利用遗传算法优化育种策略的计算机模拟分析

本研究通过提供一个结合遗传算法的育种策略模拟方法,期望更高效地预测和评估不同育种策略的效果,从而做出更明智的决策,为育种家在科学研究与实践中打开一个全新的视角。通过遗传算法,可以实现自动化、智能化的育种策略优化,这不仅可以大大节省人力资源,而且可提高优化的准确性和效率。传统的育种策略往往需要经过长时间的实验和调整,而通过遗传算法,则可以在短时间内得到更佳的策略选择。同时,本研究还展示了计算机模拟在农业科研中的巨大潜力。在当前数字化、智能化的趋势下,计算机模拟已成为农业研究中不可或缺的工具,为我们提供了更加客观、准确的研究数据和预测结果。     

RAPD-PCR系统优化用于对水稻穗型性状的分析

本实验优化了RAPD-PCR体系,并用于对重组自交系F12群体中随机挑选直穗水稻和弯穗材料进行分析.结果表明,优化的RAPD-PCR体系可用于多态性分析,从100条随机引物中筛选到7条对模板DNA扩增出了具有重复性较好、清晰、稳定、多态性高的谱带,优化后的RAPD-PCR系统可望应用于对直穗和弯穗这一对性状的分析.     

伊犁垦区耕作制度的分析及优化

伊犁垦区是新疆的粮油作物主产区。通过对1990—2019年伊犁垦区主要农作物种植结构变化进行梳理,阐述伊犁垦区耕作制度现状,分析存在的主要问题及发展趋势,从而提出优化对策。建议今后伊犁垦区农业发展应从种植业结构调整出发,在保证粮食绝对安全的基础上,兼顾产量与质量,优化种植结构与耕作制度,推动伊犁垦区农业高质量发展。     

两种穗型水稻穗上不同粒位籽粒淀粉黏滞谱特征的比较分析

利用3个直立穗型和3个弯曲穗型粳稻品种研究了两种不同穗型水稻穗上不同粒位籽粒淀粉RVA谱特征的差异。结果表明:穗内不同粒位间籽粒的淀粉黏滞特性的差异幅度和变异系数大小因品种而异,与穗型特征无关。淀粉黏滞特性好坏与其颖花在穗上的开花顺序有密切联系,早开花籽粒的淀粉黏滞特性强于晚开花籽粒。一次枝梗上的6个粒位的RVA谱特征值排列顺序以第1,6,5粒位较高,第2粒位最低;二次枝梗上的3个粒位排序为第1粒位>第3粒位>第2粒位。从空间上看,整穗粒位间从上到下,淀粉黏滞特性有逐渐变劣的趋势。     

Physical simulation of fluid field and structure optimization in two-strand tundish

The influence of the structure and location of dam and weir on fluid flow state in a two-strand tundish is studied, and a set of optimal structure, combining with the average residence time calculated from RTD curve, is obtained. The result indicates that the fluid flow state can be changed and the path of the fluid flow can be prolonged as well as the average residence time is improved after using dam and weir. But there are some dead zones after fluid passed through the dam and weir. Combination scheme of No. one dam and weir is better than the others. Its average residence time is 299 s and the volume fraction of dead zone is 31.0%. After the optimization of flowing control parameters in tundish, the best case is that the distance between dam and weir is 290 mm and the distance between weir and the long nozzle is 383 mm. The longest average residence time is 351 s and the minimum volume fraction of dead zone is 19.0% under the above situation. Compared with that of no dam and weir, the average residence time increases by 65 s and the dead zone volume fraction decreases by 15.0%. Based on Newton formula, the calculated results show that the inclusions with diameter larger than 17.5 μm can float up within 351 s under this optimization situation.     

