检索结果-南通市图书馆

Enhancement of coercivity,permeability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites for memory and high frequency devices

引用

Journal of Rare Earths 2024年第6期42卷 1128-1135,I0005页

作者： I.Sardar M.D.Hossain M.S.Sikder M.N.I.Khan M.R.Rahman Physics Discipline Khulna UniversityKhulna9208Bangladesh Department of Physics Khulna University of Engineering&TechnologyKhulna9203Bangladesh Department ofComputer Science and Engineering Northern University of Business&Technology KhulnaKhulna9100Bangladesh Material Science Division Atomic Energy CentreDhaka1000Bangladesh

Spinel cubic ferrites have huge applications in me mory and high frequency *** the improvement of these modern devices,the magnetic coercivity,permeability,and dielectric properties of a ferrite are the important *** article focuses on improving the magnetic coercivity,magnetic permeability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites,where x=0.00,0.06,and *** X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM),energy dispersive X-ray(EDX),vibrating sample magnetometer(VSM),and an impedance analyzer were used to characterize the structural,magnetic,and dielectric properties of the *** XRD patterns indicate the formation of spinel cubic structure of the samples with a secondary peak(EuFeO_(3))for Eu doped *** densities and porosities of the samples follow an inverse trend,where the doped samples’lattice parameters are increased with the increment of rare earth Eu *** FTIR analysis also proves the spinel cubic phase of the *** average grain size of the ferrites is obtained via FESEM images,and it is increased from 121 to 198 *** analysis confirms that doping of the Eu content also changes other hysteresis loop properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ***,the coercivity of the Eu doped samples is greater than that of the mother alloy(x=0.00).The EDX study shows that there is no impurity contamination in the *** permeability and dielectric measurements show an improved quality factor of the Eu-doped samples with low magnetic and dielectric *** dependent resistivity and impedance analysis also show the improved *** the observed properties of the samples,all the investigated ferrites might be strong candidates for potential applications in memory devices,magnetic sensors,and high frequency applications.

关键词： Ferrites Raree arths Coercivity Permeability EDX Resistivity

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

Influence of austenization temperature on the erosion behavior of austempered ductile irons

引用

Journal of university of Science and technology Beijing 2008年第1期15卷 29-33页

作者： L.C. Chang L C. Hsui L.H. Chen S.T. Lui Department of Mechanical Engineering Technology and Science Institute of Northern Taiwan Taipei 112 China Talpei Department of Materials Science and Engineering Cheng-Kung University Talnan 800 China Taipei

The erosion behavior of austempered ductile irons austenized at different temperatures was studied. The results indicate that the erosion rate well correlates with the mechanical properties. At high impact angles, increasing ductility and mechanical energy density results in decreasing erosion rate, whereas increasing hardness reduces the erosion rate at low impact angles. 2008 university of Science and technology Beijing. All rights reserved.

关键词： austempered ductile iron erosion mechanical properties austenization

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

Orthogonal Drawings of Graphs for the Automation of VLSI Circuit Design

引用

Journal of Computer Science & technology 1999年第5期14卷 447-459页

作者：刘彦佩 Institute of Mathematics Northern Jiaotong University Beijing P.R. China

This article shows the recent developments on orthogonal draw-ings of graphs which have applications for the automation of VLSI circuit ***, a number of problems are posed for further research.

关键词： graph surface embedding algorithm orthogonal drawing VLSI

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

Some Open Problems in Parameterized Complexity Related to the Work of Jianer Chen

引用

Tsinghua Science and technology 2014年第4期19卷 325-328页

作者： Michael Ralph Fellows Engineering and IT Charles Darwin UniversityDarwin 0909 Northern TerritoryAustralia

This short paper highlights some open problems related to the work of Jianer Chen in the area of parameterized/multivariate algorithmics.

关键词： parameterized complexity multivariate algorithmics open problems

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

Health Assessment Method of the Aircraft Hydraulic System Based on Gray Clustering

Health Assessment Method of the Aircraft Hydraulic System Ba...

