Results 11 to 20 of about 4,664 (157)
新型电力系统下负载因素对三相油浸式变压器振动噪声特性影响的试验研究
为了研究新型电力系统下负载因素对S13-M400/10配电变压器振动噪声特性的影响,文中在半消声室中搭建了振动噪声试验平台探究了该变压器的整体模态及其散热片的振动噪声特性,研究了谐波、不平衡负载、过励磁、过载等因素对于该变压器振动噪声特性的影响。研究结果表明,S13-M400/10配电变压器整体模态频谱复杂,固有频率较多;散热片的振动比相邻的油箱箱体部分振动更强烈;三相不平衡负载中不平衡相为B相时振动、噪声小于不平衡相为A相和C相时的振动、噪声;5次谐波下该变压器振动噪声剧增 ...
张壮壮 +5 more
doaj
Analysis and experimental study on the vibration characteristics of the spiral drum of a shearer based on two-way coupling method [PDF]
In order to study the vibration characteristics of shearer’s spiral drum under various occurrence conditions,the coal-rock contact model was optimized by taking the MG2×55/250–BWD thin seam shearer as the engineering object, and discrete element model of
Lijuan ZHAO +3 more
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Research Progress of Galloping of Overhead Iced Transmission Lines [PDF]
[Introduction] The galloping of transmission lines will lead to trip, worn hardware, broken insulator string, damaged tower-arm and other accidents. In serious cases, collapsed tower accidents may occur.
Guangyun MIN, Xiaohui LIU, Xin ZHAO
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Qtech-413 粘弹阻尼材料在盾构隧道中减振性能研究 [PDF]
根据盾构隧道的结构特点,用Qtech-413 粘弹阻尼材料对盾构管片标准块进行约束阻尼处理,通过单点锤击振动实验,得到处理前后结构的时域波形、固有频率、复合损耗因子等振动特性。实验结果显示:经过约束阻尼处理后,盾构管片振动加速度幅值降低了26.7%,振动时长降低了50%;各阶固有频率均有所降低,且随着频率的增加,降幅逐渐增加;各阶复合损耗因子均有所升高,高频增幅比低频增幅更大;振动总级值降低了10 dB 左右。因此,Qtech-413 粘弹阻尼材料应用于盾构隧道能降低振动加速度幅值、振动时间 ...
黄舰 +1 more
core
Read the free Plain Language Summary for this article on the Journal blog. Abstract The nested subset pattern (nestedness) has been widely used to explain species distributions in island and fragmented systems. Mountain sky islands serve as critical natural laboratories for understanding the evolutionary consequences of geographic isolation and climate
Caiwen Zhang +5 more
wiley +1 more source
机械故障是断路器发生的主要故障之一,断路器分合闸过程中产生的振动信号可以有效反应其运行状态。针对现有的时频域分析等线性分析方法在提取断路器振动信号时存在的局限性,提出并探讨了一种基于相空间重构的断路器振动信号边缘特征提取方法,用于刻画断路器的非线性特征,为断路器的状态诊断提供依据。搭建故障模拟平台模拟断路器正常状态、触头磨损、线圈老化、低操作电压、合闸弹簧失效的振动信号;结合分形理论和边缘检测算法提取振动信号的边缘图像和边缘特征量,从边缘图像形态 ...
盛健 +6 more
doaj
Research of Resonator-sound-generator Atomizing Nozzle [PDF]
喷嘴技术的应用范围几乎包含所有工业领域、农业生产、交通运输以及人们的日常生活。作为必备组件在燃烧装置上的应用尤为重要。以往对于新型的流体动力式超声波雾化喷嘴研究表明:这类喷嘴的雾化粒径小(小于50μm)且分布均匀性好,对实现低氧燃烧、减少烟气中烟尘和氮氧污染物的排放有实质性的意义。因此本文以谐振腔式声能雾化喷嘴为研究对象,通过设计结构,利用FLUENT软件对其流场、声场以及雾化性能进行多参数的数值模拟,通过雾化性能的变化规律分析了其雾化机理。 研究首先基于哈特曼发声哨的原理设计了谐振腔式声能雾化喷嘴 ...
邢盼
core
ABSTRACT Harnessing solar energy for self‐heating presents an effective strategy to suppress surface ice formation. In this paper, we fabricated nano‐silver‐modified multilayer graphene sheets (Ag@MGs) that integrate photothermal and superhydrophobic properties for anti‐icing applications.
Yihan Zhang +7 more
wiley +1 more source
Study on Vibration Characteristic of Operational Bridge Based on Monitoring Data [PDF]
桥梁结构监测系统能够对结构进行实时自动的状态监测,为评价运营桥梁的承载能力、使用功能和安全可靠性提供数据基础。近年来因为缺乏科学监测与管理所引起的桥梁垮塌事故频频发生,因此有必要利用监测数据对重要大桥的结构运营状态进行评估。本文基于厦门天圆大桥结构监测系统的实测数据,对单拱肋中承式梁拱组合桥型的振动特性进行研究,重点包括大桥的模态参数识别与短吊杆疲劳寿命估计两方面。本文主要工作内容如下: 首先,阐述了桥梁结构监测系统与模态分析方法的发展现状,总结了中承式拱桥结构特点与短吊杆疲劳问题 ...
何文朋
core
China's Eco‐Civilisation, Climate Leviathan, and Hobbesian Energy Transition
Abstract Scholars have hitherto tended to theorise China's ecological civilisation project either as a form of environmental authoritarianism or as a vision of eco‐socialism. This paper contributes to the conversation by conducting a textual analysis of Chinese scholarly discussions on eco‐civilisation.
David Chen
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