北美内燃机车的三相交流传动技术

从对２６８号机车、Ｆ６９ＰＨＡＣ型机车、ＳＤ６０ＭＡＣ型机车的研究试验到提出第一批大批量ＳＤ７０ＭＡＣ型交流传动内燃机车的订货，北美走过了很长的发展道路，德国西门子和美国ＥＭＤ从８０年代初开发的合作，在北美获得了第一次大的成功。     

机动性专家系统

传统的数据合成系统使用部队运动的过分简化的模型。相反,TESS使用知识型技术来产生部队运动能力的精确判断。 这个信息在许多指挥和控制任务中是很适用的。例如,一个情报军官,或先进的数据合成系统,可以使用部队行为的预告来证实关于当前战术态势的假设。如果TESS认为一个部队要合并到另一部队必定要渡河,那末架桥活动的报告可能增加对两个部队合并决策的支持。此外,部队行为预告可以用于驱动情报收集活动。     

绝热发动机的发展趋势

本文综述了美国、西欧和日本的绝热柴油机的发展状况,对隔热涂层的利用前景和高性能结构陶瓷的开发持乐观态度。还简述了当前绝热柴油机发展存在的问题,以及正在进行的研究工作和发展的趋势。     

一种新的柴油机喷油系统

这种柴油机喷油系统(UFIS)适用于现有各种用途的发动机,也为重视排污和噪音的新的高性能柴油机提供了所需要的喷油量,喷油特性和定时控制。 这是一种电子液压喷油系统,它是采用电子控制的按一般传动原理工作的单体喷油器。这种喷油系统的特点是能准确地调节输出油量、增大油压和控制喷咀针阀。 这种喷油系统适应性强,而且具有一般喷油系统所没有的喷油特性。     

油船货油阀和压载阀的液压操纵与阀位指示

引言油船的泵浦、管路以及阀系统必须设计得使船的周转尽可能快,而且使装卸所用的劳动最少。当操纵和控制都很方便时,则压载和清舱也使用这些系统。由于原油和成品油船上的阀门比例数增大,而且由于下述两个原因或其中一个原因,阀门需用动力操纵: 1) 因阀门的尺寸和在装卸期内通过阀门的流体降增大,从而打开和关闭阀门所要的功率超过了人力;     

绝热涡轮复合发动机性能的分析

众所周知,现在可供实用的带中冷器的涡轮增压柴油机,是效率最高和可靠性最好的发动机之一。本文对绝热涡轮复合柴油机进行了分析,认为现有的不带冷却系统的狄塞尔循环,对传统的柴油机效率、可靠性和寿命来说,将显示出新的划时代的发展的可能性。这里着重指出柴油机的冷却系统在实际使用中的各种问题,并阐述无冷却系统的绝热涡轮复合发动机的性能。     

凯特匹勒3406B卡车发动机

新开发的具有新式结构的卡车用3406B强化柴油机是直列六缸机,功率范围为255—400马力(190—298千瓦),相应的额定转速为1600—2100转/分。开发规划的主要目标是继续改善燃油经济性,重点放在改进燃烧室零件和燃油系统,使能满足现在和将来的气体排放和噪音级要求。新的燃油系统是实现这一目标的关键部件之一。本文详述了3409B发动机在设计、研制和性能改进方面的内容。     

大型加强板结构焊接顺序的效果研究(英文)

Welding sequence has a significant effect on distortion pattern of large orthogonally stiffened panels normally used in ships and offshore structures. These deformations adversely affect the subsequent fitup and alignment of the adjacent panels. It may also result in loss of structural integrity. These panels primarily suffer from angular and buckling distortions. The extent of distortion depends on several parameters such as welding speed, plate thickness, welding current, voltage, restraints applied to the job while welding, thermal history as well as sequence of welding. Numerical modeling of welding and experimental validation of the FE model has been carried out for estimation of thermal history and resulting distortions. In the present work an FE model has been developed for studying the effect of welding sequence on the distortion pattern and its magnitude in fabrication of orthogonally stiffened plate panels.     

Development and validation of analytical method for the estimation of lamivudine in rabbit plasma

Lamivudine has been widely used in the treatment of HIV disease. A reliable, sensitive reversed phase high performance liquid chromatography （RP-HPLC） method was developed and validated for lamivudine ...     

船舶SOFC燃料电池与汽轮机联合动力装置能效分析(英文)

Strong restrictions on emissions from marine power plants(particularly SOx,NOx)will probably be adopted in the near future.In this paper,a combined solid oxide fuel cell(SOFC)and steam turbine fuelled by natural gas is proposed as an attractive option to limit the environmental impact of the marine sector.The analyzed variant of the combined cycle includes a SOFC operated with natural gas fuel and a steam turbine with a single-pressure waste heat boiler.The calculations were performed for two types of tubular and planar SOFCs,each with an output power of 18 MW.This paper includes a detailed energy analysis of the combined system.Mass and energy balances are performed not only for the whole plant but also for each component in order to evaluate the thermal efficiency of the combined cycle.In addition,the effects of using natural gas as a fuel on the fuel cell voltage and performance are investigated.It has been found that a high overall efficiency approaching 60%may be achieved with an optimum configuration using the SOFC system.The hybrid system would also reduce emissions,fuel consumption,and improve the total system efficiency.