检索结果-内蒙古大学图书馆

arXiv 2024年

作者： Amiri, Mahsa Foumani, Zahra Zanjani Cao, Penghui Valdevit, Lorenzo Bostanabad, Ramin Materials and Manufacturing Technology Program University of California IrvineCA92697 United States Department of Mechanical and Aerospace Engineering University of California IrvineCA92697 United States Department of Materials Science and Engineering University of California IrvineCA92697 United States Department of Civil and Environmental Engineering University of California IrvineCA92697 United States

Achieving desired mechanical properties in additive manufacturing requires many experiments and a well-defined design framework becomes crucial in reducing trials and conserving resources. Here, we propose a methodology embracing the synergy between high-throughput (HT) experimentation and hierarchical machine learning (ML) to unveil the complex relationships between a large set of process parameters in Laser Powder Bed Fusion (LPBF) and selected mechanical properties (tensile strength and ductility). The HT method envisions the fabrication of small samples for rapid automated hardness and porosity characterization, and a smaller set of tensile specimens for more labor-intensive direct measurement of yield strength and ductility. The ML approach is based on a sequential application of Gaussian processes (GPs) where the correlations between process parameters and hardness/porosity are first learnt and subsequently adopted by the GPs that relate strength and ductility to process parameters. Finally, an optimization scheme is devised that leverages these GPs to identify the processing parameters that maximize combinations of strength and ductility. By founding the learning on larger "easy-to-collect" and smaller "labor-intensive" data, we reduce the reliance on expensive characterization and enable exploration of a large processing space. Our approach is material-agnostic and herein we demonstrate its application on 17-4PH stainless steel. © 2024, CC BY.

关键词： Global positioning system

来源：评论

学校读者我要写书评

暂无评论

Enhancement in thermoelectric performance of hydrothermally synthesized Ca and Sb co-doped Bi2Te3 nanostructures

引用

Physica Scripta 2024年第3期99卷 035961-035961页

作者： Rani, Kavita Gupta, Vivek Dalal, Ranjeet Pandey, Abhishek Department of Physics Guru Jambheshwar University of Science and Technology Hisar125001 India School of Mechanical and Materials Engineering Indian Institute of Technology Mandi Kamand175005 India

−Ca & Sb co-doped Bi2Te3 compounds have been prepared by hydrothermal method at 210 °C for 24 h and investigated their thermoelectric properties. Phase purity and crystallinity were analyzed by XRD. All the prepared samples have rhombohedral crystal structure with space group R-3m. The hexagonal nanoplate-like morphology was examined by FESEM. Elemental analysis was done with EDX. Band gap energy of prepared samples has values in the range of ∼0.40-0.65 eV, obtained by Tauc plot. The Raman shift was obtained at a lower frequency with doping. Carrier concentration increased with doping from 3.18 × 1020 cm−1 to 9.34 × 1020 cm−1. The high value of power factor (PF) of ∼10.8 × 10-4 Wm−1K−2 was obtained due to high carrier concentration. An ultralow lattice thermal conductivity of ∼0.28 and ∼0.63 W mK−1 at 420 K, was obtained for Ca0.06Bi1.88Sb0.06Te3 and pure Bi2Te3, respectively. A maximum ZT of ∼0.78 at 386 K was obtained for Ca0.03Bi1.94Sb0.03Te3. The value of ZT thus obtained is about ∼ 51% higher than the ZT of pure Bi2Te3 (∼0.39 at 386 K). © 2024 IOP Publishing Ltd.

关键词： Thermal conductivity

来源：评论

学校读者我要写书评

暂无评论

A Multiscale Parametric Study to Drug Delivery Modeling in Stented Arteries

A Multiscale Parametric Study to Drug Delivery Modeling in S...

