分裂法曾成功应用于求解牛顿流体问题.在本文中,首次将分裂法成功地应用解决非牛顿流体流动问题.对于圆管内热流,给出了差分格式,使基本方程组化为一个三对角方程组.其结果,给出了不同时刻的模腔内二维温度分布. 相似文献
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在G.H.Lin与M.Fukushima思想的启发下,针对一般形式的互补约束问题,本文构造了一种新的松弛规划.通过修正和简化G.H.Lin与M.Fukushima的证明方法,在比其更弱的假设条件下获得了该松弛规划的收敛性质. 相似文献
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人文素质教育最重要的功能是教人做人.数学教育必须以人性完善为终级目标,这是人文主义教育观坚持的核心观点.在数学教学中,应重视把人文知识或人文精神与数学内容融合在一起,浸润在数学知识中.渗透人文素质教育,关键在教师. 相似文献
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本文研究向量优化问题在严有效解意义下的最优性条件.在局部凸Hausdorff拓扑线性空间中.在近似锥一次类凸假设下,利用凸集分离定理得到了最优性必要条件.借助Gateaux导数引进了几种新的凸性,在新的凸性假设下得到了最优性充分条件. 相似文献
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有效课堂教学的核心应该是“议”.“议”是课堂教学中对话的主要方式.教育走向对话又是教育发展的总趋势只有通过教师转变观念.师生共同做好课前准备.在融洽的师生情感下实施有效的课堂组织.才能使学生在课堂上真正“议”起来. 相似文献
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Optimal control of nonlinear evolution inclusions 总被引:1,自引:0,他引:1
N. S. Papageorgiou 《Journal of Optimization Theory and Applications》1990,67(2):321-354
In this paper, we study the optimal control of nonlinear evolution inclusions. First, we prove the existence of admissible trajectories and then we show that the set that they form is relatively sequentially compact and in certain cases sequentially compact in an appropriate function space. Then, with the help of a convexity hypothesis and using Cesari's approach, we solve a general Lagrange optimal control problem. After that, we drop the convexity hypothesis and pass to the relaxed system, for which we prove the existence of optimal controls, we show that it has a value equal to that of the original one, and also we prove that the original trajectories are dense in an appropriate topology to the relaxed ones. Finally, we present an example of a nonlinear parabolic optimal control that illustrates the applicability of our results.This research was supported by NSF Grant No. DMS-88-02688. 相似文献
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《Journal of Pure and Applied Algebra》2023,227(4):107249
If every subring of an integral domain is atomic, we say that the latter is hereditarily atomic. In this paper, we study hereditarily atomic domains. First, we characterize when certain direct limits of Dedekind domains are Dedekind domains in terms of atomic overrings. Then we use this characterization to determine the fields that are hereditarily atomic. On the other hand, we investigate hereditary atomicity in the context of rings of polynomials and rings of Laurent polynomials, characterizing the fields and rings whose rings of polynomials and rings of Laurent polynomials, respectively, are hereditarily atomic. As a result, we obtain two classes of hereditarily atomic domains that cannot be embedded into any hereditarily atomic field. By contrast, we show that rings of power series are never hereditarily atomic. Finally, we make some progress on the still open question of whether every subring of a hereditarily atomic domain satisfies ACCP. 相似文献
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ngela Jimnez‐Casas 《Mathematical Methods in the Applied Sciences》2019,42(18):6791-6809
Viscoelastic fluids represent a major challenge both from an engineering and from a mathematical point of view. Recently, we have shown that viscoelasticity induces chaos in closed‐loop thermosyphons even when we consider binary fluids, this is, when we consider a solute in the fluid, as water and antifreezes, for example. In this work, we consider a linear friction law, and we show that in this case with the addition of a solute to the fluid we can prove, under some conditions, chaotic asymptotic behavior for suitable geometry of the circuit and heat flux or ambient temperature functions. 相似文献
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《Annals of Pure and Applied Logic》2022,173(10):103143
This article provides an algebraic study of intermediate inquisitive and dependence logics. While these logics are usually investigated using team semantics, here we introduce an alternative algebraic semantics and we prove it is complete for all intermediate inquisitive and dependence logics. To this end, we define inquisitive and dependence algebras and we investigate their model-theoretic properties. We then focus on finite, core-generated, well-connected inquisitive and dependence algebras: we show they witness the validity of formulas true in inquisitive algebras, and of formulas true in well-connected dependence algebras. Finally, we obtain representation theorems for finite, core-generated, well-connected, inquisitive and dependence algebras and we prove some results connecting team and algebraic semantics. 相似文献
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Ye-min Chen 《应用数学学报(英文版)》2005,21(3):389-398
In this paper, we consider an inviscid, incompressible, irrotational fluid in a region of R^3 with free boundary. Motivated by [1], we find that in this particular case, we do not need the complicated energy functional in [1], instead we can use a simpler replacement and get the a priori energy estimate for a positive time, which depends only on the initial data. 相似文献
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Yuanhong Zhi 《Applied mathematics and computation》2011,218(2):233-238
In this paper we consider the boundary quenching behavior of a semilinear parabolic problem in one-dimensional space, of which the nonlinearity appears both in the source term and in the Neumann boundary condition. First we proved that the solution quenches at somewhere in some finite time. Then we assert that the quenching can only occur on the left boundary if the given initial datum is monotone. Finally we derived the upper and lower bounds for the quenching rate of the solution near the quenching time. Thus we generalized our former results. 相似文献
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艾尼·吾甫尔 《应用泛函分析学报》2011,13(3):225-245
根据近10多年来的研究成果介绍以补充变量方法建立的排队模型的动态分析.首先介绍问题的来源,其次介绍研究排队模型的泛函分析工具,然后以D.R.Cox在1955年建立的M/C/1排队模型为例介绍排队模型的适定性,解的渐近行为及排队队长等数量指标的渐近性质的研究方法.最后提出需要进一步研究的一些问题. 相似文献
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本文研究了Finsler流形中的子流形,特别地,我们给出了闵可夫斯基空间中超球面的一个特征,同时,我们讨论了闵可夫斯基空间中超曲面的第二基本形式。 相似文献
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《Expositiones Mathematicae》2021,39(4):540-565
Although planar quadratic differential systems and their applications have been studied in more than one thousand papers, we still have no complete understanding of these systems. In this paper we have two objectives.First we provide a brief bibliographical survey on the main results about quadratic systems. Here we do not consider the applications of these systems to many areas as in Physics, Chemist, Economics, Biology, …Second we characterize the new class of planar separable quadratic polynomial differential systems. For such class of systems we provide the normal forms which contain one parameter, and using the Poincaré compactification and the blow up technique, we prove that there exist 10 non-equivalent topological phase portraits in the Poincaré disc for the separable quadratic polynomial differential systems. 相似文献
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Pierre Gaillard 《Journal of Nonlinear Modeling and Analysis》2022,4(4):615-627
Here, we construct rational solutions to the KdV equation by particular polynomials. We get the solutions in terms of determinants of the order $n$ for any positive integer $n$, and we call these solutions, solutions of the order $n$. Therefore, we obtain a very efficient method to get rational solutions to the KdV equation, and we can construct explicit solutions very easily. In the following, we present some solutions until order $10$. 相似文献