Results 31 to 40 of about 28,211 (172)
Dianci bileiqi, 1977 本文就本世纪二十年代前后日本悬式绝缘子的劣化情况作了论述。并总结了绝缘子的劣化原固及其后来的改进措施。文中还介绍了从实际输电线路上取下来的劣化绝缘子的分析情况,提出了可供参考的绝缘子劣化的有益数据。
新宫行太, 姜惇
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Gaoya dianqi, 2022 近年来,复合绝缘子酥朽断裂问题引起了学术界及工业界的高度重视,但断裂原因一直莫衷一是。研究表明了复合绝缘子酥朽断裂的原因可能包括湿气侵蚀、电蚀、酸性介质腐蚀等因素。针对湿气侵蚀因素,文中研究了复合绝缘子芯棒在湿热条件下的劣化过程。首先观察了芯棒湿热作用后芯棒的宏观形貌,发现芯棒呈现发黄发白的颜色,质地变得疏松,形如腐朽的木头。随后对芯棒在高湿环境下的发热情况进行了观测,发现劣化后芯棒的温升明显高于未劣化芯棒的温升。通过扫描电镜(SEM)、傅里叶红外光谱(FTIR)、热失重分析(TGA ...
王成 +5 more
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Polyphasic analysis of the fungal biodeterioration of mural paintings and plaster walls of the Takamatsuzuka and Kitora Tumuli, Nara, Japan [PDF]
, 2013 Thesis (Ph. D. in Agricultural Science)--University of Tsukuba, (B), no.
喜友名 朝彦
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Understanding consumers to inform market interventions for Singapore's shark fin trade
People and Nature, Volume 6, Issue 2, Page 733-748, April 2024.Abstract Sharks, rays and their cartilaginous relatives (Class Chondrichthyes, herein ‘sharks’) are among the world's most threatened species groups, primarily due to overfishing, which in turn is driven by complex market forces including demand for fins.
Christina Choy +2 more
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Dianci bileiqi避雷器不仅在长期运行中因承受系统电压和偶然短时过电压而带来以阻性电流增大为主要特征的缓慢劣化过程，而且在重复雷击工况下存在因短时间内吸收较多的雷电能量而造成内部电阻片快速劣化过程，增大了避雷器发生热崩溃的风险。本研究提出避雷器劣化评价方法和判据，给出阈值为阻性电流增大1倍的缓慢劣化判据，以及在重复雷击过程增加短时间内累计吸收雷电能量阈值为达到通流容量30%的快速劣化判据，在此基础上，提出由缓慢劣化和快速劣化两种预警组成避雷器劣化预警方法以及相应的避雷器劣化预警装置 ...
王云龙 +4 more
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Dianci bileiqi, 2014 用MOV（氧化锌压敏电阻）的静态参数（压敏电压U1mA和漏电流IL）判定其劣化程度,只能直观反映压敏电阻的整体性能,而不能及时有效地的表征出压敏电阻的老化劣化趋势。根据MOV的U-I特性,结合肖特基势垒模型及离子迁移理论,提出MOV劣化过程中必然伴随着动态电阻Rd的变化。通过针对同一型号的MOV在不同脉冲电流下的大量实验分析得出:劣化前,8/20下Rd都呈"U"型分布,10/350下Rd呈缓慢递增后急速上升的趋势;劣化后,8/20下Rd没有明显变化,只有局部降低趋势而10/350下的Rd则出现不规则震荡。
徐乐 +4 more
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People and Nature, Volume 6, Issue 2, Page 792-799, April 2024.Abstract The ongoing degradation of Earth's ecosystems through human activities poses a severe threat to biodiversity. To mitigate this crisis, substantial changes in human behaviour are required. The frequency of nature experiences, particularly during childhood, has been established as a key predictor of actions that support biodiversity (hereafter ...
Yutaro Aota, Masashi Soga
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Dianci bileiqi, 2020 在使用传统红外热像法对绝缘子进行检测时,绝缘子的劣化特征并不稳定,容易导致漏检、误检。针对这个问题,本文提出了时间序列模型与红外热像处理技术相结合的劣化绝缘子识别方法。本方法使用中值滤波与线性平滑滤波优化图像质量;采用OTSU分割法结合钢帽、盘面的形态差异将绝缘子钢帽部分进行提取,实现绝缘子钢帽温度的自动提取;考虑到绝缘子温升受到多因素影响,采用ARIMA时间序列模型对绝缘子串温度时间序列进行拟合,对其温升变化进行预测,从预测结果中找到劣化特征明显的温度曲线进行判别;试验结果表明 ...
周友维 +6 more
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Untangling the threads of conservation: A closer look at restoration and preservation
Journal of Applied Ecology, Volume 61, Issue 2, Page 215-222, February 2024.Now that the Global Biodiversity Framework has just been set, there is a critical need to recognize their fundamental differences between the types of places that are priorities for preservation, restoration or both to make collective actions for achieving the targets and goals for nature and people.
Akira S. Mori, Forest Isbell
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Gaoya dianqi, 2018 为有效检测出高压输电线路劣化绝缘子,降低劳动强度,文中首先分析了绝缘子串周围的电场分布规律,并利用Ansys软件仿真验证了利用电场分布原理实现绝缘子劣化检测的可行性,简要阐述了基于电场分布原理设计的劣化绝缘子自动检测装置。考虑到检测装置本身可能会对绝缘子串的周围电场分布造成影响,利用Ansys软件对比分析了有无检测装置时的绝缘子电场分布,仿真结果表明,检测装置的存在不影响劣化绝缘子的判别。最后,在实验室及现场对劣化绝缘子检测装置进行了零值绝缘子及存在导通性缺陷的绝缘子检测试验,结果表明 ...
王力农 +5 more
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