连续方程

In this paper a new variational method for approximating the semilinear singular parabolic equation is given by using continuous finite elem...

本文利用连续时空有限元法对半线性奇异抛物方程进行了研究，利用线性化方法给出了有限元解的存在性证明和理论误差估计。

Based on a nonclassical theory of plasticity and the continuum damage mechanics,a damage constitutive equation is obtained for the ferrite phase with the damage evolution law for mixed hardening materials from an ellipsoidal void model under particular coordinates,where the void shape variation is considered.

基于非经典塑性理论和连续介质损伤力学，利用在一个特殊坐标系下基于椭球形孔洞模型得到的可考虑孔洞形状变化混合强化材料的损伤演化率得到了铁素体相的损伤本构方程，通过混合物理论利用铁素体和渗碳体相各自本构关系并考虑其几何特征得到了珠光体团的损伤本构模型。

The finite difference method is employed to discretize the governing equations and the projection method is used to derive a pressure Poisson equation that can ensure the satisfaction of continuity equation.

控制方程式采用有限差分法求解，并利用投影法导出压力的波松方程，使得能自动满足连续方程式。

It contains boththe finite element equations and finite difference equations in one equation.

拟协调元法是广义协调方程的解，自然满足平衡对弱连续条件的要求。

Differential equations of tile first order in the finite discrete function are established, the solutions of which have very simpler structure.

引入了有限离散函数的微分与积分新概念，它具有与连续函数微分和积分相类似的性质，由它建立的一阶微分方程的解有较简单的代数结构。

In this article two functional modes of the Fly-back Converter (Continuous Conduct Mode and Discontinuous Conduct Mode) are particularly analyzed, which include their characteristics, applications, the critical pattern of two functional modes is argued, both the exact boundary from the angle of circuit parameters is crystallized, at the same time, basic principle of PFC under the DCM mode is introduced, which settle theoretical basis for the subsequent design; by establishing the mathematic model of the converter, a further investigation of the configuration is made, qualitatively and quantitatively, analyzed to settle exactly theoretical basis for the subsequent emulation and the experimental parameter; from the angle of steady-state analysis, the transfer function of the system is deduced to establish dynamic small-signal state equation, emulating the system with the help of matlab, then according to the simulation result and the theory of PFC revise the system, lastly, we adopt the project which add a zero-pole compensator to the voltage loop, by this way, a satisfied system performance is gained and the PFC scheme is ensured successfully; finally, based on the previously-done work, we combining with the situation of specific design requirement, acquired the numerical value of each unit devices in this converter

详细分析了反激式变换器的两种工作状态，连续模式(Continuous Conduct Mode ，简称CCM)和断续模式(Discontinuous Conduct Mode，简称DCM)以及各自的特点、应用场合，论证了两种工作状态的临界模式，从电路参数的角度明确了二者的界限，同时还介绍了DCM模式下PFC的基本原理，为后面的设计奠定理论基础；通过对整个变换器系统建立准确的数学模型，对此变换器的电路结构做了进一步的研究，定性、定量地分析了变换器各部分的工作状态，为仿真和实验参数的确定以及电路参数的优化提供理论依据；从稳态分析的角度，为系统建立了动态小信号状态方程并推导出系统的传递函数，利用matlab对系统进行仿真，进而根据仿真结果以及PFC的相关理论对系统进行校正，采用在电压环加入零点—极点补偿器的设计方案，得到了满意的系统特性并且保证了PFC的顺利实现；最后，在前面所做工作的基础上，结合设计要求计算出此变换器系统中每个元器件的数值，利用Pspice对其进行了仿真、优化，然后根据仿真结果搭建了硬件电路。

Some sufficient conditions for the forced oscillation of solutions of the systems are obtained.

研究具有连续分布滞量的非线性中立型双曲偏泛函微分方程系统，获得了该类系统解强迫振动的充分条件。

These results also indi- cated the validity of the generalized constitutive equation with fractional order.

这同时也从另一个侧面证明了第二章给出的广义分数阶连续介质本构方程的正确性。

Many problems of dynamical systems can be reduced to an iterative functional equation or an iterative functional differential equation.

根据系统变化的规律可分为由微分方程描述的连续动力系统和由映射迭代揭示的离散动力系统。

To study the oscillatory of solutions to a class of nonlinear neutral hyperbolic differential equation with continuous distributed delay.

研究一类具有连续分布滞量的非线性中立型双曲方程解的振动性质。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。