分布矩

Feature of principal lines spatial distribution: detect the principal lines through edge detecting technology, and then divide the image of palmprint into blocks with same dimension, compute the mean and variance as feature; Feature of palmprint direction: divide the image into sub-images; compute the max angle of projection and coordinate of each sub-image, which stand for the direction and location of the line on the palm; Feature of moment invariants: compute the moment invariants of each sub-image and the whole image as feature.

掌纹主线空间分布特征：利用边缘检测技术检测出掌纹的主线，将图像分割成相同大小互不重叠的子图，提取每一个子图的均值和方差作为特征；掌纹线方向特征：将图像分成不重叠的子图，利用Radon变换求出每一个子图的最大投影角度和坐标，也就是子图内掌纹线的方向和位置，构造特征向量；掌纹不变矩特征：提取图像整体和分割后的子图的不变矩作为特征。

This technique is used for the axisymmetric magneticstatic problems and the result is good. In the second example of the forth chapter, the error of the third–order Asymptotic Boundary Condition is lower than that of the second-order Asympototic Boundary Condition.

第五章针对这一问题，进一步对渐近边界条件进行了推导，分析了一些特殊电荷和电流分布情况下，电位、标量磁位和矢量磁位的多极矩展开式中各极矩项的性质。

The electronic structure and magnetism of clusters Nin(n=2-6) have been studied by spin-polarized MS-Xα method. The results show that the effect of the cluster symmetry on its atomic magnetic moment and electronic density of states is very notable.

采用MS-Xα方法研究了Nin (n=2—6)原子簇的电子结构和原子磁矩，发现团簇的几何对称性对原子磁矩和电子态密度的分布有重要影响。

The modified double weight function method is to introduce new weight functions doing subtraction between two negative exponential-type functions. For a Pearson type three probability distribution, the MDWF is able to make estimations of the Standard Deviation and Coefficient of Skewness C(subscript S from the second-order weighted central moments reduced to the first-order weighted central moment estimations.

修改的双权函数法是将两个负指数型函数之差所构成的函数类取作权函数，对于皮尔逊Ⅲ型分布，它能使σ和Cs的估计由原权函数法的二阶加权中心矩降低为一阶加权中心矩估计。

In 1988, Song Dedun and Ding Jing further verified that the distributions whose inverse forms must be explicitly defined could by no means be a prerequisite for using the PWM method, and they applied PWM method successfully to the estimation of parameters in Pearson Type-Ill distribution (P-III distribution) although this sort of distribution nev...

由我国宋德敦、丁晶(1988年)将美国Greenwood等人(1979年)提出的概率权重矩法，应用于P-Ⅲ分布，取得较好效果。本文将PWM法应用于指数Γ分布的参数估计。统计试验结果和实例分析表明，PWM法用于指数Γ分布的参数估计时，具有较好的统计特性。

The equations of optimal probability density function of stochastic variable or limit state function are derived by use of the higher moments of the function.

一次二阶矩法主要利用随机变量的均值和方差信息以及分布概型来计算结构的失效概率，属于低阶矩法。

The random errors of main factors in flood regulation process are identified; and combining flood forecast, the randomnesses of main parameters such as initial reservoir level, inflow flood, outflow flood, etc., are analyzed. By using the first order second moment method and theoretic distribution, the random distributions of parameters are described then the routing process of a certain preflood limit water level is random, which can well reflect the random preflood influences in actual regulation.

对防洪调度过程各主要相关参数进行了随机误差识别，结合洪水预报对起始水位、人库洪水、泄流等主要参数的随机性进行分析，应用一次二阶矩法和相应的理论分布函数描述事件的随机分布，对应某一汛限水位的调洪过程不再是一确定过程，而是具有随机分布特性，反映了实际防洪调度中各随机因素的影响作用。

This problem is also important and valuable in Nonlinear Optics. It will be very helpful to understand how the aberrations affect the course of three- wave mixing, such as the change of conversion efficiency, the distribution of intensity and phase.Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental waves aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.

首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解；通过建立国防科学技术人学研究生院学位论文三维数值模型，编写相应仿真程序，首次得到了位相畸变光束倍频过程的大量计算结果，深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素；得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同，但谐波的远场发散角明显地比相应基波的小的结论；得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下，位相畸变传递到二次谐波的估算式；举例分析了KDP三倍频方案中，基波位相畸变对二次谐波和三次谐波的影响；实验工作中，用哈特曼一夏克传感器分别对IO64nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量，给出了相应结果。

Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental wave's aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.

首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解；通过建立三维数值模型，编写相应仿真程序，首次得到了位相畸变光束倍频过程的大量计算结果，深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素；得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同，但谐波的远场发散角明显地比相应基波的小的结论；得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下，位相畸变传递到二次谐波的估算式；举例分析了KDP三倍频方案中，基波位相畸变对二次谐波和三次谐波的影响；实验工作中，用哈特曼-夏克传感器分别对1064nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量，给出了相应结果。

The company has windowed corrugated plate packing, small ripple from the saddle ring loose fill, such as utility model patents, the main processing and manufacturing of petroleum, chemical, oil refining, coking, pharmaceutical and other industries within the pieces of stainless steel towers, such as: air-tube distributor, distributor disc groove, double row vane distributor, driven valve trays, tongue-shaped tray, floating tongue trays, sieve trays, bubble cap trays, metal mesh corrugated structured packing, metal packing puncture calendering, sheet corrugated structured packing, turtle nets, packing bearings, all kinds of loose packing such as Rasi ring, Pall Ring, ladder ring, flat ring, Intalox ring, metal wreath tower, etc.

公司拥有开窗式孔板波纹填料，细波纹环距鞍散堆填料等实用新型专利技术，主要加工制造石油、化工、炼油、焦化、制药等行业不锈钢塔器内件，如：管式空气分布器、槽盘式分布器、双列叶片式分布器、导向浮阀塔盘、舌形塔盘、浮舌塔盘、筛孔塔盘、泡罩塔盘，金属网孔波纹规整填料、金属压延刺孔波纹填料、板波纹规整填料、龟甲网、填料支承，各种散堆填料如拉西环、鲍尔环、阶梯环、扁环、矩鞍环、金属花环等塔内件。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了