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Bifurcations of travelling wave solutions for two generalized Boussinesq systems

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science china Mathematics 2008年第9期51卷 1577-1592页

作者： LI JiBin1,2 1 Department of Mathematics, Zhejiang normal university, Jinhua 321004, china 2 Department of Mathematics, Kunming university of science and technology, Kunming 650093, china Department of Mathematics Zhejiang Normal University Jinhua China Department of Mathematics Kunming University of Science and Technology Kunming China

Using the methods of dynamical systems for two generalized Boussinesq systems, the existence of all possible solitary wave solutions and many uncountably infinite periodic wave solutions is obtained. Exact explicit parametric representations of the travelling solutions are given. To guarantee the existence of the above solutions, all parameter conditions are determined.

关键词： nonlinear wave bifurcation solitary wave exact explicit solution generalized Boussinesq system 34C37 34C23 74J30 58Z05

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,Nanjing 210016,china 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

Microstructure and formation mechanism of twins of laths of austenite with high nitrogen

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science china(Technological sciences) 2007年第6期50卷 755-764页

作者： WU CuiLan1,2 & LUO ChengPing2 1 Center for High Resolution Electron Microscopy, college of Materials science and Engineering, Hunan university, Changsha 410082, china 2 college of Mechanical Engineering, South china university of technology, Guangzhou 510641, china Center for High Resolution Electron Microscopy College of Materials Science and Engineering Hunan University Changsha China college of Mechanical Engineering South China University of Technology Guangzhou China

The microstructure of composite diffusion layer of the nitrided and chromized 0.2% carbon steel is investigated using TEM and EDS. It is found that laths of austenite with high nitrogen (γ N) precipitate from α-ferrite matrix in the deeper zone of the diffusion layer. These γ N laths are all twins, with their {111} twinning planes parallel to the lath axis, thus forming a characteristic "back-to-back" morphology. There are two types of γN lath. The first is a genuinely {111} twin, and γ N and α keep the accurate K-S relationship, and each γ N and α form a sharp and smooth γ N/α inter- face of {335}γN//{341}α, namely habit plane {335}fcc. The second is a pseudo-twin, with micro-twins {111} or faults formed within the two twin components. Localized lattice deformation (relaxation) seems to have occurred at the interfaces of the second type of γ N due to the formation of micro-twins or faults within the twin components. These micro-twins or faults make the orientation relationship (OR) between each of the γN and the α-matrix deviate from the accurate K-S OR, and the OR between two γ N twin components deviate from the genuine {111} twin relation- ship. In addition, the γ N/α interface of the second type of γ N is not as sharp or smooth as that of the first one.

关键词： austenite containing nitrogen, twins, steel 20, nitriding, composite chromizing

Cross-linked Polyethylenimine as Potential DNA Vector for Gene Delivery with High Efficiency and Low Cytotoxicity

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Acta Biochimica et Biophysica Sinica 2006年第11期38卷 780-787页

作者： Wei DONG~(1,2) Guang-Hui JIN~1 Shu-Feng LI~(1,3) Qi-Ming SUN~1 Ding-Yuan MA~1 Zi-Chun HUA~1 1 State Key Laboratory of Pharmaceutical Biotechnology,college of Life science,Nanjing university,Nanjing 210093,china 2 School of Chemical Engineering Nanjing university of science and technology,Nanjing 210094,china 3 college of Basic Medical science,Southeast university,Nanjing 210009,china State Key Laboratory of Pharmaceutical Biotechnology College of Life Science Nanjing UniversityNanjing 210093 China School of Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094 China college of Basic Medical science Southeast UniversityNanjing 210009 China

