泵站单机组变速运行优化方法研

考虑峰谷电价与站下水位变幅等因素,提出了以日开机运行总耗电费用最少为目标函数,各时段水泵转速为决策变量,规定时段内抽水总量为约束条件的单机组变速优化运行动态规划模型.对江都四站单机组变速优化运行与恒速运行进行了比较分析,结果表明:满负荷工作时,无论是否考虑峰谷电价,变速带来的效益不足以抵消安装变频装置产生的耗损;考虑峰谷电价、非满负荷工作时,效益明显;不考虑峰谷电价情况下,80%和60%负荷工作时,变速节省的电费偿还相应配套功率的变频装置投资约需15～18年和7～10年.     

Neural network prediction of performance parameters of an inclined plate seed metering device and its reverse mapping for the determination of optimum design and operational parameters

Seed planting equipment with inclined plate seed metering devices is the most commonly used equipment for planting of peanut crop in India. For obtaining the high yield, it is very essential to drop the peanut seeds in rows maintaining accurate seed rate and seed spacing with minimum damage to seeds during metering. This mainly depends on forward speed of the planting equipment, rotary speed of the metering plate and area of cells on the plate. The relationship between these factors and the performance parameters viz., seed rate, seed spacing and percent seed damage can be established using regression analysis. But they may not be very accurate and may pose difficulty in the determination of inputs for a set of desired outputs (reverse mapping). Hence, an attempt has been made in this paper to develop the feed forward artificial neural network (ANN) models for the prediction of the performance parameters of an inclined plate seed metering device. The data were generated in the laboratory by conducting experiments on a sticky belt test stand provided with a seed metering device and an opto-electronic seed counter. The generated data was used to develop both statistical and neural network models. The performance of the developed models was compared among themselves for 4 randomly generated test cases. The results show that the ANN model predicted the performance parameters of the seed metering device better than the statistical models. In order to determine the optimum forward speed of the planting equipment, peripheral speed of the metering plate and the area of cells on the plate to obtain the recommended seed rate of 33.33 seeds/m², seed spacing of 100 mm and percent seed damage of 0.2% with 100% fill of the cells, a novel technique of reverse mapping using ANN model was followed. It was observed that the optimum forward speed of the planting equipment and optimum area of cells on the metering plate had good correlation with size of seed. Linear regression equations were developed to predict the optimum forward speed of the planting equipment and optimum area of cells on the metering plate using the size of seeds as independent parameter. The peripheral speed of the metering plate of 0.237 m/s was found to be optimum for the size of seeds in the range of 95.42-123.01 mm². However, the results need to be verified by conducting planting operation under actual field conditions.     

Optimal on-farm irrigation scheduling with a seasonal water limit using simulated annealing

As water resources are limited and the demand for agricultural products increases, it becomes increasingly important to use irrigation water optimally. At a farm scale, farmer's have a particularly strong incentive to optimize their irrigation water use when the volume of water available over a season is production limiting. In this situation, a farmer's goal is to maximize farm profit, by adjusting when and where irrigation water is used. However, making the very best decisions about when and where to irrigate is not easy, since these daily decisions require consideration of the entire remaining irrigation season. Future rainfall uncertainty further complicates decisions on when and which crops should be subjected to water stress. This paper presents an innovative on-farm irrigation scheduling decision support method called the Canterbury irrigation scheduler (CIS) that is suitable when seasonal water availability is limited. Previous optimal scheduling methods generally use stochastic dynamic programming, which requires over-simplistic plant models, limiting their practical usefulness. The CIS method improves on previous methods because it accommodates realistic plant models. Future farm profit (the objective function) is calculated using a time-series simulation model of the farm. Different irrigation management strategies are tested using the farm simulation model. The irrigation strategies are defined by a set of decision variables, and the decision variables are optimized using simulated annealing. The result of this optimization is an irrigation strategy that maximizes the expected future farm profit. This process is repeated several times during the irrigation season using the CIS method, and the optimal irrigation strategy is modified and improved using updated climate and soil moisture information. The ability of the CIS method to produce near optimal decisions was demonstrated by a comparison to previous stochastic dynamic programming schedulers. A second case study shows the CIS method can incorporate more realistic farm models than is possible when using stochastic dynamic programming. This case study used the FarmWi$e/APSIM model developed by CSIRO, Australia. Results show that when seasonal water limit is the primary constraint on water availability, the CIS could increase pasture yield revenue in Canterbury (New Zealand) in the order of 10%, compared with scheduling irrigation using current state of the art scheduling practice.     

