Results 41 to 50 of about 4,894 (167)
Gaoya dianqi, 2020 为探究工作在气温条件多变、昼夜温差大的环境下室温硫化硅橡胶（RTV）绝缘保护材料的老化特性,文中制备了RTV硅橡胶试样,并对其进行了冷热循环老化模拟试验,通过红外光谱测试（FTIR）及扫描电子显微镜（SEM）研究了老化前后微观结构的变化规律及老化机理,并通过拉伸试验、介电性能测试及击穿试验,分析了冷热循环老化过程中力学性能、体积电阻率、介电性能及击穿强度等宏观特性的变化规律。结果表明,冷热循环老化过程中,试样分子链交联网络劣化,同时产生-OH等强极性基团。在老化温度及高低交变温度应力共同作用下 ...
金海云 +6 more
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Gaoya dianqi, 2022 依据油纸绝缘时域介电响应介电谱及其能量谱，定义了两个能反映油纸绝缘老化程度的新特征量——去极化能量初始斜率SW和去极化能量半衰期thalf。通过测试样本分析确定了SW、thalf与油纸绝缘老化程度之间的关联性，验证了其作为绝缘老化指标在油纸绝缘老化评估中的有效性。针对复合油纸绝缘介电特征量，提出了一种新的未确知测度理论的绝缘老化特征指标综合评估体系。建立了绝缘老化评估结构层次与评价指标分级区间，在复合特征指标的权重分析基础上，引入未确知测度理论，针对其中等级评定环节的主观性问题 ...
舒恺, 高飞翎, 余萃卓, 苏凯强
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Integrative Conservation, Volume 4, Issue 1, Page 85-94, March 2025.Chromolaena odorata and Ageratina adenophora are invasive species in Southern Yunnan, China; they have very differing, yet overlapping, climate niches. Both invaders produce a large number of small pappus‐bearing achenes every year. They grow in, and their seeds are dispersed to, both suitable and marginal habitats.
Bin Wen +5 more
wiley +1 more source
Gaoya dianqi, 2018 电力变压器绝缘纸板的复弹性模量与纸板所处温度和老化程度等密切相关,对其进行研究有助于深入掌握电力变压器绕组动力学特性及基于振动信号的绕组机械状态检测技术。文中从材料的粘弹性理论出发,对绝缘纸板进行加速老化试验,使用动态热机械分析仪（DMA）研究了老化纸板在100 Hz应力作用下,在不同温度和老化程度的情况下,储能模量和机械损耗角的变化规律,建立了纸板复弹性模量与温度和老化程度的联系。结果表明,纸板的复弹性模量随着老化程度的增加和温度的升高而降低,机械损耗角的正切值则基本保持不变,其值小于0.055 ...
李秀广 +6 more
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Gaoya dianqi, 2019 液体硅橡胶（LSR）具有优异的机械性能和良好的憎水性,广泛应用于制造互感器、避雷器等输变电设备的绝缘护套。文中对LSR进行200℃的热空气老化试验,发现随着老化时间增加,LSR的拉伸性能和撕裂性能都出现了明显的下降,硬度则出现小幅增加。通过平衡溶胀法测量了老化过程中LSR的交联密度,发现随着老化时间增加,总交联密度和化学交联密度都显著上升,而物理交联密度变化微弱。对LSR进行SEM、EDS和FTIR分析发现,在热老化的过程中LSR的微观形貌、元素组成和官能团组成的变化都较小 ...
晏年平 +5 more
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Dianci bileiqi, 2023 酥朽断裂是如今高压输电线路中复合绝缘子的新型机械故障，现有的研究均集中于酥朽断裂绝缘子芯棒的老化过程和理化特性，但很少有研究在实验室试验中模拟这种现象。建立了一种具有高温，酸腐蚀和高电场强度等多种老化条件的人工加速老化平台，一定程度上模拟了酥朽断裂绝缘子芯棒的典型特征。结果表明，当施加电压数小时后，使用热红外成像仪检测发现温度明显升高。与单一老化应力相比，芯棒样片在多应力条件下的温度高达61℃。此外，采用扫描电子显微镜(SEM),傅立叶变换红外(FTIR)光谱，X射线光电子能谱(XPS)和热重分析 ...
蔡汉贤 +5 more
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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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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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Effect of Fatty Acid Chain Length on Properties of Rice Starch-Fatty Acid Complexes [PDF]
Rice starch-fatty acid complexes were prepared by compounding rice starch with different chain lengths of lauric acid (C12), myristic acid (C14), and palmitic acid (C16). By measuring the composite index, gelatinization properties, rheological properties,
Boxin DOU +6 more
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Reforming the Dutch pension system to ensure sustainability
International Social Security Review, Volume 77, Issue 3, Page 99-122, July/September 2024.Abstract The Netherlands is on the brink of reforming its system of occupational pensions as part of a more general reform of its three‐pillar pension system. This reform features important changes to first pillar pension benefits. The focus of this article is however on the coming reform of occupational pensions, the second pillar of the system, which
Ed Westerhout +2 more
wiley +1 more source