检索结果-内蒙古大学图书馆

Computational study of the effect of friction coefficients and particle shape on the repose angle and porosity of sinter piles

引用

Particuology 2025年第3期98卷 231-240页

作者： Meng Li Yaowei Yu Henrik Saxén Process and Systems Engineering Laboratory Faculty of Science and EngineeringÅbo Akademi University20500TurkuFinland State Key Laboratory of Advanced Special Steel Shanghai Key Laboratory of Advanced FerrometallurgySchool of Materials Science and EngineeringShanghai University200444ShanghaiChina

Shape has an undeniable impact on particle behaviour,and the shapes of naturally occurring granular matter are typically *** studies of irregularly shaped particles are challenging but necessary to gain a better understanding of the flow of particulate *** study focuses on the behaviour of irregular sinter particles and applies the discrete element method to examine the effects of static and rolling friction coefficients and particle shape on the angle of repose and porosity of sinter piles.A three-dimensional model of an irregular sinter particle reconstructed by close-range photogrammetry served as the template for generating multi-sphere particles with varying numbers of sub-spheres(1,3,7,22,and 135)and sphericity ranging from 1 to *** of particle piles were conducted for a range of values of the coefficients of static and rolling *** results indicate that the angle of repose increases with static friction and also increases with rolling friction coefficient when it is lower than the static *** angle of repose shows clear dependence on particle shape,particularly for lower rolling friction *** friction coefficients for particles of five different shapes were individually determined through bulk calibration,and irregularly shaped particles in DEM were found to require lower friction *** was marginally affected by the static and rolling friction coefficients for spherical particles,while non-spherical particles showed porosity increasing with the rolling friction *** relationship between particle sphericity and porosity was nonlinear:as sphericity decreases from 1.00 to 0.69,the porosity first decreases to a minimum and then *** findings confirmed that both friction and particle shape have a significant influence on the structure of sinter piles,with implications for material handling and processing in industrial applications.

关键词： Sinter Discrete element method Friction coefficients Particle shape Repose angle Porosity

来源：评论

学校读者我要写书评

暂无评论

Type synthesis and mechanical performance analysis of novel coupled metamorphic mechanisms inspired by muscle-protein connections

引用

Science China(Technological Sciences) 2025年第3期68卷 377-379页

作者： Zhizhong DENG Yuling ZHANG Shaoze YAN Division of Intelligent and Biomechanical Systems State Key Laboratory of Tribology in Advanced EquipmentDepartment of Mechanical EngineeringTsinghua UniversityBeijing100084China

Deployment structures with latch capabilities have different applications in various engineering fields owing to their convenience in foldable storage,diverse configuration properties,and controllable deformation pathways[1].This latch capability is typically achieved through one of the three approaches:conventional latch designs[2],energy-dependent multistable structures[3],and metamorphic mechanisms.

关键词： deformation synthesis typically

来源：评论

学校读者我要写书评

暂无评论

An Integrated Sensor Fault Estimation and Fault-Tolerant Control Design Approach for Continuous-Time Switched systems

引用

Journal of Dynamic systems, Measurement and Control 2025年第4期147卷 041006页

作者： Elouni, Mohamed Hamdi, Habib Rabaoui, Bouali Rodrigues, Mickael Braiek, Naceur Benhadj Advanced Systems Laboratory National Higher Engineering School of Tunis ENSIT University of Tunis La Marsa2078 Tunisia Advanced Systems Laboratory Tunisian Polytechnic School University of Carthage La Marsa2078 Tunisia Automation and Process Engineering Laboratory IUT Lyon1 University of Lyon CNRS UMR 5007 Lyon69100 France

This paper proposes a robust integrated fault estimation (FE) and fault-tolerant control (FTC) strategy for a class of continuous-time switched systems in the presence of unknown external disturbances and sensor faults. The main idea focuses on designing a switched descriptor observer to achieve simultaneous estimations of system states and sensor faults. With the acquired estimation information, an integrated development of the estimated state feedback fault-tolerant controller is constructed to compensate for the fault effects by stabilizing the switched closed-loop system. Based on the average dwell time (ADT) concept and the Lyapunov-Krasovskii functional method, new and less conservative stability conditions are established with a prescribed H∞ performance level in a single-step linear matrix inequality (LMI) formulation. Finally, both a numerical example and a highly maneuverable aircraft technology (HiMAT) vehicle are provided to illustrate the effectiveness of the developed strategy. Copyright © 2025 by ASME.

