共查询到20条相似文献,搜索用时 125 毫秒
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本文主要讨论组合地图列举问题.刘的一部专著中提出了一个判定两个地图是否同构的算法.该算法的时间复杂度为O(m2),其中m为下图的规模.在此基础上,本文给出一个用于地图列举以及进而计算任意连通下图的地图亏格分布的通用算法.本文所得结果比之前文献中所给结果更优. 相似文献
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一、专题的背景与分析
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闵行区的沪闵路─春申路口是交通特别拥挤的交叉路口之一.家住莘庄地区的同学有一个共同的感受,在他们到校或回家路上必经的沪闵路─春申路口时常遇到塞车现象.…… 相似文献
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"牛吃草"问题又称为消长问题,是17世纪英国伟大的科学家牛顿提出来的.典型牛吃草问题的条件是假设草的生长速度固定不变,不同头数的牛吃光同一片草地所需的天数各不相同,求若干头牛吃这片草地可以吃多少天.由于吃的天数不同,草又是天天在生长的,所以草的存量随吃的天数不断地变化.…… 相似文献
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导数作为大学的重要内容,进入中学数学教材后,给传统的内容注入了生机与活力,为中学数学命题的研究提供了新视角,新方法.由于导数是研究函数性质的一个很好的工具,它的用途十分广泛,它在解决函数、不等式、解析几何等问题有独到的功能.因此,近几年的高考正逐年加大对导数问题的考查力度,本文通过对07年全国各地高考题的整理和分析寻找命题规律,希望能对今后的教学提供一点复习思路.…… 相似文献
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利用极值理论来考虑上证综指收益率的尾部.为了选择合理的超越门限,采用平均剩余函数和De-Haan矩估计相结合的方法.在学生t分布和广义误差分布的新患假设下,用GARCH和EGARCH新息的ARMA模型拟合指数收益率,并且使用极值理论的极大似然方法估计模型残差的尾指,估计结果表明收益率的尾指和模型的残差尾指基本一致. 相似文献
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2010-2011学年度武汉市部分学校新高三起点调研测试的一道试题引起了我的注意.原题如下:
在正四面体P-ABC中,M为△ABC内(含边界)一动点,且点M到三个侧面PAB,PBC,PCA的距离成等差数列,则点M的轨迹是
A.一条线段 B.椭圆的一部分
C.双曲线的一部分 D.抛物线的一部分 相似文献
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Yipeng Shi 《偏微分方程(英文版)》2001,14(3):193-206
In this paper, we prove that the convexity of the negative thermodynamical entropy of the equations of relativistic hydrodynamics for ideal gas keeps its invariance under the Lorentz transformation if and only if the local sound speed is less than the light speed in vacuum. Then a symmetric form for the equations of relativistic hydrodynamics is presented and the local classical solution is obtained. Based on this, we prove that the nonrelativistic limit of the local classical solution to the relativistic hydrodynamics equations for relativistic gas is the local classical solution of the Euler equations for polytropic gas. 相似文献
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Ling Hsiao 《Journal of Differential Equations》2006,228(2):641-660
Global in time classical solutions near the relativistic Maxwellian are constructed for the relativistic Landau equation in the whole space. The construction of global solutions is based on refined energy analysis. 相似文献
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傅景礼 《数学物理学报(A辑)》2001,21(1):70-78
定义相对论性Pfaff作用量,得到相对论性Pfaff Birkhoff原理和相对论性Birkhoff方程.证明了自治形式和半自治形式的相对论性Birkhoff方程具有相容代数结构和Lie代数结构;一般非
自治形式的相对论性Birkhoff方程没有代数结构.研究一种特殊的非自治形式的相对论性Birkhoff方程,它具有相容代数结构和Lie容许代数结构.给出相对论性Birkhoff方程的Poisson积分
方法.最后给出应用性实例. 相似文献
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The Riemann solutions to the isentropic relativistic Euler system for Chaplygin gas with a small parameter are considered. Unlike the polytropic or barotropic gas cases, we find that firstly, as the parameter decreases to a certain critical number, the two-shock solution converges to a delta shock wave solution of the same system. Moreover, as the parameter goes to zero, that is, the pressure vanishes, the solution is nothing but the delta shock wave solution to the zero-pressure relativistic Euler system. Meanwhile, the two-rarefaction wave solution tends to the vacuum solution to the zero-pressure relativistic system, and the solution containing one rarefaction wave and one shock wave tends to the contact discontinuity solution to the zero-pressure relativistic system as pressure vanishes. 相似文献
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Bogorodskii generalized the classical mechanical concept of a homogeneous gravitational field to the case of Einstein's general relativity. We seek such a generalization to the case of the relativistic theory of gravity. The corresponding solutions in these two theories differ substantially. The solution obtained in accordance with the relativistic theory of gravity does not satisfy the causality principle in that theory. The problem of constructing a generalization of the classical notion of a homogeneous gravitational field in the framework of the relativistic theory of gravity therefore remains open. 相似文献
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We obtain a new relativistic Coulomb-like resummation factor (L-factor) for an arbitrary orbital moment ℓ ≥ 0. We work within
the fully covariant quasipotential approach in quantum field theory formulated in the relativistic configuration representation
in the case of two interacting relativistic particles with arbitrary masses. 相似文献
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We consider the Riemann problem of three-dimensional relativistic Euler equations with two discontinuous initial states separated by a planar hypersurface. Based on the detailed analysis on the Riemann solutions, special relativistic effects are revealed, which are the variations of limiting relative normal velocities and intermediate states and thus the smooth transition of wave patterns when the tangential velocities in the initial states are suitably varied. While in the corresponding non-relativistic fluid, these special relativistic effects will not occur. 相似文献
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We consider the Riemann problem of three-dimensional relativistic Euler equations with two discontinuous initial states separated
by a planar hypersurface. Based on the detailed analysis on the Riemann solutions, special relativistic effects are revealed,
which are the variations of limiting relative normal velocities and intermediate states and thus the smooth transition of
wave patterns when the tangential velocities in the initial states are suitably varied. While in the corresponding non-relativistic
fluid, these special relativistic effects will not occur. 相似文献
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朱平 《数学物理学报(A辑)》2004,24(1):123-128
该文运用椭圆积分的理论,给出了一维相对论振子运动的解析解以及振子的振动周期. 指出相对论振子的振动周期不但与振子的固有性质有关,而且还与振子的振幅有关. 相似文献