Results 21 to 30 of about 1,327,458 (165)

Classifier of silicon content in hot metal based on support vector machines(基于支持向量机的高炉铁水硅含量多类别分类)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2007
支持向量机是基于统计学习理论发展而来的一种机器学习算法,本文介绍了非线性软间隔分类机、最小二乘分类机和加权最小二乘分类机的算法.以山东莱钢1号高炉在线采集数据作为应用案例,使用C-均值算法对[Si]做聚类分析将其分成5类,改进M-ary分类方法实现对铁水硅质量分数[Si]的多类别分类,并对各分类机的性能作出评价.
JIANLing(渐令)   +2 more
doaj   +1 more source

基于威布尔分布的真空断路器可靠性分析

open access: yesGaoya dianqi, 2020
针对真空断路器的可靠性研究问题,对12 kV永磁操动式真空断路器做了寿命试验。将采集到的试验数据用Weibull变换进行预处理,变换后的数据在普通坐标系内接近于直线,基于图形法可接受二参数Weibull分布作为拟合模型;采用最小二乘法计算确定了Weibull分布模型的具体参数;最后,在小样本试验数据的情况下,采用针对Weibull分布的Mann检验方法进行模型检验。结果表明,真空断路器的寿命数据符合二参数Weibull分布模型,并计算得到了模型的可靠性评价指标和真空断路器的平均寿命。
穆艳   +4 more
doaj  

Transfer Learning‐Guided Discovery of Advanced Tetrametallic Single‐Cluster Catalysts for Urea Electrosynthesis

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT Developing advanced electrocatalysts for urea synthesis is pivotal to alleviating environmental burdens as well as advancing sustainability in the industrial and agricultural sectors, yet untargeted catalyst screening still suffers from the notorious drawbacks of being time‐consuming, labor‐intensive, and inefficient.
Xinyuan Yang   +8 more
wiley   +1 more source

Complete elliptic Fourier descriptor normalization and its application in quantitative morphological analysis

open access: yesMethods in Ecology and Evolution, Volume 17, Issue 7, Page 2123-2134, July 2026.
Abstract Elliptic Fourier analysis (EFA) is often employed in geometric morphometrics (GM), but the normalization of elliptic Fourier descriptor (EFD) has persistently posed challenges for obtaining unique and comparable results, especially in the application of outline‐based GM methods, which limits the implementation in automated analysis of numerous,
Hui Wu   +6 more
wiley   +1 more source

The underappreciated roles of fog and dew on vegetation and biocrusts

open access: yesNew Phytologist, Volume 251, Issue 1, Page 46-63, July 2026.
Summary Fog and dew represent minor components of ecosystem water budgets in most ecosystems. However, fog and dew can play an essential role in ecosystem dynamics and are particularly important for water‐limited systems. In addition to serving as direct water inputs, fog and dew can influence microclimate and water redistribution, thereby promoting ...
Lixin Wang, Yue Li, Mengyun Sun, Na Qiao
wiley   +1 more source

Inversion of Net Photosynthetic Rate in Winter Rapeseed Based on UAV Multispectral Vegetation Indices and Texture Features

open access: yesFood and Energy Security, Volume 15, Issue 2, March/April 2026.
ABSTRACT Net photosynthetic rate (Pn) serves as a key indicator for evaluating plant growth and yield. In order to explore an effective method for monitoring winter rapeseed Pn using unmanned aerial vehicle (UAV) multispectral technology, the winter rapeseed was taken as the research object and the multispectral images were obtained through UAVs in ...
ChengYang Ni   +7 more
wiley   +1 more source

Evolutionary and environmental determinants of heat tolerance and acclimation capacity in herpetofauna

open access: yesConservation Biology, Volume 40, Issue 1, February 2026.
Abstract Exploring heat tolerance and acclimation capacity can provide an effective approach to evaluating species’ sensitivity to extremely high temperatures due to climate warming. Despite some work on amphibian and reptile thermophysiological adaptation, related questions remain. We reviewed the literature to provide a synthesis of worldwide data on
Zijian Sun   +8 more
wiley   +1 more source

小学3-6年级创造性课堂环境数据

open access: yes, 2019
为了解小学创造性课堂环境的情况,探讨小学生创造力的培养问题,编制了《创造性课堂环境量表》,并于2018年对河北廊坊市某小学3-6年级的学生进行问卷调查。实际收回有效问卷1365份。本数据集可使用多种数据分析软件进行分析,在关于创造力、创造性课堂环境的理论研究与实践中有广泛用途。
刘正奎   +6 more
core   +1 more source

不同类型光缆对地表和井中分布式声波传感信号质量的影响研究

open access: yesDizhen xuebao
近年来,分布式声波传感技术(DAS)以其低成本、高密度、可实时观测等优势在地震学等多个学科领域迅速发展并得到了广泛应用。光纤作为DAS观测系统中重要的传感元件,其本身结构可直接影响数据采集质量,进而影响数据分析结果;同时光纤的物理特性还会影响野外观测成本和观测难度。然而,如何在地球物理观测中选择合适的光纤依然缺乏定量参考。为此,本文根据地震数据的关键特征定义了一套评价指标,用来定量评估DAS观测数据的质量;然后,针对地表浅埋布设DAS设备和垂直井中布设DAS设备两种主要的地震观测系统,设计了对比试验方案,
Bao Deng   +4 more
doaj   +1 more source

Extent of threats to marine fish from the online aquarium trade in the United States

open access: yesConservation Biology, Volume 40, Issue 1, February 2026.
The global marine aquarium hobby is a multibillion‐dollar industry, largely driven by demand from the United States. Much of this trade occurs online. We web scraped 4 major US‐based e‐commerce platforms selling marine aquarium fish to determine the retail price and source (wild capture, aquaculture, or both) of 13 families of ray‐finned marine fish ...
Bing Lin   +6 more
wiley   +1 more source

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