关键词： Continuous time systems

来源：评论

学校读者我要写书评

暂无评论

Preamble Design for Joint Frame Synchronization, Frequency Offset Estimation, and Channel Estimation in Upstream Burst-Mode Detection of Coherent PON

引用

Journal of Lightwave Technology 2025年第9期43卷 4127-4138页

作者： Sun, Yongxin Jiang, Hexun Xu, Yicheng Fu, Mengfan Zhu, Yixiao Yi, Lilin Hu, Weisheng Zhuge, Qunbi Shanghai Jiao Tong University State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai200240 China

Coherent optics has shown significant potential as a viable solution for achieving 100 Gb/s and higher speeds in single-wavelength passive optical networks (PON). However, upstream coherent burst-mode detection is a major challenge in deploying coherent optics in access networks. To accelerate digital signal processing (DSP) convergence with minimal preamble length, we propose a novel burst-mode preamble design based on a constant amplitude zero auto-correlation (CAZAC) sequence. This design facilitates comprehensive frequency-domain estimation of various impairments, including state of polarization, chromatic dispersion and differential group delay, providing overall system response information for the equalization pre-convergence. Additionally, this preamble utilizes the same training unit to jointly achieve three key DSP functions: frame synchronization, frequency offset estimation, and channel estimation. This integration contributes to a significant reduction in the preamble length. The feasibility of the proposed preamble with a length of 400 symbols and corresponding DSP was experimentally verified in a 15 Gbaud coherent system using dual-polarization 16 quadrature amplitude modulation. The experimental results based on this scheme showed a superior performance of the convergence acceleration. © 1983-2012 IEEE.

关键词： Frequency domain analysis

来源：评论

学校读者我要写书评

暂无评论

Reconfigurable Fiber-Optic Time Transfer Network Architecture Based on SD-TTU

引用

IEEE Internet of Things Journal 2025年第11期12卷 15736-15747页

作者： Xie, Kunfeng Yang, Yansong Wang, Long Hu, Liang Chen, Jianping Wu, Guiling Shanghai Jiao Tong University State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai200240 China

Network architectural is indispensable for a wide-area and robust fiber-optic time transfer network, however, there is currently a deficiency in effective scheme. This paper proposed a reconfigurable fiber-optic time transfer network architecture based on Software-Defined time transfer units, enhancing the network's capability for flexible resource allocation, automatic protection and restoration. The architecture consists of three layers: (1) Time Transfer Layer for time signal transmission and clock difference cancellation;(2) Monitor & Control Layer for monitoring network states, fault detection, and dynamic reconfiguration of the Software-Defined time transfer units;(3) Service & Configuration Layer for customizable service construction and proactive network reconfiguration. A polymorphic Software-Defined time transfer unit is further designed, which can operate as a master station, intermediate station, and slave station using the same hardware. The proposed architecture and the designed Software-Defined time transfer unit are experimentally demonstrated over chained and ring networks, respectively. Network expansion, contraction, topology reconfiguration, failure and fault recovery are validated. The changes of measured mean clock differences are below 43 ps across different scenarios, verifying the robustness and flexibility of the proposed architecture. © 2014 IEEE.

关键词： Clocks

来源：评论

学校读者我要写书评

暂无评论

Recent advances in photopolymerization 3D printing of alumina-ceramic

引用

Progress in Natural Science:Materials International 2025年第1期35卷 1-30页

作者： M.Irfan Hussain Min Xia XiaoNa Ren Zhen Shen Muhammad Jamil Changchun Ge Institute of Powder Metallurgy and Advanced Ceramics School of Material Science and Engineering University of Science and Technology Beijing State Key Laboratory of Multimodal Artificial Intelligence Systems Beijing Engineering Research Center of Intelligent Systems and Technology Institute of AutomationChinese Academy of Sciences College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

Digital light processing(DLP) 3D printing has a huge potential for manufacturing intricate and customized ceramic parts with high precision and cost-effectiveness. Research in this field contributes to material innovation,opening the avenues for new process designs in both scientific and industrial sectors. However, the implementation of DLP 3D printing technology in ceramic research has not yet reached the maturity level as that in polymer and tissue engineering. Necessarily, a holistic in-depth literature reporting the successful integration of alumina ceramics within DLP 3D printing technology is urgently needed. This review, systematic examines recent progress in DLP technology, focusing on photopolymer resins that incorporate UV-sensitive monomers, photoinitiators, and dispersants, as well as their synergistic effects on achieving high-quality printing, desirable material properties, and enhanced performance. Further, the review discusses key factors including post-processing characteristics such as debinding and sintering, which influence microstructure, and defect formation including microcracks, porosity and voids. Finally, the challenges associated with printing and sintering are highlighted,aiming to identify focused focused development pathways and potential solution to optimize outcomes. This analysis clarifies existing challenges and also propsoes future applications for DLP technology in the aluminaceramic field.

关键词： Al2O3 ceramics Applications Digital light processing (DLP) Post-processing Resin

来源：评论

学校读者我要写书评

暂无评论

Stability and Stabilization of Sampled-Data Based LFC for Power systems:A Data-Driven Method

引用

IEEE/CAA Journal of Automatica Sinica 2025年第1期12卷 291-293页

作者： Yu-Long Fan Chuan-Ke Zhang Yong He the School of Automation China University of Geosciences the Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems the Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of Education IEEE

Dear Editor,This letter is concerned with stability analysis and stabilization design for sampled-data based load frequency control(LFC) systems via a data-driven method. By describing the dynamic behavior of LFC systems based on a data-based representation, a stability criterion is derived to obtain the admissible maximum sampling interval(MSI) for a given controller and a design condition of the PI-type controller is further developed to meet the required MSI. Finally, the effectiveness of the proposed methods is verified by a case study.

