检索结果-内蒙古大学图书馆

Multi-chamber Silencer Composed of Screw-perforated Tubes and Straight-perforated Tubes

Journal of Marine science and Technology (Taiwan) 2023年第2期31卷 119-127页

作者： Lan, Tian-Syung Chiu, Min-Chie School of Intelligent Engineering Shaoguan University Guangdong512005 China Department of Information Management Yu Da University of Science and Technology Miaoli County 361 Taiwan Department of Mechanical and Materials Engineering Tatung University Taiwan

The use of silencers to reduce noise is mandatory due to severe hearing damage caused by high venting noise in the engine room of ocean-going vessels. While straight and perforated tubes have been used as acoustical elements in traditional silencer design, studies have shown that the acoustical design still requires improvement. To enhance acoustical efficiency, the use of multi-chamber mufflers is proposed composed of screw and perforated tubes. Additionally, a mathematical finite element model built for acoustical simulation using the COMSOL program expedites the analysis of silencers with complicated acoustical elements. A sensitivity analysis of transmission loss concerning the geometric factors of two-chamber and three-chamber silencers is conducted to investigate the relationship between sound transmission loss and silencer shape. The results demonstrate that the multi-chamber silencer with screw tubes and straight perforated tubes performs well in reducing noise. © 2023 National Taiwan Ocean University. All rights reserved.

关键词： Screws

来源：评论

学校读者我要写书评

暂无评论

DYNAMIC POWER CABLE CONFIGURATION DESIGN FOR FLOATING OFFSHORE WIND TURBINES USING GRADIENT-BASED OPTIMIZATION 42

DYNAMIC POWER CABLE CONFIGURATION DESIGN FOR FLOATING OFFSHO...

引用

ASME 2023 42nd International Conference on Ocean, Offshore and Arctic engineering, OMAE 2023

作者： Schnepf, Anja Giljarhus, Knut Erik Teigen Johnsen, Øyvind Lopez-Pavon, Carlos Department of Mechanical and Structural Engineering and Materials Science University of Stavanger CoreMarine Stavanger Norway Department of Mechanical and Structural Engineering and Materials Science University of Stavanger Stavanger Norway CoreMarine Oslo Norway CoreMarine Madrid Spain

ISBN: (纸本)9780791886908

Power cables transmit the electric energy generated by offshore wind turbines to consumers on land and at sea. The power cables usually lie statically on the seabed to prevent them from moving and being damaged. Since floating offshore wind turbines (FOWTs) are positioned using mooring systems, their power cables are placed from a hang-off location at the floater through the water to the seabed. In this dynamic section, they must withstand environmental loads and the loads induced by the FOWT motions. A minimized power cable length is crucial for low transmission losses during operation, which is a priority during the design of the overall configuration. This work presents a dynamic power cable configuration modeling approach using gradient-based optimization. The applied method is Sequential Least Squares programming (SLSQP). Its applicability is shown in the example optimization of a tethered lazy-wave dynamic power cable configuration connected to a spar-FOWT. The optimization method is applied with two and three design variables. Steady-state analyses with extreme environmental loads are performed at each iteration, considering three distinct loading directions. The resulting optimized power cable configurations have a shorter cable length than the initial configurations. Dynamic analyses of the optimized configuration show that it satisfies the design limits. Copyright © 2023 by ASME.

关键词： Offshore wind turbines

来源：评论

学校读者我要写书评

暂无评论

Hierarchical crystalline-amorphous nanocomposites with high strength and large deformability enabled by elemental diffusion

引用

Journal of materials science & Technology 2024年第4期171卷 150-161页

作者： Liqiang Wang Heyi Wang Xin Zhou Huangliu Fu James Utama Surjadi Shuo Qu Xu Song Rong Fan Yang Lu Department of Mechanical Engineering City University of Hong KongHong KongChina Nano-Manufacturing Laboratory(NML) Shenzhen Research Institute of City University of Hong KongShenzhen 518057China Chengdu Research Institute City University of Hong KongChengdu 610200China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina Department of Mechanical Engineering The University of Hong KongHong KongChina