变流量冷冻水系统温差控制法的适用性

研究了末端设置通断控制阀的一次泵变流量系统在温差控制下的水力特性,并结合风机盘管与房间的非线性换热耦合特性,进一步探讨了温差控制的适用条件以及变温差控制温差值的设定方法。结果表明：末端设置通断控制阀的系统,当管网整体负荷分布均匀且各开启用户的负荷变化规律相近时,温差控制同样是较为适用的,此时系统的水力失调对室内温湿度的影响较小;采用变温差控制时,仅以不同的总负荷率分段设置温差值,并不能获得良好的室内温湿度控制效果,建议以优先保证风盘除湿能力和室内干球温度为原则设定温差值,相比于目前的方法,在同等的室内相对湿度波动下,室内温度的稳定性可以得到保证。     

Numerical simulation of solid liquid flow of Yangtze River water in a semi annulus reentry tube

The flow of Yangtze River water in a semi annulus reentry tube was numerically simulated using a Eulerian Two phase Flow Model and computational fluid dynamics. The results show that, for Reynolds number Re=28×104, silt particles with representative diameter ds=0030 3 mm are separated in reentry tubes of all curvature (R/r) sizes, while silt particles with ds=0010 2 mm separate only slightly. Silt particles with ds=0108 5 mm, which posses a strong separation effect, are separated relatively less in reentry tubes of R/r=10~40 than in tubes with other R/r sizes.     

POD analysis of flow structures in thermally stratified flow in a confined space with the effects of horizontal wind

PIV measurements are carried out on the thermally stratified flows under different horizontal shear intensities in a confined space. Proper orthogonal decomposition (POD) is used to analyze the structures of these thermally stratified flows. Results show that, at the conditions without forced horizontal airflow, the low-order POD mode constitutes a high proportion of the total energy of the flow, and the horizontal flow is the dominant flow structure. The horizontal shear drives the energy to dissipate from large structure to smaller structures. Relative to the conditions without forced horizontal airflow, the ratios of vertical kinetic energy to horizontal kinetic energy become higher for each order of POD mode in the conditions with forced horizontal airflow. This indicates that horizontal shear can result in stratification instability and enhance the mass exchange in the vertical direction.     

Numerical simulation and optimization of high strength steel bumper forming process and springback control

Production of high strength steel bumper can greatly enhance the occupant safety.However,it is very hard to form high strength steel plate.There is rare domestic successful reference.The hot stamping technology aboard increases costs significantly,and the efficiency is low.Therefore,the only solution is combining advanced numerical simulation technology with current adjusting stamping process.The cold forming process of a sedan’s high strength steel bumper is simulated by FEM software Dynaform and the results show that springback and crack are the main defects.A law is summed up by researching the influence of different shapes of addendums on part forming and springback.Finally,the optimized shape of addendum is obtained by adjusting the addendum and adding convex roofs.It provides references for manufacturing similar high strength steel parts.     

Numerical simulation of the flow and temperature fields in an automotive exhaust muffler

By building a model of a typical exhaust muffler structure, a grid mesh was formed based on the calculation characteristic of the flow field. The software ANSYS CFX then was used to numerically simulate the flow and temperature fields in a muffler. The effects of the gas velocity and temperature variation on sound elimination performance, including the acoustics and aerodynamics performance, were analyzed. The result suggests that high velocity turbulence and high speed flow should be eliminated from muffler structures when designed. At the same time, to provide satisfactory noise elimination, pressure loss should be reduced as far as possible. The pressure loss can be decreased when reducing the perforation structure.     

农业多元功能耦合与都市型农业生产结构优化

多功能性是都市型农业的基本要求,都市型农业生产结构优化的目标是实现多元功能的最优耦合。以资源为约束、功能为产出、功能价值为效用,运用生产可能性曲线和无差异曲线构建了农业多元功能最优耦合的模型,在此基础上,根据都市型农业的特殊属性,构建了都市型农业多元功能最优耦合的模型,并对都市型农业生产结构优化的分析程序进行了总结。     

Optimization of Structure Parameters in Ultra-precision Plane Honing

The structure parameters of honing wheel have effects on machining accuracy in ultra-precision plane honing. This paper put forward to the optimization of structure parameters. By calculating the machining accuracy coefficient and wear coefficient of triangle radial structure honing wheels, it is obvious that the suitable triangle radial structure honing wheel can improve machining accuracy of workpiece.     

番茄营养液深液流无限生长型栽培营养液的管理与调控

根据北京地区的水质特点和非常规栽培的特殊性,制定了在营养液深液流无限生长型栽培条件下使用的营养液配方。并根据番茄生长发育的不同时期和养分吸收特性,及时调整营养液的组成成分、浓度、酸碱度等,对营养液实行动态管理。栽培试验结果表明,该配方中的各种营养成分（N、P、K、Ca、Mg等）基本可以被番茄均衡地吸收,属于营养均衡的配方。