Results 21 to 30 of about 13,621 (117)
Zhejiang Daxue xuebao. Lixue ban, 2019 针对保参数方向构造过渡曲线曲面方法的不足，构造了任意参数曲线曲面间既保持参数方向又具有形状可调性的C1 与C2 连续过渡曲线曲面。首先，基于2 类带1 个自由参数的调配函数，分别构造满足C1 与C2 连续的过渡曲线，并讨论基于能量优化模型的最佳过渡曲线构造问题； 然后，将所提出的方法推广到过渡曲面的构造。实例结果表明，2 被过渡曲线曲面为任意参数曲线曲面时，利用该方法构造的过渡曲线曲面不仅与2 被过渡曲线曲面的参数方向保持一致，而且可利用所带的自由参数对其形状进行调整。通过能量优化模型确定自由参数的取值，
LIJuncheng(李军成) +2 more
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Rare Metals, Volume 45, Issue 2, February 2026.ABSTRACT A major challenge in fabricating eutectic NiTiNb alloys is the incomplete melting of Nb due to its much higher melting point than the NiTi matrix. In this work, a novel electron‐beam freeform additive manufacturing strategy is developed to eliminate unmelted Nb particles and achieve a fully eutectic structure through independent dual‐wire ...
Qing‐Da Zhang +9 more
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Rare Metals, Volume 45, Issue 2, February 2026.ABSTRACT Regulating negative parameters of metacomposites is mainly limited by their unclear mechanisms, which affects their practical applications in new sensing, communication, electromagnetic (EM) protection and other fields. This work proposes a dual‐functional competitive design strategy based on the waste corncob‐derived carbon/polyaniline ...
Qiuyun Yang +4 more
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Rare Metals, Volume 45, Issue 1, January 2026.ABSTRACT The central challenge in the development of high‐performance electromagnetic wave‐absorbing materials lies in achieving an optimal balance between impedance matching and attenuation characteristics. This is particularly critical for purely dielectric absorbers, where precise tailoring of the real (ε′) and imaginary (ε″) parts of the complex ...
Zhixiao Wang +7 more
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New Phytologist, Volume 247, Issue 5, Page 2086-2097, September 2025.Summary The importance of marine angiosperms, or seagrasses, as foundation species for marine coastal ecosystems is in marked contrast to their low species number of only 70 described taxa. Seagrass species tend to have very similar overall morphologies dictated by hydrodynamic forces of the ocean environment.
Xiaomei Zhang +14 more
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New Phytologist, Volume 247, Issue 3, Page 1460-1473, August 2025.Summary Podocarpus pollen morphology is shaped by both phylogenetic history and the environment. We analyzed the relationship between pollen traits quantified using deep learning and environmental factors within a comparative phylogenetic framework.
Marc‐Élie Adaimé +4 more
wiley +1 more source
Ultrasound in Obstetrics &Gynecology, Volume 65, Issue 5, Page 624-632, May 2025.ABSTRACT Objectives Placental insufficiency contributes to many obstetric pathologies, but there is no bedside clinical tool to evaluate placental perfusion. We have developed a method to acquire multiple three‐dimensional (3D) power Doppler (PD) ultrasound (US) volumes of placental vasculature, with infrared camera tracking of the precise spatial ...
A. Xue +5 more
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Jianzhu Gangjiegou Jinzhan, 2020 基于有限元软件ABAQUS进行数值模拟,研究圆端形钢管混凝土构件的偏拉力学性能,有限元模拟结果和试验结果吻合较好。基于有限元模型开展机理分析和参数分析,机理分析表明:在偏拉状态下,圆端形钢管混凝土构件呈现出较高的承载能力;圆弧段钢管可有效约束核心混凝土,由于核心混凝土的支撑作用使钢管的抗拉承载力得到显著提高。参数分析表明:钢管强度、含钢率、混凝土强度和截面高宽比等参数对圆端形钢管混凝土构件的拉-弯相关曲线形状没有显著影响。基于参数分析建议了圆端形钢管混凝土构件偏拉承载力的计算公式 ...
郝怀霖, 王志滨, 吴泓均
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Dizhen xuebao, 2022 探讨了基于差分进化-人工神经网络构建沉积河谷地震响应代理模型的可行性。首先建立沉积河谷对地震波散射的求解方法，以半圆形、V形沉积河谷为例，以入射波条件、沉积内外介质属性、场地形状为特征参数，以沉积河谷地震动放大系数为预测目标参数，构建数据集；其次，建立沉积河谷地震动放大效应人工神经网络、差分进化-人工神经网络算法预测模型，对比两种算法计算精度和稳定性，并进行了特征参数敏感性分析。结果表明：人工神经网络能较好地预测沉积河谷地震动放大效应，使差分进化-人工神经网络预测模型的精度和稳定性显著提高 ...
Sibo Meng, Jiawei Zhao, Zhongxian Liu
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Jianzhu Gangjiegou Jinzhan, 2020 以顶底翼缘角钢半刚性连接和外伸端板半刚性连接为研究对象,基于三参数模型,利用有限元分析软件ANSYS建立有限元模型,得到半刚性连接的弯矩-转角曲线。通过数值分析方法拟合弯矩-转角曲线,得出两种半刚性连接形状系数的近似求解公式,并与已有的试验数据进行对比分析。研究表明,基于三参数模型,利用形状系数近似公式得到的弯矩-转角曲线与有限元模型以及试验数据的弯矩-转角曲线吻合较好,验证了形状系数近似公式的正确性和适用性,为实际工程中的半刚性连接设计方法提供了理论依据。
刘伟, 舒赣平
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