引用

Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： Dimitrios S. Pleouras Vasileios S. Loukas Georgia S. Karanasiou Anastasia Antonaki Dimitrios I. Fotiadis Antonis I. Sakellarios Dept. of Materials Science and Engineering Unit of Medical Technology and Intelligent Information Systems University of Ioannina Ioannina Greece Dept. of Materials Science and Engineering University of Ioannina Ioannina Greece Dept. of Materials Science and Engineering Unit of Medical Technology and Intelligent Information Systems University of Ioannina Biomedical Resarch Institute FORTH-IMBB Ioannina Greece Dept. of Mechanical and Aeronautics Engineering University of Patras Patras Greece

ISBN: (数字)9798350371499

ISBN: (纸本)9798350371505

The aim of this work is to investigate the dynamic behavior of retinoic acid concentration within the coronary artery, examining its distribution both on the stent and to the lumen and the arterial wall. The study aims to elucidate the effect of various factors, including variations in retinoic acid concentration on the stent, the applied blood flow velocity as boundary condition within the lumen, the polymer layer porosity, the arterial wall porosity and the drug permeability. Through a comprehensive analysis of these factors, this research seeks to advance the understanding of how retinoic acid behaves in the complex environment of the coronary artery, offering valuable insights into potential therapeutic applications and advances in cardiovascular medicine. To do this, a multiscale computational model for drug delivery is employed and applied in a stented arterial segment. 3D reconstruction of the arterial artery was achieved using optical coherence tomography (OCT) and X-ray angiography. The positioning of stent geometry was performed using finite element modeling of stent deployment. The results demonstrate that changes to important parameters of the model lead to significant changes to the drug *** Relevance: The importance of this work is related to the development and design of new coronary stents and potentially consider the patient’s phenotype and provide personalized applications.

关键词： Drugs Solid modeling Three-dimensional displays Phenotypes Lumen Drug delivery Finite element analysis Permeability Polymers Arteries

来源：评论

学校读者我要写书评

暂无评论

MAGNETIC PROPERTIES EVALUATION OF POLYAMIDE 4.6 BONDED MAGNETIC COMPOSITE

MAGNETIC PROPERTIES EVALUATION OF POLYAMIDE 4.6 BONDED MAGNE...

引用

SAMPE 2024 Conference and Exhibition

作者： Karkhanis, Pratik Arigbabowo, Oluwasola K. Gonzalez, Aaron J. Inamdar, Shreyas Ahmed, Tanvir Herrera, Andres Geerts, Wilhelmus J. Tate, Jitendra S. Ingram School of Engineering Texas State University 601 University Drive San MarcosTX78666 United States Materials Science Engineering and Commercialization Program Texas State University 601 University Drive San MarcosTX78666 United States Department of Physics Texas State University 601 University Drive San MarcosTX78666 United States

ISBN: (纸本)9781934551455

Bonded magnetic composites combine the cost-effectiveness, low density, and manufacturing flexibility of conventional polymer binders with the unique magnetic characteristics of magnetic powders/fillers to form multifunctional magneto polymeric composites that offer superior properties to conventional sintered magnets. In this study, a co-rotating twin screw extruder was used to fabricate 20 and 40 wt.% strontium ferrite/polyamide 4.6 bonded magnetic composites viable for fused filament fabrication 3D printing. The characterization conducted on the bonded magnetic composites was scanning electron microscopy, simultaneous differential thermogravimetry, and vibrating sample magnetometry. The microstructure of the bonded composite exhibited a uniform platelet morphology of the strontium ferrite magnetic particles. There was no observable depreciation in the melting transitions, which suggests a thermally resistant magnetic composite. An appreciable increment in % crystallinity of 13 and 20% for 20wt.% and 40wt.% strontium ferrites bonded magnets were observed. This is attributable to the heterogeneous nucleation phenomenon, where the metal powders act as nucleation sites for increased crystalline domains. The bonded composite exhibited significant magnetic anisotropy, with the remanence (Mr), which is the most important property for magnetic application significantly increasing to 49.8% along the easy direction in comparison to the hard axis. This suggests the viability of the fabricated bonded composites in viable in producing anisotropic bonded magnetic devices, which are considered to exhibit stronger magnetic properties. © 2024 Soc. for the Advancement of Material and Process engineering. All rights reserved.

