检索结果-南通市图书馆

Particle size influence on effective permittivity of particle-gas mixture with particle clusters

Particuology 2013年第2期11卷 216-224页

作者： Lijun Xu Chang Liu Zhang Cao Xiaomin Li Key Laboratory of Precision Opto-mechatronics Technology Ministry of EducationSchool of Instrument Science and Opto-electronic EngineeringBeihang University School of Chemistry and Environment Beihang University

The influence of particle size on the effective permittivity of a particle-gas mixture in the presence of particle clusters was studied using numerical analysis involving the three-dimensional finite element method. The effective permittivity of the mixture was obtained by calculating the electrostatic energy generated in the computation domain, Numerical results show that for fixed volume fraction of particles in the mixture, the effective permittivity of the mixture increases with decreasing particle size, Static experiments were carried out by using a differential capacitance sensor with parallel plates. The variation of the effective permittivity with particle size is shown by experimental data to agree with the numerical results. The methodology described and the results obtained in this paper may be used to help modify the measurement of particles volume fraction in the presence of particle clusters when a capacitance sensor is used.

关键词： Particle size effective permittivity Particle clusters Finite element method Capacitance sensor

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

effective medium theory of checkboard structures in the long-wavelength limit

引用

Chinese Optics Letters 2020年第7期18卷 98-101页

作者： Zhanlei Hao Yawen Zhuang Ying Chen Yineng Liu Huanyang Chen Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology Xiamen UniversityXiamen 361005China

effective medium theory is a powerful tool to solve various problems for achieving multifarious functionalities and applications. In this article, we present a concise empirical formula about effective permittivity of checkboard structures for different directions. To verify our empirical formula, we perform simulations of checkboard periodic structures in squares, rectangles, and sectors in two dimensions. Our results show that the formula is valid in a large range of parameters. This work provides a new way to understand and design composite materials, which might lead to further optical applications in transformation optics.

关键词： effective medium theory checkboard structures effective permittivity

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

effective Maxwell Equations from Time-dependent Density Functional Theory

引用

Acta Mathematica Sinica,English Series 2011年第2期27卷 339-368页

作者： Weinan E Jianfeng LU Xu YANG Department of Mathematics and Program in Applied and Computational Mathematics Princeton University Princeton NJ 08544 USA Beijing International Center for Mathematical Research and School of Mathematical Sciences Peking University Beijing 100871 P. R. China Department of Mathematics Courant Institute of Mathematical Sciences New York University New York NY 10012 USA

The behavior of interacting electrons in a perfect crystal under macroscopic external electric and magnetic fields is studied. effective Maxwell equations for the macroscopic electric and magnetic fields are derived starting from time-dependent density functional theory. effective permittivity and permeability coefficients are obtained.

关键词： Time-dependent density functional theory Maxwell equations effective permittivity electromagnetic fields

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

Electrical and magnetic properties of 0-3 Ba(Fe_(1/2)Nb_(1/2))O_(3)/PVDF composites

引用

Journal of Advanced Dielectrics 2017年第6期7卷 1-11页

作者： Hars Ranjan Uttam K.Mahto K.P.Chandra A.R.Kulkarni A.Prasad K.Prasad Aryabhatta Centre for Nanoscience and Nanotechnology Aryabhatta Knowledge University Patna 800001India Department of Physics S.M.CollegeBhagalpur 812001India Department of Metallurgical Engineering and Materials Science Indian Institute of Technology Mumbai 400076India University Department of Physics T.M.Bhagalpur UniversityBhagalpur 812007India

Lead-free Ba(Fe_(1/2)Nb_(1/2))O_(3)/PVDF O_(3) composites were fabricated using *** technique.X-ray diffraction,scanning electron microscopy,dielectric,impedance,ac conductivity,magnetic force microscopy(MFM)and vibrating sample magne-tometer studies were undertaken to characterize the *** crstallite size of the Ba(Fe_(1/2)Nb_(1/2))O_(3) powder,estimated using Williamson-Hall approach,was found to be~42 *** fller particles of~0.5-1 pum were found to disperse in the polymer matrix of all the *** concentration dependent values of real and imaginary parts of complex permittivity showed increasing trend and were seen to follow Bruggeman and Furukawa *** data for ac conductivity exhibited negative temperature coeficient of resistance character of the test materials and were found to obey Jonscher's power *** correlated barier hopping model was found to explain satisfactorily the mechanism of charge transport occurring in the *** confirmed the presence of magnetic phases in the *** magnetization versus applied field curves indicated the possibility of magnetoelectric coupling in the ***,the present composites have shown themselves as potential multi-functional candidate materials for use in high density data storage applications.

关键词： Random composite medium dielectric properties magnetic properties effective permittivity magnetic force microscopy

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

A New Approach Based on Iterative Method for the Characterization of a Micro-Strip Line with Thick Copper Conductor

引用

Journal of Electromagnetic Analysis and Applications 2016年第5期8卷 95-108页

作者： Rafika Mejri Taoufik Aguili Communication System Laboratory Sys’Com National Engineering School of Tunis University Tunis El Manar Tunis Tunisia

In this work, we applied two electromagnetic models for the characterization of a planar structure including a flat, thick copper conductor. Indeed the first model is consisted by modeling two metal ribbons without bulkiness, placed one above the other at a distance of h2 equal to the thickness of the thick conductor. This approach has been implemented and tested by the iterative method. The results of simulations have been compared with those calculated by the Ansoft HFSS software, and they are in good concordance, validating the method of analysis used. The second model is based on the calculation of the effective permittivity of the medium containing the thick conductor. This medium consists of a metallic region of complex relative permittivity , the rest of this medium is filled with air er2 = 1. The effective permittivity eeff calculated from these two relative permittivity er2 and . Comparing the simulation results of this new formulation of the iterative method with those calculated by the software Ansoft HFSS shows that they are in good matching which validates the second model.

关键词： Thick Conductor Iterative Method Micro-Strip Line Microwaves Skin Effect Phenomenon effective permittivity

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

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

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

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：