检索结果-南通市图书馆

Micro-flow structure at regime transition from bubbling to turbulent fluidization in a fluidized bed

Particuology 2024年第6期89卷 117-130页

作者： Chaoyu Yan Yue Yuan Xiaoyang Wei Jesse Zhu State Key Laboratory of Heavy Oil processing Beijing Key Laboratory of Process Fluid Filtration and SeparationCollege of Mechanical and Transportation EngineeringChina University of PetroleumBeijing 102249China China Beacons institute The University of NottinghamNingbo315100China Department of Chemical and Biochemical engineering University of Western OntarioLondonOntarioN6A 5B9Canada

Gas-solid fluidized beds have found extensive utilization in frontline manufacturing,in particular as low-velocity *** fluidization status,the bubbling or turbulent flow regime and the transition in between,determine the system performance in practical *** the convoluted hydrodynamics are quantitively evaluated through numerous data-processing methodologies,none of them alone can reflect all the critical information to identify the transition from the bubbling to the turbulent ***,this study was to exploit a coupling data processing methodology,in the combination of standard deviation,power spectrum density,probability density function,wavelet transform,and wavelet multiresolution method,to jointly explain the micro-flow structure at the regime transition from bubbling to turbulent *** transient differential pressure fluctuation was measured for the evaluation in a fluidized bed(0.267 m i.d.×2.5 m height)with FCC catalysts(d_(p)=65μm,ρ_(p)=1780kg/m^(3))at different superficial gas velocities(0.02–1.4 m/s).The results show that the onset of turbulent fluidization starts earlier in the top section of the bed than in the bottom *** wavelet decomposition displays that the fluctuation of differential pressure mainly concentrates on the sub-signals with an intermediate frequency *** sub-signals could be synthesized into three types of scales(micro-scale,meso-scale,and macro-scale),representing the multi-scale hydrodynamics in the fluidized *** micro-scale signal has the characteristic information of bubbling fluidization,and the characteristic information of turbulent fluidization is mainly represented by the meso-scale *** work provides a systematic comprehension of fluidization status assessment and serves as an impetus for more coupling analysis in this sector.

关键词： Flow regime transition Bubbling fluidization Turbulent fluidization Micro-flow structure Differential pressure fluctuation

来源：

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

Research on denoising of joint detection signal of water quality with multi-parameter based on IEEMD

引用

Optoelectronics Letters 2024年第2期20卷 107-115页

作者： LI Wen LI Dejian MA Yongyue TIAN Wang WEN Xin LI Jie institute of mechanical and Electrical engineering North China University of TechnologyBeijing 100144China1

An improved ensemble empirical mode decomposition(IEEMD) is suggested to process water quality spectral signals in order to address the issue that noise interference makes it difficult to extract and evaluate water quality spectral *** algorithm effectively solves the problems of modal mixing,poor reconstruction accuracy in the empirical mode decomposition(EMD),and a large amount of calculation in the ensemble empirical mode decomposition(EEMD).Based on EEMD,IEEMD firstly preprocesses the original water quality spectral signals,then performs Savitzky-Golay(S-G) smoothing on the decomposed effective intrinsic mode function(IMF) components,and finally reconstructs them to obtain the denoised *** sample data at different concentrations can be accurately analyzed based on the noise-reduced spectral *** this paper,three water quality parameters are used as research objects:benzene(C_(6)H_(6)),benzo(b)fluoranthene(C_(20)H_(12)),and chemical oxygen demand(COD).The original water quality multi-parameter(C_(6)H_(6),C_(20)H_(12),COD) spectral signals were subjected to denoising based on the IEEMD and the water quality multi-parameter joint detection *** signal-to-noise ratio(SNR) and the correlation coefficient(R^(2)) of the fitted curves obtained from the processing of the IEEMD were compared and analyzed with those obtained from the processing of the EMD and the *** experimental results show that the SNR of the spectral signals and the R^(2) of the fitting curve in three water quality parameters have been significantly ***,the IEEMD effectively improves the phenomenon of modal mixing,reduces the amount of calculation,improves the reconstruction accuracy,and provides an important guarantee for the effective extraction of multi-parameter spectral signals of water quality.

