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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 {2., 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 2.0 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

Multiplicity of periodic solutions to Birkhoff's billiard ball problem

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Chinese science Bulletin 1997年第5期42卷 353-355页

作者： Jl MinGraduate school, university of science and technology of china,{2., china Graduate school University of Science and Technology of Chine Beijing China

THE motion of a perfectly elastic billiard ball upon a convex billiard table is a highly typical system of dynamical systems. Let Γ be the boundary of a billiard table, strictly convex and C^1 smooth. The ball is assumed to roll on the table. It goes straight until it hits the boundary Γ where the ball bounces off according to the law that the angle of incidence is equal to the angle of reflection. Its path will be a closed n-sided polygon inscribed in Γ having no coincident sides, if and only if the motion is periodic with the positive number n as its minimal period. This is called n-bounce periodic orbit. If an n-bounce periodic orbit makes κ circuits of Γ

关键词： n-bounce stationary point periodic orbit incomplete space perimeter function.

Prescribing symmetric scalar curvature on S^2

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Chinese science Bulletin 1999年第6期44卷 514-517页

作者： Jl MinGraduate school, university of science and technology of china,{2., china Graduate school University of Science and Technology of China Bajing China

The problem of prescribing scalar curvature in S^2.is discussed, and the solvability of the equation - ΔU + 2.Re^U= 0 on S^2. is given, where R ∈ C^0 (S^2.. It is known that there are some obstructions. Some new results are given by seeking a solution of the minimax type. For example, supposing that R is G symmetric and is constant on the set of fixed points on S^2.under G ( where G is a subgroup of O (3)), it is proved that the equation is solvable if and only if R is positive somewhere.

关键词： scalar curvature critical point symmetric function minimax solution transformation group.

Theorems for Testing Local Activity of CNN and Application to Cardiac Purkinje Equations

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International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 139-146页

作者： Lequan Min(Applied science school, {2. of science and technology beijing, beijing 100083, china. Applied science school University of Science and Technology Beijing Beijing 100083 China

The theorems for testing the local in one-port cellular neural/inear network (CNN) cells with four local state variables are presented. Using the theorems computes the bifurcation diagrams of the cardiac Purkinje fiber (CPE) equations Which describethe long-lasting action and pace-maker potentials of the Purkinje fiber of the heart. The computer simulation shows that periodic trajectories or convergent trajectories of the CPF Equations can be foun if the cormsponing cell Parameters are located in a positive domainbut nearby edge of chaos. In particular a heart with approximate normal frequency of heartbeat but non-normal electrocardiogram maysuddenly stop by slightly perturbing the parameters of the corresponding CPF Equations when the Paramders are located nearby the edge of chaos in the bifurcation diagrams. This research seems to interpret reasonbly the phenomena that patients with cardiac diseases might suddenly die without warning.

关键词： cellular neural network local activity cardiac Purkinje fiber heartbeat

Applicability of mass action law to sulphur distribution between slag melts and liquid iron

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Journal of university of science and {2. beijing 2002年第2期9卷 90-98页

作者： Jian Zhang Metallurgy school, university of {2. and technology beijing, beijing 100083, china Metall. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

According to the mass action law and the coexistence theory of slagstructure, the calculating models of mass action concentration for CaO-MgO-FeO-Fe_2._3-SiO_2.CaO-MgO-MnO-FeO-Fe_2._3-P_2._5-SiO_2.and CaO-MgO-MnO-FeO-Fe_2._3-Al_2._3-P_2._5-SiO_2.slag melts areformulated and sulphur distribution between the slag melts and liquid iron is treated. It is foundthat CaO, MnO and FeO promote desulphurization, while MgO is detrimental to desulphurization. Inaddition, the sulphur distribution coefficients between the slag melts and liquid iron andpresented.

关键词： mass action law coexistence theory of slag structure activity massaction concentration

Carbon Solubility and Mass Action Concentrations of Fe-Cr-C Melts

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International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 86-91页

作者： Jtan Zhang(Metallurgy school, university of {2. and technology beijing, beijing 100083, china. Metallurgy school University of Science and Technology Beijing Beijing 100083 China

An empirical equation of carbon solubility in Fe-Cr-C melts is regressed based on the experimental data from references. Acalculating model of mass action concentrations for these melts is formulated on the basis of the coexistence theory of metaIlic melts in-volving compound formation, the phase diagram of Cr-C system as well as thermodynamic data of Fe-Cr-C melts. According to the mod-el, the standard Gibbs free energies of formation of CrC and Cr3C2.are obtained. Satisfactory agreement between the calculated and me-asured values shows that the model can reflect the structural characteristics of Fe-Cr-C melts.

关键词： activity, coexistence theory mass action concentration saturated state

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 {2. beijing 2003年第1期10卷 18-20页

作者： Jian ZhangMetallurgy school, university of {2. and technology beijing, beijing 100083, china Metall. Sch. Univ. of Sci. and Technol. 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

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 {2. 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

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 {2. 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