Polyethylenimine (PEI) has been known as an efficient gene carrier with the highest cationiccharge *** transfection efficiency of PEI,along with its cytotoxicity,strongly depends on itsmolecular *** enhance its gene delivery efficiency and minimize cytotoxicity,we have synthesizedsmall cross-linked PEI with biodegradable linkages and evaluated their transfection efficiencies in *** study,branched PEI with a molecular weight of 800 Da was cross-linked by small diacrylate[1,4-butanediol diacrylate or ethyleneglycol dimethacrylate (EGDMA)] for 2-6 *** efficiencies of thecross-linked PEI in in vitro transfection of plasmid DNA containing enhanced green fluorescent protein(EGFP) reporter gene were assessed in melanoma B 16F10 cell line and other cell *** cytometrywas used to quantify the cellular entry efficiency of plasmid and the transgene expression *** of the cross-linked PEI in these cells were evaluated by MTT ***-PEI 800-4h,atypical cross-linked PEI reported here,mediated a more efficient expression of reporter gene than thecommercially available 25-kDa branched PEI control,and resulted in a 9-fold increase in gene deliveryin B16F10 cells and a 16-fold increase in 293T cells,while no cytotoxicity was found at the optimizedcondition for gene ***,the transfection activity of polyplexes was preserved in thepresence of serum proteins.

关键词： polyethylenimine gene delivery cytotoxicity B16F10 293T cell line

Density functional theory study of the magnetic properties of rare earth complexes:the magnetic coupling mechanism in Y~Ⅲ and Gd~Ⅲ complexes with nitronyl nitroxide

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science china Chemistry 2009年第11期52卷 1961-1968页

作者： REN Jie1,2,WANG BingWu1 & CHEN ZhiDa1 1 Beijing National Laboratory for Molecular sciences,State Key Laboratory of Rare Earth Materials Chemistry and Applications,college of Chemistry and Molecular Engineering,Peking university,Beijing 100871,china 2 college of science,Hebei university of science and technology,Shijiazhuang 050018,china Beijing National Laboratory for Molecular sciences State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing China college of science Hebei University of Science and Technology Shijiazhuang China

The magnetic coupling interactions of the nitronyl nitroxide radicals bound to diamagnetic(YⅢ) and paramagnetic(GdⅢ) rare earth ions in two model magnetic systems based on novel rare earth organic radical complexes Ln(hfac)3(NITPhOCH3)2(Ln=YⅢ 1,GdⅢ 2;hafc = hexafluoroacetylacetonate;NIT-PhOCH3 = 4'-methoxyo-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been investigated by density functional theory(DFT).The magnetic coupling mechanisms were also explored from the viewpoint of molecular orbital and spin density *** calculations show that the empty 4d-orbitals of YⅢ and 5d-orbitals of GdⅢ play an important role in the antiferromagnetic coupling between the two nitronyl nitroxide radical ligands,and that the ferromagnetic coupling between the GdⅢ ion and the radical magnetic centers can be attributed to the nearly complete localization of the isotropic 4f-shell and singly occupied magnetic orbital(π) of the nitronyl nitroxide.

关键词： magnetic coupling density functional theory rare earth ion gadolinium(Ⅲ) complexes yttrium(Ⅲ) complexes

Luminosity-peak energy relation in the decay phases of gamma-ray burst pulses

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science china(Physics,Mechanics & Astronomy) 2010年第1期53卷 163-170页

作者： LU RuiJing & LIANG EnWei Physical science & technology college, Guangxi university, Nanning 530004, china Physical science & technology college Guangxi University Nanning China

Using time-resolved spectral data for a sample of 30 pulses in 27 bright GRBs detected with CGRO/BATSE, we investigate the luminosity-peak energy relation (L-E p relation) in the decay phases of these pulses. A tight L-E p relation is found for most of the pulses, but its power law index is various among pulses, which is normally distributed at 1.84±0.60(1σ) for the pulses in our sample, roughly consistent with the L-E p relation within a GRB and the isotropic gamma-ray energy-E p relation among GRBs. The large scatter of the power law index cannot be explained with both the statistical or observational effects and it may be an intrinsic feature, indicating that no universal L-E p relation would be expected among GRBs/pulses. This may strongly weaken the cosmological use of this relation.

