查询词典 marginal distribution density function

The main achievements of the project are as follows: 1 the hypothesis that a decrease in seed mass causes an increase in mean dispersal distance has been tested based on the experiments of weed dispersal by wind. The experimental results partly support the hypothesis. The results will help farmers to make an optimal strategy of weed control; 2 a statistic method for inferring probabilistic distribution function of a random variable has been developed, by which probabilistic distribution functions of weed species dispersal have been determined; 3 the reproduction structure of Bromus sterilis has been studied; 4 a more complex CA model with 25 neighborhood cells were built, which can simulate spread of a weed population. This work promotes developments in both theory and application of CA models; 5 the "mean law" in weed control has been proposed. Accordingly, the algorism of patch spring may be calibrated; 6 the "patch" and "true patch" have been mathematically defined so that herbicide can be efficiently applied; 7 simulation validates that initial configurations of weed will affect dispersal of its population and strategies of controlling it, or its distribution patterns affect its dispersal progresses.

主要完成的工作和取得的成果有：1）用实验证实了重量较轻的杂草种子并不一定飞得比较重的远，其结果有助于农民制订杂草的优化控制策略；2）发展了一种推断随机变量分布函数的统计方法并用它来获得了几个杂草种的扩散分布函数；3）对杂草Bromus sterilis的繁殖结构进行了研究；4）建立了一个具有25邻的较复杂的能模拟杂草扩散的CA模型，并在理论和应用方面促进了CA模型的发展；5）在杂草控制方面提出了&平均法则&，据此可对按块施药方法进行校正；6）精确地定义了&块&和&真块&以便在杂草控制中能更有效地使用除草剂；7）模拟证实杂草种群的初始配置影响其扩散和控制策略，或者格局影响过程。

Based on the actual conditions of the 5342 fully mechanized caving face of Wulan Coal Mine, the 3-D distribution of gas in the face is tested by measuring points arrangement in the stereo grid. The isograms of gas distribution of the face are drawn. Gas concentration nadir distribution curve along the working face incline direction is drawn by method of seeking function minimum points. The method of calculating gas emission components ratio of the face by means of the curve is brought forward.

针对乌兰煤矿5342综放工作面的实际条件，采用立体网格状的测点布置，对该工作面瓦斯体积分数三维分布进行了测定，绘出了瓦斯分布等值线图，采用求函数极值点的方法，得出了工作面沿倾向瓦斯体积分数最低点分布曲线，提出了基于瓦斯体积分数最低点分布函数的瓦斯涌出分量比例计算方法。

The vertical distribution of Aeolian sand current Based on the distribution function of lift-off velocity of saltating sand grain, this thesis develops a vertical distribution model of Aeolian flow linking with the number of lift-off sand grains percent time percent sand area. The thesis realizes the combination of microcosmic researches and macroscopical researches of Aeolian wind sand and solves primarily the isjunction of microcosmic researches and macroscopical researches.

4风沙流的垂向分布以本文获得的沙粒起跳初速度分布函数为纽带，结合本文获得的单位时间单位面积沙床起跳沙粒数，建立风沙流的垂向分布模型，实现风沙运动宏观研究和微观研究相结合，初步解决长期以来宏观与微观研究相脱节问题。

The results of calculations showed that the maximum increments in saltation height and horizontal distance due to the Magnus force were 10.2 and 24.9%, respectively, and that both increments increased with increasing lift-off angle. The maximum increments in saltation height and horizontal distance of sand grains caused by the Saffman force were only 4.6 and 3.7%, respectively. The vertical concentration distribution of Aeolian sand flow follows exponential function distribution whether or not force analysis of saltating sand grains includes Magnus and Saffman force. The effect of Magnus and Saffman force on the vertical concentration distribution of Aeolian sand current makes the rate decrease near sand bed and it is consistent with the effects of Magnus and Saffman force on the saltation height and distance of sand grains.

