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On the variational principle for the topological pressure for certain non-compact sets

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science China Mathematics 2010年第4期53卷 1117-1128页

作者： PEI Yu 1 & CHEN ErCai 1,2,1 Department of Mathematics,nanjing Normal university,{2.097,China 2 center for nonlinear science,nanjing university,{2.093,China 1. Department of Mathematics Nanjing Normal University Nanjing 210097 China2. Center for Nonlinear Science Nanjing University Nanjing 210093 China

Let (X,d,T) be a dynamical system,where (X,d) is a compact metric space and T:X → X is a continuous *** assume that the dynamical system satisfies g-almost product property and the uniform separation *** compute the topological pressure of saturated sets under these two *** the uniform separation property does not hold,we compute the topological pressure of the set of generic *** give an application of these results to multifractal analysis and finally get a conditional variational principle.

关键词： uniform separation property g-almost product property topological pressure of non-compact sets variational principle BS-dinmension

A new heuristic algorithm for the circular packing problem with equilibrium constraints

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science China(Information sciences) 2011年第8期54卷 1572-1584页

作者： LIU JingFa 1,2,LI Gang 3 & GENG HuanTong 1 1 School of Computer and Software,nanjing university of Information science & Technology,{2.044,China 2 Network Information center,nanjing university of Information science & Technology, {2.044,China 3 School of Mathematics and Physics,nanjing university of Information science & Technology,{2.044,China 1. School of Computer and Software Nanjing University of Information Science & Technology Nanjing 210044 China2. Network Information Center Nanjing University of Information Science & Technology Nanjing 210044 China3. School of Mathematics and Physics Nanjing University of Information Science & Technology Nanjing 210044 China

The circular packing problem with equilibrium constraints is an optimization problem about simplified satellite module layout design.A heuristic algorithm based on tabu search is put forward for solving this *** algorithm begins from a random initial configuration and applies the gradient method with an adaptive step length to search for the minimum energy *** jump out of the local minima and avoid the search doing repeated work,the algorithm adopts the strategy of tabu *** the process of tabu search,we improve the traditional neighboring solutions,tabu objects and the acceptance criteria of the current solution *** test two sets of benchmarks consisting of 11 representative instances from the current *** numerical results show that the proposed algorithm breaks the records in seven out of 11 instances,and obtains the optimal solutions for the other four instances.

关键词： equilibrium constraints packing problem heuristic algorithm tabu search layout optimization

QP-FREE,TRUNCATED HYBRID METHODS FOR LARGE-SCALE nonlinear CONSTRAINED OPTIMIZATION

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Journal of Computational Mathematics 1997年第1期15卷 36-54页

作者： Q. Ni(School of science, nanjing university of Aeronautics and Astronautics, nanjing, China) 南京航空航天大学研究生院江苏南京

In this paper, a truncated hybrid method is proposed and developed for solving sparse large-scale nonlinear programming problems. In the hybrid method, a symmetric system of linear equations, instead of the usual quadratic programming subproblems, is solved at iterative process. In order to ensure the global convergence, a method of multiplier is inserted in iterative process. A truncated solution is determined for the system of linear equations and the unconstrained subproblems are solved by the limited memory BFGS algorithm such that the hybrid algorithm is suitable to the large-scale problems. The local convergence of the hybrid algorithm is proved and some numerical tests for medium-sized truss problem are given.

关键词： QP-FREE,TRUNCATED HYBRID METHODS FOR LARGE-SCALE nonlinear CONSTRAINED OPTIMIZATION II

Maschke-type theorem and Morita context over weak Hopf algebras

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science China Mathematics 2006年第5期49卷 587-598页

作者： ZHANG Liangyun College of science, nanjing Agricultural university, nanjing 2.0095, China Department of Mathematics, nanjing university, nanjing 2.0008, China 1. College of science Nanjing Agricultural University Nanjing 210095 China 2. Department of Mathematics Nanjing University Nanjing 210008 China

This paper gives a Maschke-type theorem over semisimple weak Hopf algebras,extends the well-known Maschke-type theorem given by Cohen and Fishman and constructs a Morita context over weak Hopf algebras.

关键词： weak Hopf algebra, smash product, Maschke-type theorem, Morita context.

Preparation and Characterization of Nanocomposite MgFe_2O_4/SiO_2

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Journal of Wuhan university of Technology(Materials science) 2009年第3期24卷 354-358页

作者：徐莉 College of science Nanjing Forestry University

Nanocomposites MgFe2O4/SiO2 were successfully synthesized by the sol-gel method in the presence of N, N-dimethylformamide （DMF）. The formation of pure MgFe2O4 was confirmed by powder X-ray diffraction （XRD） and electron diffraction. The structural evolution of MgFe2O4 nanocrystals was followed by powder X-ray diffraction and IR absorption spectroscopy. The formation of spinel structure of MgFe2O4 started at 800 ℃, and completed at 900 ℃, The transmission electron microscopy （TEM） measurements suggest that the particle sizes increase with the increasing annealing temperature, and the mean particle sizes of the spherical samples annealed at 800 ℃, 900 ℃ and 1 050 ℃ are ca. 3 nm, 8 nm and 11 nm, respectively. Magnetization measurements at room temperature and 78 K indicate supemaramagnetic nature of these MgFe2O4 nanocrvstals.

