Results 71 to 80 of about 167,960 (336)
Jianzhu Gangjiegou Jinzhan, 2021 后置钢管式钢筋混凝土柱是一种新型的加固方法,是在外包钢方法、套管约束混凝土方法以及钢管混凝土叠合柱的基础上提出的。采用后置钢管式钢筋混凝土柱对既有钢筋混凝土柱进行加固,是在原有钢筋混凝土柱四周凿出一部分混凝土形成空腔,外包钢板,二者之间的空腔灌浆形成钢管混凝土组合结构,且不改变原有柱的尺寸。在加固施工现场对后置式钢管混凝土加固的柱子进行现场跟踪监测,监测钢管、纵向受力筋和灌浆料的应力变化,研究应力传递规律及轴力分配情况。并用ABAQUS有限元分析软件建模分析对比监测结果。
万凌昕, 肖亚明, 朱华
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Reactive oxygen species act as signaling molecules to control root hair initiation and tip growth
New Phytologist, EarlyView.Summary Root hairs (RHs) increase the surface area of roots, facilitating nutrient and water uptake and plant anchorage. RHs form from root epidermal cells and elongate by polar tip growth. Reactive oxygen species (ROS) have recently been implicated as important signals that drive RH formation and elongation using both genetic and imaging approaches ...
Megan E. Gerber +2 more
wiley +1 more source
Jianzhu Gangjiegou Jinzhan, 2008 D型偏心支撑钢框架是偏心支撑结构中常用的一种抗震耗能结构形式,但是其耗能梁段与柱直接相连,为了满足抗震设计要求,一般需要对梁柱连接节点处采取一些加强措施。本文提出了一种新型剪切型耗能梁段与柱连接节点-加侧板方案,并利用有限元分析程序,将该新型梁柱连接节点与梁柱直接相连的D型偏心支撑结构进行了理论分析比较。验证了该新型节点不仅可以使塑性铰远离柱端,而且可以放松钢柱对梁翼缘端部的局部变形约束,避免梁柱连接节点处焊缝的脆性断裂。
张营营 +5 more
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Old player, new roles: defining the role of the plastidial phosphorylase
New Phytologist, EarlyView.Summary The plastidial phosphorylase (Pho1 or Phs1; E.C. 2.4.1.1) is a ubiquitous enzyme among plants that catalyzes the formation and degradation of glucans. Although the first report connecting Pho1 with starch metabolism came out > 80 years ago, its precise role is still a matter of debate.
David Seung +2 more
wiley +1 more source
Jianzhu Gangjiegou Jinzhan, 2018 三面受火钢柱可能发生绕强轴的弯曲失稳或绕弱轴的弯扭失稳,而两相邻面受火钢柱仅发生弯扭失稳。将钢柱截面温度场假设成简化的线性分布,对不均匀受火钢柱进行恒荷载升温分析,可得到钢柱发生整体失稳破坏时的临界温度。三面受火钢柱的临界温度与欧洲规范EN 1993-1-2的结果较为接近,可直接由EN 1993-1-2公式计算。对于两相邻面受火钢柱,可由EN 1993-1-2的计算结果乘以修正系数,文中给出了该修正系数的计算公式。
夏金环, 王培军, 周吉学
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Moment-resisting properties of post-to-sill joints connected with hardwood dowels [PDF]
, 2001 Moment-resisting properties of post-to-sill joints made with glued-in hardwood dowels were studied. Dowels of 12 mm in diameter made of hard maple (Acer saccharum) are glued into post and sill members of sugi (Cryptomeria japonica) glulam with ...
ヨルゲン, イェンセン +4 more
core
Mechanisms driving functional divergence of transcription factor paralogs
New Phytologist, EarlyView.Summary Transcription factors (TFs) are core components of the regulatory toolkits that control gene expression. The sophistication of these regulatory toolkits dramatically increased during Eukaryotic evolution, accomplished in part by the duplication of existing TFs and the subsequent repurposing of these new paralogs. This process, termed functional
Isabella J. Higgins +2 more
wiley +1 more source
Local adaptation of both plant and pathogen: an arms‐race compromise in switchgrass rust
New Phytologist, EarlyView.Summary In coevolving species, parasites locally adapt to host populations as hosts locally adapt to resist parasites. Parasites often outpace host local adaptation since they have rapid life cycles, but host diversity, the strength of selection, and external environmental influence can result in complex outcomes.
Acer VanWallendael +14 more
wiley +1 more source
New Phytologist, EarlyView.Summary Ectomycorrhizal fungi (ECM) can influence soil carbon (C) accrual and loss. The mechanisms and environmental controls of this balance are unclear, and direct evidence is needed. We assessed the influence of atmospheric CO2 and inorganic nitrogen (N) on the impact of two ECM fungi on the cycling of native and new soil C. We inoculated Eucalyptus
Yolima Carrillo +4 more
wiley +1 more source
Jianzhu Gangjiegou Jinzhan, 2023 钢框架结构柱脚在地震作用下发生塑性屈曲将对震后修复造成困难。基于损伤控制概念，研究在柱脚设置盖板式滑移摩擦节点（CPSFJ）钢框架的抗震性能及损伤情况。设计并制作了2个1/2缩尺的单层钢框架试件，其中一个为柱脚设置CPSFJ钢框架试件，另一个为普通钢框架试件，对其进行拟静力加载试验。普通钢框架在加载结束后，柱脚处屈曲严重。柱脚设置CPSFJ的钢框架，在加载过程中CPSFJ如期发生滑移；钢柱段无明显损伤变形，CPSFJ拼接盖板发生弯曲变形，黄铜摩擦片表面出现磨损，可在震后复位钢柱 ...
李成玉 +4 more
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