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1.
调查4个柞蚕亲本原种、8个杂交种F1代的5龄幼虫腹足趾钩数量,并对其进行统计分析,发现柞蚕幼虫腹足趾钩数量品种间存在显著差异,但同一品种雌雄间差异不显著。其遗传方式为偏父遗传;杂种F1代表现杂种优势。同时对幼虫腹足趾钩数与若干经济性状的相关性做了分析,发现幼虫腹足趾钩数与收蚁结茧率、单蛾结茧数、单蛾茧层量、单蛾收茧量、蛹期生命率等性状呈显著正相关关系。因此,认为柞蚕幼虫双足趾钩数目可以作为一项生理(形态)指标,在柞蚕育种、杂种优势的利用及杂交组合的选配中用于预测产量及其它生命力性状。  相似文献   

2.
通过田间人工接虫、田间调查和室内生化分析研究了不同高粱材料对蚜虫的抗性及其与次生代谢物的关系。结果显示,高粱抗蚜虫性状属单基因显性简单遗传,通过回交转育方式容易获得抗性基因。高粱抗蚜虫性状与植株体内多酚氧化酶活性及丁布(DIMBOA)含量间的关系表现出年度间的差异,有时抗性与感性材料间的多酚氧化酶活性和丁布含量都不表现质的不同,说明另有更重要的次生代谢物实际控制着高粱的抗蚜性状。  相似文献   

3.
以8个不同粒型粳稻品种为试材,研究了优质米品种的产量性状、品质性状及这些性状间的关系。结果表明,普通粒型品种的成粒率较高,每穗成粒数较多,产量高于长粒型品种。糙米率、精米率与成粒率呈显著正相关,整精米率与成粒率呈极显著正相关,提高成粒率对其他米质性状无明显负作用,因此,能进一步提高米质,使高产和优质在较高的水平上统一起来。粒长与糙米率、精米率、整精米率呈极显著负相关,因此,在辽宁的自然条件下,既高产又优质的品种谷粒不宜过长。  相似文献   

4.
以粳稻沈农89-366为母本与粳、籼、爪哇3种类型稻杂交,F1代稻谷的米质表现值介于双亲之间,接近亲本均值。米形呈现正态分布的数量性状遗传特点。稻谷粒形与米形呈极显正相关。米长与米宽和出米率呈极显和显的负相关,与长宽比和AC值呈极显和显正相关。中国籼、粳稻米质改良的方向是选育米形偏籼面米质偏粳的中间类型米,改良的途径是不同类型间的杂交获得各自优良米质性状的互补。在收获前以稻谷或稻米的长度和长宽比为指标进行米质选择是简便、易行和高效的田间米质选择方法。  相似文献   

5.
采用灰色关联分析的方法,研究了气候因子对稻米品质的影响。结果表明:8月中旬至9月中旬是影响稻米品质的气候关键期,这个时段的温度是影响稻米品质最主要的气候因子。其次为日照,降水的影响最小。在此基础上进一步分析了各项稻米品质指标与其关键期气象要素的关系,得出整精米率与8月中旬至9月中旬的平均温度呈凸的抛物线关系,与日照总时数呈线性正相关:垩白粒率与8月中下旬的平均气温呈线性正相关:胶稠度和直链淀粉与8月中旬至9月上旬的平均气温分别呈抛物线关系和负的线性相关关系。最后,采用2个定点资料检验了各相关规律.证实回归值和实测值的总体残差较小.说明由历史资料所寻求的规律与实际情况相吻合,为今后的相关研究提供一定的借鉴。  相似文献   

6.
研究了珠穆朗玛峰北坡地区沿绒布河谷海拔4400~5550m的夏季土壤中水解酶类脲酶、中性磷酸酶活性,并探讨了这两种土壤酶与土壤有机质和海拔高度的相互关系.结果表明:(1)随着海拔升高,土壤脲酶、中性磷酸酶活性呈高低波动变化,在研究区域出现多个峰值,总的趋势是上升的,其最大值分别出现在海拔5500m和5450m处.(2)偏相关分析表明,土壤脲酶活性与有机质含量呈正相关,土壤中性磷酸酶活性与有机质含量呈显著正相关;土壤脲酶活性与海拔的相关性不具显著性意义,中性磷酸酶活性与海拔呈极显著正相关.  相似文献   

7.
以8个低酚棉品种(系)为亲本材料,按Griffing4方法配制杂交组合。对28个组合的F1代进行了分析,结果表明,低酚棉品种(系)间杂种F1具有较强的杂种优势,其籽棉产量和皮棉产量的最大超标优势分别达到27.74%和24.59%,对亲本10个性状的配合力方差分析表明,亲本一般配合力均达到显或极显水平,另有5个性状的组合特殊配合力达到显水平,配合力效应分析表明,中无1051和中棉所18号的综合  相似文献   

8.
以三组不同地理来源的9个亲本组配二类18个杂交组合。研究结果表明:大豆品种间杂交一代的杂种优势普遍存在;不同性状、组合间有明显差异。单株粒重的优势最强,地理远缘组合的大部分性状超亲优势率均大于相同地理来源组合。选择地理上远缘且生态类型上有差异的双亲进行组配,杂种一代的产量超亲优势最强。遗传相关分析结果表明:F_1的产量与产量因素中的单株粒数、单株荚数呈极显著遗传正相关;与每荚粒数、百粒重相关不显著。对产量因素与产量进行通径分析表明:单株粒数对产量的直接作用大于单株荚数,是杂种一代产量优势最主要的贡献因素。对 F_1的分枝、百粒重性状与双亲均值、小值亲本、大值亲本的关系进行通径分析结果表明:分枝数以双亲均值对 F_1的直接影响最大;百粒重以大值亲本对 F_1的直接影响最大。  相似文献   

9.
玉米种子经0.003mT,50mT和100mT的磁场处理后,灌浆速度增大,籽粒中营养物质含量增高;穗粒数、粒重等性状得以改善,双穗率增加,空秆和倒折率降低,产量提高2.06%-9.46%;与对照相比丹玉13号0.003mT、掖单19号100mT处理的增产效果达到了5%显水平,掖单19号0.003mT达到1%显水平。  相似文献   

10.
本研究以南昌白猪为对象,滨湖黑猪、大约克、长白、杜洛克、长×南、杜×南等作对照,对7个品种或杂交组合的11项常规肉质性状进行了研究,并对其杂种优势和遗传方式进行了初步分析。结果表明,南昌白猪肉质与大约克相近,优于长白、杜洛克、长×南和杜×南组。在三个外来纯种猪中,大约克肉质领先,长白最差,杜洛克介于两者之间。两个二元杂交组的肉质性状除个别指标以外,一般都低于南昌白猪,但优于对应的亲本外种猪。长×南和杜×南组在不同性状上各有高低。杂交亲本对杂种后裔的遗传影响强度,南昌白猪的大理石纹、96小时贮藏损失、肌肉嫩度高于长白、杜洛克;长白猪的肉色、PH值高于南昌白猪;杜洛克的肉色、24小时贮藏损失高于南昌白猪,其它各项肉质指标都呈亲本间均势状态。  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

15.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

16.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

17.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

18.
This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)SM and Team Software Process (TSP){SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.  相似文献   

19.
基于复小波噪声方差显著修正的SAR图像去噪   总被引:4,自引:1,他引:3  
提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。  相似文献   

20.
蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。  相似文献   

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