不同密集烘烤工艺对烤后烟叶质量的影响

为进一步优化密集烘烤工艺,在湖北中烟公司原料基地进行了优化密集烘烤工艺与常规烘烤工艺的对比试验,并对烤后烟叶质量进行了对比研究.结果表明:优化密集烘烤工艺与常规工艺相比,显著改善了烤后烟叶的评吸质量、外观质量和等级结构,烤后烟叶化学成分含量较为协调,优化的密集烘烤工艺显著提高了烤后烟叶的工业可用性.     

日光温室采光与下挖深度优化设计

采光优化设计是节能日光温室结构优化设计的关键和改进温室环境性能最经济有效的方式。本试验以寿光市10m跨度的下挖式节能日光温室为例,对我国北方地区下挖式节能日光温室合理采光时段屋面角进行了理论计算与分析,并利用计算线阴影的原理,通过计算不同时刻下挖壁面在室内形成的阴影区域,提出了我国北方地区下挖式节能日光温室适宜的下挖深度,为目前下挖式节能日光温室的设计建造提供理论依据和技术参数。     

微生物发酵法生产2,3-丁二醇瓶颈因素分析

2,3-丁二醇（2,3-Butanediol）是一种极具价值的化工原料和液体燃料,应用广泛。许多微生物都能代谢产生2,3-丁二醇,但产率有差异。本文着重从发酵菌株、代谢途径、发酵底物、发酵工艺以及分离提取方法等方面概述了微生物发酵法生产2,3-丁二醇的研究进展,并讨论了2,3-丁二醇发酵过程中存在的问题和瓶颈因素。指出应从选育理想菌株出发,并对2,3-丁二醇的生化代谢途径中不同酶的动力学进行针对性的研究,以廉价的发酵底物及高效节能的分离纯化工艺进行发酵工艺优化,在此基础上进一步对2,3-丁二醇的系列衍生物进行开发应用,以降低生产成本,提高2,3-丁二醇的产量。     

基于使用后评价探讨广州天河公园园林景观与优化

运用使用后评价(POE)研究方法结合模糊综合评价体系,以公众参与为事实基础,从公园总体环境品质、植物景观、水体景观、道路景观、建筑景观、文娱景观以及公共设施7个方面对广州市天河公园进行了调查研究。调查结果表明:广州天河公园园林景观属于良好,公众认可度较好,其中得分最高的为公园总体环境品质,最低的为文娱景观和水体景观;探讨公园景观存在的主要问题并在文化内涵、娱乐设施、水体以及照明设施四个方面提出相对应的优化建议。     

利用正交设计优化芦笋SRAP反应体系

以芦笋(Asparagus officinalis L.)为材料,对影响SRAP-PCR扩增结果的因素dNTPs、TaqDNA聚合酶、Mg2+、引物、模板DNA进行了正交优化设计的研究。结果表明,适合芦笋SRAP-PCR分析的最佳反应体系:20μL的反应体积中包括0.2mmol/LdNTPs0.4μL;1UTaqDNA酶1.0μL;1.5mmol/LMg2+1.2μL;上下引物各30ng,每个引物0.5μL;60ng模板DNA1.0μL;10×Buffer2.0μL;无菌双蒸水13.4μL。为今后利用SRAP标记技术研究芦笋的遗传多样性奠定基础。     

微波辅助提取莲心黄酮类物质工艺参数的优化

为了探讨微波辅助提取莲心中黄酮类物质的工艺条件,研究微波功率、微波提取时间及料液比对莲心黄酮类物质提取效果的影响,通过正交试验设计优化其提取工艺参数。结果表明：影响莲心黄酮类物质提取效果的主次因素顺序为微波提取时间>微波功率>料液比,最佳提取工艺参数为微波功率700 W,微波提取时间10 min,料液比2:100 (g:mL),在此条件下莲心黄酮类物质提取率为1.8725%;与传统水浸提方法相比,该方法可以提高提取率,缩短提取时间。     

广西城镇体系空间结构优化研究

在明确广西城镇体系空间结构历史演进和现状特征的基础上,引入引力模型和首位度指数,进一步揭示广西城镇空间发展存在的问题。结果表明,广西主要城市之间空间联系弱;小城市数量多,辐射范围小;＂双核＂规模小,首位度低。最后,提出了广西城镇体系空间结构优化思路。