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基于多尺度特征融合的航空发动机剩余寿命预测
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作者 秦子轩 张晓东 +1 位作者 白广芝 任先聪 《航空发动机》 北大核心 2024年第4期114-120,共7页
针对航空发动机原始数据中存在多样化退化信息及大量噪声干扰的问题,建立了一种基于多尺度特征融合的发动机剩余可用寿命(RUL)预测模型。构建了一种基于统计量的方法来降低原始数据中的噪声干扰;基于卷积双向长短期记忆网络(ConvBiLSTM... 针对航空发动机原始数据中存在多样化退化信息及大量噪声干扰的问题,建立了一种基于多尺度特征融合的发动机剩余可用寿命(RUL)预测模型。构建了一种基于统计量的方法来降低原始数据中的噪声干扰;基于卷积双向长短期记忆网络(ConvBiLSTM)和多头注意力机制(Multi-Attention)设计了加权时空特征提取模块(WSTFEM);采用多尺度学习策略,构建多尺度卷积双向长短期记忆网络(MCBLSTM)提取数据在不同时间尺度下的加权时空特征;提取数据手工特征为RUL预测提供具有针对性和解释性的退化信息;将上述特征进行特征融合后输入至全连接网络获得RUL预测值。以FD004子集为例,使用C-MAPSS数据集对模型进行仿真试验验证。结果表明:MCBLSTM模型在4个子数据集上RUL预测精度更高。相较于BiLSTM,均方根误差减小了20.35%,非对称评分函数下降了54.76%。 展开更多
关键词 深度学习 多头注意力机制 多尺度卷积双向长短期记忆网络 剩余可用寿命 航空发动机
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管网用膨胀节在线监测技术与应用
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作者 杨玉强 苏炎强 +3 位作者 付贝贝 李栓柱 侯伟 李德雨 《化工设备与管道》 CAS 北大核心 2024年第3期70-76,共7页
膨胀节是一个具有使用寿命的结构元件,当膨胀节的使用达到一定时间后,膨胀节就会发生失效。文章设计开发了一种基于无线传感网络的膨胀节在线监测系统,将物联网、大数据以及分布式软件等热点技术与膨胀节产品有机结合。通过试验测试及... 膨胀节是一个具有使用寿命的结构元件,当膨胀节的使用达到一定时间后,膨胀节就会发生失效。文章设计开发了一种基于无线传感网络的膨胀节在线监测系统,将物联网、大数据以及分布式软件等热点技术与膨胀节产品有机结合。通过试验测试及工程应用,能够有效地实时监测产品的运行工况,并进行预警及报警。 展开更多
关键词 膨胀节 无线传感 实时监测 可用疲劳寿命
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重型机床基础件疲劳损伤评估模型 被引量:2
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作者 卢超 潘尚峰 张玉杰 《机械设计与制造》 北大核心 2018年第3期1-3,共3页
为确定基础件可再制造性,需要对基础件进行疲劳损伤评估。采用应力-疲劳损伤模型和线性疲劳累积损伤理论,计算基础件高周疲劳损伤。使用材料HT300进行疲劳加载实验,得到描述材料疲劳寿命特性的S-N曲线,对采用经验公式计算的切削力进行... 为确定基础件可再制造性,需要对基础件进行疲劳损伤评估。采用应力-疲劳损伤模型和线性疲劳累积损伤理论,计算基础件高周疲劳损伤。使用材料HT300进行疲劳加载实验,得到描述材料疲劳寿命特性的S-N曲线,对采用经验公式计算的切削力进行基于概率分布的循环次数统计计算。以ANSYS为分析工具,建立重型机床简化模型,导入切削力循环次数分布数据和材料疲劳力学性能参数,建立基于安全系数和可用寿命的疲劳损伤评估模型,对基础件疲劳损伤进行定量分析。 展开更多
关键词 重型机床 疲劳损伤评估 可用寿命 安全系数
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Quantitative estimation of social stock for metals Al and Cu in China 被引量:5
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作者 岳强 王鹤鸣 陆钟武 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第7期1744-1752,共9页
Social stock for metal determines secondary or recoverable resources to a certain extent.Top-down analysis method for the studying of metal in social stock was given.Influences of metal consumption under three circums... Social stock for metal determines secondary or recoverable resources to a certain extent.Top-down analysis method for the studying of metal in social stock was given.Influences of metal consumption under three circumstances,that is keeping constant,varying in a linear trend and in an exponential trend,on one kind of metal’s social stock,recyclable ratio and average age were analyzed.Al-contents and Cu-contents in social stock for China during the period 2006-2009 were calculated.The results reveal that Al-contents and Cu-contents in social stock kept increasing and reached 88.9 million tons and 51.4 millions tons in 2009,respectively,their average recyclable ratios are 1.45% and 0.30%,and the average ages are 4.65 years and 6.89 years,respectively.The recyclable ratios and average ages of Al-contents and Cu-contents in social stock will rise in future along with the decline of the increasing rate of aluminum consumption and copper consumption. 展开更多
关键词 social stock secondary resource average use life recyclable ratio average age
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建设房式仓和圆筒仓各项指标的比较
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《中国稻米》 2001年第4期35-35,共1页
关键词 粮仓 房式仓 圆筒仓 造价 机械化程度 可用寿命 作业成本 占地面积 比较研究
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Investigating the Life-Span of Cork Products through a Longitudinal ApproachmOverview of Two Years Results
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作者 Ana Carina Pereira Helena Pereira 《Journal of Environmental Science and Engineering(B)》 2013年第7期436-441,共6页
