二项分布

Some conclusions are followed:(1)the reaction ratio of boron is 12% in primary combustion;(2)the degree of agglomeration can be decreased adopting boron coated with AP;(3)the content of oxygen is very important for afterburning efficiency;(4)the afterburning efficiency will be changed with different air-gas ratio;(5)the head distance of after-burning chamber is increasing, the circumfluence in the head of after-burning chamber is stronger and the distribution of fuel backward the after-burning chamber is more well-proportioned.(6)the combustion efficiency of DR will be improved by increasing the area of fuel nozzle.(7)the angle between dual air-inlets have complex influence with the combustion of DR.

通过本项研究，取得如下结论：（1）一次燃烧硼反应比例在12～15％之间；（2）AP包覆硼，可以降低硼结团度，有利于一次燃烧喷射效率的提高，也有利于硼在补燃室进行二次燃烧；（3）进气空气中的氧含量对二次燃烧非常重要；（4）对于一定配方的含硼富燃推进剂，不同的空燃比，二次燃烧效率不同；（5）补燃室头部距离的增加能增强补燃室头部回流以及提高燃料在补燃室后段分布的均匀性；（6）在一定范围内，增加一次燃气喷嘴面积能提高冲压发动机燃料的燃烧效率；（7）进气道夹角对补燃室内燃料的燃烧影响复杂。

Exponential family is the most commonly used family in statistics, which include many families such as normal?Poisson and Gamma family.

指数族是统计学中应用最广泛的分布族，它概括了许多常见的统计分布，特别是正态、二项、Poisson、Gamma等分布。

The spatial distribution of intra-node flux and source were approximated by a new orthogonal quadratic polynomial expansion, and a second-order polynomial provided the spatial expansion of transverse-leakage. The neutron angular distribution of flux and transverse-leakage were represented by the S quadrature set.

节块内横向积分通量、中子源的空间分布使用新的正交二次多项式近似；横向泄漏项的空间分布使用二阶多项式近似；中子通量和横向泄漏的角度通过离散纵坐标S

And such methods V/m ratio t-test, negative binomial parameter, index of dispersion, Cassie index, index of clumping, index of mean crowing and index of patchiness are employed to analyse various dominant populations of Heptacodium miconioides community in the Tiantai Mountain in Zhejiang province and distributive patterns of Heptacodium miconioides community in different quadrats, and this paper also examines the intensity of Heptacodium miconioides population in different quadrats by means of stand classes.

摘 要 以浙江省天台山七子花群落为研究对象，采用相邻格子样方法取样数据，应用方差／均值比的t检验法、负二项参数、扩散型指数、Cassie指标、丛生指标、平均拥挤指数和聚块性指数等方法，分析了七子花群落各优势种群以及七子花种群在各样地中的分布格局，并分立木级对七子花种群在不同样地内的集群强度进行了测定。

Rigida population were clumping, and v/m ratio, negative binomial parameter, patchiness index, clumping index, mean crowing index and Morisita＇ s index were 1.98, 1.84, 1.54, 0.98, 2.79 and 1.54 respectively.

结果表明，杜松种群的空间分布格局为聚集分布，其v／m值、负二项参数、聚块性指数、丛生指数、平均拥挤度和Morisita指数分别为1.98、1.84、1.54、0.98、2.79和1.54。

In this thesis, three major achievements were made in theoretical study: conditions and rules for preparing nano-powders by chemical precipitation are analyzed from the point of view of thermodynamics and kinetics, the principle, standards and experimental method for the aqueous dispersion of nano-scaled metal oxide powders were proposed and verified, mathematical model of nano-filming addition of dopants by chemical coprecipitation was established. In experimental research, nm-ZnO, nm-Bi〓O〓, nm-Co〓O〓 and nm-MnO powder with spherical shape, narrow particle size distribution and small particle size were prepared successfully, highly stable and dispersive aqueous suspensoid of nm-ZnO, nm-TiO〓, nm-Co〓O〓 and nm-MnO powder were prepared successfully and surface modification on these nano-powders was also achieved, 0-3 nanocomposite ZnO varistors with nm-ZnO, nm-TiO〓and nm-MnO respectively were prepared successfully by conventional mechanical attrition, and exhibited much better electrical properties than those of conventional varistors.

