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On critical values concerning the evolution of the long period families

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Chinese Journal of Astronomy and Astrophysics 2009年第4期9卷 494-500页

作者： Xi-Yun Hou1,2. Astronomy department, nanjing {2., nanjing 2.0093, china 2.Institute of Space Environment and Astronautics, nanjing {2., nanjing 2.0093, china Astronomy department Nanjing University Nanjing 210093 China Institute of Space Environment and Astronautics Nanjing University Nanjing 210093 China

In a previous paper, we proposed another special critical value concerning the evolution of the long period family around the equilateral equilibrium points, besides the two values given by Henrard. Are there any other special critical values？ After studying the stability curves of the long period family carefully, we gave a negative answer. During the study, we found an interesting family of periodic orbits which we called the homo family. We studied the evolution of this family following the increase of μ. With these findings, we were able to explain the origin of the four branches of periodic families emanating from L4 and the stability results of the equilateral equilibrium points.

关键词： celestial mechanics

An Object Extraction Model Using Association Rules and Dependence Analysis

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Wuhan university Journal of Natural sciences 2001年第Z1期6卷 405-409页

作者： Li Shen zhi 1, Chen Zhen qiang 1, Zhou Yu ming 1,Xu Bao wen 1,2.1. department of computer {2. and engineering, southeast university, nanjing 2.0096,china 2. State Key Laboratory of Software engineering, Wuhan university, Wuhan 430072.Ch department of computer {2. and engineering Southeast University Nanjing China State Key Laboratory of Software engineering Wuhan University Wuhan China

Extracting objects from legacy systems is a basic step in system's object orientation to improve the maintainability and understandability of the systems. A new object extraction model using association rules and dependence analysis is proposed. In this model data are classified by association rules and the corresponding operations are partitioned by dependence analysis.

关键词： reverse engineering data mining association rules dependence analysis program slicing

Performance Modeling and Approximate Analysis of Multiserver Multiqueue Systems with Poisson and Self-similar Arrivals

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Journal of university of science and Technology Beijing 2001年第2期8卷 145-151页

作者： Zhiguang Shan, Chuang Lin, Yang Yang, Yan Wang (Information engineering School, university of {2. and Technology Beijing, Beijing 100083, china) (department of computer {2. and Technology, Tsinghua university, Beijing 100084, china) Information engineering School University of Science and Technology Beijing 100083 China

The problem of state space explosion is still ran outstanding challenge in Markovian performance analysis for multiserver multiqueue (MSMQ) systems. The system behavior of a MSMQ system is described using stochastic high-level Petri net (SHLPN) models, and an approximate performance analysis technique is proposed based on decomposition and refinement methods as well as iteration technique. A real MSMQ system, Web-server cluster, is investigated. The performance of an integrated scheme of request dispatching and scheduling is analyzed with both Poisson and self-similar request arrivals. The study shows that the approximate analysis technique significantly reduces the complexity of the model solution and is also efficient for accuracy of numerical results.

关键词： multiserver multiqueue (MSMQ) system Web-server cluster performance analysis stochastic high-level Petri net (SHLPN) request dispatching request scheduling

Lipschitz classes on local fields

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science china Mathematics 2007年第7期50卷 1005-1014页

作者： Wei-yi SU~(1+) Guo-xiang CHEN~2.1 department of Mathematics,nanjing {2.,nanjing 2.0093,china 2.department of Mathematics,nanjing Audit {2.,nanjing 2.1815,china department of Mathematics Nanjing University Nanjing China department of Mathematics Nanjing Audit University Nanjing China

The Lipschitz class Lipαon a local field K is defined in this note,and the equivalent relationship between the Lipschitz class Lipαand the Holder type space C~α(K)is ***,those important characteristics on the Euclidean space R^n and the local field K are compared,so that one may interpret the essential differences between the analyses on R^n and ***,the Cantor type fractal functionθ(x)is showed in the Lipschitz class Lip(m,K),m＜(ln 2.ln 3).

关键词： local field Holder type space Lipschitz class Cantor type fractal function 11F85 46F05 43A2. 2.A80 2.A78

Single and Multiple Dynamic Impacts Behaviour of Ultra-high Performance Cementitious Composite

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Journal of Wuhan university of Technology(Materials science) 2011年第6期26卷 1227-1234页

作者：张文华张云升 department of Materials science and {2. Jiangsu Key Laboratory of Construction MaterialsSoutheast University

Single and multiple dynamic impacts tests were conducted on ultra-high performance cementitious composite （UHPCC） with various volume fractions of steel fibers （0, 1%, 2., 3%, 4%） by using the split hopkinson pressure bar （SHPB）. Besides, the ultrasonic velocity method was used to test the damage on specimens caused by dynamic impacts. For single dynamic impact, the data suggest that UHPCC obviously presents dynamic strength enhancement. With increasing of strain rate, the peak stress and peak strain increase rapidly. For multiple dynamic impacts, the results show that addition of steel fibers can obviously enhance the properties of UHPCC to resist the repeated dynamic impacts. Firstly, the number of impacts sharply increases with the increasing of volume fraction of steel fibers. Secondly, the energy absorption ability linearly increases with addition of steel fibers. Thirdly, the steel fibers can prevent the disruption phenomenon and maintain the integrity of specimen.

