Results 61 to 70 of about 34,473 (149)
Gaoya dianqi, 2012 油中溶解气体分析（dissolved gas-in-oil analysis,DGA）是识别变压器故障的重要手段。笔者基于油中溶解气体数据介绍灰色关联理论,给出了基于组合权重变压器故障诊断的灰色关联分析法。在判定变压器故障类型时,各溶解气体其权重不同,利用层次分析法求出各特征气体在诊断变压器故障类型时的主观权重,但各专家通过层次分析法确定指标权重会存在许多主观因素,文中应用灰色关联分析法对其进行调整,消除各专家造成的各指标权重分配不统一,用熵值法确定指标的客观权重 ...
刘俊华 +3 more
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Gaoya dianqi, 2023 文章提出了基于合闸振动信号的变压器振动固有频率识别方法，可以据此来实现对变压器机械状态的评估。首先，文章建立了变压器多自由度非线性轴向振动模型，通过计算得出变压器在发生故障时其固有频率将会发生变化，而振动固有频率可以从变压器的合闸振动信号中提取得到，基于此文章提出了基于变分模态分解和特征系统实现算法结合的变压器固有频率识别方法，并根据固有模态分量的统计特性，提出了基于延时峭度法的模态识别方法，最后通过仿真与实验证明所提方法较传统方法而言可以有效的降低谐波模态的干扰，提高固有频率的识别精度。
马宏忠 +6 more
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Evaluating synthetic substitutes to reduce illegal harvesting and support species recovery
Conservation Biology, Volume 40, Issue 4, August 2026.Abstract Providing synthetic substitutes is a widely promoted strategy to shift consumer demand away from wildlife products derived from threatened species. Yet, there is little evidence on whether product substitution prevents illegal or unsustainable harvesting and contributes to the recovery of threatened populations.
Aditya Shekhar Malgaonkar +17 more
wiley +1 more source
Gaoya dianqi, 2008 笔者基于可拓理论,提出了一种可拓评价法和可拓层次分析法相结合的变压器状态综合评估方法。首先,采用可拓层次分析法（EAHP）,将变压器状态信息之间的相对重要度采用一个可拓区间数来表示,构造可拓判断矩阵,准确计算变压器状态信息指标的权重。然后,应用可拓评价法,通过计算物元之间的关联函数同时进行定性和定量分析,实现变压器状态的综合评估。实例分析证明了该方法的正确性和有效性,为变压器的状态维修提供了合理的决策依据。
谢庆 +4 more
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Conservation Biology, Volume 40, Issue 4, August 2026.Abstract Procedural, distributional, recognitional, and epistemic justice aspects of conservation interventions are well documented in contexts where pastoralism is a key livelihood and way of life. Geospatial analyses and representations of wildlife conservation and restoration that are increasingly applied in pastoralist rangeland socioecological ...
Ryan R. Unks
wiley +1 more source
Gaoya dianqi, 2010 以变压器油中溶解气体和变压器故障之间的关系为基础,提出了一种自适应分级多分类支持向量机变压器故障诊断方法。此方法基于模式识别特征提取的思想,采用不同的输入向量,对变压器有无故障和故障类型判别时,采取分级决策结构。采用自适应优化算法对多分类支持向量机进行优化,通过诊断效果和不同类型故障识别率的比较,得出变压器油中溶解气体的组分含量比值更能反映变压器故障类型,最终测试效果比较和支持向量机参数分析,可以看出该方法具有较高的准确率和良好的泛化能力。
杨洪, 古世甫, 陶加贵, 苟建
doaj
Assessing differences among elasmobranch nurseries to aid conservation based on a genomics framework
Conservation Biology, Volume 40, Issue 4, August 2026.Abstract Elasmobranch nurseries often differ in environmental conditions, demographics, and use patterns. These differences affect the distribution of genetic variation among nurseries. However, conservation and management strategies often fail to account for such differences because they are difficult to characterize.
Dominic G. Swift +8 more
wiley +1 more source
Uncovering correlates of decline and critical refuges for a threatened terrestrial mammal
Conservation Biology, Volume 40, Issue 4, August 2026.Abstract Globally, the geographic ranges of numerous species are contracting. Identifying spatiotemporal patterns of threat impact can illuminate why species decline in some parts of their range but persist in others. We developed a correlative approach to identify species’ response thresholds and locate ecological refuge areas associated with ...
Natalya M. Maitz +5 more
wiley +1 more source
Gaoya dianqi, 2017 为准确计算高电压等级变电站噪声分布情况及对周围环境的影响,在分析变电站噪声特点的基础上对变电站主噪声源设备变压器和电抗器的声学模型进行了研究。分析表明,冷却风扇的运行和结构的不对称使得变压器和电抗器不同位置辐射噪声分布相差较大。为此,文中基于声强法提出了一种分部等效建模计算方法,将变压器和电抗器每个面进行分块并分别建立声源模型,通过研究面声源与点声源等效算法建立了变压器和电抗器多点声源模型并结合点噪声衰减理论及环境特点建立了变电站噪声衰减预测模型 ...
胡静竹 +4 more
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Conservation Biology, Volume 40, Issue 4, August 2026.Abstract Ex situ plant collections may be increasingly needed to protect representative samples of threatened or rare species and provide plant material for conservation translocation. A primary problem in these ex situ collections is loss of intraspecific variation due to plant death. Different management actions would be required depending on whether
Rebecca Sucher +6 more
wiley +1 more source