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1.
关于面积平均p叶函数(Ⅱ)   总被引:1,自引:0,他引:1  
董新汉 《数学进展》1993,22(5):441-448
假设f(z)=z^p(1+Σ^∞n=1an^z^nk)是△={|z|<1}内面积平均p叶的(如果必要,△={|z|<1}\(-1,0])。本文的主要结论是:(1)如果设M(r)=max|f(z)|,则(1-r)2p/kM(r)→αk≤1(r→1),αk=1的充要条件是f(z)=z^p(1-xz^k)^-2p/k,|x|=1。进一步,如果1≤k<4p,我们有|an|n^1-2p/k→αkГ(2p/k  相似文献   

2.
董新汉 《数学学报》1994,37(6):819-827
Lebedev-Milin方法是研究单叶函数的强有力的方法,本文建立了几个不等式,使用用这个方法来研究面积平均P叶函数成为可能,本文还给出一应用-Hamilton猜测的证明,利用上述不等式和方法我们还能得到一些有趣的结果。  相似文献   

3.
Cauchy-Stieltjes积分和面积平均p叶函数   总被引:1,自引:0,他引:1  
董新汉  杨密 《数学学报》2005,48(5):851-858
本文研究由Cauchy-Stieltjes积分形成的函数空间Fα.首先给出这个空间的一个等价定义,然后研究面积平均p叶函数的对数函数和这个函数空间的关系,最后对单叶函数的情形做进一步的讨论.根据这种研究,我们得到了有界单叶函数的系数增长估计,这是目前最好的结果.  相似文献   

4.
魏寒柏  胡克 《数学杂志》1995,15(4):436-440
本文研究了具有最大增长方向的面积平均P叶函数的渐近性质和最大增长方向的唯一性,推广并改进了I.M.Milin的一个结果。  相似文献   

5.
本讨论了用数学建模的方法计算心肌梗塞面积,是数学应用于医学的又一成功的实例。该方法是:在急性心肌梗塞初期,由电体表面电位分布状态得出心脏的局部电现象,建立数学模型,编写计算机程序实现梗塞面积的计算。  相似文献   

6.
杨国为 《数学进展》1993,22(3):263-269
本文在圆周平均单叶函数族中获得了类似于单叶函数的面积定理、Bazilevic定理的定理及有关的性质定理,并证实了I.M.Milin的一个猜测。  相似文献   

7.
面积问题与面积方法黄启林(华南师大附中510630)在各级各类国内外数学竟赛试题中,有不少关于面积的问题,面积问题是几何中的一个重要问题.面积方法─—利用面积知识来求解或证明命题的方法,是几何证明的重要方法,几乎所有的平面几何定理都可以用面积方法来加...  相似文献   

8.
杨国孝 《数学学报》1995,38(5):607-613
本文用单叶函数中的面积定理及Garabedian-Schiffer不等式的有关推论,给出了求多项式的填充Julia集及Mandelbrot集面积的方法及直径的上界估计,从而给A.Douady所提的有关问题一个回答。  相似文献   

9.
主要研究了Gamma商函数的对数完全单调性.通过引入一个新的辅助函数证明了一类Gamma商函数是严格对数完全单调的,对此类函数的系数进行了推广并证明了推广后的这类Gamma商函数也是严格对数完全单调的.  相似文献   

10.
将反比例函数与面积综合在一起进行考查,是目前比较热点的一类题型,充分体现了数形结合思想的具体应用,现举例加以说明.一、求图形的面积  相似文献   

11.
Integration has a wide variety of applications.Today you’ll learn to use a definite integral to find the area of a region bounded by two curves.Area is nonnegative number.When we find the area of a region above theχ-axis,the area is positive.When we find the area of a region below theχ-axis,the area is negative.  相似文献   

12.
To reduce labor-intensive and costly order picking activities, many distribution centers are subdivided into a forward area and a reserve (or bulk) area. The former is a small area where most popular stock keeping units (SKUs) can conveniently be picked, and the latter is applied for replenishing the forward area and storing SKUs that are not assigned to the forward area at all. Clearly, reducing SKUs stored in forward area enables a more compact forward area (with reduced picking effort) but requires a more frequent replenishment. To tackle this basic trade-off, different versions of forward–reserve problems determine the SKUs to be stored in forward area, the space allocated to each SKU, and the overall size of the forward area. As previous research mainly focuses on simplified problem versions (denoted as fluid models), where the forward area can continuously be subdivided, we investigate discrete forward–reserve problems. Important subproblems are defined and computation complexity is investigated. Furthermore, we experimentally analyze the model gaps between the different fluid models and their discrete counterparts.  相似文献   

13.
Research has found that elementary students face five main challenges in learning area measurement: (1) conserving area as a quantity, (2) understanding area units, (3) structuring rectangular space into composite units, (4) understanding area formulas, and (5) distinguishing area and perimeter. How well do elementary mathematics curricula address these challenges? A detailed analysis of three U.S. elementary textbook series revealed systematic deficits. Each presented area measurement in strongly procedural terms using a shared sequence of procedures across grades. Key conceptual principles were infrequently expressed and often well after related procedures were introduced. Particularly weak support was given for understanding how the multiplication of lengths produces area measures. The results suggest that the content of written curricula contributes to students’ weak learning of area measurement.  相似文献   

