检索结果-内蒙古大学图书馆

Journal of the Korean Wood science and Technology 2023年第3期51卷 157-172页

作者： Adfa, Morina Wiradimafan, Khafit Pratama, Ricky Febri Sanjaya, Angga Triawan, Deni Agus Yudha S., Salprima Ninomiya, Masayuki Rafi, Mohamad Koketsu, Mamoru Department of Chemistry Faculty of Mathematics and Natural Sciences University of Bengkulu Bengkulu38371 Indonesia Research Center of Sumatera Natural Product and Functional Materials University of Bengkulu Bengkulu38371 Indonesia Master of Chemistry Study Program Faculty of Mathematics and Natural Sciences University of Bengkulu Bengkulu38371 Indonesia Department of Chemistry and Biomolecular Science Faculty of Engineering Gifu University Gifu5011193 Japan Department of Chemistry Faculty of Mathematics and Natural Sciences IPB University Bogor16128 Indonesia Tropical Biopharmaca Research Center-Institute of Research and Community Services IPB University Bogor16128 Indonesia

Azadirachta excelsa, is a plant belonging to the same genus as Indian neem (Azadirachta indica), and its use as a pesticide is reported by few studies. Despite being a different species, it is expected to have the same biopesticide potential as A. indica. Therefore, this study aims to investigate the anti-termite activity of n-hexane and methanol extracts of A. excelsa seed kernel at various concentrations against Coptotermes curvignathus. The methanol extract demonstrated greater termicidal activity than n-hexane at doses test of 2%, 4%, and 8%. It also showed 100% termite mortality on the third day of administering the 8% dose. According to the gas chromatography with mass spectrometry data, the putative main components of the n-hexane extract were hexadecanoic acid, ethyl ester (18.99%), 9,12-octadecadienoic acid (Z,Z)-(16.31%), and 9-octadecenal (16.23%). In contrast, the principal constituents of methanol extract were patchouli alcohol (28.1%), delta-guaiene (15.15%), and alpha-guaiene (11.93%). Furthermore, limonoids profiling of A. excelsa methanol extract was determined using Ultrahigh-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry. The number of limonoids identified tentatively was fifteen, such as 6-deacetylnimbin, nimbolidin C, nimbolide, 6-acetylnimbandiol, 6-deacetyl-nimbinene, salannol, 28-deoxonimbolide, gedunin, nimbandiol, epoxyazadiradione, azadirone, 2',3'-dihydrosalannin, marrangin, nimbocinol, and azadirachtin. They were the same as those reported in the seed and leaves of A. indica, but its largest component in A. excelsa was 6-deacetylnimbin. As a result, the presence of these compounds may be responsible for the anti-termite activity of A. excelsa seed kernel extract. Additionally, column chromatography of methanol extract yielded 6-deacetylnimbin, which was found to be antifeedant and termiticide against C. curvignathus. © 2023 The Korean Society of Wood science & Technology.

关键词： Mass spectrometry

来源：评论

学校读者我要写书评

暂无评论

Metallic Slurry Preparation and Printability Assessment For Material Extrusion Additive Manufacturing

SSRN

引用

SSRN 2023年

作者： Li, Zhong Hu, Xiaogang Zhou, Yang Qu, Wenying Wen, Linju Meng, Xiaoxia Xu, Zhen Guo, Chuan Lu, Hongxing Zhu, Qiang Department of Mechanical and Energy Engineering Southern University of Science and Technology Shenzhen518055 China Shenzhen Key Laboratory for Additive Manufacturing of High-performance materials Southern University of Science and Technology Shenzhen518055 China Department of Mechanical Engineering Sciences University of Surrey Surrey GuildfordGU2 7XH United Kingdom BYD Auto Industry Company Limited Shenzhen518118 China Department of Mechanical Engineering Polytechnic University of Milan Milan20156 Italy

Material extrusion additive manufacturing of thermoplastics is so advanced due to the tunable rheological properties and hence a suitable printability, which is deficient for metals. Even though semi-solid modification and binder indirect modification are used to realize metal extrusion printing, the uncontrollable flow behavior and the metallurgical defects make it challenging to bridge this gap. In this study, mixed powder remelting and printability assessment were first proposed for producing metallic slurry with pre-designed microstructure and suitable printability. Specifically, the hypoeutectic Sn-Bi metallic slurry was obtained by remelting the mixed powder composed of SnBi58 powder and pure Sn powder. The microstructural characteristics at different temperatures were investigated, demonstrating the ability of microstructure predesign. Furthermore, the printability, including stability, extrudability, and buildability, was evaluated by an advanced rheometer and a screw-type 3D printer. The combined slurry preparation, printability assessment, and printing experiment provides a systematic method for parameters improvement to obtain the structural fidelity. © 2023, The Authors. All rights reserved.

