Application of the weibull proportional hazards model to aircraft and marine engine failure data

The environment in which an equipment operates and associated diagnostic variables, such as metal particle level in engine oil, are factors that can influence an equipment's failure time. These factors can be incorporated into concomitant variable models such as the proportional hazards model (PHM), which has been widely used in medical research but not in engineering reliability. A Weibull PHM is applied to both aircraft engine failure data and marine gas turbine failure data. Examination of the residuals shows a good fit of the Weibull proportional hazards model to the data.     

车用发动机正时齿形带传动系统的设计

本文概述了正时齿形带传动系统的特点、布置和计算,给出了各设计阶段计算所需的若干重要数据和推荐设计。     

铜铅合金轴瓦加锑对金相组织及使用性能的影响

本文针对铜铅合金轴瓦在熔铸中易产生铅偏析的问题,通过加入几种第三元素的对此分析,以及对加锑的研究,阐述了加入锑对于改善铜铅合金的金相组织和提高轴瓦使用性能的作用。     

车用内燃机试验台架高弹性联轴器的设计

介绍了内燃机试验台架用内燃机与测功器联轴器的种类，分析了这些联轴器的性能及使用状况，对试验中架用高弹性联轴器进行匹配设计。     

激光淬火吸光层技术的发展及在内燃机工业中的应用评述

综述了激光淬火及吸光层技术在国内外的应用和发展过程。比较了不同吸光层的性能特点，介绍了新型吸光层技术在内燃机激光淬火中的应用及发展趋势。     

凹口型三角风扇皮带的节能效果

发动机的风扇皮带拖动风扇、水泵和发电机,要消耗总功率的10%。普通三角皮带的效率仅75～85%。文章详细分析了皮带传动的能量损失,推导出有关公式。通过试验,发现采用凹口型三角皮带能提高效率6～8%,并延长使用寿命。     

基于知识的汽车发动机润滑油状态监测系统的研究

本文提出了一种基于知识的汽车发动机润滑油状态监测系统模型，并简要介绍了该系统的基本原理与构成，由于其中心处理部分基于一个知识系统上，因此具有比一般的润滑油状态监测更强的功能，能实现对在用润滑油衰变及发动机磨损状态的自动推一和判断。在具体分析的基础上，说明了该系统实现的可行性。     

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.     

Remote Sensing Monitoring and Comparison of Urban Land Cover Changes in Typical Cities in China-Kazakhstan Arid Region based on Cloud Platform

Urban land cover composition is the key factor affecting the living environment and urban ecosystem service. Based on the Google Earth Engine platform, Landsat 5/8 remote sensing image data were used to adopt the improved "Vegetation-Impervious Surface-Soil" model and linear spectral mixed decomposition method. The variation characteristics of land cover in Nur-Sudan, Almaty, Urumqi cities from 1990 to 2015 were compared and analyzed. The results show that the urban built-up area of Urumqi city expanded the largest area of the three cities from1990 to 2015, with an expansion of 349.81 km², followed by Nur-Sultan, with a city expansion area of 158.16 km². As the capital of Kazakhstan was relocated from Almaty to Nur-Sultan, the city of Almaty expanded the slowest during the entire period, with a total expansion of 126.23 km². In the urban built-up area, the urban surface in Urumqi increased by 7.10% from 1990 to 2015, and the Nur-Sultan and Almaty decreased by 14.9% and 4.49%，respectively. The green space component of the built-up area, Nur-Sultan increased by 6.68% from 1990 to 2015, while Urumqi and Almaty decreased by 6.65% and 2.75%，respectively. The different surface cover patterns of cities are different for different reasons. Urumqi is mainly supported by national policies, and Almaty is known for its historical background and urban planning, while the rapid development of Nur-Sudan was affected by the relocation of Kazakhstan.     

CISOC—化学信息和人工智能系统：十年回顾与展望

本文从 CISOC 概念,图论和化学结构处理,数据库,结构-活性关系研究系统和推理机器等方面回顾了 CISOC 系统十年来的进展,同时展望了 CISOC 的未来发展。