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Aerodynamic/Stealthy/Structural Multidisciplinary Design Optimization of Unmanned Combat Air Vehicle

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Chinese Journal of Aeronautics 2009年第4期22卷 380-386页

作者： Hu Tianyuan,Yu Xiongqing Key Laboratory of Fundamental science for National Defense-Advanced Design technology of Flight Vehicle,nanjing university of Aeronautics and Astronautics,nanjing 210016,china [a]Key Laboratory of Fundamental science for National Defense-Advanced Design technology of Flight Vehicle Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

An optimization strategy is proposed to deal with the aerodynamic/stealthy/structural multidisciplinary design optimization （MDO） issue of unmanned combat air vehicle （UCAV）. In applying the strategy, the MDO process is divided into two levels, i.e. system level optimization and subsystem level optimization. The system level optimization is to achieve optimized system objective （or multi-objective） through the adjustment of global external configuration design variables. The subsystem level optimization consists of the aerodynamic/stealthy integrated design and the structural optimization. The aerodynamic/stealthy integrated design aims at achieving the minimum aerodynamic drag coefficient under the constraint of stealthy requirement through the adjustment of local external configuration design variables. The structural optimization is to minimize the structural weight by adjusting the dimefisions of structural components. A flowchart to implement this strategy is presented. The MDO for a flying-wing configuration of UCAV is employed to illustrate the detailed process of the optimization. The results indicate that the overall process of the surrogate-based two-level optimization strategy can be implemented automatically, and quite reasonable results are obtained.

关键词： aircraft design multidisciplinary design optimization aerodynamics radar cross section structure

Birkhoff's theorem and viscosity solutions of Hamilton-Jacobi equations

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science china Mathematics 2009年第8期52卷 1796-1800页

作者： CHENG Wei department of Mathematics, nanjing university, nanjing 210093, china department of Mathematics Nanjing University Nanjing 210093 China

We obtain a partial generalization of Birkhoff's theorem of invariant curve to higher dimesional case in the context of viscosity solutions of Hamilton-Jacobi equations, or weak KAM theory. This is a new approach afte... 详细信息

关键词： Hamilton-Jacobi equation viscosity solution semiconcave function

Nonlinear boundary value problems for discontinuous delayed differential equations

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Applied Mathematics(A Journal of Chinese Universities) 2010年第1期25卷 9-17页

作者： SUN Wu-jun department of Finance & Insurance, Business School of nanjing university, nanjing 210093, china department of Finance and Insurance Business School of Nanjing University Nanjing China

In this paper nonlinear boundary value problems for discontinuous delayed differen- tial equations are considered. Some existence and boundedness results of solutions are obtained via the method of upper and lower solutions, which may be discontinuous. Our analysis can be applied to those phenomena from physics and control theory which have been successfully described by delayed differential equations with discontinuous functions, such as electric, pneu- matic, and hydraulic networks. It is also an important step to precede the design of control signals when finite-time or practical stability control are concerned.

关键词： Nonlinear boundary value problems upper and lower solutions discontinuous delayed differentialequations Carath^odory conditions existence of solutions.

Polyurethane Grafted Attapulgite as Novel Fillers for Nylon 6 Nanocomposites

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Journal of Wuhan university of technology(Materials science) 2011年第4期26卷 615-619页

作者：史建设杨绪杰 Key Laboratory for Soft chemistry and Functional Material of the Ministry Education Nanjing University of Science and Technology

Attapulgite fibers were modified by polyurethane, forming polyurethane grafted attapulgite （AT-PU）, which was confirmed by Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）. Nylon 6/AT-PU nanocomposites of different modified attapulgite loadings were prepared by melt blending in a twin screw extruder. Scanning electron microscopy （SEM） observation on the fracture surfaces of the nanocomposites showed not only a uniform dispersion of AT-PU but also a strong interfacial adhesion with the matrix. Differential scanning calorimeter （DSC） and Thermogravimetric analyzer （TGA） were used to illustrate the infiuence of AT-PU particles on the thermal properties of the nylon 6/AT-PU nanocomposites. The results indicated that the addition of attapulgite probably induced the heterogeneous nucleation and was favorable for the formation of γ -crystalline form, and that the higher thermal stability was obtained for the composites.

关键词： polyurethane grafted attapulgite nylon 6 nanocomposites

Gonadectomy affects brain derived neurotrophic factor in rats after chronic constriction nerve injury

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Acta Pharmacologica Sinica 2004年第3期25卷 32-38页

作者： Xin ZHAO,Xin WANG,Shu-yun ZHENG,Jian-guo XU1 School of Life science,nanjing university,nanjing 210093 department of Anesthesiology,Jinling Hospital,nanjing 210002,china School of Life science Nanjing University Nanjing 210093

AIM: To assess the effect of gonadectomy on brain derived neurotrophic factor (BDNF) expression in neuropathic pain. METHODS: Using chronic constriction injury (CCI) model, we detected BDNF mRNA in dorsal root gan- glion and protein content in spinal cord by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay respectively. The time point we chose was post CCI operation d 0, 3, 7, 14, and 21. RESULTS: After CCI surgery, BDNF mRNA in ipsilateral DRGs was upregulated and reached its maximum on post operation d 7. BDNF protein level in ipsilateral spinal cord was also increased and reached its maximum on post operation d 14. The magnitude of this increase in gonadectomy (GDX) rats was significantly smaller than the GDX-sham rats at each time point. CONCLUSION: Gonadectomy reduced the BDNF increment after CCI surgery. Estrogen may affect nociceptive processing by its effect on BDNF.

