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CONVERGENCE RATES TO TRAVELLING WAVES FOR A RELAXATION MODEL WITH LARGE INITIAL DISTURBANCE

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Acta Mathematica Scientia 2004年第2期24卷 213-227页

作者：张辉赵引川 departmentofmathematics BeijingNormalUniversityBeijing100825China

This paper is concerned with the convergence rates to travelling waves for a relaxation model with general flux functions. Compared with former results in this direction, the main novelty in this paper lies in the fact that the initial disturbance can be chosen large in suitable norm. Our analysis is based on the L^1-stability results obtained by C. Mascia and R. Natalini in [12].

关键词： Convergence rate relaxation travelling waves large initial disturbance

A SINGLE SERVER RETRIAL QUEUE WITH GENERAL RETRIAL TIMES AND TWO-PHASE SERVICE

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Journal of Systems Science & Complexity 2009年第2期22卷 291-302页

作者： Jinting WANG Jianghua LI department of mathematics Beijing Jiaotong University Beijing 100044 China. Commanding and Engineering institute of Chemical De fence Beijing 102205 China.

An M/G/1 retrial queue with a first-come-first-served (FCFS) orbit,general retrial time,two-phase service and server breakdown is investigated in this *** are allowed to balkand renege at particular *** that the customers who find the server busy are queued inthe orbit in accordance with an FCFS *** customers demand the first 'essential' service,whereas only some of them demand the second 'optional' service,and the second service is *** the service,the server is subject to breakdown and *** that the retrialtime,the service time,and the repair time of the server are all arbitrarily *** using thesupplementary variables method,the authors obtain the steady-state solutions for both queueing andreliability measures of interest.

关键词： Balking breakdowns retrial queue two-phase service.

Bers-Orlicz Spaces on the Product Riemann Surface

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Acta Mathematica Sinica,English Series 1994年第3期10卷 249-259页

作者： Ma Jigang department of Applied mathematics Chengdu University of Science and technology Chengdu,610065 china He Yuzan institute of mathematics Academia Sinica beijing,100080 china department of Applied mathematics Chengdu University of Science and Technology Chengdu China institute of mathematics Academia Sinica Beijing China

In this paper,the Bers-Orlicz spaces on the automorphic form A_α■(G)(or EA_α■(G)) and L_α■(G)(E_α■(G))on the product Riemann surfaces are *** prove that each f ∈A_α■(G) is a cusp *** f ∈A_α■(G),we give the reproducing ***,we give the projective operator P_αfrom L_α■(G) to A_α■(G)(or E_α■(G) to EA_α■(G)).After giving some fundamental properties of the Poincaréseries,we prove a dual theorem A_α■(G)=(EA_α■(G))~*.

关键词： Bers-Orlicz Spaces on the Product Riemann Surface

Non-Noether conserved quantity for differential equations of motion in the phase space

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Chinese Science Bulletin 2002年第24期47卷 2049-2050页

作者： MEI Fengxiangdepartment of Applied Mechanics, beijing institute of technology, beijing 100081, china department of Applied Mechanics Beijing Institute of Technology Beijing China

A non-Noether conserved quantity for the differential equations of motion of mechanical systems in the phase space is studied. The differential equations of motion of the systems are established and the determining equations of Lie symmetry are given. An existence theorem of non-Noether conserved quantity is obtained. An example is given to illustrate the application of the result.

关键词： mechanical system phase space non-Noether conserved quantity.

IR STUDY ON MONOMOLECULAR PARTICLE AGGLOMERATES OF POLYSTYRENE OBTAINED BY FREEZE-DRYING OF ITS DILUTE SOLUTION

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Chinese Journal of Polymer Science 2002年第4期20卷 381-383页

作者： Song Wang Qing-hua Wang Rong-shi Cheng Research Center of Materials beijing institute of technology beijing 100081, china department of Chemistry Nanjing University Nanjing 210093, china Research Center of Materials Beijing Institute of Technology 北京 100081 department of Chemistry Nanjing University Nanjing 210093

The monomolecular particle agglomerates of polystyrenes were obtained by freeze-drying of its very dilute solutions of 1.3 x 10(-5)-2.0 x 10(-5) g/mL in benzene:cylcohexane (100:1) solvents, and they were annealed at room temperature for hundred days before use. According to C-13-NMR measurement the polystyrenes should be practically atactic. The number average molecular weights of the samples are 2.80 x 10(3), 2.00 x 10(4), and 1.55 x 10(6), respectively. The freeze-dried aPS with a molecular weight higher than 10(4) show two new IR absorption bands at 1098 and 1261 cm(-1), which are absent in the normal aPS and freeze-dried styrene oligomer. It was also found that the low molecular weight samples can only form powders, whereas the freeze-dried aPS with higher molecular weight form a mixture of powders and fibrils, of which the longer fibrils show a much stronger 1261 cm(-1) band than the shorter fibrils and the powder. It seems that the 1261 cm(-1) band corresponds to the stacking behavior of monomolecular particles.