关键词： Sampled data control systems

来源：评论

学校读者我要写书评

暂无评论

Enhancing rheology and mechanical properties of DLP 3D-printed Si_(3)N_(4)materials via composition optimization and gas-pressure sintering

引用

International Journal of Minerals,Metallurgy and Materials 2025年第5期32卷 1220-1233页

作者： Qing Qin Gang Xiong Lin Han Yujuan Zhang Zhen Shen Changchun Ge Institute of Powder Metallurgy and Advanced Ceramics School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory of Multimodal Artificial Intelligence Systems Beijing Engineering Research Center of Intelligent Systems and TechnologyInstitute of AutomationChinese Academy of SciencesBeijing 100190China

Digital light processing(DLP)is a crucial additive manufacturing(AM)technique for producing high-precision ceramic *** study aims to optimize the formulation of Si_(3)N_(4)slurry to enhance both its performance and manufacturability in the DLP process,and investigate key factors such as particle size distribution,photopolymer resin monomer ratios,and dispersant types to im-prove the slurry’s rheological *** these optimizations,a photosensitive Si_(3)N_(4)slurry with 50vol%solid content was de-veloped,exhibiting excellent stability,and low viscosity(2.48 Pa·s at a shear rate of 12.8 s^(-1)).The effects of gas-pressure sintering on the material’s phase composition,microstructure,and mechanical properties were further explored,revealing that this technique significantly increases the flexural strength of the green sample from(109±10.24)to(618±42.15)*** sintered ceramics exhibited high hard-ness((16.59±0.05)GPa)and improved fracture toughness((4.45±0.03)MPa·m^(1/2)).Crack trajectory analysis revealed that crack deflec-tion,crack bridging,and the pull-out of rod-likeβ-Si_(3)N_(4)grains,are the main toughening mechanisms,which could effectively mitigate crack *** these mechanisms,crack deflection and bridging were particularly influential,significantly enhancing the frac-ture toughness of the Si_(3)N_(4)***,this research highlights how monomer formulation and gas-pressure sintering strengthen the performance of Si_(3)N_(4)slurry in the DLP three-dimensional printing *** work is expected to provide new insights for fabricat-ing complex Si_(3)N_(4)ceramic components with superior mechanical properties.

关键词： additive manufacturing Si_(3)N_(4)slurry low viscosity pressure sintering

来源：评论

学校读者我要写书评

暂无评论

A Forced Decoding-based Approach for Enhancing Low-resource ASR

引用

Neural Processing Letters 2025年第3期57卷 1-10页

作者： Liu, Yunpeng Yang, Xukui Qu, Dan School of Information Systems Engineering University of Information Engineering Henan Zhengzhou450001 China The Laboratory for Advanced Computing and Intelligence Engineering Jiangsu Wuxi214001 China

Multilingual automatic speech recognition represents a crucial research direction in tackling the challenges associated with low-resource scenarios. To effectively incorporate language-specific information in the joint training of a model across multiple languages and leverage linguistic similarities to enhance performance on the target low-resource language, this paper introduces a language similarity evaluation approach based on forced decoding. Specifically, when the target language is specified, the speeches of the source language are decoded into transcription in the target language, and the normalized posterior is utilized as the foundation for evaluating language similarity. Comprehensive experiments and analyses conducted on six low-resource languages reveal that the proposed approach achieves an average word error rate relative reduction of 21.74, 7.68, and 3.45% compared to three widely used benchmark methods, respectively, thereby validating the effectiveness of our approach. © The Author(s) 2025.

关键词： Decoding

来源：评论

学校读者我要写书评

暂无评论

Integrating Friction Noise for In Situ Monitoring of Polymer Wear Performance: A Machine Learning Approach in Tribology

引用

Journal of Tribology 2025年第6期147卷 061701页

作者： Chen, Shengshan Cheng, Ganlin Guo, Fei Jia, Xiaohong Wen, Xiaohao State Key Laboratory of Tribology in Advanced Equipment Tsinghua University Beijing100084 China Macau Institute of Systems Engineering Macau University of Science and Technology 999078 China

Friction and wear between mating surfaces significantly affect the efficiency and performance of mechanical systems. Traditional tribological research relies on post-observation methods, limiting the understanding of dynamic friction behavior. In contrast, in situ monitoring provides real-time insights into evolving friction dynamics. This study employs machine learning to monitor polymer wear performance through friction noise. The predictive accuracy of various machine learning methods, including Extremely Randomized Trees, Gradient-Boosting Decision Trees, AdaBoost, LightGBM, Deep Forest, and Deep Neural Networks, is compared for wear-type classification. Additionally, the LSBoost regression is selected as the optimal method for predicting polymer wear-rates across various temperatures. The results underscore the potential of using friction noise and machine learning for real-time wear monitoring, offering valuable insights for tribological system maintenance and failure prediction. © 2024 by ASME.

关键词： Tribology

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：