关键词： Magnetic anisotropy

来源：评论

学校读者我要写书评

暂无评论

Electron-hole hybridization in bilayer graphene

引用

National science Review 2020年第2期7卷 248-253页

作者： Siqi Wang Mervin Zhao Changjian Zhang Sui Yang Yuan Wang Kenji Watanabe Takashi Taniguchi James Hone Xiang Zhang NSF Nanoscale Science and Engineering Center (NSEC) University of California Materials Sciences Division Lawrence Berkeley National Laboratory Department of Mechanical Engineering Columbia University National Institute for Materials Science Faculties of Sciences and Engineering University of Hong Kong

Band structure determines the motion of electrons in a solid, giving rise to exotic phenomena when properly engineered. Drawing an analogy between electrons and photons, artificially designed optical lattices indicate the possibility of a similar band modulation effect in graphene systems. Yet due to the fermionic nature of electrons, modulated electronic systems promise far richer categories of behaviors than those found in optical lattices. Here, we uncovered a strong modulation of electronic states in bilayer graphene subject to periodic potentials. We observed for the first time the hybridization of electron and hole sub-bands, resulting in local band gaps at both primary and secondary charge neutrality points. Such hybridization leads to the formation of flat bands, enabling the study of correlated effects in graphene systems. This work may provide a novel way to manipulate electronic states in layered systems, which is important to both fundamental research and application.

关键词： band modulation periodic potential bilayer graphene

来源：评论

学校读者我要写书评

暂无评论

A GLIMPSE AT FIFTY-ONE YEARS IN ACOUSTIC EMISSION

e-Journal of Nondestructive Testing

引用

e-Journal of Nondestructive Testing 2023年第1期28卷

作者： Hamstad, Marvin A. University of Denver Daniel Felix Ritchie School of Engineering and Computer Science Dept. of Mechanical and Materials Engineering DenverCO United States

After 51 years continuously involved in acoustic emission (AE) testing and research, it has been interesting to look back over five decades. The equipment available in the early 1970s was primitive compared to now. At the start of that decade, only one, recently established, commercial company sold AE measurement equipment, and other useful equipment was internally built or adapted from other technologies. Further, the data that came from an AE monitored test was simply the number (counts) of penetrations of a fixed one-volt threshold expressed as an increasing total or a rate and recorded on an x-y plotter. The purpose of this "glimpse" is to present advances both within the author’s research as well as those that were adopted from others research that were viewed as moving AE technology forward. This "glimpse" is not intended to be comprehensive, instead it is limited to aspects the author was involved in. Among the topics to be covered are advances such as understanding hydraulic test machine continuous noise, true root-mean-square (RMS) voltage measurements, inclusion particle fracture or decohesion, tension versus compression testing for unflawed metal samples, the pencil lead break, an acoustic emission signal simulator, broadband sensors, digital waveform recorders, large transverse-dimensioned plates, absolutely calibrated flat-with-frequency AE sensors, finite element modeling (FEM) in isotropic materials, validation of FEM, computer-based digital AE systems, intensity of frequency versus time of AE signals, superposition of group velocity results and FEM beyond the case of dipoles in an isotropic plate. © 2023 The Authors.

