参数方程

However, the refraction of plane wave in reaction-diffusion system obeys Snell's law only for proper diffusion coefficients and system parameters.

在二维复金兹堡-朗道方程描述的反应扩散振荡系统中，就扩散对平面波折射率的影响进行了数值研究，从Snell定律出发导出了折射率的解析表达式，数值和理论结果表明：在纯扩散情况下，平面波的折射满足Snell折射定律，扩散只影响着平面波折射率的大小；在同时存在反应扩散情况下，只有在适当的扩散系数和系统参数下，平面波的折射才满足Snell折射定律。

The envelope of electron beam oscillates due to space charge field and solenoidal field.

通过求解电子束的横向包络方程，研究了强流电子束包络随电子束参数和螺线管聚焦磁场的变化关系。

By the numerical simulations of the free surface velocity histories and based on the best consistence between the computational results and the experimental ones, the material parameters in the damage evolution equation and the spoliation criterion are obtained.

通过自由面速度历史的数值模拟，并基于计算结果与试验结果间的最佳一致性，得到了损伤演化方程和层裂准则中的材料参数。

The discussion is focused on the determination of the minimum air rate when there is reservoir fluid influx during air drilling, injection pressure at standpipe, and bit nozzle pressure.

应用气体状态方程、热力学定律对空气钻井中各个流动参数进行分析，重点讨论储层流体涌入时空气钻井过程中最小空气流量的确定，以及立管注入压力和钻头喷嘴压力等问题。

As the main part of this thesis, based on RSJ model, a symmetric DC SQUID is theoretically studied through two-dimensional Fokker-Planck equations, by using the "potential condition" in the case of steady state, the stationary probability distribution function of this system is obtained firstly in the accurate theory, meanwhile, the expressions of all the SQUID characteristics functions are obtained, for example, the circulating current, total normalized voltage and transfer function.

作为本论文的主体工作，我们以RSJ模型为基础，利用二维Fokker—Planck方程从理论上研究了对称型双结超导量子干涉器件，利用定态条件下的"势条件"得到了系统定态概率分布的精确解析表达式，进而得到了该系统所有特性函数如环路电流、总电压、调制函数的统计表达式，利用数值计算讨论了各种参数对DC SoL71D系统特性的影响。

According to piezoelectric equation and vibration theory of quartz crystal, we studied the elastic wave＇s transmission characteristic in a AT-cut thickness-shear-vibration quartz crystal, and the frequency conditions of which quartz crystal resonator formed stationary wave in electrode district.

根据石英晶体的压电方程和晶体振动理论，研究了AT-切石英晶体厚度切变振动模式下振动频率与结构参数间的关系，以及石英晶体谐振器在电极区形成稳衡驻波的频率条件及电极区外波的传播特性。

Based on the theory of generalized estimating equations, this thesisstudies the parameter estimation in several statistical models for longitudinal data.

本文基于广义估计方程的理论研究了纵向数据下几类统计模型的参数估计问题。

A structual model of generating natural gas hydrate is summarized in this paper. It's genesis conditions are calculated by means of the equations of statistical mech-anics and thermodynamics.

本文概述了生成天然气水合物的结构模型，并利用统计力学和热力学方程计算了它的生成条件，以控制热力学参数防止其生成。

The basic principle and circuit topology of DC side series APF are analyzed; the corresponding control equations are derived; the criteria for the design and selection of principal parameters for main circuit, i.e., the filter inductor and energy storage capacitor, are given to provide theoretical basis for rational design of DC side series APF.

文中对直流侧串联型APF的电路拓扑和基本原理进行了分析，推导了相应的控制实现方程，给出了主电路主要参数的设计和选取标准，为系统的合理设计提供了理论依据。

By simulating the supersonic wave probing data with computer,an in-situ rock stress supersonic wave ellipsoid equation is achieved,the in-situ rockstress is defined thereby.

本文建立了地应力超声波检测的多元非线性计算模型，通过对声波检测参数的计算机模拟，得到地应力声波椭球面方程，从而确定原岩应力状态。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。