14.
唐万梅 《运筹与管理》2005,14(4):85-89,79
本文利用因子分析法分析比较了我国西部各地区的人口素质,分析了西部地区人口素质水平低的原因,同时对提高地区人口素质提出了建设性的意见。为政府在制定地区产业发展方向、确定地区经济走向时提供参考。  相似文献   

15.
This study focuses on the role of tools, provided by a computer microworld (C.AR.ME), on the strategies developed by 14-year-old students for the area measurement of a non-convex polygon. Students' strategies on a transformation and a comparison task were interpreted and classified into categories in terms of the tools used for their development. The analysis of the data shows that an environment providing the students with the opportunity to select various tools and asking them to produce solutions `in any possible way' can stimulate them to construct a plurality of solution strategies. The students selected tools appropriate for their cognitive development and expressed their own individual approaches regarding the concept of area measurement. The nature of tools used affected the nature of solution strategies that the students constructed. Moreover, all students were involved in the tasks and succeeded in completing them with more than one correct solution strategy thereby developing a broader view of the concept, although not all of them realized the same strategies. Three different approaches to area measurement emerged from the strategies which were constructed by the students in this microworld: automatic area measurement, provided by the environment, the operation of area measurement using spatial units and the use of area formulae. Almost all the students experienced qualitative aspects of area measurement through being involved in the process of covering areas using spatial units. Students also managed to use the area formulae meaningfully by studying it in relation to automatic area measurement and to area measurement using spatial units. Through these strategies, the concepts of conservation of area and its measurement as well as area formulae were viewed by the students as interrelated. Finally, some basic difficulties regarding area measurement were overcome in this computer environment.This revised version was published online in September 2005 with corrections to the Cover Date.  相似文献   

16.
Generalizing results of L. Fejes Toth [3], [5], we prove the following theorem. Let R be a convex domain of area |R| and let S be a finite family of at least two congruent circles of total area t. Then for the area |F| of the part of R covered by the circles of S, the inequality |F|< tf(|R|/t) holds, where f(x) is the area of the intersection of a circle of unit area and a regular hexagon of area x concentric with the circle.  相似文献   

17.
若在某单连通区域V∈R3上,向量函数A是某个数量函数u的梯度,则其旋度rotA在所定义的区域上为零.本文证明了其旋度的任意两个分量在所定义的区域V上为零,另一个分量满足在区域V的边界S上为零与其三个分量在所定义的区域V上为零是等价的,解惑教学中学生的问题.  相似文献   

18.
We generalise the notion of Heron triangles to rational-sided, cyclic n-gons with rational area using Brahmagupta's formula for the area of a cyclic quadrilateral and Robbins' formulæ for the area of cyclic pentagons and hexagons. We use approximate techniques to explore rational area n-gons for n greater than six. Finally, we produce a method of generating non-Eulerian rational area cyclic n-gons for even n and conjecturally classify all rational area cyclic n-gons.  相似文献   

19.
The purpose of this work was to explore how elementary preservice teachers responded to area conservation tasks. We administered written pre-assessments, followed by semi-structured interviews with 23 preservice teachers, asking them to respond to and reason with area conservation tasks. Findings highlighted several interesting preservice teachers' struggles when assessing area conservation tasks. In many cases, preservice teachers exhibited struggles similar to students, especially with regards to the justification of their area conservation claims. We provide recommendations to assist preservice teachers in their development of mathematical content knowledge in their teacher education programs, so that in the future they may better plan area lessons that promote procedural fluency from conceptual understanding in area measurement.  相似文献   

20.
Hsin-Mei E. Huang 《ZDM》2014,46(3):449-463
In this study, 34 children were evaluated in order to elucidate their multiplicative thinking and interpretation of the area formula of a rectangle, and to determine what roles these factors play in solving area measurement problems. One-on-one interviews and problem-solving tasks were employed to explore the problem-solving skills of the children regarding these two concepts. This study also explored how the associations changed throughout two consecutive phases, from the third to the fourth grades. The results indicated that in the third grade, multiplicative thinking was associated with the solving of area measurement problems. Third-grade children who understood the meaning of the multiplication symbol “p × q” in models (e.g., the set model and arrays) outperformed children who understood only partial multiplicative concepts or additive thinking; however, the association between multiplicative thinking and solving area measurement problems was not significant in the fourth grade. In contrast, children’s ability to interpret the area formula of a rectangle was associated with their performance at solving area measurement problems throughout the third and fourth grades. The way of interpreting the area formula was associated with the extent to which the children understood multiplication, area measurement, and the spatial concepts embedded in rectangular figures. The instructional implications of the study are discussed in terms of developing child abilities to solve area measurement problems by connecting multiplication and area measurement.  相似文献   

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