Products with long life-spans are generally acknowledged to have a significant contribution towards sustainability. This paper provides an overview and discussion of the two years results of a longitudinal study perfo... Products with long life-spans are generally acknowledged to have a significant contribution towards sustainability. This paper provides an overview and discussion of the two years results of a longitudinal study performed with users and several cork products. The research aimed to tackle the process of life-span, and the results include: (1) the identification and interrelation of the aspects influencing the life-span of the products; (2) the evolution of life-span over time; and (3) new knowledge and guidelines arising about the material. Overall, most cork products are still being used, have a very good life-span, and most issues arising are material related. 展开更多
关键词 Product life-span USERS longitudinal study cork products and materials.
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Accelerated Luminous Depreciation Testing for LED Lighting Products
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作者 钱诚 孙博 曹峻松 《China Standardization》 2014年第5期74-79,共6页
With the application of energy-saving, environmental and durable LED lighting products, the reliability testing has become a pivot point for the large scale industrialization and popularization. The paper briefly intr... With the application of energy-saving, environmental and durable LED lighting products, the reliability testing has become a pivot point for the large scale industrialization and popularization. The paper briefly introduces two methods to be respectively applied in the accelerated depreciatinn lesting for the luminous flex of LED lighting products and the life of outdoor LED-driving power, which can sharply shorten the time for lifetime lest. providing references for the LED lighting products' reliability evaluation. 展开更多
关键词 LED lighting products outdoor LED driving power accelerated attenuation
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Reliability-based service life prediction of existing concrete structures under marine environment 被引量:2
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作者 吴灵杰 周拥军 +1 位作者 寇新建 蒋萌 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第9期3608-3614,共7页
Chloride-induced corrosion of the reinforcement is considered as one of the major mechanisms resulting in the reduction of structural resistance of reinforced concrete structural elements located in marine and other a... Chloride-induced corrosion of the reinforcement is considered as one of the major mechanisms resulting in the reduction of structural resistance of reinforced concrete structural elements located in marine and other aggressive environments. A study of reinforced concrete structures located at the Fangcheng dock in the Beibu Gulf port, China, was present. The result from field survey indicates that the concrete cover depth and chloride diffusion coefficient fit best normal distribution and lognormal distribution, respectively. The service life of structure is about 55 a, while initiation time is 45 a. Sensitivity analysis indicates that the most influential factor of the structure service life prediction is concrete cover, followed by diffusion coefficient, diffusion decay index, critical chloride concentration, surface chloride concentration, current density and localized pitting corrosion. Finally, the effects of diffusion decay index and critical chloride concentration on structure service life prediction are discussed. 展开更多
关键词 CHLORIDE existing concrete structure service life marine environment
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为你的硬盘体检看它还有多长寿
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作者 PWL 《大众电脑》 2003年第8期113-113,共1页
我们都知道,硬盘是一台电脑的重要组成部分,平日里用电脑做的工作和许多重要的数据都储存在里面,一旦硬盘出现问随就可能意味着很多的努力付之东流。我们也都可以看到,现在的硬盘容量越来越大,转速越来越高,价格也越来越便宜。可... 我们都知道,硬盘是一台电脑的重要组成部分,平日里用电脑做的工作和许多重要的数据都储存在里面,一旦硬盘出现问随就可能意味着很多的努力付之东流。我们也都可以看到,现在的硬盘容量越来越大,转速越来越高,价格也越来越便宜。可是我们关心的硬盘质保期却没有随之延长,相反的除了SCSI接口的硬盘外。 展开更多
关键词 DRIVE HEALTH 硬盘监视软件 可用寿命 使用方法
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