动量守恒

From the homogeneity of time we can deduce mechanical energy conservation law, and from the homogeneity and isotrogy of space we can deduce monentum conservation law and angular momentum conservation law.

从时间的均匀性可推得机械能守恒定律，从空间的均匀性和空间的各向同性可分别推出动量守恒定律和角动量守恒定律。

The neutrino was first postulated in 1930 by Wolfgang Pauli to preserve the conservation of energy, conservation of momentum, and conservation of angular momentum in beta decay—the decay of an atomic nucleus into a proton, an electron and an antineutrino.

中微子是1930年由沃尔夫冈泡利为了保持能量守恒，动量守恒和β衰变---一个原子核（那时还没有认识到是中子）衰变成一个质子、一个电子和一个反中微子的角动量守恒，。

The tangent space and normal space of the robot motion curve is constructed by using Newton-Euler orthogonal method, which satisfies the restrictions of linear and angular momentum conservation of free-floating space robot system. An analytical expression of joint actuation torque in the floating state is given by using this method.

根据空间机器人自由漂浮状态时系统动量守恒的特点，采用Newton-Euler正交方法构建了满足系统动量守恒约束条件的空间机器人运动曲线法空间与切空间基底，并以此基础得到了自由飘浮状态下的空间机器人关节力矩的显式表达式。

Based on the quality of conservation, conservation of momentum and energy conservation principle, three-dimensional steady hydraulic mathematical model and its boundary conditions have been deduced out

基于质量守恒、动量守恒和能量守恒原理，建立天然气管道三维稳态水力计算的数学模型，并给出了模型的边界条件

Based on momentum balance and the law of momentum conservation, two new graphic methods are developed to determine the pre-impact vehicle momentum or collision speed in this paper.

本文根据动量平衡和动量守恒定律的基本原理，提出了两种推算碰撞前汽车动量或碰撞速度的图解方法。

The thesis can be divided into five parts as follows: First, the structural characteristics of finned-pipe evaporator are analyzed. After selecting suitable microelement controller, the heat-transfer and mass-transfer processes are analyzed for every microelement under the conditions of dryness, wetness and frostiness. Based on previous equations, some parameters of frostiness are confirmed and the frost-growing model is set up under frost condition. Some hypotheses are postulated and with the help of the equation of mass-conservation, energy-conservation and momentum-conservation, the evaporation model which fits in the dynamic simulation is built, which set a solid foundation for system simulation. Second, the starting and stopping behaviors under disturbed condition are analyzed and calculated by using the dynamic concentrative parameter model, which gives some advice to better prescribe refrigeration system and set theoretic foundation for carrying out automatic control of refrigeration system. Third, the normal running process is analyzed and calculated by means of rational matching theory, which gives some advice on how to better understand the parameter change under steady state and the affection of inlet-parameter on evaporator. Fourth, the simulation software with dynamic characteristic is designed, which can be applied to calculate thernio-parameter of cryogen, air humidity and frost thickness under different initial and boundary conditions, and to carry out dynamic simulation under conditions of dryness, wetness and frostiness, at the same time, to achieve detection and simulation at any stage from starting to stopping.

本文的主要内容如下：1对翅片管蒸发器结构特点进行分析，选取适当的微元控制体，就干、湿和霜工况下对每个微元分别进行传热传质分析，基于经验关系式确定霜的有关参数，对于霜工况下的霜生长建立模型，经适当假设，运用质量守恒、能量守恒和动量守恒方程建立适合动态仿真的蒸发器数学模型，为系统仿真奠定基础； 2对蒸发在大扰动下的开、停机过程，运用动态集中参数模型进行分析和计算，为更好地描述制冷系统运行的全过程奠定基础，同时也为制冷系统实现自动控制提供一定的理论基础； 3对蒸发器正常运行过程，运用动态分布参数和参数间定量耦合的观点来分析和计算，为更好地了解稳态工况下各点参数的变化情况及各入口参数对蒸发器动态特性的影响即蒸发器性能对各参数变化的敏感性； 4编写翅片管蒸发器动态特性仿真计算程序，可以计算不同边界条件和初始条件下的制冷剂热力参数、空气温湿度和霜厚度分布场，实现对翅片管蒸发器在干、湿和霜工况下的动态仿真。

The general forms of the conservation of momentum, t emperature and potential vorticity of coastal ocean are obtained in the xz pla ne for the nonlinear ocean circulation of Boussinesq fluid, and a elliptic type partial differential equations of second order are derived. Solution of the part ial differential equations are obtained under the conditions that the fluid move s along the topography.

在考虑了陆架地形后，在垂直海岸的xz剖面上，对Boussinesq流体的非线性海洋运动方程求得了总动量守恒、温度守恒和位势涡度守恒的普适形式，进而得到流函数所满足的椭圆型二阶偏微分方程，在给定流体沿地形运动的条件下，算出问题的解。

In the modified Newtonian mechanics, the law of conservation of momentum and the law of conservation of energy become invalid; instead, the inherent momentum and inherent kinetic energy can be defined to make the law of conservation of inherent momentum and the law of particle inherent kinetic energy valid.

在修改后的牛顿力学中，动量守恒定律和能量守恒定律不再成立，但可以定义固有动量和固有动能，使得质点系固有动量守恒定律和质点固有动能守恒定律成立。

Conservation of mass.conservation of moment muni and conservation of energy are basic regularity obeyed by all movement in nature.For a certain problem in natrue .if we quantify the corresponding conversation law . we can deduce partial differential equation reflecting this problem .and every differential equation reflecting a special physical phenomenon on certain codition.

质量守恒、动量守恒和能量守恒是自然界一切运动所遵循的基本规律，对于自然界的某一特定问题，如果把相应的守恒律数量化，就导出刻划这个问题的微分方程，每一个微分方程都在一定条件下刻划了某一特定的物理现象。

Because of the space is uniform,So that the momentum conservation is occurrence in nature,it explain the momentum conservation is a attribute of the space.

由空间的均匀性而导出的动量守恒，说明动量守恒是物质空间的一个基本属性，动量守恒在整个物理学的框架中应具有定律的基础地位。

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。