Results 101 to 110 of about 167,960 (336)
Jianzhu Gangjiegou Jinzhan, 2013 随着建筑钢结构市场的迅速发展,一些超高层建筑项目中设计了超大型的组合巨柱。由于这些巨柱结构较为复杂,母材材质要求较高,板厚较厚,焊接工作量大,控制巨柱的焊接变形显得尤为重要。在巨柱的制作过程中若不控制好焊接变形,会给焊后的矫正工序带来很大的困难。从巨柱焊接变形的种类、焊接变形控制的设计措施、工艺措施等方面进行分析,为各钢结构项目中巨柱的焊接变形控制提供了参考。
李朝兵 +4 more
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Jianzhu Gangjiegou Jinzhan, 2020 针对湖州奥林匹克体育场中单管柱与格构柱组合式支撑架体系,采用有限元分析方法对该体系的整体失稳特点、立柱计算长度系数的取值进行了分析;然后对影响双层单跨非对称框架结构整体稳定性的柱顶不对称荷载、柱刚度比、梁柱线刚度比三个因素进行了深入的研究,得到了以上因素下单管柱及格构柱计算长度系数理论解的图表,可以直观地查看到计算长度系数随各相关参数的变化规律,以供技术人员选用。同时,通过实例的对比分析,验证了以上计算长度系数图表的准确性和合理性。
那丽岩, 赵昀, 苏英强
doaj
, 2010 为认识我国淡水鱼类烂鳃病的病原以及柱形病在我国的发生情况,实验从发生烂鳃病的病鱼中分离细菌性病原,经过生理生化特性分析以及是否在含托普霉素的Shieh培养基中生长并形成黄色假根状菌落,是否产生降解明胶和硫酸软骨素的酶类等特性的鉴定,并结合16SrDNA序列分析,证实柱状黄杆菌(Flavobacterium columnare)是所分离的烂鳃病的病原。同时,研究也证实20世纪曾经命名为烂鳃(Gill-rot)病病原的鱼害黏球菌(Myxococcus piscicola Lu,Nie & Ko,1975 ...
姚卫建 +7 more
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New Phytologist, EarlyView.Summary Rhizobial type III effectors (T3Es) play a crucial role in the symbiotic relationship between rhizobia and legumes by manipulating host cellular processes to promote nodule formation. Previously, we identified two T3Es, ErnA and Sup3, that trigger nodulation in Aeschynomene spp. in the absence of Nod factors.
Fazal Haq +7 more
wiley +1 more source
Jianzhu Gangjiegou Jinzhan, 2018 为了考察椭圆钢管混凝土短柱的偏压性能,通过ABAQUS有限元程序建立了椭圆钢管混凝土短柱在偏压作用下的数值分析模型,并利用试验结果验证了数值分析模型的准确性。进行了偏压作用下椭圆钢管混凝土短柱的参数分析,研究了各参数对椭圆钢管混凝土短柱最大轴压承载力、最大弯矩和延性的影响,揭示了偏压下椭圆钢管混凝土短柱的破坏模式,通过数值分析拟合了轴力-弯矩相关曲线。研究结果表明,椭圆钢管混凝土短柱在偏压作用下的破坏模式包括半高截面鼓曲破坏、半高以下截面鼓曲破坏、加载柱端双褶鼓曲破坏和柱两端双褶鼓曲破坏 ...
林沁, 江汉, 沈奇罕, 王静峰
doaj
New Phytologist, EarlyView.Summary Herbarium specimens are widely distributed in space and time, thereby capturing diverse conditions. We reconstructed specimen ‘lived’ climate from knowledge of germination cues and collection dates for 14 annual species in the Streptanthus (s.l.) clade (Brassicaceae) to ask: which climate attributes best explain specimen phenological stage and ...
Megan Bontrager +6 more
wiley +1 more source
Jianzhu Gangjiegou Jinzhan, 2015 为了研究椭圆钢管混凝土柱的轴压性能和承载力,通过ABAQUS程序建立了轴压作用下椭圆钢管混凝土柱的数值分析模型,考虑了复杂接触问题、材料非线性和椭圆特征。利用试验结果验证了数值分析模型的准确性。开展了轴压作用下椭圆钢管混凝土短柱的诸多参数分析,评价了各参数对组合柱轴压承载力和刚度的影响,揭示了椭圆钢管混凝土短柱的破坏模式和受力机理,基于统一理论提出了椭圆钢管混凝土短柱的轴压承载力简化计算方法。研究结果表明,椭圆钢管混凝土短柱在轴压作用下的破坏模式包括剪切破坏、局部鼓曲破坏和整体鼓曲破坏 ...
沈奇罕, 王静峰, 王伟, 王珺
doaj
New Phytologist, EarlyView.Summary Invasion by exotic plants is a major threat to ecosystem biodiversity globally. Although mutualistic belowground associations can play a significant role in successful invasion, studies have shown mixed results regarding the effects of plant invasion on arbuscular mycorrhizal fungi (AMF). Here, we tested how exotic dominance (i.e.
John V. Ramana +6 more
wiley +1 more source