Sub-ambient cold-start emissions reduction using SwRI® PO x catalyst technology

This paper describes the application of SwRI’s cold-start PO _x catalyst technology to reduce cold-start hydrocarbon emissions from a US Tier 2 vehicle at −7 °C. A reduction in −7 °C (20 °F) cold-start hydrocarbons will help US Tier 2 vehicles meet the proposed EPA NMOG standards. Improvements in cold temperature hydrocarbon emissions would also be beneficial in many parts of Europe during the winter months. In this work, a total hydrocarbon reduction of 19% was realized at 24 °C, in line with previous results, but only up to 3% at −7 °C. Insufficient oxygen in the engine-out exhaust gas at −7 °C was determined to be the reason why the PO _x catalyst failed to significantly reduce HC emissions. Addition of supplemental oxygen to the exhaust during the cold-start, to simulate an adjustment in the engine calibration to less rich operation, resulted in a total hydrocarbon reduction of 18% with the PO _x catalysts in place, but no benefit when the PO _x catalysts were removed. Hence, the PO _x catalyst approach can be used to good effect, even under sub-ambient cold-start conditions.     

基于一致性的小型四旋翼机群自主编队分布式运动规划

设计一种小型四旋翼无人机群起飞后自主形成正多边形编队的分布式运动规划方法.在四旋翼无人机的串级控制系统框架下,分布式编队控制器以简化agent模型为基础,同时采用平均一致性算法和有领导一致性算法,共同产生各无人机位置与偏航角的期望轨迹.讨论了达成最终协调目标队形的拓扑条件,并给出一种基于有向Hamilton环的通信拓扑设计方案.最后通过数值仿真验证了所提出算法的有效性.     

沙漠风积沙地基扩展基础抗拔现场试验研究

通过在新疆、宁夏和内蒙古典型沙漠地区完成的现浇混凝土和装配式2种扩展基础在上拔、上拔与水平力组合工况下的25个现场试验,获得了风积沙扩展基础抗拔荷载-位移曲线,并确定了各试验基础的抗拔极限承载力。按照"土重法"计算原理,得到了反映沙漠风积沙地基抗拔承载性能的极限"上拔角"。经统计分析,得到沙漠风积沙极限"上拔角"标准值为16.8°,该值考虑了沙漠风积沙的区域特征、基础型式与尺寸、荷载工况等因素,可为沙漠地区输电线路杆塔基础的工程设计提供依据。     

Sliding-mode and proportional-derivative-type motion control with radial basis function neural network based estimators for wheeled vehicles

An obstacle avoidance problem of rear-steered wheeled vehicles in consideration of the presence of uncertainties is addressed. Modelling errors and additional uncertainties are taken into consideration. Controller designs for driving and steering motors are designed. A proportional-derivative-type driving motor controller and a sliding-mode steering controller combined with radial basis function neural network (RBFNN) based estimators are proposed. The convergence properties of the RBFNN-based estimators are proven by the Stone–Weierstrass theorem. The stability of the proposed control law is proven using Lyapunov stability analysis. The obstacle avoidance strategy utilising the sliding surface adjustment to an existing navigation method is presented. It is concluded that the driving velocity and steering-angle performances of the proposed control system are satisfactory.     

19 500 kVA三相6根电极制磷电炉性能考核总结

针对19500 kVA三相6根电极制磷电炉在试生产中出现的炉气温度高、电极位置高,消耗、成本居高不下等现象,通过性能考核,分析了主要原因是入炉焦炭水分高、粒度过大过细,洗涤收磷系统热量不够,电极布置有过热区,操作纪律执行不严格,仪表监测不准等。综合评价了该制磷电炉生产能力和存在问题,提出只有通过对原料质量、操作指标的严格控制、科学管理、整改和完善存在问题,以期该制磷电炉在最佳和优惠工艺条件下运行。     

高分子破乳剂及其在大庆油田的应用实验

本文文综述了中老油田采出液性质的变化和高含水采出液的油水分离特性，探讨了聚醚型破乳剂和高分子破乳剂在高含水采出液状况下的适应性。通过理论分析和大庆两个联合站的现场实验证明，高分子破乳剂特别适用于高含水采出液的事实，并指出了其适应性和提出了其质量与适应性的评价方法。     

苯胺在聚醋酸乙烯酯中的聚合研究

以过硫酸铵为氧化剂,十二烷基苯磺酸为掺杂剂,将苯胺在聚醋酸乙烯酯(PVAc)基质中进行原位氧化聚合,制备导电聚苯胺PAn/PVAc复合材料,采用溶液浇铸法制成可溶性导电复合膜,电导率达10-2s/cm。考察了反应条件对复合膜电导率的影响,并进行了环境稳定性测试,用红外光谱进行了复合膜的结构表征,用扫描电镜对复合膜的表面形态进行了观察。     

Adaptive tracking control of an autonomous underwater vehicle

This paper presents the trajectory tracking control of an autonomous underwater vehicle(AUV). To cope with parametric uncertainties owing to the hydrodynamic effect, an adaptive control law is developed for the AUV to track the desired trajectory. This desired state-dependent regressor matrix-based controller provides consistent results under hydrodynamic parametric uncertainties.Stability of the developed controller is verified using the Lyapunov s direct method. Numerical simulations are carried out to study the efficacy of the proposed adaptive controller.     

电能量采集及计费自动化系统的应用分析

当前的人工抄表和计算已很难适应电能统计和结算的要求,致使能够满足电网商业化运营的电量计费系统应运而生。介绍了电能量采集及计费自动化系统的用途、数据流和功能。