查询词典 random-mating population

Controls were a sex and age-group matched random sample of the population of each province.

从两省随机抽取性别、年龄频率匹配的人群作为对照。

Random changes in allele frequency can lead to fixation and the progressive loss of genetic variation from the population.

基因频率的随机变化导致来自种群的遗传变异的固定和逐渐丧失。

Common buckwheat ( F. esculentum ) is an allogamy crop, which is heterogony. There is heterogeneity in the species. To reveal the genetic diversity within cultivar population, In order to explore the sampling strategy that can reveal genetic diversity of buckwheat resources on the molecular level. PCR with intron-splice junction primers and long random primers was employed to reveal the genetic diversity within nine common buckwheat varieties and one tartary buckwheat cultivar population among different individuals. We established the sampling strategy in its genetic diversity study. Then we used the established sampling strategy, and the same PCR markers technique,to analysis the genetic diversity of 86 common buckwheat resources, the main results are as follows

甜荞是花柱异长自交不亲和的异花授粉作物，品种内存在一定的异质性，为了准确揭示甜荞遗传资源的遗传多样性，本研究采用因子分析法对86份甜荞遗传资源农艺性状数据进行分析；采用长随机引物和内含子切接点引物的PCR分子标记技术，对9个甜荞品种和1个苦荞品种不同个体间的遗传多样性进行了分析，建立了甜荞资源遗传多样性研究的取样策略；并利用建立的取样策略，采用PCR标记技术，对这86份甜荞资源的遗传多样性进行了分析，取得如下主要结果

CBFEC emphasizes direct correspondence of concepts in EC with its software architecture for ease of understanding and using; minimal coupling with specific problem structure for easy adaptation it to solve a large number of wholly different problems; interface-centered design for extendibility. To achieve those objects, the problem-solving method of EC is analyzed and the problem-solving procedure of EC is divided into three interactive aspects: population-based stochastic searching mechanism, problem specific information to implicitly guide the stochastic searching, and the observation and control of the computation procedure of EC. Then the key concepts of EC are identified in those three aspects; the normal implementations of those concepts are summarized; the interfaces represents those concepts in software are abstracted; the collaborations of components through those interfaces are designed. CBFEC is implemented on mainstream component software platform COM/DCOM (Component Object Model/Distributed COM from Microsoft), which includes interfaces definitions, commonly using EC components implemented those interfaces, such as Simply EA component, Steady State EA component, EA component, EA component, Population component, Tournament Selection component, Linear Ranking Selection component, Nonlinear Ranking Selection component, Random Number Generator component, etc, and the collaborations of those components through those interfaces.

具体的做法是把演化计算看作是基于组件的软件工程的一个应用领域：首先分析了演化计算求解问题的一般思路和方法，把演化计算问题求解过程分为："设计基于群体的随机搜索机制"、"研究问题的性质并以此隐含地定义算法的搜索方向"和"求解过程的观察与控制"三个部分；然后分别找出各个部分中的关键概念，总结这些概念现有的一般实现方法，抽取其本质，以此结合设计模式来定义组件软件的接口；通过分析演化计算各个概念之间的相互联系来设计组件软件间通过接口的进行交互的方式；最后还在目前一种主流组件软件开发平台COM／DCOM（微软提出的组件对象模型）的基础上实现了常用的演化计算组件，如简单演化算法组件、稳态演化算法组件、演化算法组件、演化算法组件、种群组件、锦标赛选择策略组件、线性排名选择策略组件、非线性排名选择策略组件、随机数发生器组件等等。

In chapter 10, we propose the random weighting approximation method for distribution of sample mean under simple random sampling in one-dimensional finite population.

