Responses of winter wheat (Triticum aestivum L.) evapotranspiration and yield to sprinkler irrigation regimes

The North China Plain (NCP) is one of the main productive regions for winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) in China. However, water-saving irrigation technologies (WSITs), such as sprinkler irrigation technology and improved surface irrigation technology, and water management practices, such as irrigation scheduling have been adopted to improve field-level water use efficiency especially in winter wheat growing season, due to the water scarcity and continuous increase of water in industry and domestic life in the NCP. As one of the WSITs, sprinkler irrigation has been increasingly used in the NCP during the past 20 years. In this paper, a three-year field experiment was conducted to investigate the responses of volumetric soil water content (SWC), winter wheat yield, evapotranspiration (ET), water use efficiency (WUE) and irrigation water use efficiency (IWUE) to sprinkler irrigation regimes based on the evaporation from an uncovered, 20-cm diameter pan located 0-5 cm above the crop canopy in order to develop an appropriate sprinkler irrigation scheduling for winter wheat in the NCP. Results indicated that the temporal variations in SWC for irrigation treatments in the 0-60-cm soil layer were considerably larger than what occurred at deeper depths, whereas temporal variations in SWC for non-irrigation treatments were large throughout the 0-120-cm soil layer. Crop leaf area index, dry biomass, 1000-grains weight and yield were negatively affected by water stress for those treatments with irrigation depth less than 0.50E, where E is the net evaporation (which includes rainfall) from the 20-cm diameter pan. While irrigation with a depth over 1.0E also had negative effect on 1000-grains weight and yield. The seasonal ET of winter wheat was in a range of 206-499 mm during the three years experiments. Relatively high yield, WUE and IWUE were found for the irrigation depth of 0.63E. Therefore, for winter wheat in the NCP the recommended amount of irrigation to apply for each event is the total 0.63E that occurred after the previous irrigation provided total E is in a range of 30-40 mm.     

基于BACKFILL的"削足适履"并行作业调度算法

BACKFILL方法在并行作业调度时并不能有效地的利用CPU资源.在BACK-FILL的基础上,提出一种“削足适履”算法.利用CPU的空闲空间作为判断依据,扩展了可参与填充操作作业的数量,“削足适履”算法通过合理修改队列中作业的参数-CPU数量和运行时间,将BACKFILL算法无法处理的作业填充到空闲的CPU空间中,弥补了BACK-FILL算法的不足,提高了并行系统作业调度CPU利用率.     

极端干旱区葡萄滴灌耗水规律试验研究

在水资源严重紧缺的吐哈盆地进行了葡萄滴灌耗水规律试验研究.通过对不同灌水量处理下的土壤含水率和葡萄植株生理指标进行观测和分析.得出以下结论:葡萄在整个生育期内各处理耗水呈现由低到高再降低的变化趋势.本试验中总灌水量为675 mm时,可以满足葡萄对水分的需求.此处理下吐哈盆地滴灌葡萄萌芽期耗水量45 mm,新梢生长期13...     

1961－2007年长江中下游地区水稻需水量的变化特征

该研究利用长江中下游地区91个气象站点1961－2007年地面观测资料和63个农业气象试验站1981－2006年单季稻和双季稻的生育期资料,采用美国农业部土壤保持局推荐的方法计算了有效降水量,用联合国粮食与农业组织（FAO,Food and Agriculture Organization）推荐的方法分别计算了研究区域内单季稻和双季稻需水量,探讨了不同地区单季稻和双季稻的水分利用效率。研究结果表明：研究时段内长江中下游地区早稻和单季稻生育期有效降水量均表现为增加趋势,而晚稻生育期有效降水量表现为减少趋势;早稻、晚稻和单季稻生育期内需水量皆表现为减少趋势,其中单季稻和晚稻的需水量为显著减少;为满足水稻需水要求,研究区域内双季稻生育期内的灌溉量较单季稻多125?mm,但其水分利用效率在研究区域高于单季稻;从提高水分利用效率的角度来看,长江中下游地区总体更适宜种植双季稻。     

Optimal model and algorithm for flexible job-shop scheduling problem based on demand time window

Aiming at the scheduling problem for jit delivery under the pulling type production, an optimal method for flexible job-shop scheduling problem (FJSP) based on demand time window is proposed. According to the demand time window of every workpiece, an optimal model for FJSP is constructed to maximize the average membership degree based on the completion time for every workpiece.Then, a tabu search algorithm based on multi-stage hybrid mutation is proposed and designed.To improve the convergence of the algorithm, inverse order mutation and gene segment swap mutation are used to find a good original solution, upon which gene swap mutation is used to find the optimal solution. The effectiveness of the proposed method is validated by applying to a multi-type and small-batch production manufacturing workshop.     