关键词： gonadectomy estrogens brain-derived neurotrophic factor gene expression regulation pain chronic constriction injury

Convergence of the Vlasov-Poisson-Fokker-Planck system to the incompressible Euler equations

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science china Mathematics 2006年第2期49卷 255-266页

作者： XIAO Ling, LI Fucai & WANG Shu Academy of Mathematics and Systems science, Chinese Academy of sciences, Beijing 100080, china department of Mathematics, nanjing university, nanjing 210093, china College of Applied sciences, Beijing university of technology, Beijing 100022, china 1. Academy of Mathematics and Systems science Chinese Academy of Sciences Beijing 100080 China 2. department of Mathematics Nanjing University Nanjing 210093 China 3. College of Applied sciences Beijing University of Technology Beijing 100022 China

We establish the convergence of the Vlasov-Poisson-Fokker-Planck system to the incompressible Euler equations in this paper. The convergence is rigorously proved on the time interval where the smooth solution to the incompressible Euler equations exists. The proof relies on the compactness argument and the so-called relative-entropy method.

关键词： Vlasov-Poisson-Fokker-Planck system incompressible Euler equations relative-entropy method.

A relative local variational principle for topological pressure

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science china Mathematics 2010年第6期53卷 1491-1506页

作者： MA XianFeng1,CHEN ErCai2,3,& ZHANG AiHua2,4 1department of Mathematics,East china university of science and technology,Shanghai 200237,china 2School of Mathematics and Computer science,nanjing Normal university,nanjing 210097,china 3Center of Nonlinear science,nanjing university,nanjing 210093,china 4College of Mathematics and Physics,nanjing university of Posts and Telecommunications,nanjing 210046,china 1. department of Mathematics East China University of Science and Technology Shanghai 200237 China2. School of Mathematics and Computer Science Nanjing Normal University Nanjing 210097 China3. Center of Nonlinear Science Nanjing University Nanjing 210093 China4. College of Mathematics and Physics Nanjing University of Posts and Telecommunications Nanjing 210046 China

We define the relative local topological pressure for any given factor map and open cover,and prove the relative local variational principle of this *** precisely,for a given factor map π:(X,T)→(Y,S) between two topological dynamical systems,an open cover U of X,a continuous,real-valued function f on X and an S-invariant measure ν on Y,we show that the corresponding relative local pressure P(T,f,U,y) satisfies sup μ∈M(X,T){ hμ(T,U|Y)+∫X f(x)dμ(x) :πμ=ν}=∫Y P(T,f,U,y)dν(y),where M(X,T) denotes the family of all T-invariant measures on ***,the supremum can be attained by a T-invariant measure.

关键词： pressure conditional entropy relative local variational principle

Allocation Planning for R&D with Uncertainty:Model and Procedure

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Systems science and Systems Engineering 1993年第3期3卷 204-210页

作者： FENG Junwen nanjing university of science & technology, nanjing 210014, china

A decision support model with the stochastic objective function measuring the benefit contributions of projects and stochastic resource constraint and its decision making analysis procedure with the case study are presented for selecting R&D projects, in which the uncertainty in project evaluation and selection, the technical or outcome, cost or resource and benefit or payoff interrelationships among projects, and the experience and knowledge of the R&D manager can be considered.

关键词： decision analysis decision support system R&D project selection risk decision uncertainty decision allocation planning.

[Hmim]3PW12O40:A high-efficient and green catalyst for the acetalization of carbonyl compounds

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Chinese Chemical Letters 2010年第6期21卷 678-681页

作者： Yan Dai~a,Bin Dong Li~a,Heng Dao Quan~b,Chun Xu Lü~(a,*) a School of Chemical Engineering,nanjing university of science and technology,nanjing 210094,china b National Institute of Advanced Industrial science and technology,Ibaraki 3058565,Japan [a] School of Chemical Engineering Nanjing University of Science technology Nanjing 210094 China [b] National Institute of Advanced Industrial Science technology Ibaraki 3058565 Japan

[Hmim]PWOwas developed and used in the acetalization of carbonyl compounds in excellent *** ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separation system with the ease of product as well as catalyst *** catalyst was recycled more than 10 times without any apparent loss of catalytic activity.

关键词： [Hmim]3PW12O40 Phosphotungstic acid Carbonyl compounds Acetalization Ionic liquid