Results 11 to 20 of about 24,472 (211)
Gaoya dianqi, 2010 IEC及中国相关标准推荐了几种绝缘子污秽的试验方法,但不同试验方法对复合绝缘子污闪特性的影响并不明确。以复合绝缘子为例,分别采用恒压升降法、均匀升压法、最大耐受法试验研究了复合绝缘子的交流污秽闪络特性。结果表明:试验方法对污秽影响特征指数a值的影响不明显;在标准偏差取7.0%时,采用均匀升压法得到的50%闪络电压比采用恒压升降法得到的50%耐受电压高0.5个标准偏差,采用最大耐受法得到的最大耐受电压Umw等于采用恒压升降法得到的闪络概率为10%的污闪电压;不同的试验方法得到的试验结果存在内在联系 ...
蒋兴良 +4 more
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Gaoya dianqi, 2014 笔者针对大容量开关电器试验用Weil合成试验回路,给出了一种基于递推形式的电流零点预测方法,并且分析了这种电流零点预测方法的误差来源和误差消除的方法。为了验证该方法的准确性,笔者研制了一个应用于合成试验回路的DSP测控系统,并对过零点预测算法进行了实验验证。实验测试表明,文中所提的电流零点预测方法是准确的,相关测控系统的软硬件实现方式是可行的,具有实际应用价值。
李鹏, 高飞, 刘朴, 刘平, 何健
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Gaoya dianqi, 2012 复合绝缘子人工污秽试验方法和标准至今还不完善,试验方法对研究绝缘子污秽闪络特性具有重要的现实意义和参考价值。综述了复合绝缘子人工污秽试验方法研究取得的成果,总结了复合绝缘子染污方法以及加压方式、盐密和灰密、污层受潮方式、憎水特性对复合绝缘子污闪特性的影响,认为今后研究工作的重点是自然污秽与人工污秽试验的等价性评价研究。
罗明武, 肖代波
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Dianci bileiqi, 2002 简要介绍了金属氧化物避雷器产品的分类 ,并从试验角度阐述了依据不同技术标准进行型式试验时 ,试品的准备、数量和选取方法及有关试验项目的检验方法。
张益民
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Application Research of Slag mixed Sand in the Concrete [PDF]
, 2016 随着我国城镇化进程的加快，对混凝土的需求量逐渐增长，混凝土的用砂量也逐渐增大，随着对砂子的不断开采，我国天然河砂资源逐渐枯竭，导致很多地方出现了无砂可采、一砂难求的情况。随着天然砂资源的紧缺，寻找新型骨料替代天然砂做为混凝土细骨料已经成为亟需解决的问题。 炉渣混合砂系本课题组为福建省龙澄建设集团所研发的新型混凝土细骨料，是将经过特殊预处理的生活垃圾焚烧炉渣与天然河砂按照一定配比复配而成的新型混合砂。如若将炉渣混合砂应用于混凝土，既可以缓解因为天然砂短缺而造成的原材料紧缺问题 ...
傅荣兴
core
When and why to give shorebirds a head start
Conservation Biology, EarlyView.Abstract Headstarting is a translocation technique involving the hatching or rearing of wild eggs or young in captivity and the release of those individuals back to the wild at or before independence. It has been trialed as a conservation intervention for shorebirds over recent decades to improve the population trend of target populations by increasing
Lynda Donaldson +4 more
wiley +1 more source
Research and application of heavy metal leaching of waste concretein Xiamen area [PDF]
, 2016 重金属是我国“十二五”规划中重点防控的污染物，重金属对环境和人体极具潜在的威胁，它不但不能被微生物分解，反而可以被生物体富集，或与某些阴离子（团）形成其他毒性更强的金属化合物。重金属在环境中将经历地质和生化双重循环迁移转化，并通过各种渠道（如大气、饮水、食物等）进入人体，这种摄取将对人体造成极大危害。重金属的过量能抑制生物酶的活性，影响人体正常的生物化学反应。重金属与人体蛋白质、核糖、激素等反应，形成金属络合物或螯合物，使其丧失或改变原来的生理化学功能而产生病变。 我国建筑产业飞速发展 ...
王振华
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Using incentive payments to promote human–carnivore coexistence
Conservation Biology, EarlyView.Abstract For many large carnivores, minimizing the financial burden they impose on local people is critical to their conservation. Incentive‐based programs that provide people with financial benefits for taking pro‐conservation actions or achieving conservation goals are a promising tool for promoting human–carnivore coexistence. Although the number of
Adam Pekor +9 more
wiley +1 more source
Determination of the residues of 9 kinds of antiviral drugs in animal-derived sports nutrition by HILIC-MS/MS [PDF]
, 2023 Objective: This study aimed to help with strengthening the monitoring of antiviral drug residues in animal-derived sports nutrition products. Methods: A method for determining the residues of 9 kinds of antiviral drugs in animal-derived sports nutrition ...
GUO Wei
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Conservation Biology, EarlyView.Abstract The design of experiments to investigate the combined effects of multiple stressors requires exposing target organisms to multiple combinations of stressor doses. Concurrent manipulation of stressors is often infeasible with wildlife, but long‐lasting health effects allow individual health to be used as an integrator of prior stressor exposure.
Enrico Pirotta +24 more
wiley +1 more source