共查询到19条相似文献，搜索用时 218 毫秒
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湘西植烟土壤pH状况及空间分布研究 总被引：7，自引：2，他引：5
为了解湘西州植烟土壤pH分布状况,测试了湘西州主要烟区488个土壤样本,采用传统统计学和地统计学方法分析了湘西州植烟土壤pH适宜样本分布、县域差异、土壤类型差异、海拔差异及空间分布。结果表明：（1）湘西州植烟土壤pH总体适宜,平均为5.87,变异系数为11.13%;pH处于适宜烤烟生长的5.5~7.0间的土壤样本占72.75%。（2）湘西州主产烟县植烟土壤pH大小表现为：保靖县＞龙山县＞芦溪县＞凤凰县＞花垣县＞永顺县＞古丈县。（3）湘西州烟区不同土壤类型pH大小表现为：灰黄棕土＞石灰土＞灰黄泥＞灰黄土＞黄壤＞红壤＞浅灰黄泥＞水稻土。（4）湘西州植烟土壤pH有随海拔升高而升高的趋势。（5）植烟土壤pH Kriging插值图显示,湘西州植烟土壤pH呈斑块状分布态势,在保靖县、龙山县和永顺县的部分地区各有一个高值区,在古丈县的中部有一个低值区。 相似文献
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甘蓝型油菜种皮颜色的遗传分析 总被引：1，自引：0，他引：1
应用主基因 多基因混合遗传模型并结合经典遗传学方法对甘蓝型黄籽油菜No.2127-17与黑籽油菜99Yu42和恢5148-2杂交组合的6个世代(P1,F1,P2,B1,B2和F2)群体的种子种皮颜色进行联合分析。经典遗传学表明,种皮颜色受部分显性核基因控制,并具有母体遗传特点。混合遗传分析表明,受一对加性-显性主基因 加性-显性多基因(D-1)控制,主基因对种皮颜色的表现起主要作用。其中,组合No.2127-17/99Yu42中主基因的加性和显性效应分别为7.58和2.48,而多基因则分别为1.91和1.33。在B1,B2和F2群体中种皮颜色主基因遗传率分别为35.34%,63.27%和60.76%,多基因遗传率分别为2.80%,7.12%和13.29%。环境对其遗传表现影响较大,方差占总方差的29.95%,~61.86%。 相似文献
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基于贝叶斯统计的谷物胚乳性状QTL多区间作图方法 总被引：1，自引：0，他引：1
贝叶斯统计学已被广泛地应用在现代科学的各个研究领域。本研究将贝叶斯统计方法和谷物三倍体胚乳性状数量遗传模型相结合,以F2群体中各植株的分子标记基因型以及植株上若干粒自交种子胚乳性状的单粒观测值为数据模式,提出了胚乳数量性状基因座(QTL)多区间作图的贝叶斯方法。该方法首先构建胚乳性状的多区间多QTL遗传模型,然后通过基于Gibbs抽样和Metropolis-Hastings算法实现的马尔可夫链蒙特卡罗(MCMC)方法同时获得多个QTL效应和位置的估计。方法的有效性通过一条长染色体的模拟实验进行了验证,结果表明,本文提出的贝叶斯多区间方法能够准确地估计胚乳性状QTL的位置和效应,并可有效区分两种显性效应。 相似文献
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讨论了近亲交配群体在世代交替中配子间平均互信息性质;定义了配子间的近交关联信息系数,并与近交系数比较,阐述了配子间的近交关联信息系数的优点。结果表明,应用信息论模型研究群体遗传学与以往统计学方法具有一致性,而且还具有信息学的意义和优点。 相似文献
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《分子植物育种》2017,(4)
大麦的糖化力和蛋白质含量是影响大麦品质的重要指标,对此类性状进行QTL定位具有重要的经济意义。本研究分别采用传统的单QTL扫描方法和3种贝叶斯LASSO方法实现此类性状的QTL精细解析。在对大麦蛋白质含量的QTL检测上,单QTL扫描方法共检测到了3个QTL,而3种贝叶斯方法检测到了7个QTL,其中2个与单QTL扫描方法检测的QTL吻合。在大麦糖化力的QTL检测上,传统的单QTL扫描方法共检测到了3个QTL,而3种贝叶斯方法除了检测到这3个QTL外,还检测发现了额外的2个连锁的QTL;表明贝叶斯方法在北美大麦蛋白质含量和糖化力QTL检测中可以更加有效地分离处于连锁位置或接近状态的QTL进而提高QTL的检测效力。 相似文献
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陆地棉染色质在海岛棉种质中的分布植物渐渗育种的分子分析①在主要农作物中，棉花存在两个互交可育的广泛栽培种并利用共同的经济作物棉纤维。历史上的许多证据和经典遗传学研究都暗示许多改良后的海岛棉品种（如ＳｅａＩｓｌａｎｄ棉，Ｅ－ｇｙｐｔｉａｎ棉，Ｐｉｍａ棉... 相似文献
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There are subjective uncertainty and randomness in concrete carbonation depth forecasting model and the model distribution parameters, which cause significant errors in application to practical engineering. Actual inspection data can not often be used to forecast concrete carbonation depth in the actual project due to its small sample size and lack of sufficient completeness. The weighted value of several model calculations was used to forecast the concrete carbonation depth. By using Bayesian approach, the inspection information and the prior prediction model were incorporated, and the prior model weights and model distribution parameters statistics were updated. It is more accurate to forecast the carbonation depth using the updated model weights and model distribution parameters. The procedure for updating the mechanical model selection and distribution parameter statistics was illustrated with a 10-year-long concrete carbonation test. 相似文献
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Aiming at insufficiency exists in the process of machinery fault diagnosis at present, the paper takes consider of the application of information fusion technology in fault diagnosis to make fault diagnosis effectively. The applications of information fusion methods based on neural network, the Bayesian theory and the D-S theory are discussed in detail. Example is also given to explain the validity of information fusion technology in diagnosis analysis. 相似文献
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To understand the processes of growth and biomass production in plants, we ultimately need to elucidate the structure of the
underlying regulatory networks at the molecular level. The advent of high-throughput postgenomic technologies has spurred
substantial interest in reverse engineering these networks from data, and several techniques from machine learning and multivariate
statistics have recently been proposed. The present article discusses the problem of inferring gene regulatory networks from
