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Rock fracture mechanism of buffer blasting with cushion layer at the borehole bottom

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 325-334页

作者： Xinguang Zhu Chenxi Ding Zhe sui Hong Su Xu Guo School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory for Mechanics in Fluid Solid Coupling Systems Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing 100083China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

This study primarily investigates the rock fracture mechanism of bottom cushion layer blasting and explores the effects of the bottom cushion layer on rock *** involves analyses of the evolution patterns of blasting stress,characteristics of crack distribution,and rock fracture features in the ***,blasting model experiments were carried out using the dynamic caustics principle to investigate the influence of bottom cushion layers and initiation methods on the integrity of the bottom rock *** experimental results indicate that the combined use of bottom cushion layers and inverse initiation effectively protects the integrity of the bottom rock ***,the process of stress wave propagation and dynamic crack propagation in rocks was simulated using the continuum-discontinuum element method(CDEM)and the Landau explosion source model,with varying thicknesses of bottom cushion *** numerical simulation results indicate that with increasing cushion thickness,the absorption of energy generated by the explosion becomes more pronounced,resulting in fewer cracks in the bottom rock *** illustrates the positive role of the cushion layer in protecting the integrity of the bottom rock mass.

关键词： bottom cushion layer blasting crack propagation continuum-discontinuum element method dynamic stress intensity factor

基于GAF-DarkNet的滚动轴承故障诊断方法

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轴承 2024年第2期 66-73,81页

作者：虞浒缪小冬顾寅骥荀志文隋天举南京工业大学机械与动力工程学院南京211800 南京工业大学计算机科学与技术学院南京211800 大连理工大学工业装备智能控制与优化教育部重点实验室辽宁大连116024

针对深度诊断模型较难处理信号紧邻特征点以及变工况导致模型诊断精度和泛化性能不足的问题,提出基于格拉姆角场(GAF)和DarkNet-53图像识别算法的滚动轴承故障诊断方法。通过GAF编码将原始振动信号转换为具有时序相关性的二维特征图像,... 详细信息

针对深度诊断模型较难处理信号紧邻特征点以及变工况导致模型诊断精度和泛化性能不足的问题,提出基于格拉姆角场(GAF)和DarkNet-53图像识别算法的滚动轴承故障诊断方法。通过GAF编码将原始振动信号转换为具有时序相关性的二维特征图像,将特征图像输入DarkNet-53进行特征自提取和故障诊断。基于凯斯西储大学(CWRU)滚动轴承数据集和南京工业大学转盘轴承数据集并通过变载荷工况分析对所提算法进行验证,同时与目前流行的智能诊断方法及二维重构诊断方法进行对比,结果表明变工况下GAF-DarkNet算法具有更好的泛化能力和故障识别效果。

关键词：滚动轴承故障诊断深度学习特征提取图像识别

Robust interface and excellent as-built mechanical properties of Ti–6Al–4V fabricated through laser-aided additive manufacturing with powder and wire

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 154-168页

作者： Fei Weng Guijun Bi Youxiang Chew Shang sui Chaolin Tan Zhenglin Du Jinlong Su Fern Lan Ng Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong Engineering&Technology Research Center for Superhard MaterialSchool of Materials Science and EngineeringShandong UniversityJinan 250061China Institute of Intelligent Manufacturing Guangdong Academy of SciencesGuangzhou 510095China Singapore Institute of Manufacturing Technology 5 Cleantech Loop636732Singapore

The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully circumvent defects in Ti-6Al-4V deposits for LAAM_(p) and LAAM_(w),*** the optimized process parameters,robust interfaces were achieved between powder/wire deposits and the forged substrate,as well as between powder and wire *** characterization results revealed the epitaxial prior β grains in the deposited Ti-6Al-4V,wherein the powder deposit was dominated by a finerα′microstructure and the wire deposit was characterized by lamellar α *** mechanisms of microstructure formation and correlation with mechanical behavior were analyzed and *** mechanical properties of the interfacial samples can meet the requirements of the relevant Aerospace Material Specifications(AMS 6932)even without post heat *** fracture occurred within the interfacial area,further suggesting the robust *** findings of this study highlighted the feasibility of combining LAAM_(p) and LAAM_(w) in the direct manufacturing of Ti-6Al-4V parts in accordance with the required dimensional resolution and deposition rate,together with sound strength and ductility balance in the as-built condition.