关键词： Microstructure

来源：评论

学校读者我要写书评

暂无评论

Nonlocal Nernst-Planck-Poisson System for Modeling Electrochemical Corrosion in Biodegradable Magnesium Implants

引用

Journal of Peridynamics and Nonlocal Modeling 2025年第1期7卷 1-32页

作者： Hermann, Alexander Shojaei, Arman Höche, Daniel Jafarzadeh, Siavash Bobaru, Florin Cyron, Christian J. Institute of Material Systems Modeling Helmholtz-Zentrum Hereon Max-Planck-Str. 1 21502 Geesthacht Germany Institute of Surface Science Helmholtz-Zentrum Hereon Max-Planck-Str. 1 21502 Geesthacht Germany Department of Mathematics Lehigh University Bethlehem 18015 PA United States Department of Mechanical & amp Materials Engineering University of Nebraska-Lincoln Lincoln 68588-0526 NE United States Institute for Continuum and Material Mechanics Hamburg University of Technology Eissendorfer Strasse 42 Hamburg 21073 Germany

This paper provides a comprehensive derivation and application of the nonlocal Nernst-Planck-Poisson (NNPP) system for accurate modeling of electrochemical corrosion with a focus on the biodegradation of magnesium-based implant materials under physiological conditions. The NNPP system extends and generalizes the peridynamic bi-material corrosion model by considering the transport of multiple ionic species due to electromigration. As in the peridynamic corrosion model, the NNPP system naturally accounts for moving boundaries due to the electrochemical dissolution of solid metallic materials in a liquid electrolyte as part of the dissolution process. In addition, we use the concept of a diffusive corrosion layer, which serves as an interface for constitutive corrosion modeling and provides an accurate representation of the kinetics with respect to the corrosion system under consideration. Through the NNPP model, we propose a corrosion modeling approach that incorporates diffusion, electromigration and reaction conditions in a single nonlocal framework. The validity of the NNPP-based corrosion model is illustrated by numerical simulations, including a one-dimensional example of pencil electrode corrosion and a three-dimensional simulation of a Mg-10Gd alloy bone implant screw decomposing in simulated body fluid. The numerical simulations correctly reproduce the corrosion patterns in agreement with macroscopic experimental corrosion data. Using numerical models of corrosion based on the NNPP system, a nonlocal approach to corrosion analysis is proposed, which reduces the gap between experimental observations and computational predictions, particularly in the development of biodegradable implant materials. © The Author(s) 2024.

关键词： Biodegradation Corrosion modeling Electromigration Implant materials Nernst-Planck-Poisson system Peridynamics

来源：评论

学校读者我要写书评

暂无评论

Application of phase-field method in rechargeable batteries

引用

npj Computational materials 2020年第1期6卷 206-213页

作者： Qiao Wang Geng Zhang Yajie Li Zijian Hong Da Wang Siqi Shi Materials Genome Institute Shanghai UniversityShanghai 200444China School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Physical Science and Engineering Division(PSE) King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia Department of Mechanical Engineering Carnegie Mellon UniversityPittsburghPennsylvania 15213USA

Rechargeable batteries have a profound impact on our daily life so that it is urgent to capture the physical and chemical fundamentals affecting the operation and *** phase-field method is a powerful computational approach to describe and predict the evolution of mesoscale microstructures,which can help to understand the dynamic behavior of the material *** this review,we briefly introduce the theoretical framework of the phase-field model and its application in electrochemical systems,summarize the existing phase-field simulations in rechargeable batteries,and provide improvement,development,and problems to be considered of the future phase-field simulation in rechargeable batteries.