gene expression time series, and we focus our exposition on the methodology of Bayesian networks. We describe dynamic Bayesian
networks and explain their advantages over other statistical methods. We introduce a novel information sharing scheme, which
allows us to infer gene regulatory networks from multiple sources of gene expression data more accurately. We illustrate and
test this method on a set of synthetic data, using three different measures to quantify the network reconstruction accuracy.
The main application of our method is related to the problem of circadian regulation in plants, where we aim to reconstruct
the regulatory networks of nine circadian genes in Arabidopsis thaliana from four gene expression time series obtained under different experimental conditions. 相似文献
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农业高校图书馆与地方信息网站共建信息服务平台的研究 总被引：1，自引：1，他引：0
为了更好地发挥农业高校图书馆在农业信息化进程中的作用,更好地为当地的“三农”提供信息服务。通过网络访问的方法对山东省17个市辖区的农业信息网进行了调查,发现各地的农业信息网站严重缺乏专业信息机构的信息支持。结合农业图书馆的资源优势和地方网站的平台优势,提出农业高校图书馆与地方信息网站共建信息服务平台的具体设想,构建了“实用技术”、“专家在线”、“农民培训”、“农业统计”、“农家书屋”、“信息服务”6个模块的基本框架。 相似文献
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A capital asset pricing model and the corresponding investment strategy are investigated for the financial market with asymmetric information structure. Suppose that investors can be defined with three kinds: informed trader, under-reaction trader and over-reaction trader; all traders use Bayesian principle to modify their prior distributions. The anthors obtain the equilibrium price of the risky asset in the short run and the rational investment strategy. 相似文献
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In order to solve structural multi-damage identification problem, a two-stage method based on Bayesian theory and immune genetic algorithm (IGA) is presented. Firstly, structural modal strain energy and frequency are considered as two kinds of information sources, and Bayesian theory is utilized to integrate the two information sources and preliminarily detect structural damage locations. Then, immune genetic algorithm is used to identify structural damage extents. Considering the convergence rate of basic IGA is still not very good, some improved strategies, such as culture vaccine, two termination conditions, are presented. It is shown that the two-stage method can precisely identify structural damage locations and extent, and the calculated results of the proposed improved IGA are obviously better than those of both the basic IGA and simple genetic algorithm. 相似文献
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Patricia Menéndez Paul Eilers Yury Tikunov Arnaud Bovy Fred van Eeuwijk 《Euphytica》2012,183(3):379-387
The search for models which link tomato taste attributes to their metabolic profiling, is a main challenge within the breeding
programs that aim to enhance tomato flavor. In this paper, we compared such models calculated by the traditional statistical
approach, stepwise regression, with models obtained by the new generation of regression techniques, known as penalized regression
or regularization methods. In addition, for penalized regression, different scenarios and various model selection criteria
were discussed to conclude that classical crossvalidation, selects models with many superfluous variables whereas model selection
criteria such as Bayesian information criterion, seem to be more suitable, when the goal is to find parsimonious models, to
explain tomato taste attributes based on metabolic information. An exhaustive comparison of the discussed methodology was
done for six sensory traits, showing that the most important covariates were identified by the stepwise regression as well
as by some of the penalized regression methods, despite the general disagreement on the size of the regression coefficients
between them. In particular, for stepwise regression the coefficients are inflated due to their high variance which is not
the case with penalized regression, showing that this new methodology, can be an alternative to obtain more accurate models. 相似文献
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研究不同区域农户的信息需求状况对推动农村信息服务有着重要的意义。本文基于问卷调查,对陕西不同区域农户的信息需求状况进行了分析。研究发现,农户在信息需求的内容、获取工具、获取渠道、影响信息获取的因素和信息服务的满意度方面都存在显著的区域差异。本文的研究成果将为各级政府和相关企业提供借鉴和参考。 相似文献