关键词： laser-aided additive manufacturing powder deposition wire deposition interfacial characteristic mechanical behavior

MDCFS: few-shot object detection with multilevel decoupled classifiers

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Optoelectronics Letters 2025年

作者： LI Chuanhui ZHOU Mian FENG Zhikun sui Zezhou GAO Zhan School of Computer Science and Engineering， Tianjin University of Technology

Few-shot object detection poses unique challenges as it requires effectively learning novel classes with limited labeled data. Current approaches often suffer from biases towards base classes during fine-tuning， leading to suboptimal performance on detecting novel classes. Additionally， in complex scenes， the confusion between foreground and background objects further affects the accuracy and robustness of the model. To address these issues， we propose the Multilevel Decoupling Classification Few-Shot Algorithm (MDCFS). we decouple the standard classifier into a parallel foreground classifier and a background classifier in the Few-Shot Object Detection (FSOD) setting. This decoupling enables the independent separation of positive samples from noisy negative samples， alleviating the foreground-background confusion problem commonly encountered in few-shot detectors. For Generalized Few-Shot Object Detection (G-FSOD)， where the few-shot dataset contains base classes， we further decouple the foreground classification head into a base class classification head and a novel class classification head. To ensure balance， we assign more weight to the novel class classification head， effectively addressing the bias towards base classes. Furthermore， we optimize the initial weights of the few-shot fine-tuning stage， significantly reducing training time and mitigating catastrophic forgetting in G-FSOD. Additionally， we incorporate metric learning into our model with minimal cost. Experimental results demonstrate the effectiveness of our approach. Compared to state-of-the-art few-shot object detection methods based on fine-tuning， MDCFS achieves performance improvements of up to 6.3% on the PASCAL VOC dataset and 1.5% on the COCO dataset.

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Journal of Thermal Science 2009年第1期18卷 2-7页

作者： sui Lin Department of Mechanical and Industrial Engineering Concordia University Montreal Quebec Canada H3G 1M8

The particle paths of the Lagrangian flow field between two cylinders simulate well the spiral arms of Galaxy M51 image [1] and the interface curve of the Yin-Yang balance in the ancient Tai-Cbi diagram [2]. The particle paths of the Lagrangian flow field involve four parameters. The normalization of the system of equations significantly simplifies the formulation of the flow process and reduces the original four parameters to only one parameter. Furthermore it provides the similarity between the formulation of the spiral arms of Galaxy M51 and that of the interface curve of the Yin-Yang balance in the ancient Tai-Chi diagram.

关键词： Lagrangian flow field Particle path Simulation Galaxy M51 Ancient Tai-Chi diagram

一次暴雨过程中极端短时强降水诊断和中尺度分析

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科学技术创新 2025年第1期 13-16页

作者：隋沆锐内蒙古呼伦贝尔市气象局内蒙古呼伦贝尔

【目的】对于此次极端暴雨过程进行综合分析,加深对此次极端暴雨过程的理解,为未来对此类极端暴雨过程的观测和预报提供科学思路与方法。【方法】利用FNL再分析资料,结合观测资料、卫星资料、数值预报产品对此次过程进行了分析。【结果... 详细信息

