浅谈康明斯柴油机在船上的应用

科学技术在不断向前发展,船用设备也在不停地更新。陆用康明斯柴油机在船上逐渐得到应用,并有推广的趋势。文章结合作者在船实际工作,分析了康明斯柴油机在船上应用的优缺点。     

牵引变电所馈线保护问题及其解决措施

针对2起武广高铁变电所馈线保护装置拒动原因进行分析,并提出相应对策,对馈线保护PT断线闭锁电压等保护进行重新整定,确保馈线保护装置可靠动作。     

基于单片机的智能电子遥控车位锁设计

文章运用PT2262/PT2267编解码器结合AT89C51单片机,实现的智能电子车位锁控制器,可以实现对遥控上锁、解锁、防盗、报警的功能,具有较高的实用价值。     

数字化改进PT燃油泵试验台

介绍了用微机与金属管浮子传感器和单片机组成测定装置，代替用玻璃浮子量油的传统PT燃油泵试验台，解决了目前PT燃油泵试验台现存的量油系统误差大的问题。     

有源电压箝位串联HV IGBT的适用性和优化(二)

介绍了5.2 kV高压绝缘栅双极型晶体管(HV IGBTs)的成功串联应用.穿通型HV IGBT串联应用时要完全控制感应过电压,最大的障碍是拖尾电流的关断问题.可以证明,采用先进的电压箝位技术能够限制因关断拖尾电流而引起的第二个电压尖峰.阳极采用载流子寿命局部分布的IGBT很适合这种应用;拖尾电流间隔时间越短,关断损耗越小.文中集中讨论了穿通型HV IGBT器件串联时的最佳通态等离子体分布,HV IGBT的最新发展趋势似乎与讨论结论相一致.未来先进的HV IGBT技术可完全减轻第一代HV IGBT串联时的困难.     

提高中心区公共交通服务水平的新思路——以天河地区环形小巴方案为例

根据广州天河地区公共交通改善的实例,提出了通过结合城市用地及路网的特点,在城市中心区设置环形小巴改善轨道交通衔接以提高公共交通服务水平的新思路,具有一定的参考意义.     

牵引网距离保护压互断线闭锁整定分析

针对接触网不同运行方式下的电压互感器正常运行和断线两种情况,对牵引网距离保护压互断线闭锁整定计算进行了分析和探讨,并提出了整定建议。     

Private funding and management for public interchanges in Madrid

Interchanges are key elements for improving seamless mobility in metropolitan areas where multi-stages trips are increasing. Interchange facilities make transfers short, easy and comfortable, and therefore Public Transport (PT) trips became more attractive and competitive. However, good quality interchanges are rather expensive, especially with regard to construction and operation. The solution launched in Madrid was a public-private scheme where all stakeholders involved play a key role. The first experience was Avenida America Interchange in the border of Madrid CBD, which opened in 2000. The construction was carried out through a Build and Operate and Transfer (BOT) tender. Three public bodies were involved: Municipality, Regional Government and Public Transport Authority. The concessionaire was a company constituted by a transport operator, several construction companies and a national bank. The revenues came from a fee which pays every bus using the facility, some shops, two parking lots, and other business. This positive experience has been extended to the construction of four new interchanges that were inaugurated in the years 2007 and 2008.     

基于相位校正的PT控制CCM Buck变换器研究

以CCM Buck变换器为例,分析PT控制CCM Buck变换器的控制特性,以及输出电容ESR较小时,低频振荡现象的产生机理,输出电压与电感电流之间的相位关系,并据此得到了相位校正方案.仿真和试验结果验证了PT控制CCM Buck变换器相位校正方案的正确性和可行性.     

Determination of the transportable moisture limit of iron ore fines for the prevention of liquefaction in bulk carriers

In 2013, over 500 million metric tons of Iron Ore Fines (IOF) were transported around the world using bulk carriers. Under certain conditions IOF, while being transported, can possibly undergo liquefaction. Since 2006, there has been eight reported bulk carrier casualties possibly caused by the liquefaction of IOF. The objective of this study is to evaluate, compare and verify the limitations and relevance of the Proctor/Fagerberg, Flow Table and Penetration test methods that are used to determine the Transportable Moisture Limit (TML) of IOF. The TML is the maximum gross water content that bulk cargoes, including IOF, may contain while being transported at sea without being at risk of liquefying. A thorough literature review, along with laboratory research, was carried out to compare the TML results from the three leading test methods to determine whether they produce reliable results when testing IOF. The study concludes that the three test methods, as stated in the 2012 International Maritime Solid Bulk Cargoes Code, are unverified and therefore not appropriate for testing IOF. This is due to the variation in the results produced by the three test methods and also due to the difference in the physical properties of IOF when compared with the materials that were originally intended for testing. It is noted that the TML alone may not control the potential liquefaction of IOF and further studies, regarding the physical properties and system variables, which cause the material to liquefy, are required to determine the liquefaction potential of IOF.