Results 11 to 20 of about 1,864,559 (165)
基于Biot多孔介质波动理论和Cauchy初应力分析结果给出横观各向同性介质初应力存在的本构方程。利用位移标量势函数得到介质中膨胀波传播的四个波速。通过数值计算研究初应力和孔隙压力存在对膨胀波传播特性的影响 ...
李世海, 马维
core
基于AWE GCB/GIS自力型触头接触压力分析及应力集中系数初探
为实现参数化分析,在AWE(ANSYS workbench environment)集成的DM(design modeler)环境中建立模型,并合理简化。在AWE集成开发环境下,设置自力型触头的工况对其进行接触压力分析,并对结果进行了理论计算校核。考虑到触指根部两侧小范围存在应力集中现象,利用DOE法(the design of experiments method)建立对应的参数化数值模拟,并对其小样本采集分析。根据计算结果确定其应力集中系数在1.201.27范围内变动。
张沛文, 陈伯荣, 周庆清
doaj
Compliance in Regulatory Gray Areas: The Case of the Organic Seed Standard
ABSTRACT Adaptive regulations, designed to balance flexibility with accountability, can embed provisions that unintentionally leave room for firms to shirk on their responsibilities by exploiting flexibility. We call these provisions “regulatory gray areas,” and ask: how should we understand (non‐)compliance in adaptive regulatory settings?
Liza Wood +3 more
wiley +1 more source
Legislating Uncertainty: Election Policies and the Amplification of Misinformation
ABSTRACT Can state election policies affect the spread of misinformation? This paper studies the role played by ballot processing policies, which determine when ballots can be examined and organized, in the online spread of political misinformation. We present evidence from the 2020 U.S.
Morgan Wack +5 more
wiley +1 more source
针对应力集中导致石油钻杆螺纹产生疲劳裂纹,进而发生断裂失效的事故,在API接头的基础上,研究开发了一种新型钻杆螺纹接头,该新型螺纹结构主要改进之处是内螺纹锥度保持1:6不变,外螺纹锥度变为1:6.23。有限元分析结果表明,这种螺纹形式显著改善了接头上的受力分布情况,使得螺纹上应力分布更加均匀,并降低了主台肩过渡圆角处的应力集中。对样品的上扣试验结果表明,采用新型螺纹后,外螺纹接头主台肩底部的过渡圆角处应力集中情况也得到明显改善,接头整体受力分布和不同区域应力差更趋平缓 ...
焦文鸿, 高连新, 鲁喜宁
doaj
ABSTRACT The construction of core–shell grains can enhance the coercivity of Nd2Fe14B magnets. However, it is a significant challenge to elucidate the formation of these core–shell grains particularly regarding the spontaneous core–shell structure in Y‐substituted Nd2Fe14B alloys.
Sining Fan +13 more
wiley +1 more source
基于Pro/E Mechanica的农业机械用链轮的动力学分析
链传动由于其传动可靠、结构简单,在农业机械中获得广泛应用。在工厂化水产养殖中应用的链斗式过滤装置中,作为链传动中关键零件,链轮受到工作环境恶劣、复杂载荷等因素影响,齿根磨损严重而失效。为增加链轮寿命、减少应力集中,利用Pro/E平台建立链轮的三维模型,并应用Pro/E Mechanica进行动力学分析,进行链轮设计的结构优化,在减轻其重量的同时,使链轮受力基本均匀,减少应力集中和变形。通过对链轮做全局敏感度分析表明:齿顶圆弧半径的增加削弱了最大应力的增长;最大应力随凸缘直径的增加而减小 ...
程启云 +4 more
doaj +1 more source
Recovering Critical Elements From Wastewater for Battery Materials: A Review
ABSTRACT Driven by global carbon neutrality goals, the transition toward a circular economy and sustainable resource management has become increasingly imperative. Given the indispensable role of battery technologies in modern energy storage systems, strategic elements such as lithium (Li), cobalt (Co), and nickel (Ni)—identified by the European ...
Ting Lei +5 more
wiley +1 more source
随着服役年限的增加,导管架海洋平台结构将产生缺陷和损伤。金属磁记忆技术可实现对铁磁性金属构件内部应力集中区的检测,因此可用于对导管架平台结构的应力集中检测。在介绍金属磁记忆检测机理后,将该技术应用到导管架平台结构预检测上,并以CEP导管架平台上部组块为对象开展了应力集中检测。经与超声检测结果对比,验证了金属磁记忆技术在导管架平台结构检测的适用性。研究结果表明,金属磁记忆检测能快速准确地对平台结构进行应力集中检测,其检测结果可为平台年检计划的制定提供依据和参考。
王宁, 吕涛, 徐长航, 陈国明
doaj
Read the free Plain Language Summary for this article on the Journal blog. Abstract Soil organic nitrogen (SON) transformation is critical for global nutrient cycling and ecosystem productivity, yet how its responsiveness to climate change differs across diverse land use types remains poorly resolved.
Xinyi Yang +10 more
wiley +1 more source

