黎曼

Under some reasonable assumptions of the'Distribution Matrix', the Riemann Problem with piecewise constant initial data is proved to have a unique Riemann Solver; furthermore, using'Wave Front Tracking Method'and properties of the'Generalized Characteristics', we prove the existence of weak entropy solution to the Riemann Problem with arbitrary initial data of bounded Total Variation.

在"分布矩阵"满足合理的假设前提下，证明了具有分片常值初始条件的黎曼问题的黎曼解算子的存在唯一性；并进一步运用"波前追踪法"和"广义特征"等得到了具有任意有界全变差初值条件的广义黎曼问题的弱熵解的存在性。

And because of the limitations of Riemann Integration,it can only be used for continuous function.

而由于黎曼积分具有局限性，黎曼积分只能用于连续函数类的积分。

The definitions of generalized directional derivative and generalized gradient of Lipschitz functions defined on Riemannian manifold are presented. Some properties of the directional derivative and gradient are proved by using tangent and cotangent mapping. The minimization necessary condition of nonsmooth Lipschitz functions is given. Moreover, Fritz John necessary optimality condition in mathematical programming is provided on Riemannian manifold.

在黎曼流形上给出了Lipschitz函数的广义方向导数和广义梯度的概念，利用黎曼流形局部上与欧氏空间开集微分同胚的性质以及切映射和余切映射导出了广义梯度的性质和运算法则，证明了定义在黎曼流形上的函数取得极小值的必要条件是广义梯度包含零元素，并利用这些性质给出了黎曼流形上数学规划问题的Fritz John型最优性条件。

In Riemannian manifolds, one studies Riemannian metric, covariant derivative, Riemannian connection, basic properties of the Riemann curvature tensor, curvature forms etc.

黎曼流形部分主要涉及黎曼度量，黎曼流形的定义，切向量场的协变微分，黎曼联络，黎曼几何的基本定理，曲率张量，曲率形式等概念和理论。

The complete pseudo-umbilical submanifolds with parallel mean curvature vector in constant curvature space;2. In this paper,the pseudo-umbilical submanifolds with parallel mean curvature vector in pseudo-Riemannian manifold is discussed.

研究了伪黎曼流形中具有平行平均曲率向量的伪脐子流形，Npn+p为n+p维完备连通伪黎曼流形，它的截面曲率KN满足a≤KN≤b，Mn为Npn+p中紧致的具有平行平均曲率向量的伪脐子流形。

Researches the submanifolds in nested space,for constant curvature Riemannian submanifold in quasi-constant curvature manifold and pseudo-umbilical submanifold with parallel mean curvature vector in constant curvature Riemannian submanifold,presents three sufficient conditions for this pseudo-umbilical submanifold to be total-umibilical submanifold,generalizes the result of JI Yongqiang.

对于拟常曲率流形中的常曲率黎曼子流形以及常曲率黎曼子流形中具有平行中曲率向量的紧致伪脐子流形，给出了这种伪脐子流形是全脐子流形的3个充分条件，推广了纪永强的相关结果。

At many occasions they arise quite natu-rally.For example,they appear in the Iwasawa decomposition of the isometry group ofa non-compact Riemannian symmetric space.Also,every connected homogeneous Rie-mannian manifold of non-positive sectional curvature can be represented as a connectedsolvable Lie group with a left-invariant Riemannian metric.

它们出现在非紧致黎曼对称空间的等距群的Iwasawa分解中；任一非正截面曲率的连通齐性和黎曼流形可以表为带有左不变黎曼度量的连通可解李群等，带有左不变黎曼度量的幂零及可解李群的微分几何，调和分析和谱几何是重要的研究课题。

Riemann integral can not be used in every limited function to get its definite integral.

因此，并不是每一个牛顿不定积分都可进行黎曼积分，并不是每个黎曼积分都存在牛顿不定积分，黎曼积分也并不能对每一个有界函数求定积分。

Endowed with a Riemannian metric derived from the gray scale information of a given image, the image space became a Riemannian manifold. On this Riemannian manifold, we evolved a curve by the mean curvature flow using the level set methods.

在图像空间上直接赋予一种由图像灰度信息导出的黎曼度量，使之成为黎曼流形，然后在此黎曼流形上利用水平集方法对曲线以平均曲率流进行演化。

Shen prove a short time existence theorem for manifolds with umbilical boundary. He also derived the Simons' identity for the boundary under the Ricci flow. And as a corollary, Shen show that any three-manifolds with totally geodesic boundary which admits positive Ricci curvature can be deformed to a space form with totally geodesic

而带边流形上的Ricci流的研究始于Shen，在1996年，Shen在中考虑带边三维流形上的黎曼度量的Ricci形变，证明了如果初始三维流形的黎曼度量具有正Ricci曲率和全测地边界，则此三维黎曼流形上存在着常正曲率的黎曼度量。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。