基于多目标粒子群算法的柔性作业车间调度优化方法

针对柔性作业车间的多目标调度问题,构建了以制造工期、加工成本及提前/拖期惩罚值为目标函数的柔性作业车间调度模型,提出基于密集距离排序的自适应多目标粒子群算法.采用精英策略保留进化过程中的优势个体,基于个体密集距离降序排列进行外部种群的缩减和全局最优值的更新,并引入小概率的变异机制以增强解的多样性和算法的全局寻优能力.最...     

灰色关联理想解法在秸秆综合利用方案优选中的应用

农作物秸秆是一种重要的生物质资源,其综合利用不仅保护产地环境、促进农民增收,而且是循环经济与新兴产业发展的基础与机遇。农作物秸秆综合利用方案主要分为秸秆用作饲料、食用菌基料、肥料、燃料和工业原料。为了对农作物秸秆综合利用方案进行合理优选,根据文献信息对评价指标体系进行赋值,应用基于序关系分析法和熵值法的综合集成赋权方法进行指标权重确定,采用灰色关联理想解法将指标权重和指标属性值进行集结,并将该方法应用于黑龙江地区的农作物秸秆综合利用方案优选中。该文分析的适宜黑龙江地区农作物秸秆综合利用方案排序为：饲料化利用＞肥料化利用＞燃料化利用＞食用菌基料化利用＞工业原料化利用,优选结果与黑龙江地区的实际情况及发展规划相吻合,同时优选结果为按照多元利用原则规划黑龙江地区农作物秸秆综合利用模式提供支持。此外该文评价指标的赋值根据已有文献信息进行9级赋值,方法具有较好的适应性,可很方便的用于不同区域农作物秸秆的综合利用评价。     

柔性工艺路线的改进蚁群作业调度算法

在具有柔性工艺路线的制造单元作业调度问题中，结合设备的约束以及加工过程中的费用、加工时间等因素，依据具有柔性的工艺加工路线，建立初始有向图。采用基于动态信息素更新策略的改进蚁群优化算法，在保证优化目标的基础上，迅速收敛并得到最优解，从而提高调度系统的可行性，增强系统稳定性。该方法以减少外协，均衡生产，降低总生产费用为目标，有效地支持了分布式制造单元的管理过程，增强了单元系统信息分布处理能力。最后通过算例，对计算结果进行了分析和讨论。     

海量图形数据的存储与调度

采用基于三角形二叉树剖分方式的海量数据存储方式,并通过划分数据逻辑粒度进行海量数据高效调度的数据处理方法,使得图形数据的处理效率得到显著的提高.     

Crop water stress index for scheduling irrigation of Indian mustard (Brassica juncea) based on water use efficiency considerations

The study was conducted to determine the feasibility of canopy temperature based crop water stress index (CWSI) for scheduling irrigation of Indian mustard (Brassica juncea). Field crop experiments were conducted in Hamirpur, Himachal Pradesh (India) during three consecutive cropping seasons (2015, 2016 and 2017). The experimental field was divided into five plots with different levels of irrigation treatments based on depletion of total available soil water (TASW) in the crop root zone. The maximum soil moisture depletion (SMD) of TASW at 10%, 30% and 50%, full irrigated (non-stressed) and extremely dry (full stressed) conditions were maintained in respective plots. Relationships were developed between canopy-air temperature differential (T_C-T_A) and vapour pressure deficit (VPD) for non-stressed and fully stressed conditions to generate non-water-stressed baseline (NWSB) and maximum water-stressed baseline (MWSB) baselines for Indian mustard crop. The CWSI was computed for different SMD of TASW by using a proven empirical approach based on the baselines. The irrigation treatment corresponding to 30% SMD with a mean CWSI of 0.4 resulted in optimal yield and maximum water use efficiency. Results of the study suggest that established CWSI value can be used to detect stress and schedule irrigations for Indian mustard.