分布导数

This paper Puts forward the four main parameters of the Permeability classification for coal mass es, that is,the fractal dimension of the cracks in coal mass es,the number of the cracks in one meter's characteristic scale, the conducting water coefficient of coal samples and its Porousness; and founds the mathematical pattern of the complex judgement by fuzzy sets.

提出了进行煤体渗流特性分类的四个主要指标，即煤体裂隙分布的分形维数D、特征尺度L＝1m的裂隙条数N、煤样导水系数T和煤的孔隙率η等；建立了煤体渗流特性模糊数学综合评价的数学模型；根据煤层注水工程应用的实际情况。

In each period, without the knowledge of the distribution function of the time between failures and the repair time, the PA estimate of gradient of performance function is put into the stochastic approximation algorithm which recursively optimize the threshold value of the flow control model in a manufacturing system.

在分析过程中，对故障时间和工作时间的分布不做任何假设，利用自适应控制的思想，将整个样本路径依据一定的规则分成有限长的时间段，在每一段时间内用扰动分析估计目标函数的样本导数，然后用随机逼近算法渐进地估计流程控制问题中的最优阈值，从而实现了阈值的自适应控制。

On the basis of the mechanical principle of the stress function and its derivative on the boundry of elastomer and the method of Heaviside function, the stress calculation of the function of nonlinear distributed force on the undersurface of nonsymmetric wedge block has been obtained.

用应力函数及其导数在弹性体边界上的力学意义和海维赛函数的方法，对非对称楔形体在楔面下部承受非线性分布压力作用的问题进行了应力计算，给出了应力一般解并进行了讨论，其结果具有理论和实际意义。

The differentiation states of costae indicates the ways they absorb and transport water, and their ability adapting to the dry conditions, which was elucidated by the following examples: Brachythecium plumosum, because of its thin cell-walls in the costae and the absence of hydrome, assistant and steroid cells, can absorb water and nutrition under shady and moist conditions; Plagiomnium rostratum, though often grows in shady and wet condition, has hydrome and steroid cells, a feature similar to those of xeric mosses, which endows it to grow in the conditions with periodical drought stress during its life cycle; Hygrohypnum luridum is characterized by its slender leaves with only one layer of cells, the thin cell-walls, the absence of filaments on the leaf surface, and the fewer layer cells in the costae, the absence of hydrome and steroid cells. These features make it adaptable to aquatic environments. For Pogonatum inflexum and Atrichum undulatum, their ventral surfaces covered with lamella, while for Racomitrium japonicum, Thuidium cymbifolium, Macromitrium ferriei, Diphyscium fulvifolium, Barbula unguiculata and Ceratodon purpureus, their leaves are strongly mammillose or papillos. Such appendiculate structures made them adaptable to thy conditions.

例如，荫湿生环境下的羽枝青藓Brachythecium plumosum，其中肋细胞胞壁较薄，无导水主细胞和副细胞的分化，也没有厚壁细胞分化，能够在阴湿环境下吸收水分和养分；钝叶匍灯藓Plagiomnium rostratum具有与旱生藓类植物相似的中肋结构，叶片较厚，中肋具导水主细胞，中肋背面具厚壁细胞，这些特点使该种藓类植物能够分布于间隙性干旱胁迫的环境中；水灰藓Hygrohypnum luridum叶片纤细柔弱，仅1层细胞，细胞胞壁薄，叶表无附属结构，中肋细胞层数少，无导水主细胞分化，也没有厚壁细胞，这些特点使得水灰藓'能够生长在水生环境中；东亚小金发藓Pogonatum inflerum和波叶仙鹤藓Atrichum undulatum的叶腹面覆盖着栉片，东亚砂藓Racomitrium japonicum、大羽藓Thuidium cymbifolium、福氏蓑藓Macromitrium ferriei、东亚短颈藓Diphyscium fuhifolium、扭口藓Barbula unguiculata和角齿藓Ceratodon purpureus的叶片表面有乳头状突起或疣状物，这些附属结构使它们能够适应于旱生的环境中。

In theory, firstly, the numerical simulation methods, such as the boundary element method, the finite difference method and the finite element method, were utilized to calculate the distribution of electric field intensity and potential of the electron-gun system, the focusing system and the whole equipment, respectively. Then, the trajectories of the electron-beam were traced by using of the Runge-Kutta method and the Monte-Carlo method associatively. The point spread function was also calculated.

在理论分析中，先后采用边界元方法、差分方法、有限元方法等科学数值计算方法，编制程序，对X射线源的电子枪发射系统、聚焦系统以及发射系统与聚焦系统的组合系统等的电场分布进行了严格的计算，在准确求得各系统电场内各个剖分点的电场场强、偏导数等参量的基础上，采用蒙特-卡罗模拟方法和不等距龙格-库塔方法相结合，追踪由LaB_6单晶阴极表面发射出的大量电子束在电场内的运动轨迹，求出点扩展函数，并根据点扩展函数的优劣，反复调节、大量计算对比，挑选出X射线源最佳的电极结构及其组合。

Then the spatial localization of the main well-known visual neuron's receptive field models such as DOG function, LOG function, higher order derivatives of Gaussian functions and 1—D, 2—D Gabot function models is quantitatively analysed.

如对通常被作为建立模型的主要根据的&最优的空间定域性&判据的物理意义和适用性也没有得到深入的论证，而且已有的主要几类感受野模型，如DOG函数、LOG函数、高斯函数的高阶导数和一维、二维Gabor函数等模型在空间分布形态上难以准确反映系统中神经元感受野的形态和信息处理机制等等。

Two edge detection operators of second de ivative model, the discrete Laplacian of Gaussian and Laplacian of binomial distribution operators are introduced in this paper.

摘要本文首先导入了离散的高斯-拉普拉斯及二项分布--拉普拉斯两种二阶导数型边缘检测算子。

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。