【目的】对于此次极端暴雨过程进行综合分析,加深对此次极端暴雨过程的理解,为未来对此类极端暴雨过程的观测和预报提供科学思路与方法。【方法】利用FNL再分析资料,结合观测资料、卫星资料、数值预报产品对此次过程进行了分析。【结果】此次暴雨过程是受地面倒槽,高空冷涡,低空急流等共同影响下造成的。【结论】低空急流在此次过程中充当了良好的水汽通道,中层干侵入形成了不稳定性层结,冷暖空气对峙,上升气流明显;冷暖空气对峙激发了多个中尺度对流云团,第一阶段受局地对流云团发展影响,第二阶段短时强降水中心北抬,受新形成对流云团合并发展影响,小时极端降水出现在云顶亮温梯度大值区和地面辐合线附近;地面辐合线位置是此次落区预报的关键,对于短时强降水导致的暴雨,要特别重视冷空气对暴雨的触发和增幅作用。

关键词：暴雨中尺度对流云团地面辐合线

Flow structure and shear stress in the presence of both ice cover on water surface and leafless vegetation in channel bed

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Journal of Hydrodynamics 2024年第2期36卷 340-354页

作者： Mahboubeh Barahimi Jueyi sui School of Engineering University of Northern British ColumbiaPrince GeorgeCanada

This study aimed to investigate the previously unexplored effects of ice cover and submerged vegetation on flow *** were undertaken under both open channel and ice-covered flow *** bed material consisted of three non-uniform *** findings revealed that when vegetation patches were present on the bed and an ice cover was present,the velocity profiles exhibited a distinctive pattern with two peak *** kinetic energy(TKE)also exhibited two peaks,one above the vegetation bending height and another at the sheath section,with a decreasing trend towards the ice ***,quadrant analysis showed that when the flow surface is covered by an ice cover,the contributions of inward and outward events increased compared with those observed in an open channel *** most cases,these contributions surpassed the sweep and ejection *** findings enhance our understanding of vegetation’s response to diverse surface conditions and have practical implications for river management and environmental engineering.

关键词： Ice cover vegetation flow structure Reynolds shear stress turbulent kinetic energy(TKE) quadrant analysis

Variant quantifiers in L_(3)-valued first-order logic

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Frontiers of Computer Science 2021年第5期15卷 151-159页

作者： Wei LI Yuefei sui State Key Laboratory of Software Development Environment Beihang UniversityBeijing 100083China Key Laboratory of Intelligent Information Processing Institute of Computing TechnologyChinese Academy of SciencesBeijing 100190China School of Computer Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Traditional first-order logic has four definitions for quantifiers,which are defined by universal and existential *** L_(3)-valued(three-valued)first-order logic,there are eight kinds of definitions for quantifiers;and corresponding Gentzen deduction systems will be given and their soundness and completeness theorems will be proved.

关键词： L_(3)-valued(three-valued)first-order logic sequent quantifier soundness theorem completeness theorem

Monotonicity and nonmonotonicity in L3-valued propositional logic

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Frontiers of Computer Science 2022年第4期16卷 33-43页

作者： Wei Li Yuefei sui State Key Laboratory of Software Development Environment Beihang UniversityBeijing100083China Key Laboratory of Intelligent Information Processing Institute of Computing TechnologyChinese Academy of SciencesBeijing100190China School of Computer Science and Technology University of Chinese Academy of SciencesBeijing100049China

A sequent is a pair (Γ, Δ), which is true under an assignment if either some formula in Γ is false, or some formula in Δ is true. In L_(3)-valued propositional logic, a multisequent is a triple Δ∣Θ∣Γ, which is true under an assignment if either some formula in Δ has truth-value t, or some formula in Θ has truth-value m, or some formula in Γ has truth-value f. There is a sound, complete and monotonic Gentzen deduction system G for sequents. Dually, there is a sound, complete and nonmonotonic Gentzen deduction system G′ for co-sequents Δ: Θ: Γ. By taking different quantifiers some or every, there are 8 kinds of definitions of validity of multisequent Δ∣Θ∣Γ and 8 kinds of definitions of validity of co-multisequent Δ: Θ: Γ, and correspondingly there are 8 sound and complete Gentzen deduction systems for sequents and 8 sound and complete Gentzen deduction systems for co-sequents. Correspondingly their monotonicity is discussed.

关键词： sequent mulisequent gentzen deduction system monotonicity nonmonotonicity