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1.
Based on the second gradient operator and corresponding integral theorems such as the second divergence theorem, the second gradient theorem, the second curl theorem, and the second circulation theorem on curved surfaces, a few new scalar differential operators are defined and a series of integral transformations are derived. Interesting transformations between the average curvature and the Gauss curvature are presented. Various conserved integrals related to the Gauss curvature and the second fundamental tensor are disclosed. The important applications of the results in disciplines such as the geometry, physics, mechanics, and biology are briefly discussed.  相似文献   

2.
Introduction Yin et al.[1, 2] described a gradient operator ? derived from biomembranes with “the second gradient operator” defined on a curved surface. Yin[2] then used the second gradient operator to develop a set of integral theorems named “the second category of integral theorems” on curved surfaces, including the second divergence theorem, the second gradient theorem, the second curl theorem, and the second circulation theorem: d d ?2 dA C A? A = ?K∫∫ ∫ ∫∫i v si Li v A iv (1) …  相似文献   

3.
K-quasi-additive fuzzy integrals of set-valued mappings   总被引:9,自引:0,他引:9  
We first define the quasi-addition and quasi-multiplication operations by introducing the inductive operator, and then, in the K-quasi-additive fuzzy measure space, we establish the K-quasi-additive fuzzy integral of a generally measurable set-valued mapping. Applying the integral transformation theorem, some basic properties of the K-quasi-additive fuzzy integrals with respect to this kind of set-valued mapping are studied. Finally, the generalized monotone convergence theorems of this kind of fuzzy integrals are obtained.  相似文献   

4.
In this paper,we provide a generalized block-by-block method for constructing block-by-block systems to solve the system of linear Volterra integral equations of the second kind,and then deduce some of the special cases.Compared with the expansion method and He’s homotopy perturbation method,respectively,numerical examples are given to certify the effectiveness of the method.The results show that the block-by-block method is very effective,simple,and of high accuracy in solving the system of linear Volterra integral equations of the second kind.  相似文献   

5.
In this paper,we concern ourselves with the existence of positive solutions for a type of integral boundary value problem of fractional differential equations with the fractional order linear derivative operator. By using the fixed point theorem in cone,the existence of positive solutions for the boundary value problem is obtained. Some examples are also presented to illustrate the application of our main results.  相似文献   

6.
The flowing mechanism of a low permeability gas reservoir is different from a conventional gas reservoir,especially for that with higher irreducible water saturation the threshold pressure gradient exists. At present,in all the deliverability equation,the additional pressure drop caused by the threshold pressure gradient is viewed as constant,but this method has big error in the practical application. Based on the non-Darcy steady flow equation,the limited integral of the additional pressure drop is solved in this paper and it is realized that the additional pressure drop is not a constant but has something to do with production data,and a new deliverability equation is derived,with the relevant processing method for modified isochronal test data. The new deliverability equation turns out to be practical through onsite application.  相似文献   

7.
Angel-related element belongs to the family of miniature inverted-repeat transposable elements (MITEs). In this paper we report the identification of an Angel- related element in the series Leuciscini of cyprinid fishes, which is located in the second intron of the growth hormone (GH) gene. We have also found that this element is absent in orthologous locus in the series Barbini of cyprinid fishes, that provides new evidence for the monophyly of the series Leuciscini. The insertion of Angel -related element into the GH gene might take place in the common ancestor of the series Leuciscini after its divergence from the series Barbini. The high sequence divergence and relatively broad species distribution of Angel-related elements implies that they might be ancient transposons which appeared about 26 million years ago.  相似文献   

8.
Angel-related element belongs to the family of miniature inverted-repeat transposable elements (MITEs). In this paper we report the identification of an Angel-related element in the series Leuciscini of cyprinid fishes, which is located in the second intron of the growth hormone (GH) gene. We have also found that this element is absent in orthologous locus in the series Barbini of cyprinid fishes, that provides new evidence for the monophyly of the series Leuciscini. The insertion of Angel-related element into the GH gene might take place in the common ancestor of the series Leuciscini after its divergence from the series Barbini. The high sequence divergence and relatively broad species distribution of Angel-related elements implies that they might be ancient transposons which appeared about 26 million years ago.  相似文献   

