恒量

The analytical solutions and conserved quantities are used to assess the accuracy of the method.

通过解析解和守恒量来检验该方法的精度。

Based on a constant value of gravitational acceleration at a given location of the earth and accurate measurement of tilting angle of the table, a calibrating method and procedure for primary parameters of accelerometers, i.e.

基于地球上给定地点的重力加速度为一恒量和转角的准确测量，给出了加速度计主要参数（灵敏度、线性度和横向灵敏度）的标定方法和步骤。

The sum of the two quantities remains unchanged, and is called a constant of the motion.

这两个量的和保持不变，称为运动恒量。

There are three constants in life...

生活中有三个恒量。。。

An approximate conserved quantity is derived from the conserved quantity in the neighborhood of the straight equilibrium configuration.

在直线平衡位形附近由该守恒量导出一个近似守恒量。

We present the fundamental theories of Noether symmetries and conserved quantities of mechanco-electrical dynamical systems, including variation principle of the system, Noether symmetry transformation, Noether quasi-symmetry transformation, generalized Noether quasi-symmetry transformation, Killing equations, Noether theorem, the form of conserved quantity. And then the basic theory of Lie symmetry is advanced, including the determining equation, structure equation and the form of conserved quantity.

给出机电动力系统的Noether对称性和守恒量基本理论，包括系统的变分原理、Noether对称性变换、Noether准对称性变换、广义Noether准对称性变换、Killing方程、Noether定理和守恒量的形式；给出机电动力系统Lie对称性的基本理论，包括确定方程、结构方程以及守恒量的形式。

Chapter two proposes the unified form of Hojman"s conservation law and Lutzky"s conservation law. Firstly, the author introduces the general Lie group of transformations that the variations of both the time and the generalized coordinates are considered, derives the determining equation of Lie symmetry for the system, presents a new conservation law, which contains the Hojman"s and the Lutzky"s conservation law as two special cases, and obtains a condition to exclude trivial Hojmans conserved quantities.

第二章，Hojman定理和Lutzky定理的统一形式：首先，引入一般意义下的Lie变换群(即位型变量q_s和时间变量t同时变换)，给出系统的Lie对称性确定方程，提出一个新的守恒律，Hojman定理与Lutzky定理则分别是这个新守恒律在两个特殊情况下的推论，导出一个可排除平凡Hojman守恒量的定理，并分别讨论了Birkhoff系统和非完整系统的Lie对称性和Hojman守恒量，最后，讨论了Hamilton系统的梅对称性与Lie对称性的关系，给出了由梅对称性求Hojman守恒量的方法。

Collins gave the example of a gravitational constant, saying, If it were

克林斯教授给我们举了其中一个地心引力恒量的例子，说：如果在一

For the relativistic holonomic nonconservative system, a new Lie symmetrical non-Noether conserved quantity is given under general infinitesimal transformations of groups in which time is variable.

[1]浙江理工大学数学力学与数学物理研究所，杭州310018 [2]辽宁大学物理系，沈阳110036 [3]北京理工大学理学院，北京100081研究非完整力学系统的形式不变性导致的非Noether守恒量——Hojman守恒量。

Secondly,the condition under which the Noether symmetry is a Lie symmetry is obtained.Finally,a generalization of Hojman theorem is given and two examples are given to illustrate the application of the result. analytical mechanics ; holonomic system ; symmetry ; conserved quantity

新近出现的形式不变性理论也取得进展[6～8]，文献[9]研究了完整力学系统由Lie对称性导致的Hojman守恒量，本文继文献[9]，研究完整力学系统由Noether对称性导致的Hojman守恒量。1 系统的Noether对称性与守恒量完整力学系统的运动微分方程为 Es=Qs (s=1，…，n)(1)其

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。