基于混合遗传算法的谐波齿轮传动优化设计

以谐波齿轮传动体积最小为优化设计目标,建立了混合离散变量优化设计数学模型。引入混沌移民算子,对基本遗传算法进行了改进,以维持群体的多样性,提高全局收敛能力。提出了一种设计变量的离散化处理方法,结合染色体编码的修正技术,在遗传算法中染色体按离散化后的设计变量进行离散搜索。开发了混合离散变量优化的改进遗传算法程序,给出了谐波齿轮传动的混合离散变量优化设计实例,所得优化设计参数符合设计规范,不需进一步处理就可直接用于制造。     

基于遗传算法的泵汽蚀试验数据拟合

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。     

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

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.     

机组段运转特性曲线的绘制及其应用

机组段是水电站运行的基本单元。从运行的需要出发,采用机组段运转特性曲线来指导运行,比用水轮机运转特性曲线方便。本文介绍机组段运转特性曲线的绘制方法及其在水电站运行中的作用。     

微灌毛管水力解析及优化设计的遗传算法研究

根据微灌毛管水力学特性，应用遗传算法理论和方法，提出微灌毛管水力解析及设计的新方法，建立了两种典型毛管水力解析和设计的遗传算法模型及求解方法，该方法可适用于非均匀坡度、不等间距及不等流量灌水器的毛管解析和设计。模拟计算结果表明，该方法具有较高的求解效率和计算精度。     

基于PPC模型的农机选型与优序关系研究

将投影寻踪（PP）与实数编码的遗传算法（RAGA）相结合，应用到农业机械的选型与优序关系研究中，通过寻求各种机型评价指标的最佳投影方向，将高维数据转换成一维投影指标值，实现对机器样本的分类与排序，从而克服 以往二阶模糊综合评判法及灰色系统评价法中权重取值的人为因素，取得了良好的效果。     

基于遗传算法的机械产品多参数选配方法

对机械产品多参数选配问题进行了描述，并以同时满足多个装配精度，使不适配零件数量最小化为目标，建立了求解该问题的数学模型。针对机械产品多参数选配的特点，提出了一种基于遗传算法的选配方法。根据问题的特殊性，设计了相应的编码方法和遗传算子。最后给出了应用该算法解决机械产品多参数选配问题的一个实例，证明了该算法的可行性与有效性。     

考虑陀螺效应的动力总成悬置系统分析和优化

应用陀螺力学理论，对传统动力总成悬置系统的无阻尼动力学方程进行修正，引入陀螺矩阵，得到新的动力学方程。对新的动力总成悬置系统动力学模型进行计算分析，研究了陀螺矩阵对频域、时域响应的影响。使用遗传算法分别对修改前后的方程进行优化计算，并进行比较分析。结果表明，对于低转速发动机，曲轴转动的陀螺效应不明显，而对于高转速的发动机，陀螺效应不能忽略，应以考虑陀螺力矩的方程为基础进行设计分析。     

Seasonal patterns of photochemical capacity and spring phenology reveal genetic differentiation among native Scots pine (Pinus sylvestris L.) populations in Scotland

Environment-driven genetic differentiation among populations is a common feature among forest trees, and an understanding of how populations have adapted to their home site conditions is essential for management and conservation practices. In Scotland, 84 native Scots pine (Pinus sylvestris L.) woodlands are recognised by the Forestry Commission and they occupy highly diverse environments from the maritime west coast to continental sites in eastern Scotland. However, it is not known whether adaptations to local environments along sharp temperature and rainfall gradients have occurred in different populations and as a result, the seed transfer guidelines of the species are based only on data from isozymes and monoterpenes. In this study of an outdoor common-garden trial, we used chlorophyll fluorescence to examine whether seedlings from 32 open-pollinated families and eight populations from sites experiencing contrasting annual temperature regimes differed in their response to variation in natural outdoor temperatures between September 2009 and May 2010. In addition, growth initiation in spring was recorded. Photochemical capacity at photosystem II F_v/F_m showed a distinct seasonal trend and remained at relatively high levels (∼0.7) until November. Following a period of over 2 weeks with temperatures below or close to 0 °C, F_v/F_m started decreasing towards its minimum values recorded in early March when population means varied between 0.35 and 0.45. By early May and along with rising temperatures, photochemical capacity had recovered to the same level as observed in early November. Populations were found to respond differently to the cold period starting in December. The largest drop in photochemical capacity was observed in seedlings from a low-altitude population located in the maritime western Scotland, while in seedlings from higher-altitude locations in the cooler eastern Scotland, the response was smaller. In March, the recovery of photochemical capacity was slowest in seedlings from the mildest and coolest sites. Evidence of adaptive genetic differentiation was also found in spring phenology. Initiation of shoot elongation and needle flush were earlier in families from higher altitudes (cooler areas), but population differences were not significant at the α = 0.05 level. These results suggest that adaptation to the spatially heterogeneous environment in Scotland has taken place in Scots pine and that in order to minimise the risk of planting maladapted seed stock, the patterns of environmental and adaptive genetic variation should be taken into account in the management of genetic resources in this species.     

栽培种花生遗传图谱的构建及主茎高和总分枝数QTL分析

栽培种花生是异源四倍体,基因组大,构建花生的分子遗传连锁图谱并对相关性状进行QTL定位研究的工作缓慢。本研究以遗传差异大的亲本组配杂交组合富川大花生×ICG6375构建F2作图群体,采用公开发表的2653对SSR引物,构建了一张含有234个SSR标记、分布于20个连锁群的栽培种花生遗传图谱。该图谱覆盖基因组的长度为1683.43c M,各个连锁群长度在36.11~131.48 c M之间,每个连锁群的标记数在6~15个之间,标记间的平均距离为7.19 c M。结合F3在湖北武汉和阳逻环境下的主茎高和总分枝数鉴定结果,应用Win QTLCart 2.5软件采用复合区间作图法进行了QTL定位和遗传效应分析。共检测到17个与主茎高和总分枝数相关的QTL位点,贡献率在0.10%~10.22%之间,分布于8个连锁群上。综合分析武汉和阳逻环境的鉴定结果,获得重复一致的与主茎高相关的6个QTL,其中q MHA061.1和q MHA062.1位于连锁群LG06上TC1A2~AHGS0153标记区间,贡献率为5.49%~8.95%;q MHA061.2和q MHA062.2位于LG06上AHGS1375~PM377标记区间,贡献率为2.93%~5.83%;q MHA092.2和q MHA091.1位于连锁群LG09上GM2839~EM87标记区间,贡献率为0.53%~9.43%。