上海轨道交通2号线杂散电流监测系统及应用

对目前存在的杂散电流监测系统进行了分析讨论.给出了一套基于虚拟仪器labview的杂散电流测试系统.系统可以实现对杂散电流的自动监测和连续监测.对上海轨道交通2号线世纪大道段的管地电位进行了测试.该段的燃气管道存在较为严重的杂散电流腐蚀,应采取相应的防护措施.     

基于运行数据的电动客车误踩加速踏板状态识别研究

驾驶人误踩加速踏板导致的电动客车交通事故时有发生,影响因素复杂.为准确识别误踩加速踏板行为,提醒电动客车驾驶人安全驾驶,基于电动客车车载终端采集的车辆运行状态数据,提取9项与误踩加速踏板行为相关的驾驶特征,采用随机森林算法模型对电动客车误踩加速踏板状态进行识别,结果表明整体的识别准确率为99％,召回率为0.99,表明9...     

外科学教学艺术之我见

为了提高外科学课堂教学质量,增强学生的理解力、记忆力和活跃课堂气氛,要求授课老师不仅具备扎实的专业知识及渊博的学识,而且还应特别注意教学艺术,以激发学生的学习热情,掌握医学知识学习的方法,以达到事半功倍的效果。     

混合动力汽车的研究现状与发展前景

简要分析了发展混合动力汽车的必然性。介绍了目前混合动力汽车的分类及国内外研究现状,分析了混合动力汽车的优缺点,并为混合动力汽车的发展指明了前景。     

Field Tests for Investigating the Extraction Rate of Piles Using a Vibratory Technique

Factors directly affecting the extraction rate of the piles pulled out by a vibratory pulling system are summarized and classified into five categories (excitation force, resistance, vibration amplitude, pile plumbness keeping, and slowing down at the later stage) from the mechanics and engineering practice. Field tests on steel sheet piles extracted by vibratory technique in different soil conditions are conducted to ascertain how these factors affect the extraction rate of a pile with regard to three major actors of vibratory pile pulling: the pile to be extracted, the selected pulling system, and the imposed soil conditions. The extraction rates of three different sheet pile types (having up to four different lengths) pulled out by two different vibratory pulling systems are documented. The piles with different lengths and types, pulled out with or without a clutch, have different extraction rates. The working parameters governing the vibratory hammer, such as excitation force and vibration amplitude, exert significant influences on the rate of pile extraction, especially in the early stages of up-lift process. The extraction rate of the piles driven in different soil conditions is uniform because different extraction resistances mainly refer to shaft friction. The properties of the pile-soil interface influence the extraction rate of the piles, and the extraction rate decreases with the time for which the piles have been buried in the earth.