关键词： signal parameter noise

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Multi-scale Modeling and Finite Element Analyses of Thermal Conductivity of 3D C/SiC Composites Fabricating by Flexible-Oriented Woven process

引用

Chinese Journal of mechanical engineering 2024年第3期37卷 275-288页

作者： Zheng Sun Zhongde Shan Hao Huang Dong Wang Wang Wang Jiale Liu Chenchen Tan Chaozhong Chen Nanjing University of Aeronautics and Astronautics Nanjing 210016China School of mechanical engineering Beijing Institute of TechnologyBeijing 100081China CRRC institute Corporation Limited Beijing 100070China

Thermal conductivity is one of the most significant criterion of three-dimensional carbon fiber-reinforced SiC matrix composites(3D C/SiC).Represent volume element(RVE)models of microscale,void/matrix and mesoscale proposed in this work are used to simulate the thermal conductivity behaviors of the 3D C/SiC *** entirely new process is introduced to weave the preform with three-dimensional orthogonal *** 3D steady-state analysis step is created for assessing the thermal conductivity behaviors of the composites by applying periodic temperature boundary *** RVE models of cuboid,hexagonal and fiber random distribution are respectively developed to comparatively study the influence of fiber package pattern on the thermal conductivities at the ***,the effect of void morphology on the thermal conductivity of the matrix is analyzed by the void/matrix *** prediction results at the mesoscale correspond closely to the experimental *** effect of the porosities and fiber volume fractions on the thermal conductivities is also taken into *** multi-scale models mentioned in this paper can be used to predict the thermal conductivity behaviors of other composites with complex structures.

关键词： 3D C/SiC composites Finite element analyses Multi-scale modeling Thermal conductivity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The effect of friction block hole configurations on the brake tribological performance of high-speed trains

引用

Friction 2024年第10期12卷 2241-2258页

作者： Yuanke WU Wei CHEN Youguang ZHU Zaiyu XIANG Honghua QIAN Jiliang MO Zhongrong ZHOU Tribology Research institute School of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China China Railway engineering Equipment Group Co. Ltd.Zhengzhou 450016China

Three triangular friction block configurations are commonly employed in high-speed train brake systems,namely,unperforated,perforated configuration with one circular hole,and perforated with three circular *** this study,we adopted these friction block types to investigate the effect of perforated friction block configurations on the brake performance of high-speed trains based on a self-developed brake test *** results indicate the significant impact of the number of the holes on the wear behavior,temperature distribution,and vibration characteristics of the brake *** friction surface of the unperforated block is covered by wear debris,while the perforated blocks produce less wear ***,the one-hole block exhibits a more uniform temperature distribution and better vibration behavior than that with three *** friction brake is a dynamic process,during which separation and attachment between the pad and disc alternatively occur,and the perforated structure on the friction block can both trap and expel the wear debris.

关键词： high-speed train block brake performance wear debris flow

来源：

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

Introducing electrolytic electrochemical polymerization for constructing protective layers on Ni-rich cathodes of Li-ion batteries

引用

Rare Metals 2024年第6期43卷 2536-2545页

作者： Lin-Tao Dou Bei Li Hao-Long Nie Dong-Dong Xiao Chao-Qun Shang Xiao-Min Wang Zhan-Hui Zhang Katerina E.Aifantis Pu Hu School of Materials Science and engineering Wuhan Institute of TechnologyWuhan 430205China Huairou Division Institute of PhysicsChinese Academy of SciencesBeijing 101400China Department of mechanical and Aerospace engineering University of FloridaGainesvilleFL 32603USA

LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)is the most promising cathode for high-energy Li-ion batteries,despite its poor cycling stability that originates from the reactions that occur with the ***,to solve this interfacial issue,a facile electrolytic electrochemical polymerization process was introduced in this paper,and a uniform conductive electrolyte interface(polyaniline)was successfully constructed on the surface of the NCM811 porous electrode(PANI-NCM),which facilitated the charge transfer during charge/*** side reactions at the interface between the cathode and the electrolyte are suppressed,and thereby,the cycling performance and rate capability are considerably ***-NCM delivers an initial capacity of 157.2 mAh·g^(-1)as well as excellent cyclability(capacity retention of 88%after 500 cycles at 2C),whereas the capacity of the bare NCM811 has dropped to 31.3 mAh·g^(-1).In addition,polypyrrole and polythiophene also can be formed through electrolytic electrochemical polymerization process,which provides a practicable tactic to modify the interfacial stability of cathodes for high-energy Li-ion batteries.

关键词： Lithium-ion battery Ni-rich cathode In-situ polymerization Conductive polymer Electrochemical performance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of thermo-mechanical conditions during constrained friction processing on the particle refinement of AM50 Mg-alloy phases

引用

Journal of Magnesium and Alloys 2024年第6期12卷 2298-2311页

作者： Camila Caroline de Castro AndréMartins Neves Benjamin Klusemann Helmholtz-Zentrum Hereon Institute of Material and Process DesignSolid-State Materials Processing21502 GeesthachtGermany Helmholtz-Zentrum Hereon Institute of Hydrogen TechnologySystem Design for Mobility21502 GeesthachtGermany Helmut Schmidt University/University of the German Federal Armed Forces Hamburg Department of Mechanical and Civil Engineering22043 HamburgGermany Leuphana University Lüneburg Institute for Production Technology and Systems21335 LüneburgGermany

