Results 21 to 30 of about 24,432 (139)
Conservation Biology, EarlyView.Abstract Despite the crucial role of human impacts on biodiversity loss, many assessments of this loss focus on single metrics, such as species richness, and overlook the multidimensional effects of human activities. Because of its importance to ecosystem functioning, we investigated the functional diversity of medium‐ and large‐sized mammal ...
Xueyou Li +8 more
wiley +1 more source
Dianci bileiqi, 2020 目前缺少有效的线路复合绝缘子综合评价方法,无法准确判断绝缘子运行状态,严重影响线路安全稳定运行。笔者基于主成分分析法建立了线路复合绝缘子运行状态综合评价模型,其中制定了实验参数的无量纲处理原则并选取累计方差达到85%的指标参数作为主成分。以±800 k V楚穗直流线路复合绝缘子为例,选取15支在线运行绝缘子进行了基本性能测试、电气性能试验和机械性能试验,依据主成分分析法对得到的3类主成分。评价结果与绝缘子当前状态具有良好契合度,验证了线路绝缘子运行状态综合评价模型的有效性和可靠性 ...
陈艺 +4 more
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Zhejiang Daxue xuebao. Lixue ban, 2022 为实现对4种大黄鱼（Larimichthys crocea）产地（分别来自福建宁德养殖、浙江温州养殖、浙江舟山养殖和舟山渔场自然海域捕捞）的区分，应用电感耦合等离子体质谱仪（inductively coupled plasma mass spectrometry，ICP-MS）及元素分析-同位素质谱仪对大黄鱼肌肉中19种矿物元素及δ13C、δ15N和C、N元素的质量分数进行了测定，基于质量分数差异并结合主成分分析（principal component analysis，PCA）、聚类分析 ...
MEIGuangming(梅光明) +6 more
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Conservation Biology, EarlyView.Abstract Human development is a driver of global change and a major threat to biodiversity. Protected areas maintain and support biodiversity, but outside stressors, such as climate change and land use change, can negatively influence natural resources within protected areas.
Leah J. Rudge +2 more
wiley +1 more source
UF-100尿沉渣分析仪尿液有形成分检测假阳性结果原因分析及其对策
Zhongguo shiyan zhenduanxue, 2007 目的探讨影响UF-100尿沉渣分析仪尿液有形成分检测的影响因素,寻找导致其测定假阳性结果的原因及其对策。方法分别采用UF-100尿沉渣分析仪和显微镜检查法对1000例临床尿液标本进行检测,对比两种方法的检测结果,分析引起UF-100尿沉渣分析仪测定假阳性的原因。结果UF-100尿沉渣分析仪检测管型假阳性率为7.3%,粘液丝是引起其假阳性的最主要原因;红细胞假阳性率为11.9%,一定量的结晶、细菌和酵母样菌易被仪器错误报告为红细胞;白细胞的假阳性率为5.9%,小圆上皮细胞 ...
石晶, 赵敏, 张家红, 张丽霞
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Scenarios and strategies for future‐proofing ecosystem management under climatic novelty
Conservation Biology, EarlyView.Abstract Climate change is driving unprecedented declines in dominant, habitat‐forming foundation species across marine and terrestrial ecosystems globally. As climatic novelty becomes the norm, ecosystem reassembly will become increasingly common. Predicting and understanding these transitions, and their implications for future ecosystem functioning ...
Lauren T. Toth +14 more
wiley +1 more source
Gaoya dianqi, 2017 电力设备运行的健康状态直接影响着电力系统的安全稳定。基于数据挖掘技术,利用主成分分析方法对反映电力设备状态的海量数据进行了深入分析,形成了融合电力设备状态关键参量信息的主成分体系。基于该主成分体系,建立了电力设备运行状态的综合评价模型,实现了电力设备健康状态的动态评估和异常状态的快速检出。文中以变压器绝缘状态评估为例,证明了文中提出的方法可以弥补传统的状态评估方法的不足,具有一定的可靠性和实用性。
贺川双 +5 more
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Drivers of bat researchers’ intent to adopt field hygiene practices
Conservation Biology, EarlyView.Abstract Infectious disease is a growing threat to wildlife, with zoonotic transmission most likely at the human–wildlife interface. One underappreciated activity at this interface is fieldwork with wild animals, but associated risks can be mitigated through field hygiene (FH) practices, such as using personal protective equipment and other appropriate
Joanna L. Coleman +6 more
wiley +1 more source
Striking a Balance: Stakeholder Perceptions of Risk in Horse Racing
Equine Veterinary Journal, EarlyView.ABSTRACT Background Thoroughbred racing is a major industry, and in recent years, public concerns about equine safety have become more prominent, particularly in relation to on‐track injuries and fatalities. This has challenged the industry's social licence to operate (SLO).
Jessie McCarthy +2 more
wiley +1 more source
基于主成分分析和反向传播神经网络相结合的金属氧化物压敏电阻故障诊断分析
Dianci bileiqi, 2019 准确诊断金属氧化物压敏电阻故障对电力系统安全运行十分重要。为有效提高故障诊断率,本文提出基于主成分分析与反向传播神经网络相结合的故障诊断算法。对于MOV故障数据指示指标,利用主成分分析进行降维,降低原始指标间相关性,最后利用反向传播神经网络对所选主成分进行诊断。试验结果表明:相对于反向传播模型,PCA-反向传播模型诊断误判率下降了3%,模型运行时间降低了267 s。有效降低MOV误判率,简化了反向传播网络结构,提高网络收敛性和稳定性。
王伟, 虢韬, 杨恒
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