Results 21 to 30 of about 134,344 (147)
Dianci bileiqi, 2004 根据实际情况,并结合棒形支柱瓷绝缘子的特点,介绍了棒形瓷件杆径开裂的特征,分析了产生杆径开裂的原因,指出:防污等级越高的棒形瓷件易产生杆径开裂;挤制截面比偏小,坯件致密度小,其表面的结合强度小,就易使棒型坯件产生杆径开裂;坯件进窑前吸湿,降低了其表面层的结合强度,易产生杆径开裂。提出了预防杆径开裂的方法,并获得了一定的成效。
易国富, 邓后勤
doaj
A Narrative Walks Into a Forum: Bridging the Narrative Policy and Ecology of Games Frameworks
Policy Studies Journal, Volume 54, Issue 3, August 2026.ABSTRACT Policy process research has expanded rapidly, yet many frameworks still develop in silos, limiting dialogue and leaving complementary mechanisms underused. In an effort to bridge these silos, we bring together two influential frameworks that have largely developed in parallel: the Narrative Policy Framework (NPF) and the Ecology of Games ...
Rachel McGovern +3 more
wiley +1 more source
Rare Metals, Volume 45, Issue 7, July 2026.ABSTRACT Laser powder bed fusion (LPBF) of Inconel 718 alloy inevitably introduces pronounced microstructural anisotropy, typified by columnar grains and robust crystallographic texture. This results in direction‐dependent fatigue behavior, raising critical reliability concerns for high‐stakes aerospace applications.
Zhifang Shi +9 more
wiley +1 more source
, 1997 该文研究了裂纹前方开始环绕和穿透介质中各种粗糙微粒而形成粗糙的裂纹表面等非稳定现象. 数值结果表明: 在I型情形, 振荡性裂纹前缘运动源于应力强度波的建设性——破坏性相互作用.
孟宪红, 李湘平, 王凯, 柳春图
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Shiyou jixie, 2014 非常规油气藏开采难度大，开发成本高，原有的水平井管内分段压裂技术存在分段级数少、压裂规模小等问题，无法满足非常规油气资源高效开发的要求。为此，分析了水平井泵送桥塞、固井投球滑套、连续管拖动封隔器等多级分段压裂新技术，其中，泵送桥塞射孔多级分段压裂技术分段级数不受限制，适合大排量、大液量压裂要求，是页岩油气开发的利器。固井投球滑套分段压裂技术滑套可重复开启，能满足选择性生产、堵水及重复性压裂的需求。各种水平井管内多级分段压裂新技术的成功应用，为非常规油气藏开发提供了强有力的技术支持。
伊西锋
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Gaoya dianqi, 2020 铅封作为最普遍的高压电缆金属铅护套或铝护套的中间连接方式,有着极重要的密封防水作用。为了确保高压电缆安全稳定运行并提升电缆服役寿命,需要对电缆接头的铅封状态进行定期检查,降低铅封开裂带来的安全隐患。文中首先分析了高压电缆铅封开裂的原因,并对比了针对其裂纹缺陷常用的检测方法,提出了利用涡流检测技术对高压电缆铅封裂纹缺陷进行检测的方法。文中分析了涡流检测技术的原理及信号处理方法,并通过COMSOL有限元软件仿真、模拟实验和现场检测验证了采用涡流技术对高压电缆铅封开裂进行检测的可能性。研究结果表明 ...
曹俊平 +4 more
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Rare Metals, Volume 45, Issue 7, July 2026.ABSTRACT High‐strength aluminum (Al) alloys are usually unprintable by laser powder bed fusion (LPBF) due to the severe hot cracking along the columnar grains. Doping elements scandium (Sc) and/or zirconium (Zr) is an effective way to eliminate hot cracks by refining the grain size to nearly nanoscale levels.
Zehuan Zhang +15 more
wiley +1 more source
Methods in Ecology and Evolution, Volume 17, Issue 7, Page 2123-2134, July 2026.Abstract Elliptic Fourier analysis (EFA) is often employed in geometric morphometrics (GM), but the normalization of elliptic Fourier descriptor (EFD) has persistently posed challenges for obtaining unique and comparable results, especially in the application of outline‐based GM methods, which limits the implementation in automated analysis of numerous,
Hui Wu +6 more
wiley +1 more source
, 1979 本文用三点弯曲和四点弯曲试样,在K_Ⅱ/K_Ⅰ=0—14的范围内,对GC-4超高强度钢、30Cr2MoV中强度转子钢和稀土球墨铸铁进行了线弹性平面应变复合型脆断试验。结果表明:复合型裂纹的脆断开裂方向与现有的三种复合型理论符合较好;但是,复合型裂纹扩展阻力随K_Ⅱ/K_Ⅰ比值增加而增大,与现有复合型理论差别较大。本文从塑性区的形状、大小和裂纹顶端在开裂方向的应力状态等方面对此问题进行了分析并指出,现有理论关于复合型裂纹扩展阻力与变形特征无关的假设,对于具有一定塑性变形能力的金属材料,是不合适的 ...
杨成寿, 王自强, 高桦, 周爱华
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, 2008 开发低渗透油气田最有效的手段是改善低渗透储层物性,但目前常用的水力压裂、酸化和高能气体压裂等措施也各有其不足,因此对岩石具有应力波和爆生气体双重作用的"层内爆炸"方法应运而生。针对爆生气体作用下孔壁岩石的开裂问题,通过分析试验数据,建立了考虑试样惯性的力学模型,并从动力学角度对动态载荷作用下孔壁岩石产生多裂缝的机制做了数值模拟研究。试验及数值模拟结果表明,爆生气体动态载荷作用下孔壁岩石产生多裂缝的实质是试样对动态载荷的结构响应,孔壁岩石能否产生多裂缝主要取决于载荷、约束、结构和材料属性等因素的影响 ...
林英松 +4 more
core +2 more sources