综上所述，本文在理论研究方面取得了三项成果：（1）从热力学和动力学角度推导并分析了液相化学沉淀法制备纳米粉体的反应条件和规律，（2）提出了纳米氧化物的水分散体系的设计原理、规范和通用实验步骤，（3）提出了共沉淀的数学模型和计算方法；在实验方面所取得的成果有：（1）成功制备了粒度小、分布窄、形貌对称的纳米氧化锌、纳米氧化铋、纳米氧化钴和纳米氧化亚锰，（2）成功地制备了纳米氧化锌、纳米二氧化钛、纳米氧化钴和纳米氧化锰的高稳定分散悬浮液并实现了干粉体的表面改性，（3）成功地进行了纳米氧化锌、纳米二氧化钛和纳米氧化锰对压敏电阻的0—3复合掺杂实验，试样性能远优于常规压敏电阻，为实现压敏电阻的高能高压化提供了新的方法和思路。

"Davidia involucrate" was a rare valuable and endangered plant in China. In this article, We studied the distribution pattern of its population with t test of Dispersal index, X^2 test of Poisson distribution and F test of Morisita's index. Its assemble intensity is also analyzed through Negative binomial index, Green's index, Lloyd's index and Patchness index.

采用扩散系数的t检验、Poisson分布的x^2拟合检验及Morisita指数的F检验来研究珙桐种群的空间分布格局类型，用负二项参数、Green指数和Lloyd的平均拥挤度m(上标*与聚块性指标来研究珙桐的聚集强度。

Bis (P—bromobenzylamino) ethane and 1,2—bis (m—Iodobenzylamino) ethane may be prepared by condensation of the corresponding halo benzaldehyde with ethylenediamine and followed by catalytic hydrogenation of the Schiff's bases over Pto_2 in glacial acetic acid solutions: Both Ⅱa and Ⅱb may react in neutral mediam with aldehydes to form well—defined crystalline tetrahydro—imidazole, which may be served as derivatives of identification for aldehydes: Under the same condition, however,Ⅱb may ...

用1，2-二乙烷与二十余种醛类作用，得到有固定熔点的晶体衍生物，它们的熔点分布在85—210℃之间，产率为40—96％，这试剂与甲基酮类在相同条件下无反应，因此，它可作为鉴定醛类的专属试剂。 2。上述衍生物用稀盐酸在室溫处理，能发生水解，可以定量地收回原来的醛，因此这试剂又可作为分离醛类的试剂。 3。上述衍生物可以用非水滴定法半微量地测定其分子量可作为鉴定醛类的另一项参考数据。 4.1，2-二乙烷与醛类能生成晶体衍生物，但这试剂也与甲基酮在同样条件下发生反应，所以不适合作为鉴定醛类的专属试剂。

A multi-distance measurements method is employed in this paper. A single parameter fitting method and a double parameters (reduced scattering coefficient and amplitude factor) fitting method on the basis of the least square Newton fitting algorithm is used to derive the optical parameters respectively. For the finite-thickness homogenous tissue, it can be concluded that the rest terms in expressions of diffusion reflectance and transmittance for the corresponding tissue geometries that subtract the exponential term contained source-detector distance depend on the detected position weakly.

在多程测量的基础上，使用单参数最小二乘牛顿法拟合方法和双参数（约化散射系数、幅度因子）最小二乘牛顿法拟合方法，得到有限厚均匀组织的反射率分布和透射率分布公式中除去包含测量位置的指数项的其它部分对测量位置皆具有弱依赖性的结论，并对拟合结果进行了分析讨论；而对于有限厚平板状双层组织，可根据对反射测量结果及透射测量结果进行拟合所得的约化散射系数间的差异及常数因子的正负判断双层组织的可能结构分布。

First of all, we get the distribution of the maximal deficit in the course from ruin to the first recovery in the continous time compound binomial model.

首先，算出了连续时间复合二项模型从破产到第一次恢复的过程中破产赤字的最大值所服从的分布。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。