Results 31 to 40 of about 16,622 (118)

基于机械振动信号的高压真空断路器故障诊断研究

open access: yesGaoya dianqi, 2010
提出一种基于小波-包络谱能量提取振动信号特征并进行故障诊断的新方法。首先应用小波分析对振动信号进行降噪处理,然后与希尔伯特变换相结合,提取振动信号的低频和高频包络,最后对包络信号进行谱分析及能量特征提取。实验结果表明,该方法对提取高压真空断路器机械振动信号的特征是有效的,可为故障诊断提供依据。
赵洋, 刘汉宇, 曾庆军
doaj  

Tailoring a Dual‐Scale Heterostructure With γ‐Textures and Nano‐β0 Dispersion for Synergistic Enhancement of Mechanical Properties of TiAl Alloy

open access: yesRare Metals, Volume 45, Issue 8, August 2026.
ABSTRACT The limited crack resistance of coarse grain boundaries and coarse interfaces leads to an incompatibility between high‐temperature strength and ductility in TiAl alloys. Tailoring stress‐oriented textures and multiscale heterogeneous interfaces can effectively impede crack propagation, thereby overcoming this trade‐off.
Kexuan Li   +7 more
wiley   +1 more source

基于AdaBoost和LLE的视频人脸特征提取研究

open access: yes四川大学学报. 自然科学版, 2008
特征提取是生物特征识别的关键环节.本文提出了一种基于AdaBoost和LLE的视频人脸特征提取方法.其大致思路是用VFW技术对视频图像进行采集、接着将AdaBoost算法对采集的图像进行人脸检测,最后应用LLE算法对检测到的人脸图像进行降维并提取出特征.项目实践表明,该方法具有便捷性、实用性和有效性.
王刚, 周激流, 何坤
doaj  

基于情感信息融合注意力机制的抑郁症识别

open access: yes智能科学与技术学报, 2022
当前利用社交媒体数据预测抑郁症的研究忽视语言风格和情感随时间推移变化的特征,缺乏对情感状态和帖子元数据特征的研究,基于此,提出一种基于情感信息融合注意力机制的抑郁症识别模型。首先,在现有抑郁症识别研究的基础上,使用文本分类卷积神经网络按时间顺序提取用户每个时间段的帖子信息和情感信息,引入注意力机制为得到的特征矩阵分配不同的注意力权重,进而得到用户帖子信息特征和用户情感信息特征。其次,使用正则匹配提取文本的情感倾向信息,拼接注意力机制输出分配权重后的情感特征矩阵,以增强情感学习表示。然后 ...
陈妍, 罗雪琴, 梁伟, 谢永芳
doaj  

Review of Micro‐/Nanoscale Single Crystals: Synthesis, Size‐Dependent Key Properties Versus Deformation Instabilities, and Mitigation Strategies

open access: yesRare Metals, Volume 45, Issue 8, August 2026.
ABSTRACT Micro‐/nanoscale single‐crystal materials have garnered significant attention due to their unique size‐dependent mechanical and functional properties, with applications spanning diverse cutting‐edge fields. This review provides a state‐of‐the‐art overview of these materials, encompassing their synthesis methods, advanced mechanical and ...
Yi Li   +16 more
wiley   +1 more source

基于脑机协同智能的情绪识别

open access: yes智能科学与技术学报, 2021
面部表情识别是一种直接、有效的情绪识别模式。机器学习可以对图像表情进行形式化表征,但由于缺乏大脑的认知表征能力,在小样本数据集或复杂表情(伪装)数据集上的识别性能并不理想。针对此问题,将机器人工智能的形式化表征与人脑通用智能的情感认知能力结合,提出一种基于脑机协同智能的情绪识别方法。首先,从脑电图信号中提取脑电情感特征,以获取大脑对情绪的认知表征。其次,从情感图像中提取图像的视觉特征,以获取机器对情绪的形式化表征。为了增强机器模型的泛化能力,在特征学习中引入样本间的迁移适配 ...
刘栋军   +4 more
doaj  

High‐Throughput Development of Advanced Metallic Glasses via Compositionally Graded Thin‐Film Combinatorial Strategy

open access: yesRare Metals, Volume 45, Issue 8, August 2026.
ABSTRACT Advanced metallic glasses, leveraging their ultrahigh strength, excellent corrosion resistance, superior soft magnetic properties and good biocompatibility, have gradually become indispensable strategic cornerstones in critical fields such as aerospace, electronic information and energy power. This unique combination of properties enables them
Yizhou Liu   +11 more
wiley   +1 more source

Metal‐Based Materials for Redox Modulation in Biomedicine

open access: yesRare Metals, Volume 45, Issue 8, August 2026.
ABSTRACT Metal materials have become increasingly important in modulating biological redox networks for therapeutic and diagnostic purposes, owing to their distinctive electronic properties and adaptable reactivity. This review synthesizes recent developments across various metal‐based materials, including elemental metals, metal oxides, coordination ...
Yan Fan   +7 more
wiley   +1 more source

基于法线夹角与面积分布的三维CAD模型检索

open access: yes四川大学学报. 自然科学版, 2014
三维CAD检索技术对产品设计、重用具有促进作用.经典的三维模型检索算法——形状分布算法SD,适用于全局特征相似的模型检索,但对于全局相似但局部差异明显的模型则无法有效检索.针对这一问题,本文首先提取SD特征,并利用基于法线夹角与面积分布的特征提取技术来对模型局部特征进行描述,随后通过构造特征矩阵来融合提取到的法线夹角与面积分布两类特征,最后将SD特征与法线夹角与面积分布特征进行组合,形成新的特征并应用于检索.实验结果验证了该方法的有效性.
陈强, 余永梅, 唐雁
doaj  

Conservative roots confer a larger microbial carbon pump efficacy than acquisitive roots by regulating microbial life‐history strategy

open access: yesFunctional Ecology, Volume 40, Issue 8, Page 2617-2627, August 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Root activity creates unique microbial hotspots in the rhizosphere by influencing the metabolic activities of surrounding soil microorganisms, profoundly regulating the dynamics of soil organic carbon (SOC). However, how root economic strategies affect the formation and
Qiyu Tan   +8 more
wiley   +1 more source

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