Amorphous/nanocrystalline dual-phase structures have recently emerged as an effective way for over-coming the strength-ductility trade-offand breaking the limitation of the reverse Hall-Petch ***,we proposed a new strategy to develop a hierarchical and interconnected amorphous-crystalline nanocomposite arising from the nanoscale elemental interdiffusion and oxygen adsorption behavior dur-ing thermal treatment *** nanocomposite consisted of a three-dimensional(3D)hierarchical network structure where the crystalline phase(Cr-Co-Ni-Al)was embedded into the Al-O-based amor-phous phase network with critical feature sizes encompassing three orders of magnitude(from microm-eter to nanometer scale).It can achieve ultrahigh compression yield strength of-3.6 GPa with large homogeneous deformation of over 50%*** massive interstitial atoms induced lattice distortion and hierarchical amorphous phase boundary contributed to the strength *** situ Uniaxial compression inside a transmission electron microscope(TEM)revealed that the exceptional deformability of the nanocomposites resulted from the homogenous plastic flow of nano-sized amorphous phase and the plastic co-deformation behavior restricted by the nano-architected dual-phase *** proposed dual-phase synthesis approach can outperform conventional nanolaminates design strategies in terms of the mechanical properties achievable while providing a pathway to easily tune the microstructure of these nanolaminates.

关键词： Nanolaminates Dual-phase nanocomposites In situ transmission electron microscopy Multi-component alloy

来源：评论

学校读者我要写书评

暂无评论

Gradient microstructure,recrystallization and mechanical properties of copper processed by high pressure surface rolling

引用

Journal of materials science & Technology 2022年第31期126卷 182-190页

作者： J.Guo Q.Y.He Q.S.Mei X.Huang G.L.Wu O.V.Mishin College of Materials Science and Engineering Chongqing UniversityChongqing400045China Southwest Technology and Engineering Research Institute Chongqing 400039China School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Department of Mechanical Engineering Technical University of Denmark2800 Kgs.LyngbyDenmark

The microstructure,hardness and tensile properties have been studied in copper processed by high pressure surface rolling(HPSR)both in the as-deformed condition and after subsequent annealing at 150℃.It is found that a gradient structure with significant differences in the scale of microstructural features is formed by *** deformed microstructure varies from nano-and ultrafine-scale structures with a large fraction of high angle boundaries near the surface to lightly deformed grains at depths of 1-3 mm below the *** tests of 1-mm-thick specimens demonstrate that the asdeformed material has a high strength and a low uniform *** at 150℃results in partial recrystallization,which creates new through-thickness *** for the topmost layer and several bands in the adjacent layer,recrystallization is more pronounced close to the *** fraction recrystallized is at least 80%at depths of 60-300μm after annealing for 960 *** fraction recrystallized in the subsurface decreases with increasing depth,and the deformed layer at depths greater than 500μm re-mains largely non-recrystallized after *** partially recrystallized condition demonstrates an improved combination of strength and ductility.

关键词： High pressure surface rolling Copper Gradient microstructure Annealing Hardness Strength Ductility

来源：评论

学校读者我要写书评

暂无评论

Morphology controllable urchin-shaped bimetallic nickel-cobalt oxide/carbon composites with enhanced electromagnetic wave absorption performance

引用

Journal of materials science & Technology 2023年第17期148卷 250-259页

作者： Fushan Li Qiuyu Li Hideo Kimura Xiubo Xie Xiaoyu Zhang Nannan Wu Xueqin Sun Ben Bin Xu Hassan Algadi Rami Adel Pashameah Abdullah K.Alanazi Eman Alzahrani Handong Li Wei Du Zhanhu Guo Chuanxin Hou School of Environmental and Material Engineering Yantai UniversityYantai 264005China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai 264005China School of Material Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Mechanical and Construction Engineering Faculty of Engineering and EnvironmentNorthumbria UniversityNewcastle Upon Tyne NE18STUK College of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Department of Electrical Engineering Faculty of EngineeringNajran UniversityNajran 11001Saudi Arabia Department of Chemistry Faculty of Applied ScienceUmm Al-Qura UniversityMakkah 24230Saudi Arabia Department of Chemistry College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Integrated Composites Laboratory(ICL) Mechanical and Construction EngineeringNorthumbria UniversityNewcastle Upon Tyne NE18STUK Department of Chemical and Bimolecular Engineering University of TennesseeKnoxvilleTN 37996United States

