Results 31 to 40 of about 7,537 (169)
Research on Bonnet Polishing Machine Tool Precision and Optics Surface Mid-spatial Frequency Error Controlling Technique [PDF]
, 2015 大口径自由曲面光学元件广泛应用于强激光装置、大型天文望远镜、卫星用光学系统等大中型光学系统中，随着国家重大光学工程及国防尖端技术对它们的需求量越来越大，实现大口径自由曲面光学元件的高效、高精度加工是光学元件制造领域需要解决的关键问题。抛光加工作为大口径自由曲面光学元件超精密加工的一个重要工序，其材料去除效率、加工精度以及加工表面纹理控制等对光学元件的最终质量有重要影响。气囊抛光技术采用具有一定充气压力的柔性橡胶气囊作为抛光工具，通过选取不同的工艺参数（如气囊充气压力、气囊压缩量、主轴转速、气囊头直径 ...
姜涛
core
Infant Mental Health Journal: Infancy and Early Childhood, Volume 46, Issue 6, Page 870-885, November 2025.Abstract Profiles of parental reflective functioning (PRF) may offer valuable insights into individual differences in PRF. Previous studies have identified PRF profiles; however, further validation is needed. This study aimed to investigate the convergent validity of the identified PRF profiles by examining their association with a related measure of ...
Eva Back Madsen +6 more
wiley +1 more source
Gaoya dianqi, 2018 文中提出一种基于时频分析的GIS多源局部放电信号脉冲分离方法。首先,对记录的GIS局部放电脉冲波形序列进行S变换时频分析,以提取典型局部放电脉冲的时间—频率—幅值特征。然后,与由单一典型局部放电缺陷模型构造的时频数据库进行混合,基于时频相似度分析和仿射聚类方法对记录的脉冲群进行快速分类,最终实现多局部放电源脉冲群的分离。在局部放电源个数未知的情况下,文中方法可判断出局部放电源的个数和放电类型。且该方法可抑制随机干扰源的影响,并可分离典型的脉冲扰动波形。
高敬贝 +6 more
doaj
A Review of UWB Radar Detection of Respiration and Heartbeat Signals in Different Scenarios [PDF]
Due to their many advantages, such as simple structure, low transmission power, strong penetration capability, high resolution, and high transmission speed, UWB (Ultra-WideBand) radars have been widely used for detecting life information in various ...
Bo ZHOU +6 more
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Integrative Conservation, Volume 4, Issue 3, Page 362-380, September 2025.Occurrences of dust storms and long‐distance movement of dust across landscapes is constantly increasing in south Asia. This dust is expected to have profound impact on vegetation health and sustainability as dust may contribute to nutrient budgets of the forest ecosystems, while it could impart various stresses to the plants.
Shree P. Pandey +2 more
wiley +1 more source
Dizhen xuebao, 2021 基于北美沿岸和内陆地震台站的连续地震波形记录，并结合沿岸台站附近布设的DART系统记录的海底压力数据以及预测潮汐数据，利用时频分析和极化分析方法对2011年3月11日日本东北部海域MW9.0大地震所激发的海啸对地震背景噪声所产生的影响予以深入分析。结果显示：海啸对高频噪声（1.3—1.5 Hz）以及短周期双频微地动噪声（0.18—0.4 Hz）的影响较小，但海啸显著增强了长周期双频微地动（0.1—0.15 Hz）、单频微地动（0.05—0.08 Hz）以及地球背景自由振荡（0.004—0.007 Hz ...
Fei Chen, Mei Xue
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World Water Policy, Volume 11, Issue 3, Page 735-750, August 2025.ABSTRACT Ensuring the efficient operation of water supply facilities in the agro‐industrial sector is critical for sustainable resource management. The article streamlines the grouping of works performed during the operation of water supply facilities in six stages, differing in purpose, duration, and frequency of work.
Ekaterina Khmel +3 more
wiley +1 more source
Gaoya dianqi, 2019 针对单轴传感器在断路器中应用的缺陷与不足,为了获取更多断路器分合闸时的状态信息,利用三维振动传感器同步采集断路器操作时振动信号,在时域、频域方面以及时频联合对X、Y、Z 3个方向的信号进行分析对比。在时域方面,运用X、Y、Z3个方向振动信号各个特征和能量的分布;在频域方面,运用快速傅立叶算法得出频谱分布图和功率谱图;在时频联合方面,运用小波包分解将三维传感器信号进行分解,并求出能量在各节点的分布和Wigner-Ville分布,说明三轴传感器放置方向对断路器测量信号故障诊断正确率的影响。实验分析结果表明 ...
丁巧林 +3 more
doaj
Joint vibrotactile coding for machine recognition and human perception [PDF]
, 2023 In order to accurately transmit the content meaning of vibrotactile signals and achieve intelligent recognition and signal reconstruction, a joint vibrotactile coding scheme for machine recognition and human perception was proposed.At the encoding end ...
Tiesong ZHAO, Ying FANG, Yiwen XU
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International Journal of Applied Linguistics, Volume 35, Issue 3, Page 1134-1148, August 2025.ABSTRACT E‐books, powered by multimedia and interactive features, are widely used to support young children's language and literacy development. This study examines the relations of e‐book narration and bilingual parent–child talk to children's learning during shared reading. Data from 121 English learners in China and their parents were analyzed using
Dandan Yang +3 more
wiley +1 more source