Results 21 to 30 of about 953,292 (156)
, 2016 某实验台采用了煤油进行高温壳体的冷却,在实验过程中发生了输油管线断裂并引发燃烧的现象,对此开展了断裂失效分析。首先采用体视显微镜与扫描电镜进行了断口观察与分析,结果表明:管线的开裂起源于焊缝根部,具有典型的多源起源特征;裂纹源区色泽为蓝色,表明存在明显的氧化;断口上呈现明显的疲劳辉纹,间距为亚微米量级。进一步的根据辉纹间距与管材壁厚以及工作时间可确定出疲劳载荷的频率范围,并根据理论公式对管线的共振频率进行了估算,理论分析值与断口分析的结果吻合良好,表明管线的断裂失效是典型的振动疲劳失效。为此 ...
武晓雷, 谢季佳
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Corporate Quasi‐Sovereignty: Big Tech and the Politics of Sovereign Authority in the Digital Age
Policy Studies Journal, Volume 54, Issue 3, August 2026.ABSTRACT As private technology firms expand their control over critical infrastructures, questions of sovereignty and governance are increasingly displaced from states to corporate actors. Existing scholarship on sovereignty assumes that authority is either monopolized by states or shared through institutionalized public–private arrangements.
Chee Hae Chung, Bryce J. Dietrich
wiley +1 more source
Journal of Sociolinguistics, Volume 30, Issue 3, Page 282-294, June 2026.ABSTRACT This study adopts a transnational raciolinguistic perspective to examine how Chinese international students (CISs) navigate language, race, and identity across borders and contexts. Based on semistructured interviews with 14 CISs, the study highlights that pre‐migration socialization in China influences how CISs perceive and interpret their ...
Gengqi Xiao, Hailing Wang, Jing Yu
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, 2002 用超声波断口图和扫描电镜(SEM)研究了聚甲基丙烯酸甲酯(PMMA)的失稳断裂与断口形态,发现了两个断裂临界速度。当裂纹速度达到第一临界值时,出现二次曲线记号;裂纹扩展速度超过第二临界速度时,断口表面留下二级微裂纹丛 ...
赵亚溥, 盛季生
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Gaoya dianqi, 2011 由于杂散电容的影响,多断口真空断路器的电压分布是不均匀的,但是目前尚无针对多断口真空断路器的均压电容选择方法。笔者对多断口真空断路器均压电容的研究现状进行了综述,总结了均压电容对提高多断口真空断路器开断能力的积极作用和可能带来的负面效应,并对积极作用以及负面效应的产生机理进行了分析。指出了现有研究的局限性,并进行了初步的分析。在此基础上,提出了多断口真空断路器均压电容的研究建议,可为多断口真空断路器均压电容的深入研究提供参考。
吴高波 +4 more
doaj
Ultrasound in Obstetrics &Gynecology, Volume 67, Issue 4, Page 461-469, April 2026.ABSTRACT Objective The aim of this study was to evaluate the perinatal outcomes of monochorionic diamniotic (MCDA) twin pregnancies complicated by early twin‐to‐twin transfusion syndrome (TTTS) treated with fetoscopic laser surgery (FLS), and to compare rates of fetal survival across Quintero stages.
F. G. Sileo +35 more
wiley +1 more source
Gaoya dianqi, 2006 在分析国内外高电压等级真空开关的总体现状的基础上,对多断口真空开关技术的发展与研究现状进行了综述,研究了多真空间隙串联的静态绝缘特性、多断口真空开关的动态绝缘特性及对多断口真空开关的操动机构及控制系统3个方面的内容。认为在解决各断口均压分布及同步问题后,多断口真空开关技术是实现高电压等级真空开关的合理选择。
廖敏夫, 邹积岩, 段雄英, 孙辉
doaj
How much biotic nativeness matters across human demographic groups
Conservation Biology, Volume 40, Issue 2, April 2026.Abstract Many central concepts of conservation biology—such as nativeness—are structured by ecological and social factors. However, the social consequences of using these concepts to make conservation decisions remain inadequately understood. Some researchers argue that nativeness, rather than acting as an objective proxy for important ecological ...
Harold N. Eyster, Rachelle K. Gould
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Gaoya dianqi, 2002 论述了提高双断口真空断路器开断能力的原理 ,比较了双断口和单断口真空断路器的开断能力。实验结果表明 ,双断口真空断路器的开断能力较单断口高 2倍。讨论了均压电容对开断能力的影响 ,提出了对操动机构的要求 ,最后 ,介绍了多断口真空断路器的优点。
廖敏夫, 邹积岩, 段雄英
doaj
Impacts of Human Development on Wildlife Use of Corridors in Botswana 人类开发对博茨瓦纳野生动物廊道利用的影响
Integrative Conservation, Volume 5, Issue 1, Page 164-171, March 2026.This study examined the effect of landscape‐scale human impact on wildlife in Botswana. We examined how species use wildlife corridors in two different human‐dominated landscapes. We identified differences in temporal overlap between wildlife and humans across both landscapes, which is fundamental to consider in both current and future conservation ...
Tempe S. F. Adams +3 more
wiley +1 more source