近似微分

In the point reactor model, the probability function(n, t0, t) of a source neutron at time t0 leading to n neutrons at time t is dealt with. The non-linear partial differential equation for the probability generating function G(z; t0, t) is derived. By solving the equation, we have obtained an approximate analytic solution for a slightly prompt supercritical sys tem.

在点堆模型基础上，考虑了在t0时刻系统引入一个源中子，在t时刻产生n个中子的概率(n， t0， t)推导了概率生成函数G(z； t0， t)所满足的偏微分方程，并得到了近似解。

A variational method with differential forms gives better precision for numerical solution of transport critical problem based on spherical geometry, and its computation seems simple than other approximate methods.

对于球几何问题，讨论了一种基于微分方程的变分形式求解方法，数值计算显示达到了较满意的精度，而且计算过程比起其他近似方法要简单

The standard parabolic equation method was obtained by the decompocition of the scalar wave equation and the expansion of the pseudo-differential operator.

通过对传统波动方程的分解和伪微分算子的近似展开，获得了标准抛物线方程。

The algorithm for constructing the approximating model of the Markov chain of an Ito stochastic differential equation is discussed.

探讨了构造伊藤随机微分方程的马尔可夫链近似模型算法。

Therefore, basic methodologies for stochastic seismic and filtering responses of nonlinear structure are studied, the approximate solution methodologies and their practical applications are investigated in the dissertation employing equivalent linearization and moment equations method based on FPK equations and Ito stochastic differential equations. The research works are mainly concerned with the following aspects:Firstly, the differential expression of bilinear hysteretic is studied and a new differential expression is developed, then they are demonstrated.

因此，本文基于FPK方程和伊藤随机微分方程，研究了滞后结构物的随机地震反应和随机滤波问题的基本方法，并利用等效线性化法和矩方程法，研究了非线性结构随机地震反应分析和随机滤波分析的近似解法及它们的工程应用。

By introducing the nonlinear complementarity problem function, the Karush-Kuhn-Tucker conditions of OPF model are transformed equivalently into a set of semismooth nonlinear algebraic equations. Then the set of semismooth equations can be solved by a semismooth L-M method based on the subdifferential. The method belongs to Newton-type method. It can ensure the positive defmitiveness of the iterative coefficient matrix by using the L-M parameter, which avoids the ill-conditioning of iterative equations. The method, requiring only the approximate solution of a linear system at each iteration, is quite applicable to the large-scale cases.

在利用非线性互补函数将OPF模型的KKT条件转化为半光滑非线性代数方程组后，采用基于次微分的半光滑L-M法求解，该方法属于牛顿法范畴，可通过对L-M参数的调整保证迭代系数矩阵的正定性，克服了系数矩阵的奇异引起的"病态"，且该方法在确定搜索方向时只需求解线性系统的加热器近似解，适用于大规模系统的求解。

This paper extends the analysis for axial-system torsional oscillation into the nonlinear domain,and the research for Hopf ramification phenomena in axial-system torsional oscillation has been made using the time-domain simulating results,it verified the analysis results of similar nonlinear differential equation describing the axial-system torsional oscillations.

文中把发电机轴系扭振的分析扩展到非线性领域，并对轴系扭振中的Hopf分歧现象进行了研究，利用时域仿真结果对从描述轴系扭振的近似非线性微分方程分析所得结果进行了验证。

The method of simulate wavelet edge multi-scale detection was used to extract feature of characteristic bands successfully,based Gaussian filter and vector differential operator.

提出了基于高斯滤波与矢量微分算子的近似小波变换多尺度杂交玉米种子电泳图谱特征谱带边缘检测算法，成功实现了特征谱带特征参数的提取。

In the sense of Von Karman large displacement, the governing equation of nonlinear dynamic response of the clamped circular plates under impact of a mass is established by using the virtual displacement principle and Galerkin's method in this paper. The effect of coupling between the impact load and the displacement of. the circular plates is considered. The governing equation is solved by applying the time increment method and the singular perturbation theory, and the asymptotic solutions of nonlinear dyna...

本文在Von Kármán大位移的意义上，利用虚位移原理伽辽金方法建立了圆板在物体撞击下的非线性动力响应的控制微分方程，在研究响应问题时，考虑了冲击载荷与圆板位移响应之间的耦合影响，文中使用时间增量法和奇异摄动理论求解问题的控制方程，获得了固支圆板非线性动力响应的近似解，并且求解了具体算例，绘出了圆板位移、应力响应曲线以及冲击力随时间的变化曲线。

The solutions were found to be good agrees with experimental results. The transfer characteristic of air dry/wet bulb temperature and spraying water temperature were discussed. The LMTD method based on this mathematical model is applicable to design and verify for the plate wet air cooler. The ratio of the wet bulb heat transfer coefficient to the heat transfer coefficient under air-cooled conditions was investigated theoretically and experimentally. The relative errors of the ratio between theoretical and experimental valves are small than 7 percent.

分别得到了平行流型式微分方程组的解析解与交叉流型式的近似解析解，实验验证了该解析解具有较高的计算精度；探讨了空气干湿球温度与喷淋水温的迁移特性；分析得到基于湿球温度迁移模型的对数平均温差法在湿式空冷器的设计与校核计算中是适用的，给出了空气湿球换热系数与空冷时空气对流换热系数比值的理论与实验确定方法，比值系数理论值与实验值比较最大相对误差小于7％。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。