第十章 将随机加权法首次应用到简单随机抽样方案下的样本均值分布逼近问题中，从数字特征角度说明了随机加权方法在抽样理论中的可用性，从而拓广了随机加权法的应用范围。

The main achievements of the project are as follows: 1 the hypothesis that a decrease in seed mass causes an increase in mean dispersal distance has been tested based on the experiments of weed dispersal by wind. The experimental results partly support the hypothesis. The results will help farmers to make an optimal strategy of weed control; 2 a statistic method for inferring probabilistic distribution function of a random variable has been developed, by which probabilistic distribution functions of weed species dispersal have been determined; 3 the reproduction structure of Bromus sterilis has been studied; 4 a more complex CA model with 25 neighborhood cells were built, which can simulate spread of a weed population. This work promotes developments in both theory and application of CA models; 5 the "mean law" in weed control has been proposed. Accordingly, the algorism of patch spring may be calibrated; 6 the "patch" and "true patch" have been mathematically defined so that herbicide can be efficiently applied; 7 simulation validates that initial configurations of weed will affect dispersal of its population and strategies of controlling it, or its distribution patterns affect its dispersal progresses.

主要完成的工作和取得的成果有：1）用实验证实了重量较轻的杂草种子并不一定飞得比较重的远，其结果有助于农民制订杂草的优化控制策略；2）发展了一种推断随机变量分布函数的统计方法并用它来获得了几个杂草种的扩散分布函数；3）对杂草Bromus sterilis的繁殖结构进行了研究；4）建立了一个具有25邻的较复杂的能模拟杂草扩散的CA模型，并在理论和应用方面促进了CA模型的发展；5）在杂草控制方面提出了&平均法则&，据此可对按块施药方法进行校正；6）精确地定义了&块&和&真块&以便在杂草控制中能更有效地使用除草剂；7）模拟证实杂草种群的初始配置影响其扩散和控制策略，或者格局影响过程。

The two methods had accurate results in forecasting Cricetulus barabansis, but not in Meriones unguiculatus. It was mainly because Meriones unguiculatus population was affected by environment factors at random, and the dynamic tendency was not obvious. It meant that the two time series methods were accurate for the populations which were little affected by environment factors at random.

两种方法对黑线仓鼠捕获率的预测都比较准确，对长爪沙鼠捕获率的预测结果不准确，主要是因为长爪沙鼠种群数量受周围环境因素的影响随机性较大，趋势不太明显，说明此两种时间序列分析方法适用于受随机因素的影响较小，去掉随机因素的影响后有较好的趋势变化的种群。

Results of pattern dynamic analysis are that Fraxinus mandshurica, Phellodendron amurense, Ulmus propinqua, Ulmus macrocarpa population patterns turined to random type from aggregative type in series of seedling, sapling, little tree, middle scale tree and big tree, because of higher tiller capacity, Quercus mongolica population pattern is still aggregative type in big tree stage.

格局动态的分析表明，水曲柳、黄菠萝、春榆、大果榆种群幼苗一幼树一小树一中树一大树分布格局由集群分布逐渐变为随机分布，而蒙古栎由于较强的萌生性，大树阶段仍为集群分布。

Results of pattern dynamic analysis are that Fraxinus mandshurica, Phellodendron amurense, Ulmus propinqua, Ulmus macrocarpa population patterns turned to random type from aggregative type in series of seedling, sapling, little tree, middle scale tree and big tree, because of higher tiller capacity, Quercus mongolica population pattern is still aggregative type in big tree stage.

格局动态的分析表明，水曲柳、黄菠萝、春榆、大果榆种群幼苗―幼树―小树―中树―大树分布格局由集群分布逐渐变为随机分布，而蒙古栎由于较强的萌生性，大树阶段仍为集群分布。

In a no overlapping generation population with selection, mutation、migration and random drift under consideration, two mathematical models presented in this paper might describe change of frequencies of multiple alleles at a locus and population mean of metrical characters resp.

在假定无世代重叠，群体内存在选择、突变、迁移，且考虑漂变效应的情况下，本文所构建的两个数学模型可分别用来描述一个座位上多个主基因频率或数量性状群体均数的动态变化。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。