关键词： Acoustic emission testing

来源：评论

学校读者我要写书评

暂无评论

A contextual ontology for distributed urban data management

引用

Proceedings of the Institution of Civil Engineers: Smart Infrastructure and Construction 2021年第3期172卷 96-105页

作者： Hoare, Cathal Pinheiro, Sergio Hu, Shushan O’Donnell, James School of Materials and Mechanical Engineering UCD Energy Institute University College Dublin Dublin Ireland Digital Construction BAM Ireland Dublin Ireland School of Computer Science and Information Engineering Hubei University Wuhan China

The evolution of information and communication technology in the construction domain has yielded a variety of heterogeneous data sources. While bespoke approaches have been developed to explore data merging for a variety of purposes, few have explored how to develop a multipurpose information organisation that can be reconfigured on a per-project basis. This paper describes an approach that, using a lightweight central server, is used to investigate the effectiveness of loose federations of information sources that together serve the information needs of a project. The central server provides both a common context through which relationships between the information sources can be expressed and a data register to enable information discovery. The paper describes the creation of an ontology to capture this context and a software architecture to support its use. The efficacy of the approach is illustrated through describing the use of the server for marshalling data used in a renovation project. © 2020 American Association of Clinical Endocrinologists. All rights reserved.

关键词： Knowledge management

来源：评论

学校读者我要写书评

暂无评论

Effect of Zr on phase separation,mechanical and corrosion behavior of heterogeneous CoCrFeNiZr_(x) high-etropy alloy

引用

Journal of materials science & Technology 2022年第14期109卷 76-85页

作者： Wu Qi Wenrui Wang Xiao Yang Lu Xie Jiaming Zhang Dongyue Li Yong Zhang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of Fluid Interaction with Material Ministry of EducationBeijing 100083China Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

CoCrFeNi high entropy alloy(HEA)has attracted extensive attention due to its excellent corrosion resistance,but the low strength limits its engineering application *** order to develop CoCrFeNi based HEAs with high strength,ductility and corrosion resistance,the effects of Zr content on the microstructure,mechanical properties and corrosion resistance of heterogeneous CoCrFeNiZr_(x)(x=0,0.25,0.5 and 1)HEAs were investigated in this *** results indicate that the increase of Zr content can significantly affect the phase stability of the alloy,and promote the formation of intermetallic compounds(Ni_(7)Zr_(2)and/or Laves phase)and the transformation of solid solution from face-centered cubic(FCC)structure(x=0,0.25 and 0.5)to body-centered cubic(BCC)structure(x=1).Reasonable control of the Zr content can endow the alloy excellent comprehensive ***,for CoCrFeNiZr_(0.25) alloy,composed of FCC matrix and a small amount of Ni_(7)Zr_(2)phases,the yield strength(~655 MPa)is increased by nearly four times higher than that of Zr-free alloy,and it also has good ductility(fracture stain>50%).Meanwhile,the corrosion resistance of CoCrFeNiZr_(0.25) alloy is better than that of *** EIS results show that the addition of Zr reduces the stability of the passive film on the alloy,which can be related to the content of the beneficial oxide in the passive film and the thickness of the passive film through XPS ***,the work functions of different phases in CoCrFeNiZr_(x)alloys were obtained by firstprinciples calculations,which further confirmed the selective corrosion mechanism of the CoCrFeNiZr_(x) alloy combining the experimental results.

关键词： High-entropy alloy Microstructure Corrosion resistance First-principles Work function

来源：评论

学校读者我要写书评

暂无评论

A Flexible Pressure Sensor with Parallel Fiber Structure for Wireless Capsule Detection

SSRN

引用

SSRN 2023年

作者： Zhang, Xianwen Yang, Ning Zhou, Debao School of Materials Science and Engineering Tiangong University Tianjin300387 China Department of Mechanical and Industrial Engineering University of Minnesota Duluth United States

