守恒

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。

Further, with the help of Riccati equations, an infinite number of conservation laws for the solton hierarchy are deduced. For the sake of simplicity, taking the general TD hierarchy as an illustrative example, we prove that its 2×2 Lenard pair of operators forms a Hamiltonian pair. Thus the isospectral evolution TD hierarchy is the general Hamiltonian system and possesses the Bi-Hamiltonian structures and Multi-Hamiltonian structures. By using the method of derivation of functional under some constraint condition, a complete one-to-one correspondence between the Hamiltonian functions of the hierarchy and its conservation density functions can be built. These results can also be applied to the isospectral evolution soliton hierarchy of this paper. Finally, there's a gauge transformation between the spectral problem of this paper and the AKNS system. Moreover, the potentials in these spectral problems satisfy the general Miura transformation, the corresponding relationship between the two soliton hierarchies is also given.

进一步本文还通过特征函数的组合关系所满足的Riccati方程，得到了该等谱方程族的无穷多个守恒律；为简便起见，本文以广义TD族为例，由它的2×2 Lenard算子对的性质证明了此算子对为Hamilton算子对，这说明广义TD族是广义Hamilton系统且具有Bi-Hamilton结构和Multi-Hamilton结构；进而利用它的依赖于谱参数的一般守恒密度的积分在约束条件下求泛函导数的方法，得到了广义TD族的Hamilton函数与守恒密度之间的对应关系，这些性质对于由本文提出的2×2谱问题所导出的等谱孤子族仍成立；另外此谱问题与AKNS系统存在着规范变换，位势之间有广义Miura变换，而孤子方程之间也满足一定的等价关系。

It contains Euler equations for conservation of mass, momentum and energy, and Poisson equation through which the gravitational potential is determined by the density distribution of the gas itself.

它包括由质量守恒方程、动量守恒方程和能量守恒方程构成的Euler方程组以及由星体本身的密度分布决定的自引力势能所满足的Poisson方程。

For the heavy structure and complex performances of the hybrid system, based on the photovoltaic effect, the state equation of ideal gas, mass and energy conservation equations, physicochemical principles, power transformation relations, flow and transmission of the heat energy, first give a set of proper assumptions and simplifications, then a set of dynamic model of all subsystem are established completely and detailed.

由于PVFC联合发电系统结构复杂，涉及到电化学、传质学、传热学等多门学科知识，以及光生伏打原理、质量守恒、动量守恒、能量守恒、第一热力学定律等多种原理和定律，所以，首先对各子系统在不影响系统性能的基础上进行适当的假设和简化，然后根据各种原理和定律分别建立各子系统的动态数学模型。

Combining with the theory of the conservation law of mass,momentum,energy and gas explosion dynamics,the attenuation law of shock wave in excavation roadway was deduced during gas explosion.

运用质量守恒、动量守恒和能量守恒定律及爆炸气体动力学理论等，对掘进巷道瓦斯爆炸冲击波的衰减规律进行研究。

In part I, using the concatenating method and the discrete Leibnitz rule, we construct three multisymplectic algorithms, three local energy-conserving algorithms and one local momentum-conserving algorithm for the second order nonlinear Schrodinger equations.

第一部分利用复合构造方法和离散Leibnitz法则，给出了二阶非线性Schrodinger方程的多辛守恒格式，局部能量守恒格式和局部动量守恒格式，并给出了详略的推导过程。

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。

A dynamic simulation mathematic model consisted of conservation equations of mass, momentum, energy, superheat steam equation, pressure drop equation, two-phase flows equations and relations before and after oblique shock.

建立了由两相流体质量守恒方程、动量守恒方程、能量守恒方程，过热蒸汽关系式、压降关系式、激波前后关系式及其它两相流关系式组成的动态仿真数学模型，模型形式为非线性方程组。

Conservations of mass, momentum, and energy are used to determine liquid film thickness and temperature.

液膜厚度、速度与温度等参数通过求解液膜的质量守恒、动量守恒、能量守恒方程获得。

The mathematical model for predicting the profile of water wall flow rate and temperature was established on account of mass, momentum and energy conservations.

根据质量守恒、动量守恒和能量守恒方程，建立了超临界锅炉水冷壁流量和壁温计算的数学模型。

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％。