查询词典 population parameter

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。

Mutation rate is a fundamental parameter in models of population genetics and molecular evolution.

突变机率在族群遗传学以及分子演化的模型中是个基础的参数。

Genetic algorithm ; initial population ; operational parameter ; convergence ; uniform design

遗传算法；初始种群；操作参数；收敛性；均匀设计

Nonlinnear ; population model; parameter system; singularity; stability

非线性；人口模型；参数系统；惟一性；稳定性

The basic conceptions and primary characteristics are introduced in this paper. This paper discuss some primary factor when genetic algorithm applied on optimal design, for example the mathematical model the constrained problem、the initial population and the controls parameter of genetic algorithm .

在广泛阅读文献和调研的基础上，本文对遗传算法及其在结构优化设计应用中的相关内容进行了分析和综合，对结构优化设计的基本概念、主要特点进行了介绍，对遗传算法应用于结构优化设计时的数学建模、约束条件处理、初始种群的产生及其遗传算法控制参数的选择几个关键因素作了概要的分析与研究。

Seed dispersal is one of the processes of landscape ecology. Acknowledge of seed dispersal process and mechanism not only revealing future construction composition and dynamic about species population and community, applying parameter for landscape model, but also providing theoretical foundation for vegetation resume and environment protection.

种子扩散研究是有关景观过程的研究，了解种子扩散的过程以及扩散机制，不仅能够了解物种、种群以及群落未来的结构、组成与动态、为景观模型提供参数，而且为植被的恢复、自然环境的保护提供理论依据。

Based on a great many literature, this paper analyzes and summarizes the genetic algorithm for the design of structural optimization. The basic conceptions and primary characteristics are introduced in this paper. This paper discuss some primary factor when genetic algorithm applied on optimal design, for example the mathematical model、the constrained problem、the initial population and the controls parameter of genetic algorithm Aimed at the characteristic of structural optimization and finite-element analysis, this paper accomplishes the optimal program based on the simple genetic algorithm.

在广泛阅读文献和调研的基础上，本文对遗传算法及其在结构优化设计应用中的相关内容进行了分析和综合，对结构优化设计的基本概念、主要特点进行了介绍，对遗传算法应用于结构优化设计时的数学建模、约束条件处理、初始种群的产生及其遗传算法控制参数的选择几个关键因素作了概要的分析与研究。

Based on a great many literature, this paper analyzes and summarizes the genetic algorithm for the design of structural optimization. The basic conceptions and primary characteristics are introduced in this paper. This paper discuss some primary factor when genetic algorithm applied on optimal design, for example the mathematical model、the constrained problem、the initial population and the controls parameter of genetic algorithmAimed at the characteristic of structural optimization and finite-element analysis, this paper accomplishes the optimal program based on the simple genetic algorithm.

在广泛阅读文献和调研的基础上，本文对遗传算法及其在结构优化设计应用中的相关内容进行了分析和综合，对结构优化设计的基本概念、主要特点进行了介绍，对遗传算法应用于结构优化设计时的数学建模、约束条件处理、初始种群的产生及其遗传算法控制参数的选择几个关键因素作了概要的分析与研究。

Acute toxicity testing method was used to study effects of different density of Prorocentrum donghaiense,Heterosigma akashiwo and Alexandrium tamarense on mortality rates and population growth parameter of Brachionus plicatilis under controlled experimental conditions.

应用急性毒性试验方法，研究了可控生态条件下不同密度的东海原甲藻、赤潮异弯藻和塔玛亚历山大藻对褶皱臂尾轮虫的致死率和种群增长参数的影响。

We show that a supercritical Hopf bifurcation will occur under some conditions by using the density dependent rate in immature prey population as bifurcation parameter. Sufficient conditions which guarantee the uniform persistence and global stability of boundary equilibrium are also obtained.

我们以幼年食饵个体之间的密度制约率作为分支变量得到在一定条件下将出现超临界Hopf分支，并得到了系统一致持续生存和边界平衡点全局渐近稳定的充分条件。

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。