Results 41 to 50 of about 16,478 (205)
A Systems Thinking Approach to Nuclear Pedagogy and Workforce Development
ABSTRACT Nuclear technology's controversial status has been shaped by its early use in military applications, fear driven by high‐profile accidents, and unresolved waste management challenges. There have, on the other hand, been periodic claims that a “nuclear renaissance” is imminent, driven by different dynamics at different times, most recently ...
Brandon Costelloe‐Kuehn+4 more
wiley +1 more source
ABSTRACT Objective A soluble fms‐like tyrosine kinase‐1 (sFlt‐1)‐to‐placental growth factor (PlGF) ratio cut‐off of 38 is currently considered optimal for ruling out pre‐eclampsia (PE); however, implementation of this ratio in clinical practice is limited.
M. N. Nan+15 more
wiley +1 more source
在大跨度空间钢结构施加预应力是一个钢结构应用的新技术,预应力空间钢结构与传统的大跨度钢结构相比,具有节省用钢和建设速度快两大优点。在国内某民航基地維修机库的建造中,采用了国外某公司的预应力钢结构专利新技术。与传统的大跨度钢结构相比,该项技术使该工程妁用钢量减少了40%,并使工期缩短了50%。本文介绍了这一工程中应用的大跨度空间预应力钢结构的张拉新技术。
朱光照
doaj
Abstract Accelerating rate of human impact and environmental change severely affects marine biodiversity and increases the urgency to implement the Convention on Biological Diversity (CBD) 30×30 plan for conserving 30% of sea areas by 2030. However, area‐based conservation targets are complex to identify in a 3‐dimensional (3D) ocean where deep‐sea ...
Laetitia Mathon+19 more
wiley +1 more source
预应力撑杆构件造型优美、省材高效,但由于其柔度较大,易产生多个屈曲模态交互耦合即“交互屈曲”模式的破坏,且交互屈曲对其极限承载力、屈曲性能影响显著。研究了交互屈曲对预应力对称、不对称撑杆构件轴压、压弯作用下的屈曲性能、极限承载力影响,并据此采用基于回归算法的人工神经网络建立了其极限承载力估计模型。研究结果表明,对于预应力撑杆构件,模态交互易造成不稳定后屈曲,且对其极限承载力有显著的削弱效应;该削弱效应是否产生影响由结构几何参数与参与交互的模态屈曲荷载决定,其削弱程度受结构撑杆不对称性、预应力水平影响 ...
毋凯冬, 李国强, 常好诵, 邢哲
doaj +2 more sources
运用蒙特卡洛有限元法,考虑预应力的随机性,分析并计算了点支幕墙预应力索桁架支承体系的挠度最大值的统计特征值,得到其失效概率。进而对索桁架的预应力控制进行探讨。
汤伟方, 吕令毅
doaj
Abstract Recognition of the value of multidisciplinary research that bridges natural and social science perspectives has come with calls for conservation scientists to reflect critically on underlying assumptions and power relations involved in the production of knowledge and its application.
Marie‐Annick Moreau, Emily Woodhouse
wiley +1 more source
提出一种基于损伤可控的梁柱节点(Web-Connected and Prestressed节点,简称WCP节点)。通过在梁端腹板设置连接钢板、摩擦耗能螺栓以及预应力筋,将梁柱连接在一起。为了研究该类节点的滞回性能、自复位能力和损伤特征,设计、制作并完成了4个足尺节点试件的低周往复试验,分别考虑了预应力筋的初始张拉力、高强度螺栓的预紧力以及拼接板的表面处理方式对节点性能的影响。试验结果表明:该类节点的破坏主要集中在拼接部分;节点通过螺栓的滑移变形提供了较好的耗能能力;预应力筋能够增强节点的刚度 ...
蔡鑫+6 more
doaj
预应力波纹腹板开孔组合梁力学性能不同于普通平腹板开孔组合梁。为研究腹板开孔对预应力波纹钢-混凝土组合梁抗火性能的影响,采用有限元软件ABAQUS对该类组合梁在高温作用下的力学性能进行非线性有限元分析,重点考察了预应力波纹腹板开孔组合梁的内力、跨中挠度以及破坏模式,并对其耐火性能进行了参数研究。结果表明:孔洞所在截面波纹腹板剪应力呈非均匀分布,临界状态时,该截面腹板基本丧失抗剪能力。预应力波纹腹板组合梁纯弯区开孔时,其破坏模式与无孔组合梁一致,均为弯曲破坏,孔洞基本不影响其跨中挠度与耐火性能 ...
周焕廷, 陈祥, 伍先兴
doaj
Climate change is widely recognized as a major threat to biodiversity and a critical factor contributing to the decline of species and populations. The study investigates the differential impacts of climate change on endangered continental and island specie.
Ling Hu+9 more
wiley +1 more source