Results 61 to 70 of about 19,278 (163)
Gaoya dianqi, 2008 针对27.5kV永磁机构真空断路器并根据其动作特点,进行了基于Ansoft和Matlab软件的静态、动态特性仿真。首先,建立有限元模型,利用Ansoft软件包对永磁机构的静态特性进行仿真。其次,根据耦合电压平衡方程和达朗贝尔机械运动特征方程,在静态仿真基础上采用Matlab构建永磁机构断路器的运动模型,对永磁机构动铁心、断路器动触头运动特性进行了仿真分析。最后,对设计的样机进行了动态测试,测试结果表明仿真的正确性。
周丽丽 +5 more
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Hobbyist preferences for pet freshwater turtles
Conservation Biology, EarlyView.Abstract The burgeoning pet trade is a primary threat to wild freshwater turtles worldwide. Although the risks from commercial exploitation of turtles have been discussed widely, there is little empirical research on preferences for pet turtles from a hobbyists’ perspective.
Jingjing Zhao +7 more
wiley +1 more source
Gaoya dianqi, 2011 针对40.5kV新型磁力机构工作原理及其运动特点,进行了多场耦合的静态和动态特性仿真研究。首先,建立磁力操动机构的有限元模型,利用Maxwell软件对磁力机构的静态特性进行仿真;其次,根据电压平衡方程和达朗贝尔运动方程,在静态仿真基础上采用ADAMS和MATLAB建立40.5kV磁力机构SF6断路器运动模型,对磁力机构的动铁心、SF6断路器触头运动特性进行了仿真研究。最后,分析了磁力机构运动特性对SF6断路器性能的影响,为新型磁力机构在中压SF6断路器中应用提供了一定理论基础。
茹晶晶 +5 more
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Lessons from an eradication under multiple constraints of an island rat population of record density
Conservation Biology, EarlyView.Abstract Invasive rats threaten island biodiversity, disrupting ecosystems and endangering native species. Although rat eradication has succeeded on many islands, tropical islands present unique management challenges. Strict regulations and financial constraints on some tropical islands further limit proven eradication methods, complicating rodent ...
Tatiane Micheletti +7 more
wiley +1 more source
Conservation Biology, EarlyView.Abstract Prioritization in conservation is crucial for the development of efficient and effective decision‐making policies. For many decades, the importance of some species and their habitats has been assessed and applied in conservation legislation, but bats and their diurnal roosts have ofbeen overlooked.
David López‐Bosch +6 more
wiley +1 more source
Gaoya dianqi, 2017 缓冲器是弹簧操动机构的重要部件,其缓冲性能优劣直接影响到断路器的工作性能指标和弹簧操动机构的稳定性与使用寿命。文中基于断路器分闸操作时缓冲器的工作原理和数学模型,在对断路器与弹簧操动机构整体进行建模后,采用Adams与MATLAB的联合仿真,得到动触头位移时间特性,发现与试验结果一致。利用粒子群优化算法,对缓冲器阻尼孔直径与分布位置2个参数进行优化。优化后的缓冲器不仅能够满足断路器机械特性要求,还平滑了动触头的减速过程,降低了缓冲力峰值,提高了缓冲效率,改善了弹簧操动机构的工作可靠性与使用寿命 ...
马曾锐, 赵伟涛
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野生动物学报, 2021 对野生动物非法交易案件进行信息特征分析,可以把握案件的发生规律,提供决策者参考,以便有针对性预防和打击犯罪,更好地保护野生动物资源。本研究应用大数据分析的方法,对野生动物非法交易犯罪案件的文本数据进行结构化处理,建立了word2vec模型。从犯罪因素的角度统计分析了本类案件的信息特征,包括侵害人的特征、作案行为特征、侵害的动物或动物制品、侵害的时间和案件发生的地点等。在梳理基本特征的基础上应用关联算法构建了关联规则。根据特征分析和关联规则,提出了开展季节性防控、对特定群体和场所进行有针对性预防 ...
朱明
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Conservation Biology, EarlyView.Abstract Recognition and engagement of Indigenous Peoples and local communities (IP&LCs) and other traditional knowledge (TK) holders in formal biodiversity governance remain limited, despite their significant contribution to the conservation and sustainable use of biodiversity through their knowledge, innovations, practices, and land stewardship.
Kinga Öllerer +8 more
wiley +1 more source
Gaoya dianqi, 2017 针对126 kV真空断路器电机操动机构在实际操作中出现的驱动电机永磁体松动和脱落等问题,文中提出燕尾槽表贴埋入型、直线内嵌型和外V内嵌型等3种驱动电机转子的改进型方案。在对其结构进行对比分析的基础上,采用有限元法对各种改进型转子在驱动电机操动断路器进行分、合闸操作时的瞬态磁特性和动态机械特性进行仿真分析。结果表明,燕尾槽表贴埋入型转子改进结构能有效避免电机永磁体因机械冲击造成的松动和脱落,提高了操动机构的工作可靠性,是驱动电机转子的理想改进设计方案。
王亮 +5 more
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Conservation Biology, EarlyView.Abstract In the western United States, conservation practitioners are increasingly working with private landowners to restore habitat for North American beavers (Castor canadensis) and to use nonlethal mitigation techniques when beavers damage crops and infrastructure.
Brian D. Erickson, Megan S. Jones
wiley +1 more source