关键词： nanocomposite sol-gel magnesium ferrite magnetic property

Study on the thermal stability and electrical properties of the high-k dielectrics (ZrO_2) _x(SiO_2)_(1-x)

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science China(Technological sciences) 2009年第8期52卷 2222-2226页

作者： Lü ShiCheng1,2, YIN Jiang1,2, XIA YiDong2,3, GAO LiGang2,3 & LIU ZhiGuo2,3 1 Department of Physics, nanjing university, nanjing 2.0093, China 2 National Laboratory of Solid Sate Microstructures, nanjing university, nanjing 2.0093, China 3 Department of Materials science and Engineering, nanjing university, nanjing 2.0093, China 1. Department of Physics Nanjing University Nanjing 210093 China 2. National Laboratory of Solid Sate Microstructures Nanjing University Nanjing 210093 China 3. Department of Materials science and Engineering Nanjing University Nanjing 210093 China

(ZrO2)x(SiO2)1-x (Zr-Si-O) films with different compositions were deposited on p-Si(100) substrates by using pulsed laser deposition technique. X-ray photoelectron spectra (XPS) showed that these films remained amorphous after annealing at 800℃ with RTA process in N2 for 60 s. The XPS spectra indi- cated that Zr-Si-O films with x=0.5 suffered no obvious phase separation after annealing at 800℃, and no interface layer was formed between Zr-Si-O film and Si substrate. While Zr-Si-O films with x >0.5 suffered phase separation to precipitate ZrO2 after annealing under the same condition, and SiO2 was formed at the interface. To get a good interface between Zr-Si-O films and Si substrate, Zr-Si-O films with bi-layer structure (ZrO2.0.7(SiO2.0.3/(ZrO2.0.5(SiO2.0.5/Si was deposited. The electrical properties showed that the bi-layer Zr-Si-O film is of the lowest equivalent oxide thickness and good interface with Si substrate.

关键词： high-k dielectric film pulsed laser deposition pseudo ternary alloy

A Raw Signal Simulator for Bistatic SAR

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Chinese Journal of Aeronautics 2009年第4期22卷 434-443页

作者： Xia Weijie,Zhou Jianjiang College of Information science and Technology,nanjing university of Aeronautics and Astronautics,{2.016,China [a]College of Information science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

This article proposes a new efficient raw signal simulator for the bistatic synthetic aperture radar （SAR） based on 2D fast Fourier transform （FFT） to deal with cases of both ideal trajectory and trajectory deviation. It begins with analyzing the geometric configuration and the range history of the bistatic SAR in side-looking and squint modes of ideal trajectory as well as trajectory deviation. Then a detailed and mathematical study is conducted on the equivalence relation of bistatic-to-monostatic applications （BTMA） in the case of ideal trajectory and trajectory deviation. Also a set of formulas are derived for the equivalence relation between bistatic SAR and monostatic SAR on some reasonable assumptions. Therefore, the application of the simulation method based on the 2D FFT for the monostatic SAR can be extended to the case of bistatic SAR. Finally, the simulation results prove the validity of this method. By comparing the efficiency of the proposed method with that of the time domain method, it is shown that the former is a few orders of magnitude higher.

关键词： bistatic synthetic aperture radar raw signal simulation fast Fourier transform

Lie comodules and the constructions of Lie bialgebras

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science China Mathematics 2008年第6期51卷 1017-1026页

作者： ZHANG LiangYun College of science,nanjing Agricultural university,nanjing 2.0095,China College of science Nanjing Agricultural University Nanjing 210095 China

In this paper,we first give a direct sum decomposition of Lie comodules,and then accord- ing to the Lie comodule theory,construct some(triangular)Lie bialgebras through Lie coalgebras.

关键词： Lie coalgebras Lie comodules Lie bialgebras triangular Lie bialgebras 16W30

Quantitativ　estructure－activity　relationships　for　studying　alkyl（1－phenylsulfonyl）　cycloalkane－carboxylates

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Journal of Environmental sciences 1996年第2期8卷 157-166页

作者： He Yibing Wang Liansheng (Department of Environmental science and Engineering, nanjing university, {2.093, China) Department of Environmental science Nanjing University Nanjing 210093 China

Octanol/water partition coefficients,adsorption coefficients for soils and sediments and acute toxicities to Daphnia magna of 28 alkyl (1-phenylsulfonyl) cycloalkane-carboxylates were measured. These properties were correlated by linear solvation energy relationship (LSER) and chromatographic retention data determined by reverse-phase high performance liquid chromatography (RP-HPLC). The accuracy and range of applicability of these two quantitative structure-activity relationship (QSAR) methods were compared in this paper.

关键词： alkyl (1-phenylsulfonyl) cycloalkane-carboxylates LSER R-PHPLC.