Magnus力对跃移高度和水平距离产生的最大增量分别可达到10.2%和24.9％，这两个增量均随起跃角度的增加而增大；Saffman力对跃移高度和水平跃移距离产生的最大增量分别为4.6%和3.7%；是否考虑Magnus与Saffman力，风沙流垂向质量百分浓度均服从指数函数分布，Magnus与Saffman力使得风沙流垂向质量百分浓度较不考虑它们的作用呈现出底层的比例较小，上层较大，Magnus与Saffman力对跃移高度的影响基本与其对风沙流垂向质量分布的影响一致，不过Magus力对风沙流垂向质量百分浓度分布影响较大，0-2cm范围内尤为强烈(7.16-10.81)，其他高度层(2-20 cm)的影响相对较小(0-2.95)。

In the meanwhile, the TS characteristics of a scattering particle and their relationship are studied when it is passing through the scattering area, In addition to this, the distribution function of particles' shape is defenited in terms of math's method and a new method is putout of which the distribution of particles' shape is captured in according to the power spectrum and spectral distribution characterist of light scattering and finally, the utility of the perturbation ameliorating method and the effect of the particles' shape is modified, so far, the accuracy of measurement of the particles' size is improved effectively.

对此，本文在以Mie散射理论为原理，依据前向接收器接收的前向散射光信息以获取微粒大小信息的测量基础上，对微粒穿越光敏区时的时域与空域的特征以及相关性开展了研究，从数学上定义了微粒的形体分布函数，提出了一种依据光散射功率潜和频谱分布特征来获取微粒形体分布信息的方法，完善了微扰修正理论的应用性，有效地改善了形体的影响问题，从而可提高微粒粒度分布测量结果的准确性。

In this paper, the multivariate archimedean copula is used to analyze the asymmetric dependence structure among financial asset returns, whose marginal processes are captured by nonparametric kernel density estimation.

在研究金融资产的组合风险分析中，描述多个金融资产间的相关结构是选择最优组合权重的关键因素之一，如何准确地刻画金融资产间的非对称尾部相关结构，在定量研究组合资产的风险分析中尤其重要。

We discuss the mechanism of wave beam forming for the phase array vibrators, give a definition of the marginal energy density for the seismic wave field, and make some quantitative analyses to the energy intensity along each direction on the snapshot of the wave field.

本文讨论这种相控阵震源的波束形成机制。引入了地震波场的边际能量密度的概念，利用地震波场的时间切片技术，对模型空间各个方向上的能量强度进行了定量分析。

Through conducting research on the classification of high density drilling fluid, the optimal grain distribution of adulterant is determined using the density-grain-viscosity curve.

对高密度钻井液进行了分类，以密度－粒度－黏度曲线确定了最优化加重剂粒度分布，通过优化基浆配制工艺、优选强抑制钻井液体系、优化加重剂与钻井液的粒度分布研究，应用超微细、亚微态粒子稳定技术，强化固相控制，形成一套优化的高密度阳离子钻井液技术工艺。

Statistical characteristics include Tectonic Density, Degree of Central Symmetry, Skewness Index, Degree of Tectonic Optimal Direction, Power Spectrum Density, Cubic Entropy and so on. The former four indexes are implemented in this paper; Structural characteristics show the characteristics of spatial distribution of geological bodies. In chapter four, a quantitative method for describing geological structure by using the structure "tree" is studied and implemented, including its formalized definition and the measurement of the similarity of different "trees".

统计特征有构造密度、中心对称度、失真指数、优益度、密度功率谱、方位熵等等，本文实现了前四个参数值的提取；结构特征是反映地质体空间分布的结构特点，第四章研究和实现了用"树结构"描述地质结构的定量方法，包括结构的形式化描述和结构的相似性度量。

We investigate the distribution of charge density and spin density in an interchain coupled quasi-one-dimensional organic ferromagnet.

对具有链间耦合的准一维有机铁磁体系统的电荷密度和自旋密度的分布进行了研究。

For the head-teacher of the class said that I had seriously broken the school rules,which led me to a three-day suspend class.

为什么呢？因为我的班主任说我严重的违反了校规，于是让我停课三天。

Many of them believe that the conversion of thousands of working-class folk in England spared that nation from the mass carnage and the tyranny that came with the revolution in France.

他们之中有许多人相信，在英国数以千计的劳工阶级之悔改信主使英国免於遭受如法国大革命所造成的大屠杀和专制暴政。