With the rapid development of science and technology, flexible pressure sensors with high sensitivity and excellent stability have generated considerable attention due to their potential applications. However, the challenge of low sensitivity remains for pressure sensors with high performance. Polyaniline (PANI) has been widely used in various fields as a sensing material owing to its simple preparation and good electrical conductivity. In this study, a pressure sensor with a sandwich structure was developed to sensitively monitor body signals. The micro-nanofiber mats were prepared by electrospinning of thermoplastic polyurethane (TPU). The constructed parallel TPU mats (P-TPU) and staggered TPU mats (S-TPU) possess a non-woven structure with a fiber diameter of (0.68±0.14) μm and (1.0±0.24) μm, respectively. PANI was grown in-situ on the mat to form a conductive layer. After stacking S-TPU fiber mats bonded with commercial medical polyurethane (PU) films and orderly conductive mats to form a PANI-coated mat/S-TPU mat structure, another layer of the S-TPU mats was also packed for the construction of a sandwich-structured piezoresistive sensor. The device could tolerate more than 600 pressing cycles without affecting its sensing capability. The human body-attached experiments further demonstrated that the sensor could real-time monitor actions of finger/arm bending, cheek swelling and holding their breath, speaking-caused throat vibration, and moving of the gastrointestinal tract. The electrospinning method could be used as a cost-effective strategy with a simple preparation process to obtain flexible piezoresistive sensors with good skin compatibility and powerful pressure sensing capabilities. © 2023, The Authors. All rights reserved.

关键词： Electrospinning

来源：评论

学校读者我要写书评

暂无评论

Commercially Viable Hybrid Li-Ion/Metal Batteries with High Energy Density Realized by Symbiotic Anode and Prelithiated Cathode

引用

Nano-Micro Letters 2022年第9期14卷 174-186页

作者： Kui Lin Xiaofu Xu Xianying Qin Ming Liu Liang Zhao Zijin Yang Qi Liu Yonghuang Ye Guohua Chen Feiyu Kang Baohua Li Shenzhen Key Laboratory on Power Battery Safety Research and Shenzhen Geim Graphene Center Tsinghua Shenzhen International Graduate SchoolShenzhen 518055People’s Republic of China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084People’s Republic of China Contemporary Amperex Technology Co.Ltd. Ningde 352100People’s Republic of China Shenzhen Graphene Innovation Center Co.Ltd. Shenzhen 518055People’s Republic of China College of Materials Science and Engineering Hunan UniversityChangsha 410082People’s Republic of China Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong Kong 999077People’s Republic of China

The energy density of commercial lithium(Li)ion batteries with graphite anode is reaching the *** is believed that directly utilizing Li metal as anode without a host could enhance the battery’s energy density to the maximum ***,the poor reversibility and infinite volume change of Li metal hinder the realistic implementation of Li metal in battery ***,a commercially viable hybrid Li-ion/metal battery is realized by a coordinated strategy of symbiotic anode and prelithiated *** be specific,a scalable template-removal method is developed to fabricate the porous graphite layer(PGL),which acts as a symbiotic host for Li ion intercalation and subsequent Li metal deposition due to the enhanced lithiophilicity and sufficient ion-conducting pathways.A continuous dissolution-deintercalation mechanism during delithiation process further ensures the elimination of dead *** a result,when the excess plating Li reaches 30%,the PGL could deliver an ultrahigh average Coulombic efficiency of 99.5% for 180 cycles with a capacity of 2.48 m Ah cm^(-2) in traditional carbonate ***,an air-stable recrystallized lithium oxalate with high specific capacity(514.3 m Ah g^(-1))and moderate operating potential(4.7-5.0 V)is introduced as a sacrificial cathode to compensate the initial loss and provide Li source for subsequent *** on the prelithiated cathode and initial Li-free symbiotic anode,under a practical-level3 m Ah capacity,the assembled hybrid Li-ion/metal full cell with a P/N ratio(capacity ratio of Li Ni_(0.8)Co_(0.1)Mn_(0.1)O_(2) to graphite)of 1.3exhibits significantly improved capacity retention after 300 cycles,indicating its great potential for high-energy-density Li batteries.

关键词： Hybrid lithium-ion/metal battery Symbiotic anode Porous graphite layer Cathode prelithiation Lithium oxalate

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：