9.
To make the geometrical basis for soft matters with curved surfaces such as biomembranes as simple as possible, a symmetrical analytical system was developed in conventional differential geometry. The conventional second fundamental tensor is replaced by the so-called conjugate fundamental tensor. Because the differential properties of the conjugate fundamental tensor and the first fundamental tensor are symmetrical, the symmetrical analytical system including the symmetrical differential operators, symmetrical differential characteristics, and symmetrical integral theorems for tensor fields defined on curved surfaces can be constructed. From the symmetrical analytical system, the symmetrical integral theorems for mean curvature and Gauss curvature, with which the symmetrical Minkowski integral formulas are easily deduced just as special cases, can be derived. The applications of this symmetrical analytical system to biology not only display its simplicity and beauty, but also show its powers in depicting the symmetrical patterns of networks of biomembrane nanotubes. All these symmetrical patterns in soft matters should be just the reasonable and natural results of the symmetrical analytical system.  相似文献   

10.
Image segmentation based on Mumford-Shah functional   总被引:2,自引:0,他引:2  
In this paper, the authors propose a new model for active contours segmentation in a given image, based on Mumford-Shah functional (Mumford and Shah, 1989). The model is composed of a system of differential and integral equations. By the experimental results we can keep the advantages of Chan and Vese‘s model (Chan and Vese, 2001 ) and avoid the regularization for Dirac function. More importantly, in theory we prove that the system has a unique viscosity solution.  相似文献   

11.
本文给出了多连域内Cauchy积分定理的两种新证法,一是以双连域内Cauchy积分定理为基础,并用数学归纳法加以证明;二是把问题转化为单连域的情形,并且应用单连城内的Cauchy积分定理,在此基础上,证明多连域内Cauchy积分定理,这两种新证法比通常的证法简明,推导颇为简捷,方法也易于掌握。  相似文献   

12.
讨论变分法中含哈密顿算子即梯度、散度和旋度的并联式张量的泛函变分问题.根据n阶张量并联式内积和串联式内积运算规则,给出张量泛函变分问题的基本引理.提出并证明含哈密顿算子的张量泛函变分问题的定理;通过直接对张量的梯度、散度和旋度进行变分,得到欧拉方程和相应的自然边界条件.通过若干算例验证了欧拉方程的正确性.扩展伴随算子的内涵,提出右伴随算子的概念,讨论伴随算子或自伴算子与梯度、散度和旋度算子的关系,指出所讨论的泛函变分问题实质上是符合伴随算子或自伴算子定义的运算.   相似文献   

13.
首先指出数学分析中反映二重积分和第二类平面线积分联系的Green公式可以看成是散度定理的一种特殊情形,然后利用散度定理给出广义分部积分公式、第一Green公式和第二Green公式的证明.  相似文献   

14.
研究了四阶一致椭圆型算子第二特征值的上界估计.利用试验函数、Rayleigh定理、分部积分、Schwartz不等式和Young不等式等估计方法与技巧,获得了用第一特征值来估计第二特征值的上界的不等式,上界与区域的几何度量无关.  相似文献   

15.
本文考虑Banach空间中非线性积分 -微分方程的周期边值问题 ,利用抽象锥、推广了的比较定理及非线性算子的不动点定理 ,构造出两个单调迭代序列 ,证明了Banach空间中非线性积分 -微分方程具有周期边值的最小解、最大解存在定理。  相似文献   

16.
本文引入序Lipschitz条件 ,无需考虑算子的紧性 ,连续性或凹凸性 ,利用锥理论和单调迭代技巧 ,得到了方程A(x ,x) =x解的存在唯一性 .将所获得的结果应用于无界域上Hammerstein非线性积分方程 ,得到了新的结论 .  相似文献   

17.
针对长江水污染问题中污染水层与未污染水层均为受限制含水层的情况,利用Darcy定理和质量守恒定律建立了一个三维耦合抛物线方程组的数学模型;基于偏微分方程的基本理论,采用积分的方式将三维数学模型降成二维数学模型,通过构造截断函数和一个满足一致性假设的算子,利用Schauder定理证明了该二维数学模型解的存在性,从而证明了长江水污染含水层与未污染含水层之间临界面的可行性,为研究长江水污染问题提供了理论依据。  相似文献   

18.
首先在Banach空间中考虑一类非线性Volterra型积分方程的逼近解与精确解之间的关系,由此并通过比较定理在紧型条件下获得方程解的存在性结果.由于非线性项中含有非线性积分算子,相对于线性积分算子,所得结论推广并丰富了已有献的一些结果.  相似文献   

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