查询词典 vortex of vector field

The key point of this paper made a study of the application of FDTD method to dispersive, nonlinear materials. Two methods are introduced to deal with the relationship between the electric flux density vector and the electric field vector: auxiliary differential equation method and Z transform method.

本文的重点在于研究时域有限差分法在非线性色散媒质中的应用，主要采用了两种方法来处理电通量密度矢量D和电场强度矢量E之间的关系：辅助差分方程法和Z变换法。

In order to improve the correct rate of enterprise's financial distress prediction and reduce the sample number and training time, renyi-entropy and least squares support vector machine is applied to the field of financial distress prediction on the basis of the traditional support vector machine prediction model and advances a kind of prediction model which is based on Renyi-entropy and LS-SVM.

为了提高企业财务困境预测的正确率，减少训练模型的样本数和训练时间，在传统支持向量机预测模型的基础上，将Renyi熵和最小二乘支持向量机算法应用于财务困境预测，提出了一种基于Renyi熵的最小二乘支持向量机预测模型。

Vector mainly in plane geometry, Cartesian coordinate system, trigonometric functions, such as knowledge-based, learning through Vector, on the one hand, our mathematical expression of understanding entered a new field, on the other hand will enhance our space imagination capacity, the ability of thinking and analysis, the ability to solve practical problems.

向量主要以平面几何，直角坐标系，三角函数等知识为基础，通过向量的学习，一方面将我们对量的数学表达式的认识进入到一个新的领域，另一方面将增进我们的空间想象能力，思维能力和分析，解决实际问题的能力。

If Q2 were negative, this might be representation of E2, pointing to negative charge, and if this one (Q3) were negative, then I would have here the contribution E3, and so on, and now we use the superposition principle as we did last time which Coulomb's law, that the net electric field at point p is a vector, is E1 influence of charge Q1, plus the vector E2, plus E3 and so on.

如果Q2是负的，这就是Q2的表示法，方向指向负电荷。如果这个是带负电，它将贡献电场E3，等等。现在我们使用叠加原理，就像我们上次在库伦定律中使用到的。

Some uniform formulae are established, which link the Laplacian of the position vector function to the mean curvature vector field on any submanifold in the space forms.

讨论空间型中的位置向量场，建立一组统一的公式，将子流形的平均曲率向量场与位置向量及其衍生函数的Laplacian联系在一起。

The far-field analytical expressions for the electromagnetic fields of a cylindrically polarized vector beam propagating in free space are obtained based on the vector angular spectrum and the method of stationary phase.

基于矢量角光谱法与静态位相方法，推导出了矢量圆柱偏振光束在自由空间传输的电磁场的远场解析表达式。

In this thesis, molecular electronegative distance vector and 3D holographic vector of atomic interaction field (3D-HoVAIF) are applied and extended, the former is based on the 2D information of molecular structure, the latter is based on the 3D information of molecular structure.

本文在实验室已有的良好基础上，应用和发展了基于分子二维结构信息的系列分子电性距离矢量和基于分子三维结构信息的三维原子场全息作用矢量(3D-HoVAIF)。

By using the CFD software FLUENT, the inner-flow field of centrifugal fans with ruled-surface impeller versus with enveloping surface impeller has been simulated. The static pressure distribution, the dynamic pressure distribution, the total pressure distribution, the turbulent intensity and the speed vector of the two kinds of centrifugal fans are then analyzed and compared. From the calculating results, we found that the pressure distribution, the speed vector and other parameters of the two kinds of centrifugal fans are basically same. This implies that the tool-path generating arithmetic for the machining of the impeller can meet the aerodynamic requirements of the centrifugal fan. Furthermore the method can provide proof for designing department to establish sound manufacturing tolerance for impeller.

最后采用CFD软件FLUENT，利用标准k-ε湍流模型，采用分离隐式求解器，分别对直纹面叶轮离心通风机和包络面叶轮离心通风机整体风机内部三维流场和单个通道流场进行了数值模拟计算，在计算结果的后处理中，对相同坐标值处的静压力、动压力、湍流强度和速度矢量等参数进行了分析与比较，结果表明：在相同的计算参数条件下所得到直纹面叶轮离心通风机和包络面叶轮离心通风机内部流场差别不大，从而揭示所采用的叶轮数控加工的刀位规划方法的规划误差对流体机械动力性能的影响不大，这也为设计部门制定合理的叶轮加工公差提供了依据。

The constitutive equation between current density vector and electric field strength vector is tranformed into s-domain by the principle of Laplace transform,and the inverse Laplace transform is adopted for the explicit equations between them in time-domain. Finally through exponential time stepping,the FDTD iteration equations are obtained,which can be easily solved in discrete-time-domain.

该方法是将电流密度矢量与电场强度矢量之间的本构方程基于拉普拉斯变换原理转到复频域，然后再逆变换到时域得到它们之间显式的方程，最后再结合指数差分，得到离散时域的显式的FDTD迭代方程，解决了本构方程中电流密度矢量的分量相互耦合而不易直接离散的困难。

Week 14 Magnetic effect of current, Ampere molecule current hypothesis, current intensity and current density vector, condition of steady current, magnetic field of steady current, magnetic induction vector B;Biot-Savar- Laplace law and its application.

第14周电流的磁效应；安培分子电流假说；电流强度和电流密度矢量；稳恒电流的条件；稳恒电流的磁场；磁感应强度矢量B；毕奥-萨伐尔-拉普拉斯定律及应用。

For every one of my New Year resolutions, I have been a backslider for years.

说到我的新年决心，我每年都做

With empathy and focus on a feeling level, we can all relate to the common ground of mutuality of emotions.

有了同情心和感觉上一级的重点，我们都可以涉及到相互的情感共同点。