关键词： field phase method

来源：评论

学校读者我要写书评

暂无评论

Nano-heterogeneity-stabilized and magnetic-interaction-modulated metallic glasses

引用

science China materials 2021年第7期64卷 1813-1819页

作者： Chengliang Zhao Anding Wang Aina He Chuntao Chang Chain-Tsuan Liu School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Department of Materials Science and Engineering College of Science and EngineeringCity University of Hong KongHong Kong 999077China

Because of their boundary-free and long-rangedisordered microstructure,Fe-based metallic glasses(MGs)exhibit an ultra-low pinning effect on the magnetic domain and unparalleled soft-magnetic properties[1-3],and thus a... 详细信息

关键词：非晶形成能力金属玻璃软磁性能非晶合金合金设计强化机制饱和磁感应强度磁相互作用

来源：评论

学校读者我要写书评

暂无评论

MFC 5.0: An exascale many-physics flow solver

arXiv

引用

arXiv 2025年

作者： Wilfong, Benjamin Le Berre, Henry A. Radhakrishnan, Anand Gupta, Ansh Vaca-Revelo, Diego Adam, Dimitrios Yu, Haocheng Lee, Hyeoksu Chreim, Jose Rodolfo Barbosa, Mirelys Carcana Zhang, Yanjun Cisneros-Garibay, Esteban Gnanaskandan, Aswin Rodriguez, Mauro Budiardja, Reuben D. Abbott, Stephen Colonius, Tim Bryngelson, Spencer H. School of Computational Science & Engineering Georgia Institute of Technology AtlantaGA30332 United States Mechanical and Materials Engineering Worcester Polytechnic Institute WorcesterMA01609 United States Daniel Guggenheim School of Aerospace Engineering Georgia Institute of Technology AtlantaGA30332 United States Department of Mechanical and Civil Engineering California Institute of Technology PasadenaCA91125 United States School of Engineering Brown University ProvidenceRI02912 United States Mechanical Science & Engineering University of Illinois at Urbana–Champaign UrbanaIL61820 United States Oak Ridge National Laboratory Oak RidgeTN37830 United States Hewlett Packard Enterprise BloomingtonMN55435 United States George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology AtlantaGA30332 United States

Many problems of interest in engineering, medicine, and the fundamental sciences rely on high-fidelity flow simulation, making performant computational fluid dynamics solvers a mainstay of the open-source software community. A previous work (Bryngelson et al. Comp. Phys. Comm. (2021)) made MFC 3.0 a published, documented, and open-source solver with numerous physical features, numerical methods, and scalable infrastructure. MFC 5.0 is a marked update to MFC 3.0, including a broad set of well-established and novel physical models and numerical methods and the introduction of GPU and APU (or superchip) acceleration. We exhibit state-of-the-art performance and ideal scaling on the first two exascale supercomputers, OLCF Frontier and LLNL El Capitan. Combined with MFC’s single-accelerator performance, MFC achieves exascale computation in practice. New physical features include the immersed boundary method, N-fluid phase change, Euler–Euler and Euler–Lagrange sub-grid bubble models, fluid-structure interaction, hypo- and hyper-elastic materials, chemically reacting flow, two-material surface tension, magnetohydrodynamics (MHD), and more. Numerical techniques now represent the current state-of-the-art, including general relaxation characteristic boundary conditions, WENO variants, Strang splitting for stiff sub-grid flow features, and low Mach number treatments. Weak scaling to tens of thousands of GPUs on OLCF Summit and Frontier and LLNL El Capitan see efficiencies within 5% of ideal to over 90% of their respective system sizes. Strong scaling results for a 16-times increase in device count show parallel efficiencies over 90% on OLCF Frontier. MFC’s software stack has further improved, including continuous integration, which ensures code resilience and correctness through over 300 regression tests;metaprogramming, which reduces code length and maintains performance portability;and code generation for computing chemical reactions. © 2025, CC BY.

关键词： Fluid structure interaction

来源：评论

学校读者我要写书评

暂无评论

Metallic Slurry Preparation and Printability Assessment for Material Extrusion Additive Manufacturing

SSRN

引用

SSRN 2023年

作者： Li, Zhong Hu, Xiaogang Zhou, Yang Qu, Wenying Wen, Linju Meng, Xiaoxia Xu, Zhen Guo, Chuan Lu, Hongxing Zhu, Qiang Department of Mechanical and Energy Engineering Southern University of Science and Technology Shenzhen518055 China Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials Southern University of Science and Technology Shenzhen518055 China Department of Mechanical Engineering Sciences University of Surrey Guildford SurreyGU2 7XH United Kingdom BYD Auto Industry Company Limited Shenzhen518118 China Department of Mechanical Engineering Polytechnic University of Milan Milan20156 Italy

