Results 91 to 100 of about 433 (146)
, 2019 薄板问题的控制方程为四阶微分方程,因而当采用伽辽金法进行分析时,形函数需要满足C~1连续性要求,且至少使用二次基函数才能保证方法的收敛性.无网格形函数虽然易于满足C~1连续性要求,但由于不是多项式,其二阶导数的计算较为复杂耗时,同时也对刚度矩阵的数值积分提出了更高的要求.本文提出了一种薄板分析的线性基梯度光滑伽辽金无网格法,该方法的基础是线性基无网格形函数的光滑梯度.在梯度光滑构造的理论框架内,无网格形函数的二阶光滑梯度可以表示为形函数一阶梯度的线性组合,因而可以提高形函数二阶梯度的计算效率.分析表明 ...
吴俊超 +3 more
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Effectiveness of three auxiliary irrigation methods for cleaning the internal walls of root canals of curved isolated teeth. [PDF]
Hua Xi Kou Qiang Yi Xue Za Zhi, 2023 Wen C, Zuo W, Luo W, He F.
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Jianzhu Gangjiegou Jinzhan基于可恢复功能的概念，提出了一种摩擦耗能型摇摆柱节点。阐述了该节点的构造形式并研究了其抗震性能。通过试验和数值模拟，分析了轴压比、弹簧刚度等参数对节点抗震性能的影响及节点在余震和修复情况下的韧性。研究结果表明，在±3%层间位移角内，节点呈现出低损伤特性，摇摆柱始终保持弹性。在轴向力作用下，滞回曲线呈明显的“旗帜形”，节点具有良好的自复位性能，最大残余转角仅为0.23%。通过重新拧紧螺栓，节点性能即可恢复至震损前水平，实现抗震韧性。弹簧刚度的增大可以显著提高节点的抗弯承载力；增大轴压比可以提高节点的“屈服”
李成玉 +4 more
doaj
[Effectiveness of sagittal top compression reduction technique in treatment of thoracolumbar vertebral fractures]. [PDF]
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi, 2023 Ji P +8 more
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Jianzhu Gangjiegou Jinzhan, 2018 为防止火灾下防屈曲支撑的抗震性能降低,需确保在给定的耐火时间内,防屈曲支撑的芯材温度不高于临界温度和防屈曲支撑的弯曲刚度不低于最小需求刚度。通过增加防屈曲支撑填充层厚度,一方面可以降低火灾下支撑芯材的温度,另一方面可以增加火灾下防屈曲支撑的刚度。通过对芯材截面形状为十字形的防屈曲支撑火灾升温的有限元分析,研究了填充层厚度对支撑芯材温度和火灾下支撑刚度的影响。随着填充层厚度的增大,芯材温度降低,支撑刚度增大。根据火灾下防屈曲支撑强度和刚度均不降低的条件 ...
张晓亮, 王培军, 肖邵文
doaj
Jianzhu Gangjiegou Jinzhan, 2019 为了研究冷弯薄壁型钢组合楼盖的振动性能,对3榀足尺比例的冷弯薄壁型钢组合楼盖开展了静载与动载试验。试验考察不同边界条件、楼盖梁形式、有无抗剪件对冷弯薄壁型钢组合楼盖振动性能的影响。研究结果表明:加强边界条件可以提高组合楼盖的刚度及自振频率,在实际工程的设计及应用时应考虑边界条件的影响;在相同截面高度下,不同截面形式的楼盖梁对组合楼盖的振动性能有一定影响;组合楼盖内部是否设置抗剪件对楼盖的刚度、自振频率与峰值加速度无影响。建议组合楼盖在1kN集中力的作用下最大挠度不大于2mm;在空载状态下 ...
门雨, 肖亚明, 王静峰, 庞帅
doaj
Multi-agent Modeling and Optimal Pumping Control of Magnetic Artificial Cilia
Tiny cilia drive the flow of surrounding fluids through asymmetric jumping, which is one of the main ways for biological organisms to control fluid transport at the micro-scale. Due to its huge application prospects in medical and environmental treatment
Chen, Ge, Ning, Zheng, Yu, Shuangshuang
core
[Treatment options and research progress of proximal tibial extra-articular fractures]. [PDF]
Zhongguo Xiu Fu Chong Jian Wai Ke Za ZhiZhang Y, Zhang Q, Lin Y, Fan Y.
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[Structural design and mechanical analysis of a "drum-shaped" balloon-expandable valve stent in expanded configuration]. [PDF]
Sheng Wu Yi Xue Gong Cheng Xue Za ZhiZhao Y +5 more
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[Protective effects of escin and dextromethorphan on Alzheimer disease in <i>Caenorhabditis elegans</i> models]. [PDF]
Beijing Da Xue Xue Bao Yi Xue BanZhang Y, Li L, Zhu A, Xiao W, Wang Q.
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