The microscopic morphology of electromagnetic wave absorbers influences the multiple reflections of electromagnetic waves and impedance matching,determining the absorption ***,the urchin-shaped bimetallic nickel-cobalt oxide/carbon(NiCo_(2)O_(4)/C)composites are prepared via a hy-drothermal route,whose absorption properties are investigated by different morphologies regulated by changing calcination temperature.A minimum reflection loss(RL_(min))of-75.26 dB is achieved at a match-ing thickness of 1.5 mm,and the effective absorption bandwidth(EAB)of 8.96 GHz is achieved at 2 ***-advantages of the synthesized NiCo_(2)O_(4)/C composites contribute to satisfactory absorption ***,the interweaving of the needle-like structures increases the opportunities for scattering and multiple reflections of incident electromagnetic waves,and builds up a conductive network to facilitate the enhancement of conductive ***,the carbon component in the NiCo_(2)O_(4)/C composites en-hances the interfacial polarization and reduces the density of the ***,generous oxygen va-cancy defects are introduced into the NiCo_(2)O_(4)/C composites,which induces defect polarization and dipole *** summary,the ternary coordination of components,defects and morphology led to out-standing electromagnetic wave absorption,which lightened the path for improving the electromagnetic wave absorption property and enriching the family of NiCo_(2)O_(4) absorbers with excellent performance.

关键词： NiCo_(2)O_(4)/C Oxygen vacancies Interfacial polarization Electromagnetic wave absorber

来源：评论

学校读者我要写书评

暂无评论

Additive manufacturing of immiscible/incompatible systems

引用

materials Today 2025年 87卷 125-150页

作者： Das, Rakesh Joshi, Sameehan S. Owuor, Peter Samora Khan, Abdullah Ike, Sandra Kumar, Pankaj Dahotre, Narendra B. Tiwary, Chandra Sekhar Department of Metallurgical & Materials Engineering Indian Institute of Technology Kharagpur West Bengal 721003 India Materials Science and Engineering Center for Agile and Adaptive Additive Manufacturing University of North Texas DentonTX76207 United States Carbon Center of Excellence Morgan Advanced Materials State College PA16803 United States The John and Willie Leone Family Department of Energy and Mineral Engineering Penn State University 16801 United States Department of Mechanical Engineering University of New Mexico AlbuquerqueNM87131 United States

The advent of additive manufacturing (AM) has propelled significant innovation in industries due to its capacity for technological advancement as a sustainable, adaptable, and personalized manufacturing method. Exploring the (AM) of immiscible systems is a critical area that requires exploration to achieve both multifunctionalities of different elements or phases and stability during the service period. The review commences with an overview of the fundamental AM processes followed by an in-depth case study of the innovation in this immiscible alloy and composite development. We have also systematically illustrated AM of immiscible systems and development in design and material innovations. A framework is provided to computationally model various AM processes tailored for immiscible/incompatible systems. In the end, the current obstacles with limitations of AM techniques in manufacturing immiscible systems are highlighted, followed by their prospects for possible future innovations. AM can precisely control the microstructure of immiscible systems through tailored processing parameters and has the ability to create functionally graded materials where immiscible phases serve specific roles. © 2025 Elsevier Ltd

关键词： Functionally graded materials

来源：评论

学校读者我要写书评

暂无评论

Delayed plasticity during spherical nanoindentation of an iron-chromium-aluminum alloy:Effect of ferric ion irradiation

引用

Journal of materials science & Technology 2023年第36期167卷 228-236页

作者： Y.Zhang C.W.Li J.L.Jiang J.F.Gu H.Wang Y.D.Jia G.Wang X.G.An Q.Wang J.Lu Institute of Materials Shanghai UniversityShanghai 200072China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical Engineering City University of Hong KongKowloonSARChina Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu 610041China Interdisciplinary Materials Research Center Institute for Advanced StudyChengdu UniversityChengdu610106China