关键词： Microstructure

来源：评论

学校读者我要写书评

暂无评论

Influence of stacking sequences of woven jute-carbon hybrid composites: Diffusion mechanism and mechanical characterization

引用

Heliyon 2024年第17期10卷 e36632页

作者： Alvy, Md Sadbin Azad Hossain, Md Foisal Rana, Muhammed Sohel Rahman, Md Motinur Ferdous, Md Shafiul Department of Materials Science and Engineering Khulna University of Engineering & Technology Khulna 9203 Bangladesh Department of Electronics and Communication Engineering Khulna University of Engineering & Technology Khulna 9203 Bangladesh Central Engineering Facilities Atomic Energy Research Establishment Savar Dhaka 1349 Bangladesh Institute of Electronics Bangladesh Atomic Energy Commission Dhaka 1349 Bangladesh Former Faculty Department of Mechanical Engineering Khulna University of Engineering & Technology Khulna 9203 Bangladesh

In this study, different stacking orders of carbon-jute fiber mats were used to fabricate the composites and hybrids. The impact of different stacking orientations on mechanical properties was investigated experimentally. The experimental results were verified by finite element analysis (FEA). In addition, the impact of the fiber orientation on the loading direction was also investigated. Four layers of fabrics were piled to fabricate the composites by hand-layup with the cold press process. A NaCl solution was used to create a corrosive medium (pH 8), and the composites and hybrids were immersed in that medium, and their mechanical properties were compared. In this research, it has been found that the laminates with the stacking sequence of type-C (C/J/J/C) show the best result among other composites. Jute composites where all the fibers are in the loading direction possess a high strain compared with the other composites and hybrids. On the scanning electron microscope (SEM) image, delamination, buckling of fiber, fiber pullout, and voids were observed. In addition, the kinetics of the diffusion mechanism were also investigated, and it was found from the experimental results that the composites and hybrids immersed in pH 8 absorbed water via Fickian diffusion. © 2024 The Authors

关键词： Composites Corrosive impact Diffusion mechanism FEM Flexural strength Tensile strength

来源：评论

学校读者我要写书评

暂无评论

Design and Modeling of a Cable-Driven Hollow Continuum Manipulator

Design and Modeling of a Cable-Driven Hollow Continuum Manip...

引用

International Conference on Advanced Robotics and Mechatronics (ICARM)

作者： Changchao Sun Rongjie Kang Peikang Yuan Le Chang Xin Dong Shumin Wan Zhibin Song Jian S. Dai Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education School of Mechanical Engineering Tianjin University Tianjin China Department of Mechanical Materials and Manufacturing Engineering University of Nottingham Nottingham U.K. Institute for Robotics Southern University of Science and Technology Shenzhen China

Continuum manipulators (CMs) have redundancy and flexibility and show good adaptability in unstructured environments. Traditional CMs mostly utilize a backbone to provide structural support and produce bending, which limits the internal space. In this paper, an internally hollow CM is designed. The orthogonal segment ensures two bending degrees of freedom in a single module. In this design, each module contains four cables that can be divided into two pairs driven by two motors respectively, forming a closed-loop cable drive mechanism. For each pair of cables, they have different length change when the module bends. Thus, the actuation space of the manipulator is further mapped to the “motor space” to form the complete kinematic model. As the multi-moduled body has motion coupling, kinematic decoupling is achieved through using Bowden tube. Simulated and experimental results show that the CM designed in our work has high structural load capacity and flexible motion ability.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Generative Design for Buffer Layer Structures

Generative Design for Buffer Layer Structures

引用

Intelligent Design (ICID), International Conference on

作者： Ding Zhou Jiawei Huang Zhengxiang Zhang Bingjian Liu School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen China Department of Mechanical Materials and Manufacturing Engineering University of Nottingham Ningbo China Ningbo China

Discarded used tires, commonly referred to as ‘black pollution’, are a significant environmental issue. Airless tires have been considered as a potential solution, but their adoption is impeded by their stiff ride quality. This study leverages generative design methods to optimize the structure and form of the buffer layer in airless bicycle tires, striving to create a safe, durable, and high-performance tire with characteristics akin to those of pneumatic tires. The research delves into thousands of design possibilities using parametric model generation, finite element analysis, and genetic algorithms, with the aim of generating designs that fulfill all requirements effectively. The proposed method could significantly reduce waste and improve the cycling experience by offering a reliable alternative to conventional tires.

关键词：

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：