近似方法

New factorized quasi-Newton equation not only uses the gradient information of the objection function ,but also uses the function information .

本文利用二次函数近似梯度的方法构造新分解拟牛顿方程，不仅利用到了目标函数的梯度信息，而且用到了目标函数值的信息，比传统的分解拟牛顿方程具有更高的二阶曲率逼近。

During the process of consecutive first-order reaction, the trend of the intermediate is largely determined by the ratio of the rate coefficient; therefore this case leads to an important method:steady-state approximation.

在连续反应中，速率系数的比值很大程度上决定了中间产物浓度的走向，并由此引出了一个重要的方法：稳态近似法。

Compressible fluid with non-return valve Although the use of compression fluid valve pipeline aims to reduce the impact valve flap to a minimum, but can not be compressed fluid selection method with a similar valve toFlanged Ball Check Valves choose.

压缩性液体用止回阀只管压缩性流体管路选用止回阀的目的在于使阀瓣的撞击减小到最小水平，但可以按照不成压缩性流体用止回阀的近似选择方法来进行选择。

Simultaneously, the exports of ionization rate and nonionzed concentration are set up as a powerful tool for studying thoroughly the freeze-out effect. dN〓/dp and dN〓/dn are neglected in the linearized equation system of the iteration methods of Newton and Gummel, due to having lower 15 orders or more than dN〓/dn and dN〓/dp, thus the computing effort is cut down with no effect on precision. A new cut-off technique is adopted to accelerate the convergence speed, about twice reduced for Newton iteration method and six times or so for Gummel iteration method. The approximate formulae of Fermi-Dirac statistics are also put forward with simpler form and higher precision. 3. A term dependent on time is added to the electron and hole current succession equations respectively. It is only this model that conservation of charge in transient analysis and alternating small-signal analysis at low temperature can be kept by. 4. The performance of SE-PISCES is explained by the simulation example of PISCES-2B, diode.

研究了低温半导体器件模拟的数值方法：对载流子浓度进行了新的归一化；编制了不考虑掺杂所引进的内建电场时的电离率计算程序；由于低温杂质电离率随偏压状态而变化，为此编制了每次求解迭代时的电离浓度计算程序，并将其插入到求解迭代程序中；同时，设置了杂质电离率和未电离杂质浓度的出口点，为更深入地研究冻析效应提供了有力工具；在Newton迭代法和Gummel迭代法的线性化方程组中忽略了dN〓/dp、dN〓/dn，是因为它们比dN〓/dn、dN〓/dp低15个数量级以上，这样减小了计算量又不影响模拟精度；对Newton迭代法和Gummel迭代法采取了新的截断技术，提高了收敛速度，Newton法迭代法和两次左右，Gummel法减少六次左右；给出了表达式更简单而精度更高的Fermi-Dirac积分近似计算公式。

A typical simulated signal and real-life vibration fault signal measured from a turbine generator unit were used to test this method.

通过对冗余提升小波分解得到的近似信号和细节信号采用傅里叶变换的方法消除了与其对应频带无关的频率成分，以突出相应频带信号的时域特征。

A method was proposed for approaching the glide trajectories based on nsegment constant gliding angle.

提出用包含地球旋转效应的n个常滑翔角飞行段近似实际滑翔飞行轨迹的方法。

This paper applies simulation and actual data to make a comparative analysis of the effects of the four different references:average reference,linked mastoids reference,Cz reference and zero reference realized by the recently-developed REST(reference electrode standardization technique) for calculating the center of mass of EEG.

针对脑电头皮电位质心的计算问题，用仿真和实际数据计算比较了平均参考、连接耳参考、头顶参考和新近出现的近似零参考技术方法的差异，结果表明，采用REST可使得电位质心的计算误差在多数情况下更小。

In this paper, the following progress has been discussed:(1) the improved conjugate gradient algorithm which combines the inversion equation;(2) the formulation for velvet gene at all directions and the approximation method of Jacobian matrics based on disturbance method;(3) the model is adjusted by analyzing the influence of damp coefficient and correction factor to inversion result ;(4) the influence of damp coefficient to the resolution of inversion is studied. to some degree, we improved the problem of "barycenter ascending shift" to electric anomalous body in 3-D resistivity inversion.

本文主要讨论了以下几个方面的内容：（1）结合反演方程式改进的共轭梯度算法；（2）基于扰动法的线源Jacobi矩阵的近似计算方法及光滑系数矩阵在各个方向上的光滑因子的计算公式；（3）通过分析阻尼系数与修改量校正量对反演结果的影响，提出了利用校正系数对模型修正量进行校正；（4）较为系统的讨论了阻尼系数λ对反演分辨能力的影响，较好的改善了三维电阻率反演中的电性异常体重心的&上漂&现象。

From Maxwells equations, the vectorial and scalar wave equations for 3D, 2D and 1D are given out one by one using the slowly varying envelope approximation.

从电磁场的Maxwell方程组出发，分别导出了缓变包络近似条件下矢量及标量波动方程的三维、二维、一维形式，然后对其横向和纵向数值处理方法分别作了介绍。

The cutoff conditions of metal-clad waveguides or loss dielectric waveguides are discussed. The effects of metal-cladding on the cutoff condition of graded index waveguides are analyzed at first. The principle of cutoff intensity modulator has discussed in detail.

本文首次提出一种适合于分析含金属覆盖层的均匀和渐变介质波导在截止点附近的光学特性的近似的解析方法，并对金属覆盖层的均匀阶跃介质波导在截止点附近的模传播特性作了全面的分析，所得到的结果同精确的数值解结果相吻合。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。