等周不等式

In order to study the popular curve shortening flow in the plane, Gage[3] has shown in 1983 the following inequality, if k is the signed curvature of a closed convex plane curve γ with length L and enclosing area A, then one gets Gage calls it an isoperimetric inequality in [3], but he does not show that the equality holds if and only if the curve γ is a circle, while as an isoperimetric-type inequality, one should prove this kind of result.

Gage称之为等周不等式，但他没有证明其中等号成立当且仅当，γ为圆周，而作为等周型的不等式是应该证明这种结果的，本文我们利用单位速率外法向量流，通过努力证明了这种结果，从而把Gage不等式加强成更加等周的形式。

And then, in this part, following the idea of Topping [51, 52], we will show an isoperimetric inequality (6.3.1) on surfaces of non-positive Gaussian curvature by means of the curve shortening flow on surfaces, this inequality can be considered as a generalization of the Banchoff-Pohl inequality in the Euclidean plane.

然后，仿照Topping[51]和[52]利用平均曲率流证明等周不等式的想法，我们利用曲面上的曲线缩短流在Gauss曲率非正的曲面上证明了一个等周不等式(6.3.1)，它可以看成欧氏平面上Banchoff-Pohl [8]不等式在曲面上的推广。

The chord-integral inequalities are the development and summary of isoperimetric inequalities and the important contents of integral geometry and related disciplines.

弦幂积分不等式是等周不等式的发展和概括，是积分几何和相关学科研究的重要领域。

Then I introduce the isoperimetric inequality on minimal surfaces with connect boundary.

LI，R.SCHOEN和S-T YAU的文献[4]中边界连通的极小曲面的等周不等式。

The first section introduces some basic concepts[9].The second section introduces Schmidt"s method of proving isoperimetric inequality [2].The third section introduces Hurwitz"s method [9].The fourth section takes from my tutors lecture notes.The method is due to REILLY [10].Finally,I make use of variational method to prove the circle among the curves of length L encloses the biggest area on the plane.

首先介绍了平面上的一些基本概念[9]，其次介绍了文献[2]中Schmidt证明等周不等式的方法，再次介绍了文献[9]中Hurwitz证明等周不等式的方法，然后介绍了导师吴发恩整理的文献[8]中REILLY的方法证明平面上的等周不等式[10]，最后我利用变分的方法证明了平面上等长的曲线围成的面积最大时为圆。

This thesis works for theoretical study on isoperimetric problem and related inequalities by using theory of geometry analysis, way of integral transformations and analysis inequalities.

本学位论文利用几何分析中的凸体理论，积分变换方法和解析不等式理论，研究了凸体和星体的等周问题和相关的不等式问题。

The basic concept of FOP can be summarized as to further optimize effective prescription according to the standard of curative effects and with the aid of modern science and technology and theories of traditional Chinese medicine.

其基本内涵可概括为：以确有疗效的中药复方为研究对象，以现代科学技术和传统中医药理论为技术支持，以该复方所治病证的药效响应为评价标准，以优化重组疗效更优的新复方为研究目的。

Ever since our world has been a world, native forests have been indiscriminately exploited by man.

自从我们的世界一直是世界原生森林被任意剥削人。