关键词： UHPCC SHPB dynamic behavior multiple impacts

Complete quantum circuit of Haar wavelet based MRA

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Chinese science Bulletin 2005年第16期50卷 1796-1798页

作者： HE Yuguo1,2.& SUN Jigui1,3 1. College of computer science and Technology, Jilin {2., Changchun 130012. china 2. department of computer science and engineering, Beijing Institute of Technology, Beijing 100081, china 3. Key Laboratory of Computation and Knowledge engineering of Min-istry of Education, Jilin {2., Changchun 130012. china College of computer science and Technology Jilin University Changchun China department of computer {2. and engineering Beijing Institute of Technology Beijing China Key Laboratory of Computation and Knowledge engineering of Ministry of Education Jilin University Changchun China

Wavelet analysis has applications in many ar- eas, such as signal analysis and image processing. We pro- pose a method for generating the complete circuit of Haar wavelet based MRA by factoring butterfly matrices and con- ditional perfect shuffle permutation matrices. The factoriza- tion of butterfly matrices is the essential part of the design. As a result, it is the key point to obtain the circuits of I 2. ⊕ W ⊕ I 2. ? 2. ?2. In this paper, we use a simple means to de- velop quantum circuits for this kind of matrices. Similarly, the conditional permutation matrix is implemented entirely, combined with the scheme of Fijany and Williams. The cir- cuits and the ideas adopted in the design are simple and in- telligible.

关键词：量子计算量子算法量子电路 Haar微波 MRA

A note on the crossed product R(A, α) associated with PSL_2.R)

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science china Mathematics 2008年第11期51卷 2081-2088页

作者： WU WenMing 1 School of Mathematical and computer science, Chongqing Normal {2., Chongqing 400047, china 2.department of Mathematical science, Tsinghua {2., Beijing 100084, china School of Mathematical and computer science Chongqing Normal University Chongqing China department of Mathematical science Tsinghua University Beijing China

Given the hyperbolic measure dxdy/y2.on the upper half plane H, the rational actions of PSL2.R) on H induces a continuous unitary representation α of this group on the Hilbert space L2.H, dxdy/y2.. Supposing that A = {Mf : f ∈ L∞(H, dxdy/y2.}, we show that the crossed product R(A,α) is of type I. In fact, the crossed product R(A,α) is *-isomorphic to the von Neumann algebra B(L2.P,ν))■LK, where LK is the abelian group von Neumann algebra generated by the left regular representation of K.

关键词： crossed product rational actions PSL2.R) von Neumann algebras

REACTION MECHANISM OF BENZOPHENONE-PHOTOINITIATED CROSSLINKING OF POLYETHYLENE

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Chinese Journal of Polymer science 2002年第4期20卷 291-307页

作者： Bao-jun Qu State Key Laboratory of Fire science and department of Polymer science and engineering university of science and Technology of china Hefei 2.002. china university of science and Technology of{2. State Key Laboratory of Fire Science and Department of Polymer Science and Engineering Hefei 230026

The radical intermediates, the crosslink microstructures, and the reaction mechanism of benzophenone (BP)-photoinitiated crosslinking of low-density polyethylene (LDPE) and model compounds (MD) have been reviewed in detail. The spin-trapping electron spin resonance (ESR) spectra obtained from the LDPE/BP systems with spin-trap agents show that two kinds of polymer radical intermediates are mainly formed: tertiary carbon and secondary carbon radicals. The spin-trapping ESR studies of MD/BP systems give further evidence that photocrosslinking reactions of PE predominantly take place a sites of tertiary carbon, secondary carbon, and especially allylic carbon when available. The high resolution C-13-NMR spectra obtained from LDPE and MD systems show that the crosslink microstructures have H- and Y-type links and that their concentrations are of the same order. The fluorescence, ESR, C-13 and H-1-NMR spectra from the PE and MD systems demonstrate that the main photoreduction product of BP (PPB) is benzpinacol formed by the recombination of two diphenylhydroxymethyl (K-.) radical intermediates. Two new PPB products: an isomer of benzpinacol with quinoid structure, 1-phenylhydroxymethylene-4-diphenylhydroxymethyl-2.5-cyclobexadiene and three kinds of alpha-alkyl-benzhydrols have been detected and identified. These results provide new experimental evidence for elucidating the reaction mechanism in the BP-photoinitiated crosslinking of polyethylene.

关键词： photocrosslinking mechanism polymer radical intermediates crosslink microstructures photolytic products of benzophenone polyethylene model compound

MICROSTRUCTURES AND OXIDATION RESISTANCE OF Fe_3Al WELD OVERLAY

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Acta Metallurgica Sinica(English Letters) 2001年第4期14卷 253-256页

作者： X.G. Mi X.Q. Yu, Y.S. Sun and J.R. Sun department of Materials science and {2., southeast university, nanjing 2.0096, china Dept. of Mat. Sci. Southeast Univ. Nanjing 210096 China

Using the Fe3Al electrode through manual arc surfacing (MAS), Fe3Al coatings were deposited on the stainless steel substrate. The microstructures, hardness and oxidation resistance of the weld overlay were investigated. The results show that crack-free overlays can be obtained when pre-heating the substrate at 500°C and postweld heat treatment at 700°C are used. Elements of Al, Cr and Ni, etc. transfer between the substrate and the overlay, but this does not influence the microhardness of the substrate and the Fe3Al overlay. Oxidation tests show that the Fe3Al overlay has excellent oxidation resistance in comparison with the stainless steel substrate at 800°C and 900°C.

关键词： Aluminum Intermetallics Iron Microstructure Oxidation resistance