Spherical nanoindentation of an iron-chromium-aluminum alloy was conducted to study the effect of ferric-ion(Fe 3+)irradiation on the time-dependent plasticity behavior in the surface layers of this *** was observed that the initiation of plasticity by the appearance of displacement burst or“pop-in”event occurred after a period of waiting time in the apparent elastic regime and that Fe^(3+)irradiation at 360°C and up to∼0.5 displacements per atom could make it happen under the lower applied loads but with a reduced *** the experimental data,an activation volume and activation energy were extracted for the delayed *** results show that Fe^(3+)-irradiation significantly reduced its acti-vation volume from∼3.05 b 3 to∼1.75 b 3(where b=Burgers vector),but slightly increased its activation energy from∼0.65 to∼0.71 *** the other hand,high-resolution scanning transmission electron mi-croscopy observations reveal that the irradiation at the elevated temperature created interstitial atom pair onto the(100)habit plane that can serve as the nucleation site of a100dislocation loop while elim-inating the pre-existing ***,it is indicated that heterogeneous nucleation of the dislocation loop was predominant in the delayed plasticity initiation of this alloy and that the nucleation of the interstitial-type dislocation loop was involved due to Fe^(3+)-irradiation.

关键词： Spherical nanoindentation Delayed plasticity FeCrAl alloy Fe^(3+)-irradiation

来源：评论

学校读者我要写书评

暂无评论

A Novel Machine Learning Approach for Detection of Coronary Artery Disease Using Reduced Non-linear and Chaos Features

引用

International Journal Bioautomation 2022年第3期26卷 273-296页

作者： Singh, Ram Sewak Gelmecha, Demissie Jobir Mishra, Satyasis Dengia, Gemechu Sinha, Devendra Kumar Department School of Electrical & Computing Engineering Adama Science & Technology University Adama Ethiopia Mechanical Design & Manufacturing Engineering Department Center of Excellence in Advanced Manufacturing Engineering School of Mechanical Chemical & Materials Engineering Adama Science & Technology University Adama Ethiopia

In this research paper, authors present an automated system in this paper that integrates a ranking technique with Principal Component Analysis (PCA), Generalized Discriminant Analysis (GDA) and a 1-Norm Bidirectional Extreme Learning Machine (1-NBELM) to reliably classify normal and coronary artery disease groups. Twenty chaotic and non-linear attributes were hauling out from the Heart Rate Variability (HRV) signal to detect coronary artery disease groups. The HRV data for this study derived from a typical database of Normal Old (ELY), Young (YNG), and Coronary Artery Disease (CAD) people. Fisher, Wilcoxon and Bhattacharya were used to compute the rankings of attributes. GDA then turned the ranking features into a new feature. The Radial Basis Function (RBF) kernel was used to transfer original features to a high-dimensional feature space in GDA and PCA, and then it was deployed to 1-NBELM, which utilized the sigmoidal or multiquadric non-linear activation. Numerical experiments were performed on the combination of database sets as Young-ELY, Healthy-CAD, and Healthy ELY-CAD subjects. The numerical results show that ROC with GDA and 1-NBELM approach achieved an accuracy of 98.12±0.14, 96.21±0.12 and 99.87±0.28 for Young-CAD, Young-ELY and Healthy ELY-CAD groups with the use of sigmoidal and multiquadric activation function. The Fisher with GDA and 1-NBELM and Bhattacharya with GDA and 1-Norm Extreme Learning Machine (1-NELM) approach achieved an accuracy of 99.98±0.21 for all databases. © 2022 by the authors. Licensee Institute of Biophysics and Biomedical engineering, Bulgarian Academy of sciences. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://***/licenses/by/4.0/).

