Excel的应用小技巧

现代计算机的使用越来越普及,办公自动化也随之热门起来,而Office系列办公软件也就首当其充的成了办公的常用工具。并且对于办公软件的应用要求也越来越高,工作也越来越细,而Office套餐中的Excel在实际应用中却隐藏着不少的小技巧。     

静电粉尘初等模型与场势分布的研究

通过建立静电粉尘的Ｂｏｌｔｚｍａｎｎ分布初等模型计算静电粉尘的场势分布，讨论了击穿条件下粉尘浓度的经验公式，并通过已发表的实验报告证实了上述结论的有效性。     

适用于亚微米沟道MO SFET的阈值电压解析模型

本文利用本征函数方法,采取一定的边界条件,得到了二维泊松方程的解析解.并由此导得适用于亚微米沟道MOS场效应管阈值电压的解析表达式.本解析模型未引进复杂的几何结构参数及经验参数,适用于不同的衬底反偏电压、漏极电压等条件.这些结果与数值模拟的结果以及有关实验的结果符合得较好,对短沟道MOSFET的设计及性能的了解有实际参考价值.     

A Multi-Net System for the Fault Diagnosis of a Diesel Engine

A multi-net fault diagnosis system designed to provide an early warning of combustion-related faults in a diesel engine is presented. Two faults (a leaking exhaust valve and a leaking fuel injector nozzle) were physically induced (at separate times) in the engine. A pressure transducer was used to sense the in-cylinder pressure changes during engine cycles under both of these conditions, and during normal operation. Data corresponding to these measurements were used to train artificial neural nets to recognise the faults, and to discriminate between them and normal operation. Individually trained nets, some of which were trained on subtasks, were combined to form a multi-net system. The multi-net system is shown to be effective when compared with the performance of the component nets from which it was assembled. The system is also shown to outperform a decision-tree algorithm (C5.0), and a human expert; comparisons which show the complexity of the required discrimination. The results illustrate the improvements in performance that can come about from the effective use of both problem decomposition and redundancy in the construction of multi-net systems.     

Detecting natural crack initiation and growth in slow speed shafts with the Acoustic Emission technology

This paper presents results of an experimental investigation to assess the potential of the Acoustic Emission (AE) technology for detecting natural cracks in operational slow speed shafts. A special purpose built test rig was employed for generating natural degradation on a shaft. It was concluded that AE technology successfully detected natural cracks induced on slow speed shafts.     

Modeling and simulation of the engagement dynamics of a wet friction clutch system subjected to degradation: An application to condition monitoring and prognostics

In this paper, a friction model appropriate for wet friction clutches based on the extension of the Generalized Maxwell Slip (GMS) friction model is integrated to a four-DOF lumped-mass-spring-damper system which represents a typical SAE#2 test setup. Degradation models expressing the evolutions of the friction model parameters are also proposed, where the structure of the degradation models is inspired from experimental results obtained in the earlier work. This way, the engagement dynamics of the clutch system during the useful lifetime can be simulated. It appears that the previously developed pre-and postlockup features extracted from the simulated signals obtained in this study are qualitatively in agreement with the experimental results. Those features show their predictive behaviors that confirm their feasibility to be used for clutch monitoring and prognostics. Furthermore, the models and simulation procedure discussed in this paper can be employed for developing and evaluating prognostics algorithms for wet friction clutch applications.     

基于LabVIEW的磨加工状态监控系统双线程技术研究

为开发实时性好、精度高的磨削加工状态监控系统,提出了利用磨削加工中的声发射技术实现磨削加工状态监控的方案。采用LabVIEW软件,在开发基于AE的磨削加工状态监控程序各个模块的基础上,分别利用局部变量法和生产者/消费者模式的两种双线程方式设计总体程序结构。最后通过实验对两种双线程方式的实时性、精确性优劣进行了比较。实验结果表明,采用生产者/消费者模式的磨加工状态监控系统双线程程序的实时性更高,精确性更好。     

船用主机运动部件的振动状态监测

本文介绍8NVD48A-2U船用主机缸内零部件和主轴承状态的振动监测研究,讨论了柴油机振动激励源的基本特征以及机身表面振动的特征参数与这些零部件工作状态之间的关系,并给出了适于柴油机振动故障诊断的判据。     

地震地质条件复杂地区高精度重力勘探的应用效果

在地震地质复杂地区，用单一的地震方法解决油气地质方面的问题有一定的 。若用针对性地使用某些非地震方法后，情况就不一样了。在ＧＹ凹陷应用高精度重力勘探成果。分析了全凹陷区域构造特征和油气地质情况，在此基础上查证，落实了下第三系内局部构造，并对凹陷含油气远影及地震地质进行了评价，取得了良好的地质效果。     

柳钢高炉炉况失常处理方法及特点

总结了柳钢高炉近年来多次出现的炉况失常及其处理过程的经验教训，提出了在处理失常炉况过程中减少反复、快速恢复的措施。