分布

For example, we use geometric distribution to describe the life distribution of runs of a species in transect surveys of plant populations and inventory demand distributions. In the theory of reliability, geometric distribution is one of the most important discrete probability distributions because of its loss of memory.

在可靠性理论中，由于几何分布的无记忆性，使得其是离散型寿命分布中最为重要的寿命分布之一，其相当于指数分布在连续型寿命分布中的地位，这正如程侃研究员在文献[5]中所指出的"在离散寿命的情形，几何分布起着连续情形下指数分布所起的作用"一样。

Since Leptokurtosis, skewness and fat-tail are always used to depict market risk, this paper introduces the improved Laplace distribution to risk management of stock portfolio. Empirical results show, improved Laplace distribution and asymmetric Laplace distribution are similar for estimating Leptokurtosis, while improved Laplace distribution is better for estimating skewness.In order to analyze the correlation between return distribution and volatility, the thesis uses ARCH-M Models to simulate the return series of China's Stock Market and developed markets ao as to discover the relation between investment return and time-varying risk.

对尖峰、厚尾、偏态的刻画有助于正确估计市场风险，本文将改进型Laplace分布引入到股票组合的风险管理中，实证结果发现，改进型Laplace分布和非对称Laplace分布对尖峰、厚尾的刻画效果接近；而非对称Laplace分布对负偏性考察不足，改进型Laplace分布的拟合结果能够准确地反映股指收益的负偏态，这也正是改进型Laplace分布相对于传统的非对称Laplace分布的优势所在。

The main purpose of the thesis is choosing the more superior distribution among normal distribution, logarithmic normal distribution, weibull distribution, beta distribution and gamma distribution when they are used for fitting and forecasting ten main trees diameter distribution of natural secondary forest in baotianman on basis of analyzing and comparing the data from the 32 plots of natural secondary forest in baotianman.

以宝天曼天然次生林32块样地的调查数据为依据，分别以正态分布、对数正态分布，Weibull分布，Beta分布，Gamma分布拟合及预测宝天曼自然保护区天然次生林10种主要乔木树种直径分布，并对其适用性进行分析、比较，选出最适合于拟合及预测该林分直径结构的分布。

The model uses the Pearson distribution system to simulate the backscattering distribution of ocean surface on SAR imagery. In the Pearson distribution system, four distributions including the Pearson distributions of typeⅠ,Ⅲ,Ⅳ and Ⅵ are employed.

模型使用Pearson分布系统模拟SAR图像海洋背景散射分布， Pearson分布系统由4种参数分布组成，包括Pearson I分布、Ⅲ分布、Ⅳ分布和Ⅵ分布。

Nowadays the researches of frequency distribution of data are almost limited to normal distribution, while other distributions are seldom studied. Many frequency distributions of data are not normal. This kinds of frequency distribution of data widely exist. Unimodal frequency distribution of data often occurs.

现在绝大多数关于频数资料分布的研究都是基于正态分布的，而对其他类型的分布研究得比较少，实际上频数分布在许多情况下并非呈现正态分布，分布的形态丰富多彩，很多资料都是呈现单峰分布，本研究就是利用数学上常见的八种连续型变量的分布类型去拟合单峰频数资料。

As a result of error distribution\\\'s non-uniqueness, draws out to the standard deviation understanding again, by about standard deviation reflected that the erroneous zero rank value two side the variation targets, the application unimodal distribution fits the error distribution, the goal is: By approaches the rationality which under the enhancement goodness of fit\\\'s premise determines to the error.

从文章的上下文感觉此标准值似乎是人为规定的，并不受实测数据本身分布的影响，不具有客观性。个人认为：研究在实际中实测数据相对于均值的分布更有意义。按照作者的观点，误差的分布都是单峰的，除了正态分布这种对称分布外，作者认为还有不对称的偏峰分布。因此研究这种偏峰分布模型可能更有意义。

The representative families are Dryopteridaceae, Athyriaceae, Polypodiaceae, Thelypteridaceae, Selaginellaceae and Aspleniaceae. The main genera are Dryopteris, Selaginella, Asplenium, Arachniodes, Pteris, Allantodia and Plagiogyria. The top families' distribution types are cosmopolitan and pantropic ones, the main genera are pantropical ones, while species distribution type belong to the east Asia type and represents the feature of subtropics transition to warm temperated areatype. As for the order of closeness, the sequence of pteridophytes floristic relations between Songyang and the adjacent regions goes as Southwest China, South China, Central China, Japan, North China, Northwest China and Northeast China. The six upland pteridophytes next to Songyang can be put into the same natural flora because of its closest relationship. But compared with other 11 upland fern flora in China, fern in Songyang is not rich enough. There are 37 species endemic to China in Songyang.

