检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

机器学习辅助的WC-Co硬质合金硬度预测

物理学报 2024年第12期73卷 300-310页

作者：宋睿刘雪梅王海滨吕皓宋晓艳北京工业大学材料科学与工程学院新型功能材料教育部重点实验室北京100124

硬度是硬质合金材料的一项典型代表性能,受多种因素的影响且各因素间常存在关联关系.本文旨在获得WC-Co硬质合金硬度的关键影响因素并实现硬度的高通量预测.建立了以硬质合金硬度为目标变量,以原料成分、烧结工艺和烧结体表征信息为特... 详细信息

硬度是硬质合金材料的一项典型代表性能,受多种因素的影响且各因素间常存在关联关系.本文旨在获得WC-Co硬质合金硬度的关键影响因素并实现硬度的高通量预测.建立了以硬质合金硬度为目标变量,以原料成分、烧结工艺和烧结体表征信息为特征的数据集;通过对特征的皮尔逊相关系数和SHAP分析,发现WC晶粒尺寸和Co含量对硬质合金硬度的影响最为显著.基于机器学习的支持向量机、多项式回归、梯度提升决策树、随机森林等算法,分别构建了硬质合金硬度预测模型.采用10折交叉验证方法对模型进行定量评估,结果表明梯度提升决策树算法模型具有最高的精度和较强的泛化能力,是最适合硬质合金硬度预测的机器学习方法.基于优选模型的高通量预测数据,采用多项式回归算法确定了硬质合金硬度与Co含量和WC晶粒尺寸之间的定量关系,预测准确率达到0.946.本研究为硬质合金性能的准确高效预测提供了数据驱动方法,可为高性能硬质合金材料的设计研发提供重要参考.

关键词：硬质合金硬度机器学习高通量预测

川滇高原高寒草甸生态系统不同功能群植物分布格局的MaxEnt模型预测

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

草业学报 2024年第3期33卷 1-12页

作者：油志远马淑娟王长庭丁路明宋小艳尹高飞毛军西南民族大学青藏高原研究院四川成都610225 西南交通大学地球科学与环境工程学院四川成都610031

为探究青藏高原高寒草甸生态系统不同主要功能群适宜生境的空间分布格局、主控气候因子及在气候变化背景下的变化趋势,基于青藏高原第2次科考数据(2019-2021年),利用MaxEnt模型预测川滇高原高寒草甸生态系统主要功能群的4种典型物种(莎... 详细信息

为探究青藏高原高寒草甸生态系统不同主要功能群适宜生境的空间分布格局、主控气候因子及在气候变化背景下的变化趋势,基于青藏高原第2次科考数据(2019-2021年),利用MaxEnt模型预测川滇高原高寒草甸生态系统主要功能群的4种典型物种(莎草科-矮嵩草;禾本科-垂穗披碱草;杂类草-鹅绒委陵菜;豆科-异叶米口袋)在未来气候变化条件下空间分布格局及影响其分布的主要气候因子。结果表明,矮嵩草、垂穗披碱草、鹅绒委陵菜和异叶米口袋在当前气候条件下的适宜生境面积分别为11.09万、9.23万、17.12万和16.53万km^(2),主要位于川滇高原中部和北部区域。环境因子贡献率和响应曲线显示,4个物种生境适宜性对生存环境具有相似的生态要求,且影响其分布的主要气候因子均为气温年较差、等温性和年均温等与温度有关的环境因子。在未来气候背景下,4个物种适宜生境面积均呈扩张趋势且平均海拔均升高了100~200 m,但变化速率趋于减缓,高寒草甸生态系统的物种多样性、生物量和稳定性可能随着气候变化而增强。

关键词：川滇高原高寒草甸功能群气候变化生境适宜性

A Facile and Efficient Synthesis of Substituted Pyrroles by Three Component Coupling Reaction of Amines, Aldehydes and Nitroalkanes

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2003年第9期14卷 893-896页

作者： Yi song xiao, yan Guang WANG Department of Chemistry, Zhejiang University, Hangzhou 310027 Department of Chemistry Zhejiang University Hangzhou 310027

A facile and efficient synthesis of highly substituted pyrroles has been achieved by a one-pot three-component coupling reaction of aldehyde, amine and nitroalkane by triethyl orthoformate.

关键词： Pyrrole nitroalkane aldehyde.

New Spheroidizing Technique of Ultra-High Carbon Steel With Aluminum Addition

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2006年第3期13卷 9-13页

作者： LI Hong-juan WANG Bao-qi song xiao-yan GUO Su-zhen GU Nan-ju School of Material Science and Engineering Hebei University of Technology Tianjin 300132 China School of Materials Science and Engineering Beijing University of Technology Beijing 100022 China

A new spheroidizing process of ultra-high carbon steel （UHCS） containing C 1.55%, Cr 1.45%, and Al 1.5% in mass percent has been proposed. The effect of processing parameters on the microstructure was analyzed. The UHCS produced by this new process has a microstructure with recrystallized ferrite matrix and fine and uniform carbide particles. After this spheroidizing, the UHCS exhibits good mechanical properties at ambient temperature, for example σb= 1 100 MPa, σs =915 MPa, δ=8% and high ratio of σs/σb.

