Results 51 to 60 of about 8,393 (169)

直升机旋翼系统可靠性分析 [PDF]

open access: yes, 2003
本文针对某型号直升机旋翼系统,从现场数据着手研究和分析了旋翼系统的可靠性。在整理现场数据得到的随机截尾数据的基础上,运用极大似然估计法估计了该混合型数据的威布尔分布参数。运用故障树分析方法建立和分析了旋翼系统的故障树结构。最后 ...
翁梓华
core  

Exploring gaps, biases, and research priorities in the evidence for reptile conservation actions

open access: yesConservation Biology, Volume 39, Issue 5, October 2025.
Abstract With over 21% of reptile species threatened with extinction, there is an urgent need to ensure conservation actions to protect and restore populations are informed by relevant, reliable evidence. We examined the geographic and taxonomic distribution of 707 studies that tested the effects of actions to conserve reptiles synthesized in ...
Oliver Speight   +9 more
wiley   +1 more source

真空断路器中关键零件机械可靠性计算与分析

open access: yesGaoya dianqi, 2005
给出了两种与高压断路器机械可靠性特点相适应的机械可靠性计算模型,并运用模型对目前在我国中压电网中应用十分广泛的真空断路器的机械可靠性进行了计算与分析,得到了对断路器机械可靠性影响较大的主要机械零部件的设计可靠度和在断路器不同开断次数下的可靠度,为提高高压断路器的可靠性提供了理论依据。
石飞   +5 more
doaj  

Reliability test for frequency estimation of sinusoid based on LMP detection [PDF]

open access: yes, 2015
A reliability test method based on locally most powerful (LMP) detection was proposed to evaluate the fre-quency estimation of sinusoid.The hypothesis test was created at first,and then a reference signal was generated depend-ing on the specific ...
AOAn-ping B   +4 more
core   +1 more source

Effects of Shifting Cultivation on the Western Hoolock Gibbon (Hoolock hoolock) in Western Myanmar 刀耕火种对缅甸西部西部白眉长臂猿 (Hoolock hoolock) 的影响摘要

open access: yesIntegrative Conservation, Volume 4, Issue 3, Page 503-513, September 2025.
Fire occurrence increased with proximity to roads and villages, indicating that human access and activity are major drivers of fire risk. We analyzed spatial patterns of fire in relation to human settlements. Our findings highlight the need for fire management strategies that consider accessibility and human presence in conservation planning.
Aung Lin   +4 more
wiley   +1 more source

电磁干扰对高压开关设备可靠性影响的研究

open access: yesGaoya dianqi, 2012
高压开关设备的可靠性在电力系统中所起的作用至关重要,笔者主要从影响开关设备工作可靠性的电磁干扰方面开展研究,依据可靠性的评价原则,提出反映可靠性的主要特征参量,结合相关标准及设备应用的现实状况,逐一开展电磁干扰试验,并对试验结果进行记录、分析,根据得到的试验数据,运用层次分析法的原理,在构造判断矩阵的基础上,通过计算,得出了不同干扰项目针对不同高压开关设备类别在可靠性影响方面所占的权重。结果表明,浪涌冲击具有破坏性,电快速瞬变脉冲群和阻尼振荡易引起设备工作故障,但不易造成设备损坏 ...
贾涛   +6 more
doaj  

Research on Dynamic Probabilistic Safety Assessment Methodologies of Nuclear Power Plant Digital Instrumentation and Control Systems [PDF]

open access: yes, 2014
动态概率安全评价(PSA)方法是指在系统可靠建模时通过考虑系统演化的时间因素来解释触发或随机逻辑事件之间耦合的方法,它能弥补传统PSA方法的不足,更有效地验证数字化仪控系统的可靠性及安全性。我们对美国核管会报告NUREG/CR-6901指出的最适合分析数字化仪控系统可靠性的两种方法——马尔可夫/区间映射技术(Markov/CCMT)和动态流图机制(DFM)进行研究。 本文先假设系统在满功率工况运行时发生主给水管道小破口事件,应用Markov/CCMT机制对AP1000主给水简化系统进行PSA分析 ...
陈培锋
core  

Universal cervical‐length screening to prevent preterm birth in twin pregnancy: cost‐utility analysis

open access: yesUltrasound in Obstetrics &Gynecology, Volume 66, Issue 3, Page 290-297, September 2025.
ABSTRACT Objective The purpose of this cost‐utility analysis was to model the clinical and economic impact of three cervical‐length screening strategies among low‐risk twin pregnancies: two‐step universal screening (at 18–20 and 20–22 weeks), one‐step universal screening (at 18–20 weeks) and no screening.
Y. Khaikin   +4 more
wiley   +1 more source

110kV以上GIS中断路器机械特性数据的统计和分析

open access: yesGaoya dianqi, 2015
GIS中断路器机械特性试验可以有效地反应GIS操动机构的动作状况,通过分析在运设备机械特性数据可以有效发现机构和控制回路可能存在的缺陷,减少故障的发生,提高GIS运行可靠性。文中通过对某地市局在运GIS中断路器部分机械特性试验数据和GIS设备中断路器机械缺陷的统计和分析,得出GIS中断路器分合闸时间和线圈电阻变化的规律及其原因,找出影响GIS中断路器机械特性的因素,提出了提高GIS可靠性的方法,为提高GIS设备运行可靠性提供了依据。
张欣   +5 more
doaj  

Simulation and analysis method for dynamic fatigue reliability of shovel stick for mining electric shovel [PDF]

open access: yes
In order to reduce the stick fracture caused by random load during the operation of the electric shovel in open-pit mines, a simulation and analysis method of the dynamic reliability of the stick of the electric shovel in the mining was proposed.
Chong CHEN   +3 more
core   +1 more source

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