小麦随机多交后代中抗条锈(Puccinia striiformis)性的选择   总被引：1，自引：1，他引：1  

冯锋  曾士迈 《作物学报》1991,17(2):107-114

本试验用16个被认为可能具有水平抗性的小麦品种为基础材料,采用乙烯利化学杀雄或太谷核不育为手段进行随机多交,以相对抗病性综合指数(RRCI)表示抗病性强度,研究了小麦条锈病水平抗性的遗传力及人工选择下的遗传进度,结果指出:1)随机多交的后代系统中,出现了一些抗条锈性显著高于优良亲本的系统。2)抗条锈性的遗传力较高:化  相似文献   

大豆化学诱变育种及其规律的研究   总被引：12，自引：0，他引：12  

杜连恩  魏玉昌 《华北农学报》1989,4(2):39-43

应用化学诱变剂处理大豆种子,对M_1代植株的生育及形态均有强烈的抑制作用.M_1代所产生的形态变异主要是由于化学物质扰乱了植株生理而产生生理损伤所致.在M_2代植株各性状中以分枝数、株高、单株荚数的遗传变异系数较大,说明这些性状选择的潜力是大的,通过选择容易达到预期目标.诱变M_3代绝大多数性状仍在分离.加强选择,能选出早熟、大粒、农艺性状好、丰产的新品系.  相似文献   

基于B/S结构的数字地质图元数据信息系统设计与实现     

徐金鸿  朱秀峰  徐瑞松  夏斌 《农机化研究》2006,(9):106-109

以国土资源环境与区域经济信息系统信息共享元数据内容标准草案(“NREDIS”)为依据,结合ASP.NET技术,利用C#语言,设计了一个基于B/S(浏览器/服务器)结构的数字地质图元数据信息系统。实现了元数据标准的浏览和元数据的输入、查询及维护4大功能。研究成果为国家空间信息基础设施和数字地球的建设提供了一定的理论基础和技术原型,推动了地理空间信息的网络发布和共享。  相似文献   

离心泵整体叶轮流道数控加工误差的仿真     

于源  张连凯 《农业机械学报》2006,37(2):55-57

对数控加工所获得的叶轮流道的加工误差进行仿真。首先对刀位轨迹线进行归一化处理,以此计算出脊棱高度曲线,再采用线性插值的方法得到曲面上采样点的加工误差。由于自由曲面加工中的刀位点比较密集,本文利用彩色云图将加工误差可视化,完善了对数控加工结果的计算机几何仿真。该算法已在自行研制的叶轮CAM系统中得到验证,并且与实际加工结果一致。  相似文献   

基于遗传算法的泵汽蚀试验数据拟合   总被引：1，自引：2，他引：1  

唐平  李金伴  张荣标 《排灌机械》2002,20(1):37-39,46

文章对标准的遗传算法进行改进，采用了浮点数直接编码方式最优保留策略、算术交叉和非一致性变异算法等方法，并对泵汽蚀试验数据拟合问题进行分析，引入了此改进的遗传算法。最后给出了一组汽蚀试验数据，分析采用常规方法拟合和基于遗传算法拟合。结果说明了本文提出方法的可行性。  相似文献   

Combining deliberative and computer-based methods for multi-objective land-use planning     