引用

第25届中国控制与决策会议

作者： Jianguo Cui Zeli Lin Liying Jiang Yiwen Qi Fengxia Ma Xin Jin School of Automation Shenyang Aerospace University College of northern Science and technology Shenyang Aerospace University Shenyang Aeroengine Research Institute

ISBN: (纸本)9781467355339

In connection with the problem which is difficult to be accurately assess the present health status of the aircraft hydraulic system, in this paper, a gray cluster analysis method has been put forward and used to comprehensively assess the health status of the aircraft hydraulic system. Firstly, according to the expertise to rate for the key components of the aircraft hydraulic system. Then it uses and relies on piecewise linear function to determine the whitening weight function. At last it uses the gray clustering algorithm to accurately assess the health status of the aircraft hydraulic system （divided into five levels: health, sub-health, available, fault, scrap）. And it uses a case to verify the accuracy of the assessment methods. And it has a good application value for the maintenance and security of the aircraft hydraulic system.

关键词： PHM Aircraft Hydraukics Health State Evaluation Grey Clustering

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

An algorithm of sequential systems of linear equations for nonlinear optimization problems with arbitrary initial point

引用

Science China Mathematics 1997年第6期40卷 561-571页

作者：高自友贺国平吴方 northern Jiaotong university Beijing 100044 China Shandong Institute of Mining and technology Taian 271019 China Institute of Applied Mathematics Chinese Academy of Sciences Beijing 100080 China

For current sequential quadratic programming (SQP) type algorithms, there exist two problems; (i) in order to obtain a search direction, one must solve one or more quadratic programming subproblems per iteration, and the computation amount of this algorithm is very large. So they are not suitable for the large-scale problems; (ii) the SQP algorithms require that the related quadratic programming subproblems be solvable per iteration, but it is difficult to be satisfied. By using e-active set procedure with a special penalty function as the merit function, a new algorithm of sequential systems of linear equations for general nonlinear optimization problems with arbitrary initial point is presented This new algorithm only needs to solve three systems of linear equations having the same coefficient matrix per iteration, and has global convergence and local superlinear convergence. To some extent, the new algorithm can overcome the shortcomings of the SQP algorithms mentioned above.

关键词： constrained optimization problem algorithm of sequential systems of linear equations sequential quadratic programming algorithm convergence.

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

Mass Loss Behavior and Volatile Composition during Pyrolysis of a Bituminous Coal

引用

China Petroleum Processing & Petrochemical technology 2018年第4期20卷 44-50页

作者： Fan Junfeng Tian Bin An Xiaoxi Zhang Yaqing Yin Mengmeng Tian Yuanyu College of Chemical and Environmental Engineering Shandong University of Science and Technology Advanced Chemical technology for Utilization of northern Shaanxi Energy of the Engineering Research Center of the Ministry of Education Shaanxi Research Center of Engineering Technology for Clean Coal Conversion School of Chemical Engineering Northwest University

The thermogravimetry analyzer coupled with the pyrolysis gas chromatography/time-of-flight mass spectrometry technology was used in this study to investigate the mass loss behavior and volatile release characteristics of a bituminous coal. The results showed that with an increasing heating rate, the characteristic parameters and TG/DTG curves shifted obviously to the higher temperature region. The pyrolysis of a bituminous coal at different heating rates can be divided into two stages according to the Coats-Redfern(C-R) plots. The activation energy obtained from the C-R method is 50.21—85.14 kJ/mol and 5.14—7.24 kJ/mol at a heating rate range of 8—300 °C/min for the first and second pyrolysis stages, respectively. Aromatic hydrocarbons were dominant in the volatile products during fast pyrolysis of the coal, followed by the olefins, whereas the phenols were the third major components. With the increase of pyrolysis temperature, the heavy components in the volatile species increased; meanwhile the phenol cracking reactions were intensified. The carbon number of olefins was mainly concentrated in 3—9, and the aromatics were mainly composed of the compounds of C_6—C_(13).This study can provide a basic reference for fast pyrolysis of coal and other thermal chemical conversion processes.