Constrained Friction processing(CFP)is a novel solid-state processing technique suitable for lightweight materials,such Mg-and *** technique enables grain size refinement to fine or even ultrafine *** this study,the effect of CFP on the microstructural refinement of AM50 rods is investigated in terms of particle size and morphology of the eutectic and secondary phases originally present in the base material,in particular the eutecticβ-Mg_(17)Al_(12)and Al-Mn *** that purpose,as-cast and solution heat-treated base material and processed samples were *** Al_(8)Mn_(5) intermetallic phase was identified as the main secondary phase present in all samples before and after the processing.A notorious refinement of these particles was observed,starting from particles with an average equivalent length of a few micrometers to around 560 nm after the *** refinement of the secondary phase refinement is attributed to a mechanism analogous to the attrition comminution,where the combination of temperature increase and shearing of the material enables the continuous breaking of the brittle intermetallic particles into smaller *** for the eutectic phase,the results indicate the presence of the partially divorcedβ-Mg_(17)Al_(12)particles exclusively in the as-cast base material,indicating that no further phase transformations regarding the eutectic phase,such as dynamic precipitation,occurred after the *** the case of the processed as-cast material analyzed after the CFP,the thermal energy generated during the processing led to temperature values above the solvus limit of the eutectic phase,which associated with the mechanical breakage of the particles,enabled the complete dissolution of this ***,CFP was successfully demonstrated to promote an extensive microstructure refinement in multiple aspects,in terms of grain sizes of theα-Mg phase and presence and morphology of the Al-Mn and eutecticβ-Mg_(17)Al_(12).

关键词： Constrained friction processing AM50 Refill friction stir spot welding Extrusion β-Mg_(17)Al_(12) Al-Mn phases

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Superconducting joints using reacted multifilament MgB_(2)wires:A technology toward cryogen-free MRI magnets

引用

Journal of Magnesium and Alloys 2024年第1期12卷 159-170页

作者： Dipak Patel Akiyoshi Matsumoto Hiroaki Kumakura Yuka Hara Toru Hara Minoru Maeda Hao Liang Yusuke Yamauchi Seyong Choi Jung Ho Kim Md Shahriar A.Hossain School of mechanical and Mining engineering The University of QueenslandSt LuciaQueensland 4072Australia National institute for Materials Science(NIMS) 1-2-1 SengenTsukubaIbaraki 305-0047Japan Department of Electrical engineering and Kangwon High Magnetic Field Center Institute of Quantum Convergence TechnologyKangwon National UniversityGangwon 24341Republic of Korea Australian institute for Bioengineering and Nanotechnology(AIBN) The University of QueenslandSt LuciaQueensland 4072Australia Department of Materials process engineering Graduate School of EngineeringNagoya UniversityNagoyaAichi 464-8603Japan institute for Superconducting and Electronic Materials Australian Institute for Innovative MaterialsUniversity of WollongongNorth WollongongNew South Wales 2500Australia

The development of superconducting joining technology for reacted magnesium diboride(MgB_(2))conductors remains a critical challenge for the advancement of cryogen-free MgB_(2)-based magnets for magnetic resonance imaging(MRI).Herein,the fabrication of superconducting joints using reacted carbon-doped multifilament MgB_(2)wires for MRI magnets is *** achieve successful superconducting joints,the powder-in-mold method was employed,which involved tuning the filament protection mechanism,the powder compaction pressure,and the heat treatment *** fabricated joints demonstrated clear superconducting-to-normal transitions in self-field,with effective magnetic field screening up to 0.5 T at 20 *** evaluate the interface between one of the MgB_(2)filaments and the MgB_(2)bulk within the joint,serial sectioning was conducted for the first time in this type of superconducting *** serial sectioning revealed space formation at the interface,potentially caused by the volume shrinkage associated with the MgB_(2)formation or the combined effect of the volume shrinkage and the different thermal expansion coefficients of the MgB_(2)bulk,the filament,the mold,and the sealing *** findings are expected to be pivotal in developing MgB_(2)superconducting joining technology for MRI magnet applications through interface engineering.

关键词： Mg B2 superconducting joint MgB_(2)conductor MRI applications Cryogen-free magnet Persistent-mode operation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Interface property of dissimilar Ti-6Al-4V/AA1050 composite laminate made by non-equal channel lateral co-extrusion and heat treatment

引用

Defence Technology（防务技术） 2024年第3期33卷 197-208页

作者： Juan Liao Mengmeng Tian Xin Xue School of mechanical engineering and Automation Fuzhou UniversityFuzhou 350116China