关键词： gamma ray bursts observations statistical luminosity-peak energy relation

Synthesis and characterization of a strong-fluorescent Eu-containing hydrotalcite-like compound

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science china Chemistry 2010年第6期53卷 1273-1280页

作者： CHEN Hong & ZHANG WenGong Institute of Polymer science,college of Chemistry and Materials science,Fujian normal university,Fuzhou 350007,china Institute of Polymer science College of Chemistry and Materials Science Fujian Normal University Fuzhou China

A novel strong-fluorescent Eu-containing hydrotalcite-like compound (Eu-HTlc) was synthesized using the coprecipitation method,in which aluminum(III) was partially substituted by Europium (III) in the hydrotalcite-like layers,and thenoyltrifluoroacetone,1,10-phenanthroline were dispersed into the anions in the interlayer *** sample was characterized by XRD,XPS,FT-IR,ICP,TG-DSC,TEM and fluorescence spectra,and its composition and structure were *** results indicated that the sample exhibited a characteristic red light (614 nm).The fluorescent lifetime and fluorescence quantum yield of Eu-HTlc were measured to be respectively 893 -s and 66.44%,higher than those of Eu(III)-thenoyltrifluoroacetone1,10-phenanthroline complex [Eu(TTA)3phen].The result of TG-DSC measurement showed the enhanced thermal stability of Eu-HTlc compared with that of MgAl-LDHs and Eu(TTA)*** excellent photoluminescent property and thermal stability,low contents of rare earth ions and ligands,the Eu-HTlc may become one of the novel fluorescent materials with potential applications.

关键词： hydrotalcite-like compound Europium fluorescence intercalation supramolecule

Interactive group decision making procedure based on uncertain multiplicative linguistic preference relations

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Journal of Systems Engineering and Electronics 2010年第3期21卷 408-415页

作者： Zeshui Xu1,2,1.college of Economics and Management,Southeast university,Nanjing 210096,P.R.china 2.Institute of sciences,university of science and technology of the PLA,Nanjing 210007,P.R.china college of Economics and Management Southeast University Nanjing 210096 P. R. China Institute of sciences University of Science and Technology of the PLA Nanjing 210007 P. R. China

Group decision making problems are investigated with uncertain multiplicative linguistic preference *** unbalanced multiplicative linguistic label set is introduced,which can be used by the experts to express their linguistic preference information over *** uncertain linguistic weighted geometric mean operator is utilized to aggregate all the individual uncertain multiplicative linguistic preference relations into a collective one,and then a simple approach is developed to determine the experts＇ weights by utilizing the consensus degrees among the individual uncertain multiplicative linguistic preference relations and the collective uncertain multiplicative linguistic preference ***,a practical interactive procedure for group decision making is proposed based on uncertain multiplicative linguistic preference relations,in which a possibility degree formula and a complementary matrix are used to rank the given ***,the proposed procedure is applied to solve the group decision making problem of a manufacturing company searching the best global supplier for one of its most critical parts used in assembling process.

关键词： group decision making uncertain multiplicative linguistic preference relations unbalanced multiplicative linguistic label set consensus degree interaction.

Kinetics analysis of volume phase transition of intelligent neutral thermo-sensitive hydrogels

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science china(Physics,Mechanics & Astronomy) 2008年第5期51卷 532-540页

作者： WANG XiaoGui1 & LI YiQuan2 1 college of Mechanical Engineering,Zhejiang university of technology,Hangzhou 310032,china 2 School of Mechanical & Electronic Engineering,Changchun university of science and technology,Changchun 130022,china college of Mechanical Engineering Zhejiang University of Technology Hangzhou China School of Mechanical & Electronic Engineering Changchun University of Science and Technology Changchun China

In this work,utilizing the first law of thermodynamics and the Flory mean-field theory,the kinetic deformation studies concerning the volume phase transition of the neutral thermo-sensitive hydrogels were performed *** hydrogel was assumed as a biphasic mixture medium in the framework of the continuum mixture *** the energy conservation of the thermodynamics system of the hydrogel,the governing equations for the kinetics of the nonlinear large deforma-tion were *** explicit analytical expressions of the effective stress tensor and the chemical potential of the fluid of the thermo-sensitive hydrogel PNIPA were also obtained from the Helmholtz free energy,which can model the steady-static volume phase transition quantitatively.

关键词： thermo-sensitive hydrogel volume phase transition effective stress energy conservation