共查询到20条相似文献，搜索用时 250 毫秒
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热传导方程是工程中很重要的偏微分方程,工程上利用它描述某个区域内的温度如何随时间变化,这种方程常被称作扩散方程。研究热传导方程的解具有很重要的意义。本文主要介绍解一维线性初边值热方程的分离变量法及其pdepe数值解法。结合实例讲述了如何用pdepe函数编程求解热传导方程。 相似文献
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本文在热传导方程vt-△v=0的解的性态的基础上引入热球的概念,对热传导方程的次解v（x,t）的性态作了初步研究,得到了一些结果。váv0 相似文献
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从微波处理木材中木材内部温度分布的热传导模型出发,对单向照射微波类模型进行求解,得到了方程的解析解,并讨论了此解析解的唯一性并且证明了此解析解就是真解,为微波处理木材问题提供了一定的理论依据。 相似文献
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孤子方程是非线性科学领域中很有潜力的研究课题。本文根据长水波方程的Lax对,借助长水波方程的谱问题和规范变换,构造出一个含多参数的达布变换。通过此变换,最终求得长水波方程的孤子解,并且讨论了和两种孤子解的情况。 相似文献
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针对二维热传导方程的Dirichlet初边值问题,可以采用带时间变量的基本解,利用基于单层位势的间接边界积分方程及其等价的Galerkin变分形式求解,该方法时问步长可以取得较大,能节省计算时间且计算精度高,但涉及到与时空相关的四重奇异积分的计算及指数积分函数的积分处理.文中在采用常单元离散的情况下,推导了具体实施数值计算所需的所有积分公式,完成了数值实验,验证了该方法的有效性和可行性. 相似文献
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《科技通报》2018,(10)
自然科学及社会科学发展使人们对各类复杂系统研究逐渐深入,高阶波动积分方程在材料科学、力学及电磁学等诸多领域得到成功运用。波动积分方程优势明显,其数值解尤为重要,文中提出对高阶波动积分方程整体解存在性进行研究。运用有限差分法及sinc配置逼近高阶波动方程初边值数值解,先采用有限差分法在时间方向区域上对原问题实行半离散化处理,同时在空间方向区域上运用sinc配置法获得全离散格式,将原问题转换为求线性代数方程数值解,初步分析了波动积分方程边值问题。基于方程边值数值解存在性分析,采用标准压缩映像原理对方程局部解存在性先进行分析,通过能量积分法及连续性技术获得方程整体解,同时运用边界层强度的小性控制方程数值解稳定性。 相似文献
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应用题在数学中是占比重很大的一类题型,也是数学中很重要的一部分,而应用题的解题方法也有很多种,如何找到一种简便有效的方法对解应用题有很大帮助,往往可以提高几倍的解题速度,并且提高正确率。在各种解题方法中,利用等量关系解题是一种很普遍并且很有效地方法,如果无法找到正确的等量关系,往往会给解题过程造成一定的麻烦,所以掌握利用等量关系解应用题就显得尤为重要,下面就一起探讨一下如何利用等量关系来解决数学上的各种应用题。 相似文献
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应用题在数学中是占比重很大的一类题型,也是数学中很重要的一部分,而应用题的解题方法也有很多种,如何找到一种简便有效的方法对解应用题有很大帮助,往往可以提高几倍的解题速度,并且提高正确率。在各种解题方法中,利用等量关系解题是一种很普遍并且很有效地方法,如果无法找到正确的等量关系,往往会给解题过程造成一定的麻烦,所以掌握利用等量关系解应用题就显得尤为重要,下面就一起探讨一下如何利用等量关系来解决数学上的各种应用题。 相似文献
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In this paper, we present a new method for solving unsteady heat conduction problems, which is based on a time–space boundary residual method with heat polynomials. More specifically, it employs an integral least squares criterion for the initial and boundary residuals so as to determine the unknown coefficients in a trial expansion of heat polynomials. Though it treats only one-dimensional cases, the present approach shows a good applicability for such heat conduction problems. 相似文献
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In this paper, the Bagley-Torvik equation, which has an important role in fractional calculus, is solved by generalizing the Taylor collocation method. The proposed method has a new algorithm for solving fractional differential equations. This new method has many advantages over variety of numerical approximations for solving fractional differential equations. To assess the effectiveness and preciseness of the method, results are compared with other numerical approaches. Since the Bagley-Torvik equation represents a general form of the fractional problems, its solution can give many ideas about the solution of similar problems in fractional differential equations. 相似文献
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收益法对无形资产价值评估的应用探析 总被引：2，自引：0，他引：2
在价值评估领域中，无形资产评估是一个难点，因为从无形资产所得来的收益比从有形资产所得来的收益的风险要大得多，未来收益很难预测。而收益法是运用货币时间价值的观念，将无形资产可能给企业带来的预期收益按折现率折算成现值的一种评估方法。合理预测其未来收益，是正确评估无形资产价值的关键所在。首先介绍了在收益法评估无形资产价值时所存在的两大难题一超额收益与折现率的确定，然后对解决应用难题的方法作了初步探讨。 相似文献
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用已发展的双倒易边界元和Laplace变换、反变换相结合的方法求解非傅立叶导热 ,对于一类等温进口条件下的问题 ,数值预示了热波导热、非傅立叶导热和傅立叶扩散的温度场随时间推进的不同特征 ,并且发现了温度变化前缘的推进速度存在着明显的差异 相似文献
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Two different bond-graph schemes for the modeling of circulating fluids are discussed and compared. The first uses a heuristic approach wherein the flow path is broken into segments. Each segment has separate hydraulic and thermal submodels which are linked with active bonds. The model is general enough to handle natural convective flows, heat storage, conduction, forced convective heat transfer and heat energy sources. The second method, applicable to pumped flows, uses a modal analysis approach to derive state equations for the modal temperatures, the time varying coefficients of the spatially varying mode shapes in a separation of variables solution for the temperature partial differential equation. Two examples are worked to illustrate the models. Numerical simulation results are presented using the first method and a simple analytic solution given to illustrate the second. 相似文献
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Nonlinear two-point boundary value problems have always been difficult to solve. The difficulty is compounded if the problem tends to be inherently unstable. This paper describes an algorithm for solving such sensitive boundary value problems. The procedure is based on a computational method for finding the general solution of systems of ordinary differential equations used in conjunction with the multi-point quasilinearization method of Miele. The method is demonstrated by solving Troesch's problem and a singular perturbation problem. 相似文献
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Certain inequalities are presented, related to the L2 norms of the solutions to the vibrating string and heat conduction partial differential equations; in particular, an “L2 maximum principle” is derived for the heat equation, and similar inequalities for the vibrating string problem. 相似文献
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求解任意体与环上矩阵方程是近年来矩阵方程研究的一个热点问题,特别是四元数体上矩阵方程的研究。本文利用任意体上的双矩阵分解的方法,讨论了任意体上矩阵方程AXB＋CYD=E,并给出了其一个实用的解法和它的通解表达式。 相似文献
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V.S. Kulkarni 《Journal of The Franklin Institute》2008,345(1):29-38
The present paper deals with the determination of unknown temperature and thermal stresses on the upper surface of a thick circular plate. A thick circular plate is subjected to arbitrary known interior temperature under steady state. The fixed circular edge and lower surface of the circular plate are thermally insulated. The governing heat conduction equation has been solved by using Hankel transform methods. The results are obtained in series form in terms of Bessel's functions. The results for displacement and stresses have been computed numerically and illustrated graphically. 相似文献