离散谱

The expansion coefficients Of aperture fields are Obtained after the three-dimensional arbitrary aperture fields have been represented by the sum of three-dimensional Gaussian function in the configuration-spatial wavenumber phase space.

本文利用Gabor原理把三维任意口面场表示成离散结构－波数相位空间中三维高斯基函数的叠加，将二维高斯基函数与相位空间谱双重正交的函数推广到三维，从而得到口面场展开函数。

From the point of view of geobotany, with the method of correlative factors of growth of plants, a countrywide theoretic ecological division was done for the introduction of Camptotheca acuminata and three kinds of areas of ecological preferent zone, ecological adaptive zone and ecological unadaptable zone were divided. With the theory of synecology, the characteristic on environment, constitution, life form spectrum, diversity, similarity of plots of communities were researched. Applying the method of species association, discrete distribution, indensity index, fractal geometry, etc. to research relations between the species of the communities, space distribution of Camptotheca acuminata, structure of age of Camptotheca acuminata, in different communities. Using the theories of autoecology, distibutons of seeds on land and growth of seedlings in vertical and horizontal directions, biomass of organ of Camptotheca acuminata were analyzed. On the opinions of conservation biology, the external and internal factors impressing Camptotheca acuminata were analyzed to research the mechanism of the endangered species, and with using of CTM Model, the future development direction of Camptotheca acuminata in different communities were forecasted, and. Standing on the position of resources ecology, discussing the regularity of camptothein in Camptotheca acuminata of different sites and seeding of different resources, also the the derive technics of camptothecin.

本文从地植物学的角度，运用植物生长相关因子法，对我国喜树资源的生态适宜区进行了划分，理论上确定了我国的喜树的引种栽培的最适生活区域、生态适宜区域和不适宜生活区域；从群落生态学的角度，对野生喜树所在的典型群落的群落环境、群落组成、群落生活型谱、群落的物种多样性特点、群落样地间相似性进行了研究；从种群生态学的角度，运用种间联结性、离散分布模型、聚集强度指数、分析几何等分析手段，对野生喜树所在典型群落间的种间关系、喜树的空间分布格局、年龄结构等进行了分析；从个体生态学的角度，对不同年龄组的喜树的种子的散落的垂直分布、水平分布、时间分布及种子发芽率和千里重等特点、不同种源的人工喜树苗期特点、喜树的高生长和茎生长特点、喜树的器官生物量特点进行了研究；从保护生物学的角度，对野生喜树的濒危的内部因素和外部因素进行了探讨，并运用CTM模型对不同群落中野生喜树的种群趋势进行了预测；从资源生态学的角度，对我国地理环境下喜树中喜树碱含量的地理分布规律、不同种源的喜树幼苗中喜树碱含量变化规律进行了研究，并对喜树碱的提取工艺进行了探讨。

The incom- pressible Navier-Stokes equations are solved using finite volume method and pseudo-spectral method, respectively.

其中对气相不可压缩Navier-Stokes方程的求解分别采用有限容积方法和拟谱方法，对离散惯性颗粒的跟踪采用单向耦合的拉格朗日方法。

Inthis paper, we collect 119 γ-ray-loud Blazar 97 flat spectrum radioquasars (FSRQs and 22 BL Lacertae objects,and investigaterespectively the correlation between the γ-ray emission (maximum,minimum, and average data) at 1GeV and the radio emission at 8.4GHz bydiscrete correlation function method.

收集了119颗有γ射线噪的Blazar天体样品(97个平谱射电类星体和22个BL Lac天体)，用离散相关函数方法分析了1GeVγ射线辐射流量(最大值、最小值和平均值)与8.4GHz射电辐射流量之间的相关性。

The matrix forms of the LLA remove the gap between preparative chromatography theories and Markov decision processes or optimal control approaches based on discrete time states.

该LLA的矩阵形式消除了制备色谱理论和Markov决策过程或其他基于离散时间状态的现代控制方法之间的鸿沟。

The thesis mainly completes the transient analysis and dynamic response calculation. It obtains the datas of drilling well places for many times in order to get the value of hook loads and establishes the modal of logarithmic normal distribution at hook loads as statiscic variables.

通过到现场进行数据采集，获得了大钩的载荷值，以大钩载荷为统计变量，建立对数正态分布模型，以离散的统计特征值来代替连续的实际载荷历程，编制得到动态研究所用的试验用程序载荷谱。

In the case of discrete systems, some simple stability criteria are given in terms of matrix norm and the spectral radius of matrix, which are delay-independent and are therefore valid for any large delay.

对带滞后的线性定常离散广义系统，则通过矩阵的范数与谱半径建立了一些形式简单的稳定性判据，用它们判别系统的稳定性时，不会因滞后的增大而明显地增加计算量。

The unified discrete iterative map model of peak current and valley current controlled buck, boost, and buck-boost converters is established, and the unified piecewise smooth iterative map and their corresponding characteristics equations are also derived.

本文建立了峰值电流和谷值电流控制Buck，Boost，及Buck-Boost变换器的统一离散迭代映射模型，并导出了统一的分段光滑迭代映射方程及特征值方程，通过数值仿真得到了占空比变化时的正、逆分岔图和Lyapunov指数谱。

It is indicated by the performance analysis that the approach here has comparative bias and variance as the approach of discrete prolate spheroidal sequence multitaper spectral analysis.

性能分析的结果表明，此方法与离散长球序列多窗口谱分析方法具有相当的估计偏差与方差性能。

Its discretization is based on spectral elements in space and central differences method in time. The numerical result, shows that this approximation has spectral accuracy in space and up to second-order in time.

该解法引入一阶Clayton-Engquist-Majda吸收边界条件，在空间上利用谱元方法，在时间上利用中心差分的积分方法得到波动方程的离散形式，并给出具体算例进行了验证。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。