Results 11 to 20 of about 1,268,030 (163)
, 2023 控制圆柱体或翼型的行波壁会抑制大规模的分离流动，进而减少阻力。鱼类在游动过程中经常出现行波壁，而行波壁对鱼类游动性能的影响机制尚不清楚。以金枪鱼游动为基础，耦合行波壁，采用锐利界面浸没边界法（IBM）解决摆动过程带来的大变形运动边界问题。结果表明：行波壁的出现改变了金枪鱼体后涡的形成和发展，进而改变了摩擦阻力和压差阻力的分布；耦合行波壁使得摩擦阻力的波动幅值增加，压差阻力有所减小，从而降低了金枪鱼游动过程的阻力。研究的行波壁减阻机制可应用于提高仿生机器鱼的性能，随着智能材料的发展 ...
王一伟 +4 more
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Lughawiyah: Journal of Arabic Education and Linguistics, 2022 The purpose of this study is to determine the motivation of non-madrasa graduate students to learn Arabic at Department of Arabic Language Education of IAIN Kendari. The type of this research was descriptive qualitative in which data were collected by observation, interview, and documentation.
Rachmad Ramadhan, Kamilatul Ubudiyah
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野生动物学报, 2023 为探究菊头蝠（Rhinolophidae）回声定位声波在不同状态下的可塑性，于2022年7月在昆明市法古甸村仙人洞捕获18只蝙蝠，经鉴定隶属于菊头蝠科大耳菊头蝠（Rhinolophus macrotis，7只）、贵州菊头蝠（Rh.rex，4只）、马铁菊头蝠（Rh.ferrumequinum，4只）和中菊头蝠（Rh.affinis，3只）。使用超声波探测仪，获取4种菊头蝠在飞行、手持和悬挂3种状态下的回声定位声波，通过声学分析软件分析能量最大谐波的脉冲持续时间、脉冲间隔时间和主频。经统计分析发现 ...
张现政 +4 more
doaj
, 2002 本文着重介绍乘波飞行器构形的基础性问题。首先说明了高超声速流动的基本特色和高超声速飞行器气动布局面临的问题,在此基础上叙述了乘波飞行器的历史飞行原理,基本布局生成方法。同时还分析了转捩位置 ...
王发民, 姚文秀, 雷麦芳
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Simulation of ocean wave in the Northwest Pacific Ocean(西北太平洋海浪数值模拟)
Zhejiang Daxue xuebao. Lixue ban, 2009 以QSCAT/NCEP全年的风场资料为驱动风场,用第三代深海波浪模型WAVEWATCH III(WW3)建立波浪后报数值模式,进行西北太平洋海域波浪的数值模拟,旨在得到比传统的波浪统计方法更为精确的时空网格上长时序的波浪场,以便做出更可靠的波浪要素的统计分析.经对比QSCAT/NCEP风场资料与船测的风速资料、水下地形资料（由上海海图出版社出版的最新海图经数字化转化而成）和海浪有效波高计算值与船舶实测值（相关系数在0.9以上）,从三个方面验证了计算结果的精确性.此外 ...
ZHOUKe(周科) +2 more
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Rare Metals, Volume 45, Issue 11, November 2026.ABSTRACT High‐temperature microwave‐absorbing materials (HTMAMs) are vital for the electromagnetic stealth of hypersonic aircraft and aerospace engines. Traditional carbon‐based or magnetic‐based absorbers suffer from oxidation, Curie‐temperature limitations, and impedance mismatch under extreme conditions.
Jing Wu +6 more
wiley +1 more source
Zhejiang Daxue xuebao. Lixue ban, 2008 选择合适的滤波方法对InSar干涉相位图进行滤波处理是提高干涉图质量的关键技术环节.系统研究了圆周期均值滤波、圆周期中值滤波、加权圆周期滤波和基于梯度的自适应滤波方法，利用ERS-1/2数据进行了对比实验，并对各方法的效果进行了评价.结果表明，基于梯度的自适应滤波方法可以取得稳定效果，而梯度的自适应滤波与圆周期中值滤波组合效果更加显著.
ZHANGDeng-rong(张登荣) +5 more
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Rare Metals, Volume 45, Issue 11, November 2026.ABSTRACT Defect engineering plays a crucial role in regulating the active sites and reaction pathways of nanozymes. In this work, oxygen vacancies (Vo) were successfully introduced and stably regulated in ternary CoFeMo layered double hydroxide (CFM LDHs) via a microwave‐assisted hydrothermal strategy, leading to the construction of oxygen‐vacancy‐rich
Min An +8 more
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Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT Magnetic particles coated with carbon shells have been considered as promising electromagnetic wave absorption materials with antibacterial features. However, how to precisely control the monodispersed magnetic nanoparticles on a carbon matrix to manipulate impedance matching and antibacterial performances is still a key challenge.
Xiaofei Li +10 more
wiley +1 more source
Dizhen xuebao以震级为ML1.3—3.0的1万2 936条人工爆破微震记录和1万3 215条天然微震波形为研究对象，对其原始地震波形进行1—30 Hz带通滤波以去除长周期干扰，并基于长短时窗均值比（STA/LTA）算法进行P波识别与筛选。对处理后的地震波形数据进行S变换，获取其S谱能量曲线，然后将S谱能量曲线图转换为32×32像素的灰度特征图，并将其作为卷积神经网络的输入进行训练，基于训练好的模型进行10折交叉测试验证。结果显示地震与爆破事件的分类识别准确率高达97.80 ...
Juan Meng, Yanan Li, Qiang Gao
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