关键词： ultra-high carbon steel spheroidizing technique proeutectoid carbide equalization

Synthesis and paste properties of octenyl succinic anhydride modified early Indica rice starch

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第10期7卷 800-805页

作者： song xiao-yan CHEN Qi-he RUAN Hui HE Guo-qing XU Qiong Department of Food Science and Nutrition Zhejiang University Hangzhou 310029 China

Octenyl succinic anhydride （OSA） modified early Indica rice starch was prepared in aqueous slurry systems using response surface methodology. The paste properties of the OSA starch were also investigated. Results indicated that the suitable parameters for the preparation of OSA starch from early Indica rice starch were as follows： reaction period 4 h, reaction temperature 33.4℃, pH of reaction system 8.4, concentration of starch slurry 36.8% （in proportion to water, w/w）, amount of OSA 3% （in proportion to starch, w/w）. The degree of substitution was 0.0188 and the reaction efficiency was 81.0%. The results of paste properties showed that with increased OSA modification, the starch derivatives had higher paste clarity, decreased retrogradation and better freeze-thaw stability.

关键词： Early Indica rice OSA starch Response surface methodology Paste properties

Data augmentation method for insulators based on Cycle-GAN

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology 2024年第2期22卷 36-47页

作者： Run Ye Azzedine Boukerche xiao-song Yu Cheng Zhang Bin yan xiao-Jia Zhou School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu611731China School of Electrical Engineering and Computer Science University of OttawaOttawaK1N6N5Canada yangtze River Delta Research Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou313001China

Data augmentation is an important task of using existing data to expand data *** generative countermeasure network technology to realize data augmentation has the advantages of high-quality generated samples,simple training,and fewer restrictions on the number of generated ***,in the field of transmission line insulator images,the freely synthesized samples are prone to produce fuzzy backgrounds and disordered samples of the main insulator *** solve the above problems,this paper uses the cycle generative adversarial network(Cycle-GAN)used for domain conversion in the generation countermeasure network as the initial framework and uses the self-attention mechanism and channel attention mechanism to assist the conversion to realize the mutual conversion of different insulator *** attention module with prior knowledge is used to build the generation countermeasure network,and the generative adversarial network(GAN)model with local controllable generation is built to realize the directional generation of insulator belt defect *** experimental results show that the samples obtained by this method are improved in a number of quality indicators,and the quality effect of the samples obtained is excellent,which has a reference value for the data expansion of insulator images.

关键词： Data expansion Deep learning Generate confrontation network Insulator

Correlation of electromagnetic radiation emitted from coal or rock to supporting resistance

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mining Science and Technology 2009年第3期19卷 317-320页

作者： JIA Hui-lin WANG En-yuan song xiao-yan ZHANG Hong-jie LI Zhong-hui School of Safety Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

More accurate forecasting of rock burst might be possible from observations of electromagnetic radiation emitted in the *** analyzed experimental observations and field data from the Muchengjian coal mine to study the relationship between electromagnetic radiation signal intensity and stress during the fracturing of coal, or rock, and samples under *** results show that the signal intensity is positively correlated with *** addition, we investigated the change in the electromagnetic radiation intensity, the supporting resistance in a real coal mine environment, and the coal or rock stress in the mining *** data analysis indicates that:1) electromagnetic radiation intensity can accurately reflect the distribution of stress in the mining area;and, 2) there is a correlation between electromagnetic radiation intensity and supporting *** research has some practical guiding significance for rock burst forecasting and for the prevention of accidents in coal mines.

关键词： electromagnetic radiation rock burst supporting resistance coal or rock

Local Extrema of Periodic Function’s Wavelet Transform

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2005年第6期10卷 949-952页

作者： FAN Qi-bin song xiao-yan School of Mathematics and Statistics Wuhan University Wuhan 430072 Hubei China

The theory of detecling ridges in the modulus of the continuous wavelet transform is presented as well as reconstructing signal by using information on ridges,To periodic signal we suppose Morlet wavelet as basic wavelet, and research the local extreme point and extrema of the wavelet transform on periodic function for the collection of signal＇ s instantaneous amplitude and period.

关键词： extrema periodic function wavelet transform time-frequency analysis

Effect of Ti contents on interfacial bonding, mechanical and thermal properties of Mo-Cu composites

在线全文

学校读者我要写书评

暂无评论

Tungsten 2024年第3期6卷 549-554页

作者： Jian-Ru Chu xiao-song Jiang Tian-yan Liu Key Laboratory of Advanced Technologies of Materials Ministry of Education School of Materials Science and Engineering Southwest Jiaotong University Reactor Engineering Research Sub-Institute Nuclear Power Institute of China

Mo-Cu composites are widely used in electronic packaging, vacuum technology, microwave devices and other fields due to their excellent properties, such as excellent electrical and thermal conductivity, low adjustable ...

关键词：