K.B. Matthews  K. Buchan  A.R. Sibbald  S. Craw 《Agricultural Systems》2006

This paper reports the outcomes of a deliberative workshop comparing land-use plans proposed by land-manager or domain experts with those derived using a computer-based decision support system (DSS). The DSS integrates four main components, a geographic information system, land-use systems simulation models, impact assessments and land-use planning tools. The land-use planning tools draw on the other components to generate and evaluate alternative patterns of land use and management. Since the land-use planning tools are based on multi-objective genetic algorithms (mGAs) it is possible to generate a range of alternative plans that define the structure of the trade-off between the objectives. The workshop tasked the delegates with specifying land-use plans that achieved the best compromise between two objectives known to be non-commensurable and conflicting. The nature of the best compromise was dependent on their individual perspectives. The delegates proposed allocations both as individuals and in researcher-facilitated sub-groups. The mGA allocations were then compared with those derived by delegates and were found to be broadly similar in performance. Differences in the range of allocations considered feasible were explained by the hard and soft constraints on allocations agreed between the delegates and articulated within the workshop process. The hypothesis that part of the difference in performance between the mGA and delegate allocations was due to the delegates blocking together fields with the same land use for convenience of management was proved. The analysis of the group allocations revealed that the decision-making process had failed to improve on the individual allocations. From these results it was concluded that there was a potential role for mGA based land-use planning tools in researching into, and deliberating on, the possible impacts of policy or other factors affecting land-use systems. It was further concluded that the tools should not be used in isolation since there was the need for stake-holder inputs to adequately define the range of feasible and practical land-use plans.  相似文献   

Inverse Modeling to Quantify Irrigation System Characteristics and Operational Management     

Amor V.M. Ines  Peter Droogers 《Irrigation and Drainage Systems》2002,16(3):233-252

Remotely sensed (RS) data is a major source to obtain spatialdata required for hydrological models. The challenge for thefuture is to obtain besides the more direct observable data(landcover, leaf area index, digital elevation model andevapotranspiration), non-visible data such as soilcharacteristics, groundwater depth and irrigation practices.In this study we have explore the option of using inversemodeling to obtain these non-RS-visible data. For a commandarea in Haryana, India, we applied for the 2000–2001 rabiseason a RS-GIS-combined inverse modeling approach to derivenon-RS-visible data required in the regional application ofhydrological models. A Genetic Algorithm loaded stochasticphysically based soil-water-atmosphere-plant model (SWAP) wasdeveloped for the inverse problem and used in the study. Theresults showed good agreement with the inventoried data suchas soil hydraulic properties, sowing dates, groundwaterdepths, irrigation practices and water quality. The deriveddata could be used to predict the state of the system at anytime in the cropping season, which can be used to evaluateoperational management strategies.  相似文献   

遗传算法在离心泵叶片优化设计中的应用   总被引：2，自引：3，他引：2  

闫永强  梁武科 《排灌机械》2004,22(2):5-7

对遗传算法在流体机械优化设计中的应用现状作了较为全面的总结；提出了将遗传算法应用于离心泵叶片优化设计中，分析了遗传算法在离心泵优化设计中应用的可行性以及存在的问题；对离心泵优化设计的发展提出了一些新建议和尝试。  相似文献   

应用声强测试技术对发动机噪声源识别的研究   总被引：1，自引：0，他引：1  

谢裕智  徐凌  李捷辉  赵哲  黄国彧 《农机化研究》2007,(1):193-196

通过对一台增压柴油机的噪声进行声强测试,将测试得到的数据用STARAcoustics声强软件进行处理和分析,得出发动机各个包络面的等声强分布、声强矢量分布和声功率的计算结果;利用这些结果着重分析和识别了该发动机的主要噪声源,确定了其噪声源的位置、主要噪声频率成分和声功率的贡献,为降低发动机噪声提供了改进依据.结果表明,通过与9点法试验结果的定性比较,能够更准确地判断噪声源的位置及其频率分布.  相似文献   

低压电力系统配电母线N级联锁的算法     

苏景军  徐超 《中国农村水利水电》2004,(3):79-81

在电力系统中，由于开关容量及运行方式限制，通常在低压系统中多采用1段母线、1台变压器运行方式。为了避免这种运行方式在母线检修、故障时可能造成停电的缺点，因此可用断路器将单母线分段。母线经断路器分段后。对重要用户可以从不同段引出两个回路，有两个电源供电。母线分段的数目。可以根据电源数目和容量来分．段数越多，停电的范围越小，所需电气设备越多．一般以4～6段为宜。本文对此配电母线进行N级联锁推导其算法．有利于今后解决多级联锁的问题。  相似文献