关键词： fast pyrolysis bituminous coal kinetics volatiles

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

PROGRESS IN STUDIES ON ICE ACCUMULATION IN RIVER BENDS

引用

Journal of Hydrodynamics 2011年第6期23卷 737-744页

作者： WANG Jun CHEN Pang-pang SUI Jue-yi School of Civil Engineering Hefei University of Technology Heifei 230029 China Environmental Engineering Program University of Northern British Columbia Prince George British ColumbiaCanada V2N 4V9

River ice is an important hydraulic element in temperate and polar environments and would affect hydrodynamic conditions of rivers through changes both in the boundary conditions and the thermal regime. The river bend has been reported as the common location for the initiation of ice jams because the water flow along a river bend is markedly affected by the channel curvature. In this article, the experimental studies about the ice accumulation in a river bend are reviewed. Based on experiments conducted so far, the criteria for the formation of ice jams in the river bend, the mechanisms of the ice accumulation in the river bend and the thickness profile of the ice accumulation in the river bend are discussed. The two-equation turbulence model is used to simulate the ice accumulation under an ice cover along a river bend. A formula is proposed for describing the deformation of the ice jam bottom. Our results indicate that all simulated thickness of the ice accumulation agrees reasonably well with the measured thickness of the ice accumulation in the laboratory.

关键词： experiment ice jam/accumulation bend channel thickness profile

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

SrAl_2O_4∶Eu^(2+),Nd^(3+) and Dy^(3+) Long Afterglow Phosphor

引用

Journal of Rare Earths 2003年第2期21卷 146-148页

作者：何大伟吕菁华崔兴龙 Ministry of Education Key Laboratory Labatory of Materials for Information Storage and Display Institute of Photo Electronic Technology Northern Jiaotong University Hulan Branch Harbin Normal University

The SrAl 2O 4∶Eu 2+ , Nd 3+ and SrAl 2O 4∶Eu 2+ , Dy 3+ long afterglow phosphor were synthesized. Their excitation and emission spectra at different excitation and afterglow characteristics were analyzed after the excitation power was taken off. The effects of Eu 2+ , Dy 3+ , Nd 3+ mole concentrations on phosphorescence characteristics were also discussed. It is crucial to have trapping levels located at a suitable depth related to the thermal release rate at room temperature. The incorporation of Nd 3+ ions as an auxiliary activator into the SrAl 2O 4∶Eu 2+ system causes very intense and long phosphorescence. The response time of SrAl 2O 4∶Eu 2+ , Dy 3+ phosphors is quicker than that of SrAl 2O 4∶Eu 2+ , Nd 3+ . Phosphorescence characteristics of SrAl 2O 4∶Eu 2+, Nd 3+ is much better than those of SrAl 2O 4∶Eu 2+ , Dy 3+ . The integrate area of the excitation spectrum of SrAl 2O 4∶Eu 2+ , Nd 3+ phosphor is larger than that of SrAl 2O 4∶Eu 2+ , Dy 3+ phosphor within the range of 250～360 nm. For phosphorescence characteristics to the system of SrAl 2O 4∶Eu 2+ , Nd 3+ phosphor, the optimum concentration of Nd 3+ trivalent rare earth ions is 0.05 mol.

关键词： optics long afterglow phosphor SrAl 2O 4∶Eu 2+ , Dy 3+ trapping centers rare earths

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

Coal flotation using wash oil as a new type of collector

引用

Mining Science and technology 2010年第4期20卷 546-550页

作者： XIE Guangyuan WU Ling LI Guozhou YU Hesheng School of Chemical Engineering & technology China University of Mining & Technology Xuzhou 221116 China northern Engineering and technology Corporation MCC Anshan 114009 China Schulich School of Engineering University of Calgary Calgary T2NIN4 Canada

The use of wash oil as a coal collector is proposed to overcome the disadvantages of regular collectors in coal slime flotation. These disadvantages include high price, limited sources and high consumption. The effect of additives on flotation was studied and an innovative ＂one rough separation--one cleaning separation＂ flotation technology was developed. The experimental resuits show that the clean coal ash content decreases by about 1.36% and the clean coal yield declines by around 10% with the application of the depressant. There is an increase of 3.76% in the yield of clean coal and a decrease of 0.40% in the ash content caused by utilizing a dispersant. An ultimate product having an ash content of 10.78% and yield of 70.12% can be attained using a combination of dispersant and depressant. The use of this new technology decreases the ash content by 1.21%, decreases the yield by 2.80% and an increases the coal flotation perfect index by 2.03%. Compared to common flotation, the utilization of the new technology reduces ash by 0.17%, increases yield by 5.3% and increases perfect index by 4.18%.

关键词： wash oil coal slime flotation collector depressant dispersant

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：