结果表明，松阳蕨类植物共有38科72属161种7变种；优势科为鳞毛蕨科、蹄盖蕨科、水龙骨科、金星蕨科、卷柏科、铁角蕨科，优势属为鳞毛蕨属、卷柏属、铁角蕨属、复叶耳蕨属、凤尾蕨属、短肠蕨属、瘤足蕨属；科的分布以世界分布和泛热带分布为主，属的分布以泛热带分布为最多，种以东亚分布类型为主，特别是中国—日本分布类型最多，表现出亚热带向暖温带过渡的特点；本区与邻近地区蕨类植物区系关系的密切程度由大到小依次为西南、华南、华中、日本、华北、西北、东北；与邻近的6个山地蕨类植物区系的亲缘关系密切，可以划为同一自然区；与国内11山地蕨类植物区系相比，松阳的蕨类植物丰富程度不高；松阳拥有37种中国特有蕨类植物及一些珍稀蕨类植物，有较高的保护价值。

The 134 genera of vascular plants had 14 areal-types, including 42 cosmopolitans 55 temperate types 30 tropic types 2 Mediterranean-types, 2 East Asia types and 1 endemic species. The cosmopolitan and temperate type accounted for 31.34% and 41.04% of all the genera, respectively revealing the azonal feature of the wetland vegetations and the influences of cold and wet climate on the formation and distribution of the vegetations.

维管束植物属有14个地理分布区类型，包括世界分布属42属、温带分布属55属、热带分布属30属、古地中海属2属、东亚分布属4属、中国特有分布属1属，其中世界分布属和温带分布属分别占区系维管束植物总属数的比例较高，分别为31.34%和41.04%反映了湿地植被的隐域性和冷湿气候对湿地植被发育、分布的影响。

Higher Ca distributed in bulliformcell than in mesophyll cell and bundle sheath cell of dune reed, higher Mg distributedin mesophyll cell and higher K, Na and Cl distributed in sheath cell HigherNa and Mg distributed in mesophyll than in bulliform cell and bundle sheathcell of light salt meadow reed, and higher K, Ca and Cl distributed in itsbundle sheath cell. Higher Na and Mg distributed in bulliform cell than in mesophyllcell and bundle sheath cell of heavy salt meadow reed, higher K, Ca and Cl distributedin its mesophyll cell. This paper discussed the distribution conditions of theabove five ions in leaf cell of the four reed ecotypes and the meaning ofphysiological adaptation to habitat in detail.

沙丘芦苇的泡状细胞内Ca分布较叶肉细胞和鞘细胞高，叶细胞内Mg分布较高，在鞘细胞内K，Na和Cl布较高；轻度盐化草甸芦苇叶肉细胞内分布了较多的Na和Mg，在鞘细胞内K，Ca和C1分布较叶肉细胞和泡状细胞高；而重度盐化草甸芦苇泡状细胞内分布了较多的Na和Mg，叶肉细胞分布了较多的K，Ca和Cl；详细讨论了以上五种离子在不同生态型芦苇叶片内不同细胞类型的分布状况与环境适应的意义。

Based on the distribution of the genera in the world,the eight distribution types of the genera were divided.In addition,the distribution characters of the Perlidae in China were also probed preliminarily.So far two subfamilies,four tribe and twenty genera have been found in China.Ten of them,of which three genera are endemic to China,are the Oriental genera;one Palaearctic genus;three Oriental-Palaearctic genera;one Oriental-Nearctic genus;four Oriental-Palaearctic-Nearctic genera and one Oriental-Palaearctic-Nearctic-Afrotropical genus.

文中还就中国郋科昆虫的地理分布及特点作了初步的探讨，结果表明：在我国已知的2亚科4族20个属中，东洋区分布的有10个属，其中有3个属仅分布于我国；古北区分布的有1个属；东洋-古北区分布的有3个属；东洋-新北区分布的有1个属；东洋-古北-新北区分布的有4个属；东洋-古北-新北-非洲区分布的有1个属。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。