查询词典 abel equation

The main advantages of using the Dirac equation in a description of electrons are the following:(1) The Dirac equation is compatible with the theory of relativity (2) it describes the spin of the electron and its magnetic moment in a completely natural way.

在电子的描述中用Dirac方程描述主要优势有：（1）Diarc方程同相对论理论是一致的；（2）它很自然地描写了电子自旋和自旋磁矩。

After that, According to the induced-matter idea, we study the generalizational method of 5D Dirac equation, and point out that Dirac equation isn't formally generalized in principle because the wave function of Dirac field is multiple component matrix form.

随后，我们从诱生物质思想出发，研究Dirac方程的五维推广方案，指出由于描述Dirac粒子的波函数是多分量的矩阵形式，原则上不能只依靠单纯的形式推广。

At first, we introduce in detail relativistic mean-field theory, where a common Lagrangian density is presented. Starting with this Lagrangian density, we can obtain the Dirac equation and Klein-Gordon equations for nucleon and meson field by using Euler-Lagrangian equation.

本文首先详细介绍了相对论平均场理论的一些公式推导，给出了常用的一般的相对论平均场的拉格朗日量，从这个拉氏量出发，利用Euler-Lagrange方程就可导出核子与介子场的运动方程。

By supposing the ion sphere model, the self-consistent field method between the Poisson-Boltzmann equation and the Dirac equation is used to calculate the energy levels of H-like neon immersed in hot and dense plasmas.

采用离子球模型，通过自洽求解Poisson方程和Dirac方程，得到氖的类氢离子低能级组态的能级能量随等离子体电子温度和电子密度的变化关系，进一步研究了等离子体电子温度和电子密度对光谱漂移的影响。

The particle motion differential equation is analysed detailedly and the three-dimensional direct numerical method of particle motion differential equation is established.

论文对颗粒运动微分方程进行详细的分析讨论，建立了三维颗粒运动微分方程的直接模拟数值方法。

The quaternion calculation for spacecraft attitude determination is investigated in this paper,including the transformation between quaternion and the direction cosine matrix,the quaternion differential equation,the selection of time steps for integrating the quaternion equation,and the compensation methods for the noncommutativity error in high dynamic motion.

介绍了四元数计算中的相关问题，包括四元数与方向余弦阵之间的转换、四元数运动方程、求解四元数运动方程时积分步长的选取和高动态应用中非互易误差的补偿，此外还介绍了对偶四元数的发展。

Using the directional derivative formula, the governing equation is discreted in the physical domain in which a nonorthogonal grid system is used. Two kinds of AF2 schemes, i. e. AF2-plane relaxation and full implicit AF2, for the TSD equation are proposed. Numerical results show that the full implicit AF2 scheme converges faster than AF2plane relaxation scheme. For the rectangular wing and swept wing, the results of the present method are compared with FP results, and the agreement is good.

采用适合于梯形机翼和后掠机翼的斜网格，利用方向导数公式直接在物理空间对主管方程进行离散；将近似因式分解方法应用于绕机翼的跨音速小扰动势流问题，提出AF2—面松弛和AF2全隐式两种迭代格式，并对它们的收敛速度进行比较，结果表明后者明显快于前者；直机翼和后掠机翼的算例表明，本文方法的结果与精确势流方法的结果吻合良好。

Apparently, the approximate controllability doesn"t hold for generally linear parabolic equations with bounded control. It doesn"t hold for the semilinear heat equations presented there,either. Then, it is proved by analyzing its" solutions that no matter how long the time T is , there are targets that can"t be approximated by the solution of heat equation with Dirichlet boundary conditions;If a given target satisying certain conditions can be reached by the solution of heat equation .

本文先针对两个具体的半线性热方程系统证明了控制加约束后系统是不能控的；然后通过分析方程的解，对带位势及Dirichlet边界条件的热方程系统，无论时间多大，都存在不能控的目标；文中还证明了满足一定条件的目标可达。

In this thesis, the virtual boundary integral equation is based on double layer potential with the virtual density to be determined on virtual boundary. Since this integral equation related to double layer potential only involves the computation of the normal derivative and second normal derivative of fundamental solution, the exponential integral function is not involved in it, so numerical computation for the exponential integral function is avoid.

本文则基于双层位势，引入虚拟矩密度函数来建立虚边界积分方程，并首先对时间变量进行解析积分，在虚、实边界上采用常单元和等额配点离散，该方程只涉及含基本解的法向导数及其二阶法向导数项的计算，对时间变量进行解析积分后，不会出现对指数积分函数的空间变量的积分计算。

Through the decompositions to common-shot gathers and common-offset gathers, one can obtain common p, plane wave gathers and common P plane wave gathers which are suitable to the single square root extrapolation equation and the double square root extrapolation equation, respectively.

通过对共炮点道集和共偏移距道集地震数据的平面波分解，分别得到适用於单平方根波场外推方程和双平方根波场外推方程的共P平面波道集和共P平面波道集。

You can snipe the second and third union leaders from this position.

您可以鹬第二和第三工会领袖从这一立场出发。

Aiming at the currently shortage of XML streams quality detecting, this paper proposes a new forecasting method of XML streams quality by least squares support vector machines, which is used the method of XML keys' vector matrix as windows, and vector product wavelet transform to multilevel decompose and refactor the XML streams series, that can fulfill real-time checking demand of XML quality, and ensure constraint, consist- ency and integrality. For even more adapting net load, it proposes a control strategy by weight and adaptive adjustment to ensure XML streams quality.

针对当前XML数据流质量检测存在的不足，提出构建XML键的矢量矩阵作为窗口，利用矢量积小波变换多级分解与重构XML数据流，再结合最小二乘支持向量机对XML数据流质量进行预测的一种方法，满足XML数据流质量重构时实时检测的要求，保证XML数据的约束性、一致性与完整性；为了更好的适应网络负载，采取加权与自适应窗口调整等调度策略充分保证XML数据流的质量检测。