Robust distributed attitude synchronization of multiple three-DOF experimental helicopters

Multiple experimental three-degrees-of-freedom (three-DOF) helicopters that are equipped with active disturbance systems constitute an attractive platform to validate robust control strategies. In this paper, a distributed synchronization controller is developed for such a platform, where each helicopter is subjected to unknown model uncertainties and external disturbances, and the desired trajectories are generated online, communicated through a network and not accessible by all helicopters. The controller is composed of a continuous tracker and a continuous uncertainty and disturbance estimator (UDE). The tracker makes the nominal closed-loop system globally asymptotically stable, and the UDE output is used to reject total uncertainties. The conditions that ensure zero-error tracking for each helicopter are identified; for the case with nonzero error, explicit relationship inequalities between the involved design parameters and the ultimate bound of error are revealed. Experimental results of four cases demonstrate improved tracking and synchronization accuracy of using the UDE with small parameters.     

A two stage heuristic algorithm for the integrated aircraft and crew schedule recovery problems

Airline disruptions incurred huge cost for airlines and serious inconvenience for travelers. In this paper, we study the integrated aircraft and crew schedule recovery problem. A two stage heuristic algorithm for the integrated recovery problem is proposed. In the first stage, the integrated aircraft recovery and flight-rescheduling model with partial crew consideration is built. This model is based on the traditional multi-commodity network model for the aircraft schedule recovery problem. The objective of this model also includes minimization of the original crew connection disruption. In the second stage, the integrated crew schedule recovery and flight re-scheduling model with partial aircraft consideration is built. We proposed a new multi-commodity model for the crew schedule recovery. The main advantage of such model is that it is much more efficient to integrate the flight-scheduling and aircraft consideration. New constraints are incorporated to guarantee that the aircraft connections generated in the stage 1 are still feasible. Two stages are run iteratively until no improvement can be achieved. Experimental results show that our method can provide better recovery solutions compared with the benchmark algorithms.     

空分装置提取贫氪氙的几种方法及其特点

随着氪氙气体在国民经济中的地位日趋升高,空分行业利用空分装置副产品提取氪氙的工艺研究也大力开展,针对空分工艺的特点进行研究和模算,得出了几种切实可行的提取贫氪氙的方法,氪氙提取率高,设备结构紧凑,流程简单,可操作性强。给用户提供更多的选择。     

尾气中一氧化二氮的处理技术

对目前国内外脱除和回收纯化一氧化二氮技术的研究进展以及工业应用情况进行了简要的介绍。比较分析了不同脱除及回收方法的技术特点,在此基础上对相关技术的发展前景进行了展望。     

Retrofitting of the Heat Exchanger Network with Steam Generation in a Crude Oil Distillation Unit

Steam generation through hot streams has an important impact on the utility consumption of a crude oil distillation unit. Retrofitting of the heat exchanger network with steam generation in a crude oil distillation unit is studied with regard to efficient energy usage. The grand composite curve is employed to provide insights into the steam generation problem, and a mixed‐integer linear programming model, presented previously for heat integration through hot discharges/feeds and steam generation, is used to obtain the optimal parameters for steam generation. Three heuristic rules are then proposed to determine suitable hot streams for steam generation. Finally, the heat exchanger network is modified based on pinch technology. After the retrofit, the hot and cold utility decrease.     

CuSO4对氰化提金贫液中SCN-的沉淀效果以及对共存离子浓度的影响

针对氰化提金贫液循环利用过程SCN^-积累以及外排带来的环境污染问题，以CuSO₄作为沉淀剂处理某高浓度SCN^-贫液，考察了沉淀剂用量、沉淀时间及沉淀温度对SCN^-沉淀效果和对共存离子浓度的影响。结果表明，当在贫液中加入1.6倍化学反应计量的CuSO₄后于室温搅拌60 min，SCN^-的去除率达87.5%以上，体系中T_Cu、S₂O₃ ^2-和SO₃ ^2-浓度也大幅降低，同时得到纯度达97%以上的CuSCN产品。沉SCN^-后的贫液只需石灰中和并沉部分SO₄ ^2-后，其活性得到进一步恢复，可直接返回金精矿浸出工序充分利用其中的CN^-，实现提金贫液的循环利用。     

发动机尾气余热驱动的吸附式空调系统仿真与测试

针对在高太阳辐射地区，柴油车驾驶室内使用车载空调会增加车辆发动机的耗油量、降低柴油车经济效益的问题，搭建了一套由发动机尾气余热驱动的吸附式车载空调系统。系统由填充有氯化钙/氯化锰/硫化膨胀石墨复合吸附剂的吸附床、蒸发器、冷凝器、储液罐和阀门组成，使用氨作为制冷剂，利用车辆在行驶时接触到的自然风为吸附床冷却，在发动机尾气余热的驱动下，为驾驶室内提供连续的制冷效果。结合仿真和实验测试，对所设计系统的制冷性能进行了分析，仿真结果表明，系统最优循环时间为45 min，系统的理论平均制冷功率可达3.5 kW以上，系统COP处于0.2~0.25之间。实验结果表明，在230℃的尾气温度条件下，系统能产生3 kW的平均制冷量。在40℃环境温度条件下，系统在蒸发器进出口处的平均温差为6.5℃，平均制冷量为3.2 kW。     

摇篮式五坐标加工中心C轴转台旋转故障原因分析与处理

针对HS664RT,摇篮式五坐标加工中心力矩电动机驱动的C轴转台故障,介绍了故障排查、处理方法和力矩电动机相位角同步设置步骤。