关键词： Principal component analysis

来源：评论

学校读者我要写书评

暂无评论

Exploring the evolution of microstructure and mechanical property of aγʹ-strengthened Co-based single crystal superalloy during creep and thermal exposure at 1000℃

引用

Journal of materials science & Technology 2024年第36期203卷 39-52页

作者： Zhen Xu Chuan Guo Yu Li Zhiwei Lv Xiaogang Hu Xinggang Li Qiang Zhu Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055China Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials Shenzhen 518055China CityU-Shenzhen Futian Research Institute Shenzhen 518045China

The study provided a systematic investigation into the creep behavior of aγʹ-strengthened Co-based single crystal superalloy Co-7Al-8W-1Ta-4Ti(at.%)under compressive creep conditions at 1000℃and 137 ***,the microstructural changes during thermal exposure at 1000℃ were thor-oughly *** microstructure analysis of the creep samples revealed the presence ofγ/γʹrafts,twins,stacking faults,and dislocation *** analyses were conducted to assess the dimen-sions and volume fractions ofγʹ,alongside Vickers hardness tests and nanoindentation ***-sults show thatγʹdissolution in the creep samples with substantially higher dissolution rates compared to thermal *** Co depletion and Ti enrichment in twin is observed in creep sample,po-tentially initiating localized phase ***,lattice rotation occurred during creep,resulting in a progressive deviation of crystal orientation away from the[001]*** faults transitioned from network-like structures to parallel configurations,and twins played a significant role in creep deformation,particularly in samples subjected to 382 h *** study also explored the evo-lution of Vickers hardness and the elastic modulus,introducing a systematic linear model to describe Vickers hardness changes during both thermal exposure and creep conditions.

关键词： Superalloy Compressive creep Thermal exposure Vickers hardness Twinning

来源：评论

学校读者我要写书评

暂无评论

Structure evolution andτ_(f)influence mechanism of Bi_(1-x)Ho_(x)VO_(4)microwave dielectric ceramics for LTCC applications

引用

Journal of materials science & Technology 2024年第30期197卷 1-8页

作者： Huaicheng Xiang Yuheng Zhang Junqi Chen Yang Zhou Ying Tang Jinwu Chen Liang Fang Key Laboratory of Low-Dimensional Structural Physics and Application Education Department of Guangxi Zhuang Autonomous RegionCollege of Physics and Electronic Information EngineeringGuilin University of TechnologyGuilin541004China Guangxi Universities Key Laboratory of Non-Ferrous Metal Oxide Electronic Functional Materials and Devices Guangxi Key Laboratory of Optical and Electronic Materials and DevicesCollege of Materials Science and EngineeringGuilin University of TechnologyGuilin541004China School of Mechanical Engineering Guilin University of Aerospace TechnologyGuilin541004China

Bi_(1-x)Ho_(x)VO_(4)(0.1≤x≤0.9)ceramics were prepared via a solid-state reaction method,and all the ceram-ics could be well densified in the 920–980℃*** ceramics with 0.1≤x<0.4 were composed of both monoclinic scheelite(M)and tetragonal zircon(T)phases,and a single M phase could be obtained in the range of x≥*** measuredε_(r) decreased from 58.9(x=0.1)to 14.7(x=0.9),so do the calcu-lated values(ε_(r)(C−M)=34.3–12.1),and the main reason forε_(r)>ε_(r)(C−M)was the rattling of Ho^(3+)in the *** points with zeroτf appeared in Bi1–x Hox VO4(0≤x≤1)ceramics,and the best mi-crowave dielectric properties withε_(r)=16.6,Q×f=18,400 GHz(f=10.69 GHz),andτf=+3.29 ppm/℃were obtained in the Bi_(0.2)Ho_(0.8)VO_(4)*** change in temperature coefficient of ionic polarizability(τ_(αm))caused by the rattling effect of cations is the physical essence that affectsτ***,the rattling effect can be used as an effective mechanism to regulateτf in low-ε_(r) ***,there was no chemical reaction between Bi_(1-x)Ho_(x)VO_(4) and Ag electrode,which indicates potential applications in low-temperature co-fired ceramic(LTCC)technology.

关键词： Bi_(1–x)Ho_(x)VO_(4) Near-zeroτ_(f) Bond valence Rattling effect LTCC

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：