Results 31 to 40 of about 32,420 (170)

Safety Assessment and Research of the Thermal Power Generation Enterprise in the Pipeline [PDF]

open access: yes, 2015
由于历史原因,大部分火力发电企业的压力管道在施工及使用过程中均没有有效的监管和检验,有些管道都有可能“带病”运行,严重威胁了企业的生产安全和电网稳定。因此,摸清火力发电企业在用压力管道的实际安全状况,对企业、社会都有着重要意义。 本文以福建某火力发电企业在用天然气管道为研究对象,探索在不停机及短暂停机状态下选择合适的检测技术快速准确的查出安全隐患,同时对含超标缺陷的管道进行安全性评价,以帮助企业在不影响正常生产、保障电网稳定的前提下根据缺陷危害程度合理安排检修时间 ...
许杰
core  

基于直流局部放电的高压储能电容器缺陷的模糊识别

open access: yesGaoya dianqi, 2011
为提高脉冲功率系统中高压储能电容器的可靠性,笔者利用直流下局部放电对电容器进行缺陷检测,得到直流局部放电测量数据的统计谱图,提出基于模糊数学理论识别电容器缺陷类型的方法。首先从22个统计算子中挑选出12个具有典型特征的统计算子组成特征向量,然后通过内部缺陷、接触缺陷、重叠缺陷、油质缺陷4种典型缺陷的测量,计算出每种缺陷特征向量的正态分布隶属函数。最后对未知缺陷类型的电容器进行了模糊检测和解剖验证,对含有可视气泡已知缺陷的电容器进行了检测和模糊识别,证明了系统的实用性 ...
王鹏, 吴广宁, 张依强, 张血琴
doaj  

Acid‐Etched Co‐Vacancy‐Tunable CoFeP/N,P‐Codoped Carbon Nanocages for Highly Efficient Alkaline Water Electrolysis

open access: yesRare Metals, EarlyView.
ABSTRACT Efficient and durable bifunctional electrocatalysts are vital for scalable water electrolysis. Here, we realize cobalt‐vacancy (Covac) engineering in CoFeP supported on N,P‐codoped carbon nanocages (Co1‐vacFeP/NPC) through a simple route comprising a CoFe Prussian blue analog precursor, phosphidation–pyrolysis, tannic‐acid etching, and a ...
Yuan‐Liang Yuan   +6 more
wiley   +1 more source

GIS固体绝缘缺陷所激发特高频信号时频特征研究

open access: yesGaoya dianqi, 2021
利用特高频局部放电检测方法及时发现并处理气体绝缘金属封闭开关设备(GIS)内部固体绝缘缺陷,是GIS设备运维的重要手段。目前将异常特高频信号与现行标准、规范和典型模拟缺陷图谱进行比对从而诊断缺陷类型及严重程度的方法,因现场情况复杂、设备结构各异,准确性有待进一步提升。因此文中针对现场检测中发现的GIS固体绝缘表面放电缺陷和内部气隙放电缺陷,研究该类缺陷所激发特高频局部放电信号的PRPS统计图谱特征,并利用傅里叶变换和连续小波变换分析单次特高频原始脉冲的频谱特征和时频特征 ...
周电波   +6 more
doaj  

Broad‐Spectral Response Lead Halide Perovskite Solar Cells Through Integration of Multifunctional Organic Bulk‐Heterojunction and Quantum‐Cutting Downconversion Materials

open access: yesRare Metals, EarlyView.
ABSTRACT Expanding near‐infrared (NIR) spectral response and utilizing ultraviolet (UV) photons are effective strategies for enhancing the power conversion efficiency (PCE) of lead halide perovskite solar cells (PSCs). However, the range of NIR spectral response extension and the utilization of UV light for devices are not enough, and the loss of ...
Li He   +9 more
wiley   +1 more source

Study on the Defects and Perfection of the Crime of Dangerous Driving [PDF]

open access: yes, 2015
伴随着现代科学技术和交通行业的快速进步,我国的汽车保有量近些年有了极快速的增加,人们的生活水平及出行便利程度有了很大的提高,但也存在很多问题和隐患。近几年,各地相继出现的一些飙车、醉驾案件,不断地向我们的社会安全提出了新的要求,挑战着人们的神经。可喜的是,《刑法修正案(八)》和《刑法修正案(九)》将危险驾驶行为规定为犯罪,对抑制危险驾驶行为起到了有效的作用。但是,我国刑法对危险驾驶罪的规定比较笼统,最高人民法院尚未制定出适用危险驾驶罪的司法解释,这就使危险驾驶罪的认定 ...
郭杏琴
core  

基于热固耦合的套管缺陷参数对其强度影响分析

open access: yesShiyou jixie, 2015
针对高温高压热采井套管失效概率高的问题,建立了含缺陷套管、水泥环和地层耦合系统有限元模型。将温度场与结构场耦合,并考虑套管强度降低,利用CAE技术计算了完整套管及缺陷套管的Von Mises应力、变形位移和塑性变形。计算得出在缺陷深度、缺陷环向开度、缺陷数量和缺陷环向分布4个结构参数中,套管缺陷深度和环向开度为影响套管强度的最敏感性参数,进行套管安全评定时建议将缺陷深度和缺陷环向开度作为缺陷最敏感性参数。研究结果可为套管安全评定奠定基础,并为揭示套管失效机理提供依据,对预防套损具有指导意义。
刘少胡   +5 more
doaj  

Engineering a Tumor‐Targeted MgH2@Lip/PD‐L1 Nanoplatform for Synergistic Hydrogen Therapy and Immune Activation

open access: yesRare Metals, EarlyView.
ABSTRACT Lung cancer remains the leading cause of cancer‐related deaths worldwide, yet immune checkpoint blockade (ICB) is often compromised by an immunosuppressive tumor microenvironment (TME) with acidosis, hypoxia, and poor T cell infiltration. Here, we develop a TME‐responsive nanoplatform (MgH2@Lip/PD‐L1) that couples hydrogen gas therapy with PD ...
Xuyu Gu   +5 more
wiley   +1 more source

Characterization of mechanical properties and primary investigation of pyrolysis and sintering of polycarbosilane-derived continuous fibers [PDF]

open access: yes, 2005
Hi-NicalonSiC纤维是通过先驱体法制备并已商品化的高性能连续纤维,是制备耐高温SiC/SiC复合材料的关键原材料。降低纤维中氧的含量可提高其高温使用性能,而降低纤维的直径、减少缺陷可提高其力学性能。本论文主要对Hi-NicalonSiC纤维的力学性能进行系统表征并对PCS制备连续SiC纤维的烧成工艺进行初步探索。对Hi-NicalonSiC纤维的研究结果表明:①纤维的强度服从Weibull分布;纤维的模量服从正态分布;纤维的应变服从正态分布;纤维的直径分布服从正态分布。②Hi ...
吴清良
core  

A Multifunctional Reducing Molecular Dopant for 16% Efficient Tin Perovskite Solar Cells

open access: yesRare Metals, EarlyView.
ABSTRACT Although lead‐based photovoltaics have seen remarkable progress, tin‐based perovskite solar cells (Sn‐PSCs) continue to face challenges due to their limited power conversion efficiency and insufficient operational stability. The primary cause of this performance gap is the susceptibility of Sn2+ to oxidation, which promotes rapid defect ...
Xianyong Zhou   +12 more
wiley   +1 more source

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