The purpose of this paper is to examine the effect of processing parameters and subsequent heat treatments on the microstructures and bonding strengths of Ti-6Al-4V/AA1050 laminations formed via a non-equal channel lateral co-extrusion *** microstructural evolution and growth mechanism in the diffusion layer were discussed further to optimize the bonding quality by appropriately adjusting process *** electron microscopes(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD)were used to characterize interfacial diffusion *** shear test was used to determine the mechanical properties of the interfacial diffusion *** experimental results indicate that it is possible to co-extrusion Ti-6Al-4V/AA1050 compound profiles using non-equal channel lateral *** heat treatment processes affect the thickness of the diffusion *** the temperature and time of heat treatment increase,the thickness of the reaction layers increases ***,the shear strength of the Ti-6Al-4V/AA1050 composite interface is proportional to the diffusion layer *** is observed that a medium interface thickness results in superior mechanical performance when compared to neither a greater nor a lesser interface *** characterization of all heat treatments reveals that the only intermetallic compound observed in the diffusion layers is TiAl_(3).Due to the inter-diffusion of Ti and Al atoms,the TiAl_(3) layer grows primarily at AA1050/TiAl_(3) interfaces.

关键词： Shear strength Co-extrusion Heat treatment Microstructure Intermetallic compounds

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ag-doped CNT/HAP nanohybrids in a PLLA bone scaffold show significant antibacterial activity

引用

Bio-Design and Manufacturing 2024年第2期7卷 105-120页

作者： Cijun Shuai Xiaoxin Shi Kai Wang Yulong Gu Feng Yang Pei Feng State Key Laboratory of Precision Manufacturing for Extreme Service Performance College of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China institute of Additive Manufacturing Jiangxi University of Science and TechnologyNanchang 330013China College of mechanical engineering Xinjiang UniversityUrumqi 830017China

Bacterial infection is a major problem following bone implant ***,poly-l-lactic acid/carbon nanotube/hydroxyapatite(PLLA/CNT/HAP)bone scaffolds possess enhanced mechanical properties and show good ***,wesynthesizedsilver(Ag)-dopedCNT/HAP(CNT/Ag-HAP)nanohybrids via the partial replacing of calcium ions(Ca2+)in the HAP lattice with silver ions(Ag+)using an ion doping technique under hydrothermal ***ﬁcally,the doping process was induced using the special lattice structure of HAP and the abundant surface oxygenic functional groups of CNT,and involved the partial replacement of Ca2+in the HAP lattice by doped Ag+as well as the in situ synthesis of Ag-HAP nanoparticles on CNT in a hydrothermal *** result-ing CNT/Ag-HAP nanohybrids were then introduced into a PLLA matrix via laser-based powder bed fusion(PBF-LB)to fabricate PLLA/CNT/Ag-HAP scaffolds that showed sustained antibacterial *** then found that Ag+,which pos-sesses broad-spectrum antibacterial activity,endowed PLLA/CNT/Ag-HAP scaffolds with this activity,with an antibacterial effectiveness of 92.65%.This antibacterial effect is due to the powerful effect of Ag+against bacterial structure and genetic material,as well as the physical destruction of bacterial structures due to the sharp edge structure of *** addition,the scaffold possessed enhanced mechanical properties,showing tensile and compressive strengths of 8.49 MPa and 19.72 MPa,***,the scaffold also exhibited good bioactivity and cytocompatibility,including the ability to form apatite layers and to promote the adhesion and proliferation of human osteoblast-like cells(MG63 cells).

关键词： Ag-doped Carbon nanotube/hydroxyapatite(CNT/HAP) Antibacterial properties Bone scaffold

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling asymmetric fracture mechanics of Mg alloy wire in drawing process

引用

Journal of Magnesium and Alloys 2024年第5期12卷 2057-2069页

作者： Sunghoon Choi Jongwon Shin Joung Sik Suh Dongchoul Kim Department of mechanical engineering Sogang UniversitySeoul04107Republic of Korea Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

In this study,a numerical analysis was conducted on the ductile fracture of a 2-mm diameter Mg-1Zn-0.5Mn-0.5Sr-0.1Ca alloy wire during *** hexagonally close-packed crystal structure of Mg alloys causes asymmetric fracture behavior,especially in the compression *** aim of this study is to develop a comprehensive damage model for Mg alloy wire that accurately predicts ductile fracture,with a focus on the compression region.A novel experimental method was introduced to measure the ductile fracture of Mg alloy wires under different stress *** wire drawing process was simulated using the Generalized Incremental Stress-State dependent damage(GISSMO)Model and the Semi-Analytical Model for Polymers(SAMP)*** damage model's prediction and the experimental results were found to be in excellent agreement,especially in determining crack *** analysis established a safe zone diagram for die angle and reduction ratio,and experimental validation confirmed the feasibility of this *** proposed damage model can provide a practical and reliable analysis for optimizing the drawing process of Mg alloy wire.

关键词： Mg alloy Wire drawing Finite element method Damage model Safe zone diagram

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：