Results 81 to 90 of about 16,705 (195)
Structural analysis and lightweight study for the five-axis grinder bed [PDF]
, 2013 以五轴联动工具磨床的床身为研究对象,分析了磨床在极限位置使用情况下床身的静态特性,找到了床身变形最大区域。通过自由模态分析和约束模态分析,得到床身各阶模态的振动特点,并从最大变形区域中选取一点进行谐响应分析,预测床身的持续动力特性。根据分析结果,找出薄弱环节,在保证床身动静态特性不降低的基础上对床身进行轻量化研究,最终减重7.73%,节省了材料与成本。With the five-axis grinding machine tool bed as the research object, the ...
姚博世 +4 more
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International Journal of Applied Linguistics, EarlyView.ABSTRACT This computational linguistic study analyzes 8743 Rednote posts to examine how sentiment, emotion, and content domain collectively shape social comparison dynamics on social media. We identify four key findings: (1) an emotional gradient, where upward comparison content exhibits the highest sentiment scores and downward comparison the lowest; (
Michelle Mingyue Gu +7 more
wiley +1 more source
Zhendong Ceshi yu Zhenduan为了描述减振器的动态特性，将集总参数模型和神经网络模型进行结合，提出了一种能够精确描述减振器非线性动态特性的集总参数‑神经网络联合模型。首先，在减振器测试台架上对一个减振器的动态特性进行测量，激励工况包括谐波激励和瞬态激励两大类，测试得到减振器的动态力响应；其次，提出了联合模型的集总参数建模方法与参数辨识方法，并使用谐波激励下的测试数据完成了模型参数辨识；然后，利用神经网络模型补偿减振器的力‑速度非线性特征；最后，使用联合模型计算在瞬态激励下减振器的输出力 ...
doaj +1 more source
Key Technologies of Performances Analysis and Optimization for Fixed Axis Transmission Assembly and Box of Wheel Loader [PDF]
, 2012 近年来国外装载机及国内高配置的装载机传动系方面的发展趋势是变速器大多为电液控制动力换档定轴式变速器，其可靠性高、寿命长、通用性好。然而其高端技术和市场目前均为国外企业所垄断，国内只是对国外变速器进行简单的仿制，且制造出的变速器达不到原变速器的性能。为了避免设计的盲目性，并为新变速器的设计提供指导，本文利用有限元和模态试验技术对某型号定轴变速器进行静动态特性分析，并对变速器箱体进行了优化设计。 首先，利用ANSYSWorkbench建立了变速器箱体的有限元模型，之后对其进行静力分析和自由模态分析 ...
王帅锋
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Synthesizing Empirical Research on Learner Metacognition in Second Language Writing
International Journal of Applied Linguistics, EarlyView.ABSTRACT Despite considerable research interest in learner metacognition in second language (L2) writing, there is not yet a review that synthesizes the existing empirical findings and discusses their implications. To fill the void, this systematic review synthesized 39 empirical studies on learner metacognition in L2 writing and examined their salient
Chen Li, Icy Lee, Zhicheng Mao
wiley +1 more source
Jixie chuandong, 1989 本文运用正交试验和计算机模拟相结合的方法综合研究齿轮的设计参数对齿轮动态特性的影响。应用本方法能简捷方便地了解各参数对动态性能影响的重要程度,同时,在一定条件下能得出使动态性能最佳的齿轮设计参数。
唐增宝, 钟毅芳, 王涛
doaj
Genomic responses to increased temperature and pollinator selection in Brassica rapa L.
New Phytologist, EarlyView.Summary Rapid environmental change reshapes both abiotic stress and biotic interactions, yet it remains unclear how these combined forces structure plants' genomic adaptation. In particular, the joint influence of temperature and pollinator identity, two ecological axes undergoing simultaneous global shifts, has rarely been quantified at genomic ...
Yanqian Ding, Florian P. Schiestl
wiley +1 more source
Study on the Application of Association Rules in Temporal Data Mining [PDF]
, 2008 20世纪80年代末，数据挖掘作为一个全新的研究领域悄然出现并迅速发展。数据挖掘的研究目的是在大型数据集中发现那些隐藏的、人们感兴趣的具有特定规律的信息。作为数据挖掘对象之一的时态数据库是由随时间变化的一系列序列值或事件组成的数据库。时态数据挖掘的研究对商业、金融、医疗诊断、科学与工程等领域的数据分析具有重要意义，因而时态数据的挖掘方法也成为数据挖掘的一个研究热点。 关联规则一直是近年来数据挖掘和人工智能领域研究的热点课题，目前在客户关系管理、医学、生物等领域已有应用 ...
乐燕波
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Basic income trials and the politics of scale: A research agenda
Policy Studies Journal, EarlyView.Abstract The growing popularity of basic income has led to extensive trials of the policy in numerous settings across the world. However, analysis of the politics of basic income, and in particular the political dynamics preceding and resulting from trial programs, lags. In response, we propose a research agenda that uses political scale to investigate
Jurgen De Wispelaere +2 more
wiley +1 more source
Dianci bileiqi, 1992 提出了SiC非线性电阻的导电模型.利用半导体理论分析了SiC非线性电阻的静态及动态伏安特性,认为SiC非线性电阻的伏安特性是由形成SiC非线性电阻的两大组分—SiC、结合剂共同决定的.
贺西民
doaj