定律

In the teaching of central field, we should pay attention to turning the relative motion of two - body into one dimentuonal radial motion by introducing two physical concepts of reduced mass and effective potential energy, and we should also pay attention that the area law is the geometrical description of the conservation of angular momentum in the central field.

在有心力场教学中，应着重强调指出：通过引入折合质量和有效势能这两个物理量，把二体相对运动问题转化为单体沿径向的一维运动问题；以及面积定律是质心在有心力场中角动量守恒的几何描述。

However, the Big Bang does not explain many things, including the uneven distribution of matter that results in "voids" and "clumps," or the retrograde motion that must violate the Law of Conservation of Angular Momentum.

然而，大爆炸并不能解释许多事实，包括物质分配不均，结果造成一些"虚空"和"实体"；而且"逆行运动"必然违反角动量守恒定律。

Then the writer gave a practical case of law of conservation of mass. The conclusion is that the learning mode of the new curriculum is useful not only in theory but also in practice, and it is popular with students.

然后，给出了"质量守恒定律"一节的教学方案，通过实施得出结论：新课程学习方式不仅在理论上是可行的，在实践上也是行得通的而且是深受学生欢迎的。

It greatly depends on Conservation of Mass to analyze the mass transportation of saturated liquid.

主要利用质量守恒定律分析饱和液体的传质过程。

Typical chemistry students have difficulty connecting symbolic and visual representations of reactions and often fail to account for conservation of mass and the effects of heat and temperature.

典型的化学专业的学生在联系反应的符号和视觉展示方面遇到了困难，经常无法解释质量守恒定律及热量和温度的效应。

According to the Law of Conservation of Mass,we have established the mathematical model of heavy metal pollution in Le'an River,and have attempted to find the solution to it.

根据质量守恒定律，建立乐安河重金属污染数学模型，并对其进行了求解。

By the law of conservation of mass and the principle of effective stress as well as the equilibrium differential equation, an anisotropic coupled model for the analysis of groundwater seepage and stress is developed.

根据质量守恒定律、有效应力原理、以及土的平衡微分方程建立了各向异性渗流场与应力场的耦合分析的数学模型。

It is explained that the law of conservation of mechanical energy obeys relativity principle of mechanics.

系统地阐明机械能守恒定律无条件服从力学相对性原理。

This article analyses the meaning and prerequisite of conservation of mechanical energy , and poses different standpoints on describing the law of conservation of mechanical energy in some textbooks.

分析了机械能守恒的内涵及条件，对有的教材关于机械能守恒定律的表述提出了不同的见解。

Professor Lewin puts his life on the line in Lecture 11 by demonstrating his faith in the Conservation of Mechanical Energy.

Lewin教授在第十一讲中将他的生命系於一线之间用以证明他相信的机械能守恒定律。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。