Results 31 to 40 of about 6,687 (118)
Gaoya dianqi, 2022 为兼顾操作冲击电压、雷电冲击电压作用下对CVT的补偿效果,针对CVT的操作、雷电冲击响应所含的频率分量相差较大,本文提出了一种基于分类器和双路BP神经网络还原CVT一次侧波形的方法。通过设置频率分点计算高于频率分点的小波能量曲线以区分冲击电压类型,进而将冲击电压响应输入对应的双路BP神经网络神经元。通过多组雷电、操作冲击电压波形对神经网络进行训练,并验证了该方法能够兼顾CVT的非线性,模型具有波形适应性。现场应用表明,该方法可以用来对CVT进行暂态电压传递特性补偿 ...
谢施君 +5 more
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Veterinary Dermatology, Volume 36, Issue 5, Page 613-620, October 2025.Abstract Background Diff‐Quik (DQ) staining is widely used in clinical practice for its ease of use and rapid results. However, its potential contamination remains a concern. Hypothesis/Objectives This study aimed to investigate DQ solution contamination in veterinary hospitals and identify factors affecting it through a questionnaire on stain usage ...
Minji Cho, Seulgi Bae
wiley +1 more source
Gaoya dianqi, 2017 通过试验研究了频率响应分析法检测变压器绕组变形。首先分析了频率响应分析法检测变压器绕组变形的基本原理。建立了频率响应分析法试验平台,分析了影响频率响应分析法检测绕组变形结果的主要因素。结合相关系数法对两个典型算例变压器绕组进行了变形诊断分析。通过对变压器的频率响应测试数据比较分析,结果表明了用频率响应分析法判断变压器绕组变形仍存在一定的局限性。
张海军, 王曙鸿, 刘艳琴
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Risk, Hazards &Crisis in Public Policy, Volume 16, Issue 1, March 2025.Abstract Coastal storms are likely to increase in frequency and become even more damaging. An unresolved policy issue is whether current residents should receive federal subsidies through such programs as the Federal Flood Insurance Program or the FEMA disaster relief program that encourage thembe encouraged to rebuild in the same locations that have ...
Risa Palm +2 more
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Gaoya dianqi, 2019 频率响应分析法是现场用于检测电力变压器内部机械缺陷的重要方法。目前有几种不同的、用于分析频率响应法结果的方法,其中最常用的就是利用数值指标（如相关系数、均方差等）得出不同频响曲线之间的差异性。然而,传统的数值指标都只使用了频率响应结果的幅值,其对于变压器绕组微小变形的检测灵敏度不够理想。因此,文中提出了一种同时考虑频率响应结果幅值和相位的数值指标及一种改进传统数值指标的方法;然后通过实验得到了不同轴向微小变形程度绕组的频率响应数据;最后将不同的数值指标应用于实验所得数据并进行了对比试验 ...
刘云鹏, 程槐号, 胡焕
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Study on flutter characteristics of NACA0012 flexible straight wing with high-aspect-ratio
Xibei Gongye Daxue Xuebao, 2022 采用三维雷诺平均N-S方程和S-A湍流模型求解展弦比为16的NACA0012弹性平直机翼的非定常气动力, 结合机翼动力学方程, 建立了机翼颤振时域分析方法。利用该方法对机翼的颤振特性、颤振过程中的变形和振动响应, 以及瞬时流场进行数值模拟和分析, 并研究材料刚度和密度对机翼颤振速度和频率的影响。结果表明, 由于展弦比较大, 且材质轻柔, 机翼会出现一定幅度的静弯曲变形。第二阶(垂向弯曲)和第三阶(扭转)振动模态的耦合作用是机翼发生颤振的原因, 且颤振频率介于这两阶模态固有频率之间 ...
YU Qiuyang +3 more
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Integrative Conservation, Volume 3, Issue 4, Page 294-311, December 2024.Freshwater biodiversity in China is threatened by multiple anthropogenic factors, and while there are some reasons to suppose it may be possible to bend the curve of biodiversity loss, the variety of threats and their likely interactions with ongoing climate change provide little basis for optimism. For example, the historic overexploitation of Yangtze
David Dudgeon
wiley +1 more source
Social participation challenges and response strategies identified by adults aging with a disability
Journal of Elder Policy, Volume 3, Issue 2, Page 95-109, October 2024.Abstract Social participation is likely to decrease among older adults as disability levels increase. However, it is a modifiable determinant of health that can impact older adults' well‐being and quality of life. Thus, this secondary data analysis aimed to understand what challenges older adults aging with a mobility or vision disability face with ...
Maurita T. Harris, Wendy A. Rogers
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Integrative Conservation, Volume 3, Issue 1, Page 58-75, March 2024.Local populations are aware of the decline and disappearance of Detarium species in their habitats, attributing this trend to excessive human exploitation and the effects of climate change. Thus, Detarium plant resources may face challenges in forests with different levels of protection status due to habitat fragmentation and the effects of climate ...
Adama Taonda +4 more
wiley +1 more source
Gaoya dianqi, 2016 为研究温度和老化程度对变压器绝缘状况的影响情况,进一步推广频域谱法在油纸绝缘检测方面的应用;在实验室中制备不同温度和老化程度的油纸样品并开展频域谱测试,通过分析所得曲线变化规律,提出一种以不同频率对数点对应的tanδ值为特征量来区分温度和老化程度产生的影响,并对其进行实例探究。结果表明,温度主要影响tanδ值在频率对数为-30范围内的曲线,而老化则影响-32之间的曲线,且在-12之间更为明显,故选取频率对数为-3、-2、-1和0、1时的tanδ值分别作为温度和老化程度评估的特征参量 ...
李洁, 侯英洒, 赵建利, 张鹏
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