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Development of miniature HTSC microwave bandpass filter with multi-zigzag line structure

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Chinese science Bulletin 2003年第8期48卷 736-738页

作者： YANG Kai, BU Shirong, ZHANG Qishao & LI Hongfu College of electronics Engineering, university of electronic science & technology of china,{6., china Correspondence should be addressed to Yang Kai (e-mail: kyang@uestc. ***) College of electronics Engineering University of Electronic Science and Technology of China Chengdu 610054 China

On YBCO/LaAlO3/YBCO substrate with the dimension of 10 mm 20 mm, a miniature HTSC (high tem- perature superconductivity) bandpass filter with multi-zig- zag line structure is developed. At 77 K, the center frequency i... 详细信息

关键词：微波带通滤波器多锯齿形线结构 HTSC薄膜

Application of annexation principle to the study of thermodynamic properties of Ag-Bi-In metallic melts

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Journal of university of science and technology Beijing 2003年第1期10卷 18-20页

作者： Jian ZhangMetallurgy school, university of science and technology Beijing, Beijing 100083, china Metallurgy school University of Science and Technology Beijing Beijing 100083 China

Based on the measured activities, the phase diagrams and the annexation principle, the calculating models of mass action concentrations for Ag-Bi and Ag-Bi-In melts have been formulated. The calculated results agree with practice and obey the mass action law, showing that the models formulated can reflect the structural characteristics of both melts. Meanwhile, it confirms that annexation principle is applicable to the Ag-Bi-In metallic melts. The melts involving eulectic which give rise to phase separation, and in which activities exhibit positive deviation from Raoult's law is the basic cause of melts transforming from homogeneous to heterogeneous ones.

关键词： the mass action law annexation principle two phase melts activity, mass action concentration

A Modified Root-MUSIC Algorithm for Signal DOA Estimation

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Journal of Systems Engineering and electronics 1999年第4期10卷 42-47页

作者： He Zishu Li Yong & Xiang Jingcheng(Institute of electronic Engineering, university of electronic science & technology,chengdu {6., P. R. china) Institute of electronic Engineering University of Electronic Science & Technology Chengdu 610054 P. R. China

This paper presents a modified Root-MUSIC algorithm by which the signal DOA estimation performance can be improved when the snapshot number is limited. The operation principlesof this algorithm are described in detail. It is also pointed out theoretically that this is equivalentto have increased the snapshot number and can make the DOA estimation better. Finally, somesimulating results to verify the theoretical analyses are presented.

关键词： Array signal processing Root-MUSIC algorithm Signal DOA estimation Eigendecomposition

Calculating model of mass action concentrations for Ag-Au-Cu melts

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Rare Metals 2002年第1期21卷 43-47页

作者： ZHANG Jian Metallurgy School, university of science and technology Beijing, Beijing 100083, china Metallurgy School University of Science and Technology Beijing 北京 100083

Based on phase diagrams and measured activities, the calculatingmodel of mass action concentrations for het- erogeneous meltsAg-Au-Cu was formulated. Calculated results agree with the improvedresults of recent research work, Showing that the model formulatedcan reflect the structural characteristics of these melts. In thismodel, without the help Of any empirical parameters, only threeequilibrium constants are used, hence it is simple, lear, andfavorable to the sim- Plification of calculation.

关键词： activity mass action concentration eutectic Solid solution

Investigation of Elliptical Gaussian Beam in Optical Disk System

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Chinese Journal of Lasers 1996年第1期B5卷 87-93页

作者： LUO Yong GAO Zhenping CHENG Xiaohong(UEST of china, chengdu 610054, china) Univ of electronic science and Technology of China Chengdu China

It introduces a magneto-optical head that the elliptical scanning beam spot is used. The influence of Gaussian beam on intensity distribution of the scanning beam spot is discussed. Our optical analyizing software is used to show the tridimensional (3D) beam pro file on the focal plane and to calculate the central peak intensity and width of the spot. High intensity and high quality scanning beam spot is obtained.

关键词： optical disk system scanning beam spot Gaussian beam

Application of the annexation principle to the study of thermodynamic properties of ternary metallic melts In-Pb-Ag and In-Bi-Sb

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Rare Metals 2002年第2期21卷 142-151页

作者： ZHANG JianMetallurgical Engineering school.university of science and technology Beijing, Beijing 100083, china Metallurgical Engineering School University of Science and Technology Beijing 北京 100083

Based on the phase diagrams, measured activities an the annexationprinciple, the calculating models of mass action concentrations forin-Pb-Ag and In-Bi-Sb ternary metallic melts have been *** results of calculation both agree with practice, and obey the lawof mass action, showing that the models formulated can reflect thestructural reality of the corresponding melts and the annexationprinciple is applicable to the them.

关键词： activity mass action concnetration th annexation principle In-PB-Ag

Distribution of Nb atom in the TiAl+Nb system

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Rare Metals 2001年第1期20卷 5-12页

作者： Xiaodong Ni, Xidong Hui, Guoliang Chen (Applied science School, university of science and technology Beijing, Beijing 100083, china State Key Laboratory for Advanced Metals and Materials, university of science and technology Beijing, china) Appl. Sci. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Based on MEAM (the modified embedded atom method) potential and an average atom model similar to B-W (Bragg-Williams) method, the distribution of Nb atoms in TiAl+Nb compounds with various composition was calculated. The calculation results showed that Nb atoms prefer to occupy the Ti sublattice of L10 structure for all compounds in question. With increasing atomic fraction of Nb and Al, Nb atoms exhibited a trend of ordered distribution on the Ti sublattice and result in a new L10 derivative superlattice structure.

关键词： Computer simulation Intermetallics Superlattices Ternary systems

Fractal Structure of the Core Loss Spectrum of Co-based Amorphous Soft Magnetic Alloy with Constant Permeability

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 54-56页

作者： Yiping Chen (Applied science School, university of science and technology Beijing, Beijing 100083, china) Applied science School University of Science and Technology Beijing Beijing 100083 China

In order to check the traditional core loss formula, the core loss spectrum P(f) of Co-based amorphous soft magnetic alloy with constant permeability has been studied. It is found that within a high frequency range from 10 kHz to 200 kHz and at Bm = 0. 1 T,the P(f) has the fractal structure P (f) = Po, and with the increasing of induced anisotropy energy Ku, the fractal dimension Dfrises, thus the total power loss at high frequency increases and the frequency characteristic of P(f) becomes worse.

关键词： amorphous soft magnetic alloy constant permeability core loss fractal

AN EFFICIENT IMPLEMENTATION ARCHITECTURE FOR WIDE-BAND DIGITAL DOWNCONVERSION

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Journal of electronics(china) 2001年第1期18卷 38-45页

作者： Gao Zhicheng Xiao Xianci (university of electronic science and technology of china, chengdu 610054) university of electronic science and technology of china Chengdu 610054

The wide-band digital receiving systems require digital downconversion(DDC) with high data rate and short tuning time in order to intercept the narrow-band signals within broad tuning bandwidth. But these requirements can not be met by the commercial DDC. In this paper an efficient implementation architecture is presented. It combines the flexibility of DFT tuning with the efficiency of the polyphase filter bank decomposition. By first decimating the data prior to filtering and mixing, this architecture gives a better solution to the mismatch between the lower hardware speed and high data rate. The computer simulations show the feasibility of this processing architecture.

关键词： Digital downconversion Wide-band digital receiving Polyphase filter