关键词： monomolecular particles atactic polystyrene FTIR spectroscopy

Void damage model and service life prediction for solid high polymer

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Chinese Science Bulletin 2001年第21期46卷 1842-1845页

作者： SHEN Tingfangdepartment of Applied Physics, beijing institute of technology, beijing 100081, china department of Applied Physics Beijing Institute of Technology Beijing China

Based on the analysis of three void damage variety models, this note presents (i) a method that regards the void content as a damage variation of the grain and (ii) a geometric model for micro-unit of void damage. Equations of the void damage variety containing void content are analyzed. This work is focused on the measurement of internal damage level and the damage variety estimation is directly related to the life predication in the practical engineering applications. Nowadays, the critical service life of the solid grain/polymers is usually presumed at domestic and international level. The strength or strain reduction of 20% or the stabilizer consumption of 50% is generally regarded as a critical storage life of the solid grain/polymers, and the service life is predicted by the extrapolation method on An-henius formula. The applications, however, show that the above method is unreliable and has significant errors. With the aid of the discontiguous automatic measuring device of real time volume

关键词： void content void damage thermal aging service life damage mechanics.

The Hausdorff Dimension of Sections

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Chinese Annals of mathematics,Series B 2007年第2期28卷 187-194页

作者： Min NIU Lifeng XI department of mathematics and Mechanics Beijing University of Science and Technology Beijing 100083China institute of mathematics Zhejimag Wanli University Ningbo 315100 Zhejiang China

The notion of finite-type open set condition is defined to calculate the Hausdorff dimensions of the sections of some self-similar sets, such as the dimension of intersection of the Koch curve and the line x=α with ... 详细信息

关键词： Hausdorff dimension Self-similar set Section Open set condition

Dynamic mechanisms of the post-seismic deformation following large events:Case study of the 1999 Chi-Chi earthquake in Taiwan of china

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Science china Earth Sciences 2009年第11期52卷 1813-1824页

作者： ZHU ShouBiao1,2 & CAI YongEn2 1 institute of Crustal Dynamics, china Earthquake Administration, beijing 100085, china 2 department of Geophysics, Peking University, beijing 100871, china institute of Crustal Dynamics China Earthquake Administration Beijing China department of Geophysics Peking University Beijing China

The mechanism of postseismic deformation related to strong earthquakes is important in geodynamics, and presumably afterslip or viscoelastic relaxation is responsible for the postsesimic deformation. The 1999 Chi-Chi, Taiwan of china, earthquake occurred in the region where GPS observation station is most densely deployed in the world. The unprecedented GPS data provides a unique opportunity to study the physical processes of postseismic deformation. Here we assume that the interactions of viscoelastic relaxation, afterslip, fault zone collapse, poroelastic rebound, flow of underground fluids, and all these combined contribute to the surface displacements following the main shock. In order to know the essence of the postseismic deformation after the strong event, fault zone collapse, poroelastic rebound, flow of underground fluids, and so on, are represented equivalently by the variations of the focal medium properties. Therefore, the viscoelastic relaxation, afterslip, and the variations of the equivalent focal medium properties are inverted by applying the GPS temporal series measurement data with viscoelastic finite element method. Both the afterslip rate distribution along the fault and the afterslip evolution with time are obtained by means of inversion. Also, the preliminary result suggests that viscosities of the lower crust and the upper mantle in Taiwan region is 2.7×1018 and 4.2×1020 Pa·s, respectively. Moreover, the inversion results indicate that the afterslip contributing to postseismic deformation of 44.6% in 450 days after the Chi-Chi earthquake, with 34.7% caused by the viscous relaxation and 20.7% by other factors such as fault zone collapse, poroelastic rebound, and the flow of liquids.

关键词： mechanism of postseismic deformation viscoelastic finite element method GPS temporal series data Chi-Chi earthquake

ON THE ESSENTIAL SPECTRUM OFPSEUDODIFFERENTIAL OPERATORS (II)

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Chinese Annals of mathematics,Series B 1994年第3期15卷 327-334页

作者： FAN QIRONG(institute & department of mathematics, beijing Unversity) beijing 100071, china.)

This paper continues the studies of the essential spectrum Of nonsemi-bounded pseudodifferential operators. The author improves the results in [5] in some sense. For the relativisticSchredinger operator, ￣ + v(x), co... 详细信息

关键词： Essential spectrum Pseudodifferelltial operator Schrsdiliger operator.